WHOOP STRAP Review (WHOOP 4.0 Updates)

Last Updated: Sep 10, 2021

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The Apple Watch had been my primary workout companion for a number of years, until a friend recommended that I try the WHOOP Strap — a high-tech fitness tracker that was different from anything I had seen before.

I’ve worn WHOOP since January 2019, and the data it has provided has been incredibly insightful.

Here are some of the insights I’ve gained from WHOOP over the past few years:

  • Stress and other lifestyle factors measurably impact my sleep quality.
  • My heart rate variability is a reliable indicator of when I’m about to get sick (and when I recover).
  • Alcohol ruins my sleep (no surprise there).
  • Reading a book before going to sleep (instead of reading on my iPhone or iPad) helps me sleep better and longer.
  • Intermittent fasting dramatically impacts my sleep and recovery.

Based on feedback from my readers, I’ve also taken a closer look at Biostrap, Fitbit and Oura. Scroll down to learn how those popular fitness trackers stack up against WHOOP, or use the links above to read my in-depth comparison articles.

WHOOP just introduced the new WHOOP 4.0, and you can learn what’s new and how to upgrade your WHOOP 3.0 strap below. Once the new strap ships and I’ve had time to test it, I’ll update this entire article. The good news is that most of the content in this post still applies to WHOOP 4.0 and should help you decide whether or not WHOOP is right for you.

WHOOP Strap 4.0

Michael Kummer

Michael's WHOOP Strap 3.0 with ProKnit Strap
Fitness tracking
Sleep tracking
Reporting & Analytics


WHOOP gives you insight into exercise performance, recovery, rest and sleep in a way that no other device can. I’ve worn WHOOP since January 2019, and the data it has provided has been incredibly insightful.


WHOOP gives you insight into exercise performance, recovery, rest and sleep in a way that no other device can.

As an enthusiastic CrossFit athlete and healthy living advocate, I’m always on the lookout for ways to hack my performance and improve my sleep quality and recovery. That’s one of the reasons I was such a fan of the Apple Watch.

While I appreciate how Apple has turned its wearable into an excellent fitness companion that has already saved numerous lives, it still has many limitations, including:

  • It provides no native support for detailed sleep tracking (not even in the Apple Watch Series 6 and watchOS 8).
  • Its third-party sleep tracking apps are inaccurate and gimmicky.
  • It offers no useful analysis and reporting around exercise performance and recovery.

However, it’s not just the Apple Watch that struggles with those issues. Other wearables, such as Fitbit and Android-based smartwatches, also suffer from the same shortcomings.

YouTube - The Ultimate WHOOP Review
Watch my in-depth WHOOP review video.

WHOOP founder and CEO Will Ahmed, a Harvard graduate, must have felt similarly when he decided to develop a solution that fills all of the above gaps and more.

WHOOP accurately tracks strain, as well as exercise and sleep performance. It also tells you how well you recovered overnight, and how hard you can push it that day.

The result is WHOOP, a clever combination of wearable technology (the WHOOP Strap) with a membership* that provides professional-quality analytics of your data, paired with a community of like-minded users that includes professional athletes (e.g., NBA players), coaches, trainers and Fortune 500 CEOs.

WHOOP Strap Review


  • Packed with sophisticated sensors that collect five health metrics 100 times per second.
  • Accurate sleep and HRV tracking.
  • Provides insight into your daily strain and recovery rate, as well as detailed sleep performance data.
  • Long battery life.
  • You can recharge WHOOP without taking the strap off your wrist.
  • Comfortable to wear 24/7.


  • No integration with Apple’s HealthKit.
  • Doesn’t support third-party chest straps (HR monitors).

What Is WHOOP?

Michael's WHOOP Strap 3.0 with ProKnit Strap
My WHOOP Strap 3.0 with ProKnit Strap.

Contrary to what you might think, WHOOP is not just another fitness strap, like Fitbit. It’s also a membership that connects you to a community of like-minded health enthusiasts.

More importantly, it enables you to “unlock the secrets your body is trying to tell you.” What that means is that WHOOP provides insights into your performance, recovery and sleep data that go way beyond what most consumer-grade fitness trackers offer.

How Is the WHOOP Strap Different?

WHOOP is a high-tech gadget that can guide you through exercise, recovery and sleep. For example, it tells you if your body has recovered sufficiently to push it during your next workout, or if it’s better to take it easy for a day. It also lets you know how much sleep you’ll need tonight, based on your level of activity during the day and any sleep debt you might have accrued.

One of the things I immediately noticed when I put the strap on for the first time was that WHOOP doesn’t have a display or buttons. In fact, it can’t even tell you the time. There’s no way to interact with the device, other than double-tapping it to see the remaining battery life via three tiny LEDs on the side.

But don’t be fooled by WHOOP’s simplicity! The wearable device packs a ton of sophisticated sensors that can measure your heart’s beats per minute, heart rate variability (HRV), electro-dermal activity, ambient temperature and 3D acceleration.

I’ll explain what all that means and why it’s important in a bit, so hang tight!

The key differentiator of WHOOP is that all those sensors collect data 100 times per second (and 24/7), as long as you wear the strap. In comparison, the Apple Watch only collects heart-rate data at a high frequency during workouts. Otherwise, it only samples your heart rate every few minutes. The same is true for most of the other fitness trackers I’ve reviewed, including the Fitbit Versa and Biostrap.

By collecting such an incredible amount of data, WHOOP can detect minuscule changes in how your body responds to exercise, rest and other stimuli throughout the day and overnight.

Exercise and Fitness Tracking

Daily Strain and Exercise Tracking
My weekly strain report.

Since the WHOOP Strap doesn’t have any buttons or a display, you can’t tell the device to start an exercise routine. The good news is that you don’t have to. Remember, WHOOP measures your heart rate 100 times per second, all the time. That allows the gadget to detect when you’re working out.

WHOOP can automatically detect over 80 types of exercises that last longer than 15 minutes or result in a strain score of eight or higher.

Additionally, WHOOP uses a classic accelerometer to detect movement. That’s helpful for certain types of exercises, like lifting weights, that increase your heart rate only moderately. Alternatively, you can use the WHOOP app on your smartphone to start or log an activity, instead of relying on the tracker’s automatic detection capabilities.

What’s crucial is that WHOOP uses the collected data to calculate your daily strain. In other words, the device can tell you how hard your cardiovascular system worked on a given day. That’s important because it directly influences your recovery and sleep requirements (but not your recovery score).

WHOOP measures your daily accumulated strain score using a scale from 0 to 21:

  • 0 – 9.9: Light
  • 10 – 13.9: Moderate
  • 14 – 17.9: Strenuous
  • 18 – 21: All out

Note that WHOOP calculates strain from your max heart rate, which means that score is highly personalized. The same workout, performed by different people (or even pro athletes), might result in different strain scores. So don’t compare your results to someone else’s.

By default, WHOOP detects activities if they last for 15 minutes or longer. So it won’t recognize those 20-second sprints on CAR.O.L, the new HIIT bike I’ve been testing as a workout.

However, even strain endured during shorter physical activities — such as carrying heavy grocery bags from the store to your car — adds to your daily strain score.

Low Strain Scores

Ultimate WHOOP FAQ
Check out my ultimate WHOOP FAQ video to get all of your questions answered.

Some people, including my wife and I, often see less that optimal strain scores reported by WHOOP — even after intense types of workouts such as CrossFit.

There are a couple of reasons why you might see lower strain scores than anticipated, including:

  1. A loose-fitting strap that prevents the sensor from maintaining good contact with the skin.
  2. Physical activity that didn’t increase your heart rate (long) enough.

The first issue can be easily fixed by either making sure your WHOOP Strap is tight enough, by moving the strap farther away from your wrist bone, or by wearing WHOOP on your bicep using the bicep strap or armband.

The second issue is usually influenced by the type of activity you perform. For example, endurance training — such as running, biking or swimming — often causes your heart rate to stay elevated for extended periods. That makes it easier for WHOOP (and other wrist-worn devices) to capture your HR readings.

But high-intensity workouts like CrossFit often cause massive HR fluctuations (combined with wrist movements) that can make it difficult for any wrist-worn device to get a good reading. As a result, you can expect lower strain scores for these types of workouts.

Additionally, some HIIT workouts are relatively short. The ones I do are often in the 10-20 minute range, and while they might be exhausting they don’t cause my heart rate to be elevated for extended periods. That’s a crucial factor because WHOOP tracks strain based on how long your HR remains elevated above your “baseline.”

WHOOP starts accumulating strain when you reach 30% of your HR reserve, which is calculated based on the following formula: Max HR – Resting HR = HR Reserve. So if your max HR is 200 bpm and your resting HR is 50 bpm, then your HR reserve is 150 bpm. As a result, WHOOP would start tracking strain when your HR reaches 95 bpm (50 + 0.3 * (200-50)).

The problem is that strength training and shorter CrossFit-type workouts usually don’t cause a lot of (cardiovascular) strain (they might cause muscular strain instead) and thus you won’t see a high strain score in the WHOOP app.

High strain score after building a chicken coop
Building a chicken coop led to the highest strain score I’ve ever recorded.

For reference, I usually accumulate a strain of 8 to 12 during CrossFit workouts. But building a chicken coop for our Homestead caused a massive 20.2 strain — the highest I’ve ever recorded.

Recovery Tracking

WHOOP 2-week recovery scores
2 Weeks Recovery Score.

I’m incredibly competitive (primarily with myself), and I’m in a constant battle with my mind during workouts. For example, if my brain tells me to slow down, I speed up. Moreover, if I’m not on the floor at the end of a workout, or on the verge of throwing up, I feel like I didn’t push it hard enough.

The issue with such a strategy is that it can take an incredible toll on your body. Sometimes, I feel like although my mind is getting stronger my body isn’t — or at least not at the rate I’m expecting.

I have come to realize that there needs to be a balance between strain and recovery. If your body endures too much strain without sufficient opportunity to recover, you end up with what’s called a recovery deficit. The result? You don’t improve, but you do increase your risk of injury.

But aside from “listening to my body,” I haven’t had a means through which to evaluate how recovered I was on a particular day. That’s where WHOOP can help.

Every morning, the WHOOP app gives me a recovery score, expressed as a percentage (e.g., 75% recovered), based on key metrics from my heart, nervous system and sleep performance. Depending on my recovery, WHOOP suggests how much strain I should take on that day to prevent over-training and to lower the risk of injury.

Magnesium influences my Recovery score
I get higher recovery percentage scores on days when I supplement with magnesium.

What’s interesting is that you can use the recovery score for much more than planning your next workout. For example, having a low recovery score for a few days in a row without an obvious reason (i.e., strenuous workout sessions) has been an incredibly reliable indicator that my body is fighting off a virus.

On the flip side, my recovery score improved immediately as soon as I started to feel better.

What I’m trying to say is that you can benefit from the WHOOP Strap even if you’re not an athlete!

How Does WHOOP Know How Recovered I Am?

10 Hacks I've used to increase my HRV
Click on the image above to watch the video!

In a nutshell, the WHOOP analysis engine uses three key metrics to measure recovery:

A high heart rate variability and a low resting heart rate, compared to your baseline, indicate that your body is recovering well. A low HRV and high RHR indicate that the heart is working harder to supply nutrients via the bloodstream. It also means that the nervous system is busy trying to meet the body’s “physiological demands, such as musculoskeletal recovery, stress, illness, and fatigue.”

Of course, your sleep performance also plays a crucial role in recovery. The more quality sleep you get, the quicker you recover.

What’s important to understand is that the recovery score WHOOP calculates is not correlated with the previous day’s strain.

Sleep Tracking

My sleep performance as measured by WHOOP
My sleep performance as measured by WHOOP.

One of the features I was most excited about when I heard about WHOOP was sleep tracking. I had tried various apps and gadgets in the past, such as the now-obsolete Jawbone UP and Sleep++, but none were reliable.

Thanks to the advanced sleep monitoring technology in WHOOP, the device can not only measure how much time I spend in bed, but also how much time it takes me to fall asleep (sleep latency), how long I sleep, and what stage of sleep I’m in.

A typical sleep cycle consists of four stages:

  • Slow wave sleep (SWS, which is also known as deep sleep).
  • REM sleep.
  • Light sleep.
  • Wake.

WHOOP uses its sensors to detect changes in my heart rate, the ambient temperature and movement patterns.

Every morning, I get a detailed report telling me how much time I spent in bed, how long it took me to fall asleep, how long I spent in each stage of sleep, and how many times my sleep was disturbed.

Increase in respiration rate during COVID
My friend’s WHOOP data shows an increase in respiration rate during a COVID infection.

Additionally, you can also check your respiratory rate (how many breaths you take per minute). That number should be relatively stable from night to night. If you see significant changes, it could indicate an underlying issue, such as an infection with the new coronavirus.

How Accurately Does WHOOP Track Sleep?

According to WHOOP, their sleep metrics are 95% accurate compared to the calibration tests the company has done in sleep labs. The University of Arizona recently published a study on sleep trackers and called WHOOP “highly accurate.”

Sleep Study - Monitoring Device Accuracy
Sleep study – monitoring device accuracy.

I have read numerous studies suggesting a relationship between an increase in electrodermal activity and skin temperature during slow-wave sleep. I found another study that outlined the accuracy of various monitoring devices, including electroencephalography (EEG), skin conductance (SC), skin temperature (ST) and accelerometers (ACC).

You can see the results below:

  • EEG showed 91% accuracy.
  • EEG plus other features boosted the accuracy to 95% (EEG + SC + ACC).
  • EEG + ACC + SC + ST boosted the accuracy to 96%.

It shouldn’t be surprising that EEG-based monitoring is relatively accurate, especially when paired with additional (wrist-worn) sensors.

However, even without an EEG, scientists have confirmed the relatively high accuracy of wrist-worn devices:

  • ACC + SC + ST showed 86% accuracy.
  • SC + ST or ACC + ST showed 84% accuracy.

So, based on those findings, I expect the WHOOP Strap to be about 86% accurate. From an observational perspective, I woke up feeling groggy a few times lately, and I always suspected that I must have been in the middle or at the end of a deep-sleep cycle.

The other day, I woke up in the middle of a dream — or at least, that’s how it felt. More than that, I felt like I was dreaming the whole night, and I have vivid recollections of my dreams.

A wild night filled with dreams (REM sleep). You can see I woke up during a REM sleep cycle.
A wild night filled with dreams (REM sleep). You can see I woke up during a REM sleep cycle.

After each of those events, I compared my suspicions with WHOOP’s sleep performance report and it was always spot on.

Sleep Efficiency

In February of 2019, WHOOP launched a new sleep-related metric called Sleep Efficiency.

Sleep Efficiency is therefore a measure of sleep quality, and when considered alongside the rest of the WHOOP Sleep Pillar metrics, provides actionable insight into where your sleep could improve.

WHOOP Sleep Efficiency
My Sleep Efficiency is 99%.

In addition to my sleep performance report, WHOOP offers a sleep coach via its mobile app that suggests when I should go to bed based on my level of expected athletic performance the next day, the accumulated strain, any sleep debt I might have accrued, and how long it usually takes me to fall asleep.

WHOOP Athlete Overview
My WHOOP athlete profile.

WHOOP Application

The WHOOP app is a treasure trove of information, and you might find it intimidating at first. Besides the hamburger menu in the upper-left corner, you can navigate through the app by swiping left/right and up/down.

If you look at the bottom of the screen, you’ll see five little dots indicating the screen you’re on. If the screen offers additional information, you’ll see a down-facing arrow and you can access that information by swiping up.

But that’s not all. Some screens, like Sleep Performance, offer additional analytics via button-like controls that are marked by rectangles with rounded corners. For example, you can click on the number above the “HOURS OF SLEEP” label to get to your detailed sleep stage analysis.

Application Menu

Using the general menu, you can cycle between the home screen (athlete profile), start/add an activity, sleep coach, your weekly performance assessment, strap status, settings and help.

Strain Coach (WHOOP 3.0)

WHOOP Strain Coach
The Strain Coach screen.

Strain Coach provides you with live data — including your strain, heart rate and calories burned — that you can leverage during a workout. That way, you can make instant adjustments to your workout activity, based on your recovery.

When WHOOP first launched the Strain Coach, I thought it was a gimmick that I wouldn’t have use for. A few days ago, I woke up with a low recovery score and decided to give it a try.

I started my WOD with Strain Coach enabled and made sure I wouldn’t overreach. While I ended up with a slightly higher strain than Strain Coach suggested, the feature helped me to improve my recovery.

Some reviewers are under the impression that the Strain Coach can or should replace a real coach. Obviously, that’s an unrealistic expectation — much like it’s unrealistic for a Tesla to operate entirely autonomously. Maybe we’ll get there at some point, but we aren’t there yet as of this writing.

So if WHOOP’s Strain Coach suggests that you push it hard during a workout on a given day, but you know that you have a race coming up, maybe don’t follow the recommendation and use your brain instead.

Sleep Coach

WHOOP App Sleep Coach
The Sleep Coach screen.

The sleep coach feature of the WHOOP app gives you personalized recommendations on how to leverage sleep to increase your performance.

To get started, you can tell the sleep coach what level of performance you’re aiming for, including “peak,” “perform” or “get by.” I always go for “peak” performance!

Additionally, you can tell the app what your desired wake-up time is. In my case, that’s 5:15 a.m. From there, the sleep coach tells you when you should go to bed and how many hours of sleep you’ll need.

Regardless of your desired wake-up time, Sleep Coach also tells you when you should go to bed and when you should wake up for maximal sleep consistency and to achieve 100% of your sleep needs.

When I first installed the app, I didn’t know that I could choose my desired performance level and wake-up time, and was surprised when Sleep Coach suggested a bedtime that was much later than I was used to.

Some people get discouraged when WHOOP suggests earlier-than-expected bedtimes or a much higher-than-anticipated sleep need.

Based on everything I know about how WHOOP calculates your sleep need (and based on my personal experience), I think you should follow WHOOP’s recommendations. In many cases, extensive strain and sleep debt cause a much higher sleep need than you might like.

However, it’s important to reduce your sleep debt by sleeping longer — otherwise, you’ll never reduce it.

Weekly/Monthly/Annual Performance Assessment (P.A.)

Once you’ve worn your WHOOP Strap for 28 consecutive days, you’ll get a weekly performance assessment. The report visualizes your current training state based on your daily strain, your rate of recovery, and your sleep performance. You’ll also get an indication of how you compare to other members of the WHOOP community.

WHOOP - Training State Chart
WHOOP Training State chart.

My first weekly P.A. report told me that both my training state and sleep performance were optimal. However, my daily strain was 8% lower than the average male WHOOP user in the 35-50 age bracket. I guess that means I’m either not pushing​ it hard enough or that I’m incredibly fit!

In addition to the weekly performance assessment, WHOOP also offers a monthly (and even a yearly) report that turns a huge volume of data into actionable insights.

WHOOP Journal

The new WHOOP Journal
My WHOOP Journal.

The reason the regular performance assessments are so useful is that they give you an indication of what lifestyle factors have impacted your recovery and sleep scores.

For example, by answering a few simple questions every day, WHOOP can tell you how alcohol use impacts your sleep performance and/or resting heart rate.

However, until recently, the WHOOP app wasn’t incredibly granular in collecting that important information. But with the latest update, you can not only select the questions you want the app to ask you, but you can also tell the app exactly how much alcohol you had (and when you had it).

Overall, the app knows dozens of behaviors — from CBD use to the consumption of your last paleo meal to air travel.

I absolutely love the granularity and I can’t wait to see the results as part of my next performance assessment.

Home Screens and Today View

The “today view” is what you see after launching the app or by clicking on your athlete profile via the menu. It’s actually the second screen in the list, and by swiping to the left, you get to your complete athlete profile.

WHOOP App Overview
Overview of Strain, Recovery and Sleep.

Additional screens include Day Strain, Recovery, and Sleep Performance. On each of those screens (except for the athlete profile page) you can swipe up to get a graphical representation of your data that spans multiple days.

Graphical Analysis of the past few days
Graphical analysis of the past week.

Additionally, each screen allows you to take a photo with the key metrics of the screen you’re on superimposed. So if you met your sleep goals for the first time in forever and wanted​ to share it with the world, you can take a selfie and post it on Instagram.

Battery Life

According to WHOOP, the battery of the WHOOP Strap 3.0 should last for approximately five days.

WHOOP - App - Low Battery
The WHOOP battery life screen.

While the WHOOP app gives you an exact indication of how much juice you have left, you can also double-tap the device and get a visual indication via three LEDs:

  • Three solid white LEDs indicates a full charge.
  • Two solid LEDs indicates a battery between 60% and 79%.
  • One solid LED indicates a battery between 20% and 39%.

The device also uses flashing lights to give you a more precise readout of your remaining battery life. For example, two solid lights and one flashing light indicates a charge between 80% and 99%.

WHOOP’s battery indicator LEDs.

You can find more information about battery life on WHOOP’s support page.

With every other fitness strap I’ve used — including the Apple Watch, Oura Ring, Fitbit Versa and Biostrap — I had to take the device off for charging. WHOOP has figured out a way to recharge its strap without having to remove it from the wrist.

WHOOP comes with a charger in the form of a small battery pack that you can slide on top of your strap to charge it. A complete charge takes somewhere between 90 and 120 minutes. After charging the strap, you have to charge the battery pack using a Micro USB cable.

I’ve gotten into the habit of cycling through this charging routine every four to five days, or when my strap reaches 20% remaining battery charge.

Slide-on battery pack.

Note that while the WHOOP fitness band is waterproof, the battery pack is not. So don’t forget to remove it before taking a shower.

Design and Comfort

The WHOOP Strap is incredibly thin, lightweight, and comfortable to wear 24/7. The first review unit I received came with two bands, the Tecnica and the Hydroband. The Tecnica is incredibly soft and elastic (similar to Apple’s Sport Loop) and I wore it most of the time.

The Hydroband doesn’t stretch, and I don’t like it very much for two reasons: it’s less comfortable, and I can’t quickly move it out of the way when a workout calls for gloves or grips.

WHOOP - Strap too long
The strap was too long, so I cut a piece of it off.

One thing I noticed when putting on WHOOP with the Tecnica strap was that the band was a bit too long. As a result, it would tangle on my wrist and drive me nuts. To fix the issue (and because I don’t expect my wrist to grow in diameter) I shortened it by cutting a piece off.

While the Tecnica strap is incredibly comfortable overall, I do have to tighten the elastic band every few days to ensure the unit maintains close contact with my skin.

Liteweave has become my band of choice
Liteweave used to be my band of choice — now it’s the ProKnit.

When I was using WHOOP 2.0, I switched to the Hydroband (and later to the Liteweave band) because it allowed the WHOOP to stay in better contact with my skin during certain workout routines.

When I got the WHOOP 3.0, I started using the new ProKnit strap and fell in love with it. The ProKnit strap offers the perfect compromise between comfort and function. In other words, it allows the WHOOP’s sensors to remain in constant contact with the skin without feeling too tight or uncomfortable.

While the ProKnit strap was initially only available when you ordered WHOOP 3.0, you can now get it from the WHOOP online store and use it with your 2.0 sensor. So if you still use the older 2.0 sensor, I highly recommend getting the ProKnit strap!

How Much Does the WHOOP Membership Cost?

When the device first launched, it had a hefty $500 price tag. While that’s in line with what I paid for my Apple Watch, it’s still a lot of money.

These days, you don’t have to pay for the hardware upfront. Instead, you can sign up for a membership for as little as $18 per month.

  • 6-month commitment: $30 per month ($180 in total).
  • 12-month commitment: $24 per month ($288 in total).
  • 18-month commitment: $18 per month ($324 in total).
  • Lifetime membership: $399 one-time payment (only available to founding members).

If you’d like to give WHOOP a try, you can use the link below to get $30 off your membership fee. If you’re already a WHOOP member and would like to upgrade to the WHOOP Strap 3.0, simply renew your membership.

Get $30 Off*

In case you’re wondering, the WHOOP wristband is not available on Amazon.

WHOOP Accessories

In addition to various strap designs and colors, WHOOP also sells a bicep sleeve. That’s useful for exercises that make it difficult to wear something around your wrists, such as boxing or other forms of martial arts. Other examples include NFL players who might be prohibited from wearing a wrist strap for safety reasons.

I recently had the chance to try the bicep band, which I find incredibly useful for certain CrossFit workouts that include dumbbells, kettlebells or bear grips (workout gloves). The only downside to using the bicep band is that it takes a few seconds to put it on (because you have to take off the wrist strap first).

Michael wearing the WHOOP biceps band
Me wearing the WHOOP bicep band.

I wouldn’t want to do that five times a week for every workout. But I do it on days that I wear workout gloves.

WHOOP doesn’t offer a chest strap, which I think would be a convenient wearing method for runners who are used to wearing heart rate monitors around their chest.

WHOOP Strap 3.0 vs. 2.0

In May 2019, WHOOP released version 3.0 of its Strap. The current model features updated hardware and additional functionality via the app. Here are the highlights of the new release.

 Hardware Updates
  • Extended five-day battery life.
  • Bluetooth Low Energy (BLE) compatible.
  • New stretchy and sturdy ProKnit bands.
  • New band colors (arctic, carbide and onyx).
  • Better clasp that doesn’t accidentally open.
  • Better build quality.

I had no complaints about the battery life of the old strap, but getting five days of battery life with the new WHOOP Strap 3.0 is an awesome upgrade.

The new straps, which WHOOP made out of high-tenancy yarn and a rubber grip, look incredibly similar to the Sport Loop I have on my Apple Watch. Color-wise, I thought I was going with carbide, which looks super slick. However, WHOOP sent me Arctic White — which I also think looks super slick!

WHOOP Strap 3.0 colors
WHOOP Strap 3.0 colors.

WHOOP also confirmed that all 2.0 bands and clasps work on the new 3.0 strap.

 Software Updates
  • Strain Coach.
  • WHOOP Snap+ to film your workouts.
  • Heart rate broadcast.

With the new Strain Coach feature in the WHOOP app, you can start a workout and the app will tell you in real-time if you’re hitting your strain goals (or if you should push harder or dial it back).

With WHOOP Snap+ you can film your workout and overlay live data, including heart rate strain and calories burned.

WHOOP Snap+ video showing how I face-planted while doing box jumps
WHOOP Snap+ video showing how I face-planted while doing box jumps.

I’ll definitely try Snap+ to share some of my workout highlights on Instagram.

Heart rate broadcast allows you to livestream your heart rate to third-party apps and devices. Examples of such third-party integrations include Strava and Peloton.

What’s New in WHOOP 4.0

WHOOP 4.0 is an exciting upgrade from the previous generation WHOOP 3.0 and features the following enhancements:

  • An improved heart rate sensor featuring five LEDs (green and red) and four photodiodes. The red LEDs make blood oxygen monitoring possible.
  • Ability to track and report skin temperature changes. (WHOOP had that before, but never exposed the readings in the app.)
  • Health insights to monitor key metrics including heart rate variability, resting heart rate, skin temperature, blood oxygen levels and respiratory rate. You’ll also be able to export and share these insights with anyone, including health care professionals.
  • Haptic alarm to silently wake you up at a certain time, when you’ve slept enough or when you’re in the green.
  • The battery pack is now waterproof.
  • A smaller form factor that people with small wrists (including my wife) will appreciate.
  • An updated slide-and-click mechanism will make it easier to change straps. 

WHOOP also launched a new clothing line to enable you to wear the sensor pretty much anywhere (not just on your wrist or biceps). 

I’m super excited about WHOOP 4.0 and can’t wait to get my hands on the new strap. Based on their rollout plans, I should have my strap and (hopefully) some of the new apparel in October and will completely update this article.

What WHOOP 4.0 Doesn’t Have

While I’m excited about all the new features coming with WHOOP 4.0, I didn’t hear anything about support for third-party chest straps (HR monitors) or Apple Health. So, I assume that WHOOP 4.0 won’t support either, and that’s a bummer. I was really hoping to be able to connect WHOOP with my chest strap for even more accurate HR monitoring during CrossFit workouts.

Additionally, WHOOP didn’t announce any of the other features I had on my wishlist, including:

How to Upgrade from WHOOP 3.0 to WHOOP 4.0

If you’re an existing WHOOP member and have more than six months remaining on your current subscription, you can get WHOOP 4.0 for free without having to make any changes to your subscription. 

Michael wearing both Apple Watch and WHOOP
My wearing both Apple Watch and WHOOP.

Over the past few years, I’ve had a chance to test and review other popular fitness trackers and compare them to WHOOP. The table below gives you an overview of how the WHOOP Strap compares to the Apple Watch, Biostrap, Fitbit Sense and Oura Ring.

Below the table you’ll find links to in-depth comparison articles and YouTube videos I recorded along the way.

Heart rate tracking
Workout tracking
Automatic workout detection
Calorie tracking
Support for chest straps (HR)
HR broadcasting
Guided workoutsWith subscription
Strain tracking
Sleep tracking
Sleep stage analysisWith subscription
Sleep quality score
Recovery scoreWith subscription
Battery life16 to 28 hours1 to 2 days2 to 6 days4 to 7 days5 days
Pricing$399 to $799$249 – $329*$299.95 + $9.99 (optional premium subscription)*$299 – $399$18 to $30 per month*
Comparison of popular fitness trackers.

WHOOP vs. Apple Watch

Considering that I’m a die-hard Apple fan and love my Apple Watch, I wasn’t sure if I would continue wearing the WHOOP Strap after I was done testing it for this review. But a couple of weeks with the device had me hooked, and I haven’t looked back since. Today, I wear both devices.

In my opinion, each one fulfills a purpose by bridging the other gadget’s gaps — although there are a few areas in which their features overlap.

I use my Apple Watch primarily as a time-keeping device, as a notification center, to send and receive messages, and to interact with Siri and HomeKit-enabled devices. I also use it to track most of my workouts, because I have other apps that integrate with Apple’s Health app to correlate the data with my blood glucose levels and other biometrics.

What I don’t use the Apple Watch for is sleep, HRV and recovery tracking, because the features either don’t exist or are too rudimentary to be useful.

Check out my in-depth comparison of the differences between WHOOP and the Apple Watch to learn more.

WHOOP vs. Biostrap

Biostrap vs. WHOOP - Ultimate comparison
Watch my full comparison video here.

Much like WHOOP, the goal of Biostrap is to measurably improve your sleep, recovery and performance.

But despite their similarities, there are plenty of differences between these two wearable fitness trackers. To learn all about how these devices are different, check out my in-depth review and comparison of Biostrap vs. WHOOP.

If you don’t have time to read the full comparison article, below is an overview of the major differences:

  • Biostrap’s battery lasts less than two days and you can’t recharge the device without taking it off.
  • I really like Biostrap’s support for chest strap HR monitors and the shoe pod to capture leg movement (especially while sleeping).
  • I found WHOOP’s ProKnit strap to be more effective and comfortable at keeping the sensor in close contact with my skin.
  • Biostrap uses a pulse oximeter (red light), which allows for additional data capturing but is prone to interference.

Overall, I can say that Biostrap has a couple of interesting features, such as blood oxygen monitoring support for chest straps. What’s missing from Biostrap is recovery tracking and the actionable insights I get from WHOOP.

That said, I’m currently testing the Biostrap Evo, which came out after I published my initial WHOOP vs. Biostrap review. So stay tuned for updates over the next few weeks.

WHOOP vs. Fitbit

Whoop vs Fitbit
Click on the image above to read my in-depth comparison article.

Fitbit offers numerous fitness straps and smartwatches. Not all of them use the same technology to track activity and sleep, and it’s difficult to compare apples to oranges.

So instead of trying to compare the WHOOP Strap to a particular Fitbit model, I decided to compare the underlying technologies. That’s the same approach I took in my review and comparison of the best sleep trackers.

The top-of-the-line Fitbit straps, such as the Fitbit Versa 2 and the Fitbit Ionic watch, include the following (fitness or sleep-related) sensors:

  • 3-axis accelerometer.
  • 3-axis gyroscope.
  • Optical heart rate monitor.

That’s pretty standard and, assuming a correct fit of the strap, good enough to monitor heart rate and track physical activity (especially arm movements).

As a result, I’d argue that Fitbit can keep relatively accurate tabs on calories burned and other standard metrics.

Note: After this review was published, I decided to write a detailed comparison of WHOOP and Fitbit’s flagship smartwatch, the Fitbit sense. The article covers how the two devices stack up and takes a deep dive into Fitbit’s fitness tracking platform.

From a pure fitness tracking perspective, Fitbit is like my Apple Watch: both provide some value, but if it wasn’t for things like notifications, timekeeping and Apple Pay, I wouldn’t be wearing it. Instead, I would use WHOOP exclusively.

WHOOP adds real value by giving you insights into what your body is trying to tell you. That’s valuable, regardless of whether you’re an athlete or just someone who wants to perform better at the gym, at work, or generally in life.

WHOOP vs. Oura Ring

Oura vs. WHOOP
Oura Ring.

The Oura Ring is a fascinating device that packs numerous wearable technologies into a tiny form factor.

Oura’s goal is to provide you with daily feedback you can use to improve your health. Specifically, Oura analyzes your biometric data to calculate a sleep score, activity score and readiness score.

The latter is similar to WHOOP’s recovery feature, taking into account such parameters as:

  • Previous night’s sleep score.
  • Sleep balance over the past two weeks.
  • Activity and strain on the previous day.
  • Activity balance over the past five days.
  • Body temperature.
  • Resting heart rate (RHR).
  • Heart rate variability.

I really like the form-factor of Oura Ring and the data it provides, even though its sleep tracking appeared to be less accurate in my tests compared to WHOOP.

Check out my in-depth comparison article to learn more about how the Oura Ring stacks up against WHOOP.

Frequently Asked Questions

Ultimate WHOOP FAQ
In this video, I answer 31 of the most frequently asked questions about WHOOP.
Is WHOOP accurate?

Based on the independent validation studies I referenced throughout this article, WHOOP is one of the most accurate fitness and sleep trackers on the market.

Remember the electro-dermal activity sensor I mentioned before? The WHOOP Strap uses that sensor to detect if the unit has good contact with the skin.

Electro-dermal activity “refers to the variation of the electrical properties of the skin in response to sweat secretion.”

That’s an ingenious way of ensuring the device is receiving accurate data. However, it’s important to understand that the accuracy of any wrist-worn heart rate sensor is limited by how well it maintains contact with your skin.

As a result, such sensors are often more reliable when you’re stationary, as opposed to during high-intensity exercise routines such as CrossFit. If you suspect your heart rate readings are off during workouts, consider covering the sensor with a sleeve to keep it more securely in place.

To learn more about WHOOP’s accuracy as a fitness, recovery and sleep tracker, check out this article.

What is normal heart rate variability?

HRV is a highly-personalized metric and depends on numerous factors, including “fitness, age, gender, genetics, health, and environmental conditions.” As a result, it doesn’t make sense to compare your HRV with someone else’s. Instead, it’s more useful to understand the trend of your HRV compared to previous periods.

However, since we all like to share and compare, over the past month my HRV has been bouncing between 26 and 74.

How much data can the WHOOP band store?

The WHOOP band can store up to three days worth of data before it starts overwriting the oldest entries. However, every time the band establishes a Bluetooth connection with your smartphone, it uploads all its data to the application, which in turn sends it to the cloud.

Can you take WHOOP aboard an airplane?

You certainly can, without having to worry about airplane mode. As it turns out, the whole “electronic devices can negatively influence a plane’s navigational systems” was a big old lie. Wi-Fi and Bluetooth operate on an entirely different frequency than the critical systems of an airplane.

How tight does the strap have to be?

Proper positioning of the strap is crucial for the accuracy of the signal the sensors receive. If the strap is too loose or too tight, the sensors will either receive a lot of “noise” or no signal at all.

WHOOP recommends positioning the strap on your dominant hand, about one inch from your wrist bone. The strap should be tight enough so that it’s difficult to stick your pinky between the strap and your wrist.

My WHOOP constantly disconnects from my iPhone. What’s the problem?

If you’re having issues with your strap — especially if you were an early adopter of WHOOP 3.0 — you might have a defective unit.

A few months ago, I listened to the WHOOP podcast in which John Capodilupo, WHOOP’s CTO, explained that some users got 3.0 straps with faulty electronics. If that’s the case for you, reach out to WHOOP support via the mobile app to get your strap replaced for free.

Note that it’s normal for WHOOP to disconnect from your phone if you move out of Bluetooth range (about 30 feet). Sometimes the strap automatically reconnects when you get back in range, but often it doesn’t. As a result, you might see a notification informing you that the app hasn’t received any data from the strap in more than three hours.

To fix the issue, just open the WHOOP app and follow the on-screen instructions to reconnect the strap. Once reconnected, the app will fetch the missing data from the strap and sync it to the cloud. You won’t lose any data as a result of this process.

If you experience frequent Bluetooth disconnections, the issue could be related to the aggressive memory management of iOS 13. With the release of iOS 13 and the launch of the iPhone 11 and iPhone 11 Pro, Apple doubled down on extending the battery life of its devices. One way the company accomplished that was by limiting how much memory background processes can consume.

If an app exceeds the allotted memory, iOS kills it. Over the past few months, that has impacted numerous apps and developers. As a result, Apple has released updates to dial back some of that aggressive resource management in later versions of iOS 13.x.

Unfortunately, some apps that require a permanent background process, like WHOOP’s data sync agent, are still affected.

To find out if iOS is the culprit for the frequent disconnections you’re experiencing, open the WHOOP app and go to Menu > Strap Settings > Advanced Settings.

Click on “Email Diagnostic Data” and enter your email address to receive the logs. When you receive the email with the log data, extract the zip file and open the log. If you see a lot of lines containing the words “MEMORY WARNING,” you know that iOS is causing the disconnections.

To temporarily work around the issue, force close some of your other apps or reboot your phone.

Is WHOOP’s heart rate monitor better than others?

Most of the fitness and sleep trackers on the market use the same optical heart rate monitor technology and the same open-source algorithms to interpret the signal from the sensors.

The secret sauce of each company, including WHOOP, is the algorithm that interprets the raw heart rate data. That’s where I think WHOOP has a leg up, and independent validation studies (such as this one) confirm that belief.

Can I use WHOOP without a membership?

Unfortunately not! Without an active membership, the strap is worthless. I assume that’s the reason you don’t pay for the hardware, only the membership.

What does WHOOP do?

WHOOP is an advanced fitness and sleep tracker that provides actionable data about your daily strain, recovery and quality of sleep.

How good is WHOOP?

That depends a little bit on your definition of “good.” What I can tell you is that WHOOP is incredibly reliable and accurate — see above.

Does WHOOP measure temperature?

Yes, the WHOOP Strap measures your ambient skin temperature, which is an important parameter for ensuring accurate sleep tracking. However, WHOOP doesn’t expose the measurements via its app, so you can’t use WHOOP to actively measure your body temperature.

Can you wear WHOOP on your ankle?

Yes, you certainly can. However, keep in mind that WHOOP needs good contact with the skin to accurately measure your heart rate. So make sure you use a strap that provides a solid fit. My recommendation would be the ProKnit strap that WHOOP 3.0 ships with.

Is there a correlation between “feeling sore” and high recovery scores?

I have woken up several times with a high recovery score while feeling sore or even completely unmotivated to work out.

The interesting thing is that how we feel doesn’t always reflect how our body is doing. WHOOP’s recovery score is influenced by the presence of inflammation, not necessarily soreness.

So if your body is managing post-workout stress and inflammation well, your HRV might be virtually unaffected. If so, you’ll see higher-than-expected recovery scores.

How can my recovery be low despite good sleep?

Sleep performance is only one of three factors that influence your recovery score. The two others are resting heart rate (RHR) and heart rate variability (HRV).

So if your body is struggling with inflammation from a workout, sickness or other factors, your RHR and HRV might both be high. That’s then reflected in your lower-than-expected recovery score.

How does WHOOP measure strain during weightlifting sessions?

WHOOP measures strain based on cardiovascular output. In other words, the more time you spend in high heart rate zones, the more strain you accumulate with WHOOP.

On the flip side, if you do a workout consisting of single repetitions — for example, if you’re trying to beat your back squat 1 rep max — your heart rate will not stay elevated long enough to cause any cardiovascular strain.

However, if your weightlifting session causes muscle damage (which is normal) and inflammation, you’ll see that reflected in a lower HRV, and thus, in your recovery score.

Additionally, muscle fatigue might cause a higher strain the following day because your system is working hard to recover.

Why do I already have strain when I wake up?

Because your cardiovascular system is working and your body is burning calories, even while you’re asleep. Being able to keep tabs on your body 24/7 is one of the advantages of using WHOOP.

I’m not an athlete. Should I use WHOOP regardless?

Absolutely! Being able to understand how your body is doing, how recovered you are, and what lifestyle factors influence your overall performance and recovery is important — regardless of your fitness level. In other words, it doesn’t matter whether you’re an elite athlete, a fitness enthusiast or someone who doesn’t work out at all.

For example, if your body is run down, maybe it’s not a great idea to start skydiving. Or if you work on a construction site and wake up poorly recovered, maybe you should take it a bit slower to reduce your risk of injury.

Frankly, I don’t know anyone who wouldn’t benefit from WHOOP.

Is WHOOP worth it?

Yes, I think WHOOP is worth every penny because of the insights it has been providing me over the years. These insights have helped me make better lifestyle choices, fine-tune my workout routine and training load, and keep an eye on my respiratory rate and HRV during the pandemic.

What type of activities can WHOOP track?

The WHOOP team constantly adds new activities the strap can track. As of this writing, WHOOP can track the following: Australian football, barre, baseball, basketball, boxing, caddying, climbing, coaching, commuting, cricket, cross country skiing, CrossFit training, cycling, dancing, diving, duathlon, elliptical, fencing, field hockey, football, functional fitness, gaming, golf, gymnastics, hiking/rucking, horseback riding, ice bath, ice hockey, inline skating, jiu jitsu, jumping rope, kayaking, lacrosse, manual labor, martial arts, meditation, motocross, motor racing, mounting biking, obstacle course racing, operations – – flying, operations – medical, operations – tactical, operations – water, paddle tennis, paddle boarding, pickleball, pilates, powerlifting, rock climbing, rowing, rugby, running, sailing, skateboarding, skiing, snowboarding, soccer, softball, spikeball, spinning, squash, stair climbing, surfing, swimming, tennis, track and field, triathlon, ultimate Frisbee, volleyball, walking, water polo, weightlifting, wheelchair pushing, wrestling and yoga.

You can also pick “other” if none of the above match the activity you’d like to track.

Why does WHOOP come with a carrying case?

You can use the carrying case to securely store the battery pack and charging cable, thus reducing the risk of losing either one.

Why does the strain coach recommend a high strain goal if I have a competition coming up?

WHOOP’s Strain Coach feature can’t replace a real coach. If WHOOP suggests a high strain goal on a given day, it does so simply based on your current recovery score.

If you have a race or competition coming up, you might have to take it easy and conserve energy, despite WHOOP’s recommendation.

My strain score doesn’t seem to “add up.” What’s going on?

WHOOP uses a logarithmic algorithm to calculate your strain score. For example, if your current strain score is 5.0 and then you go for a run that clocks in at 10.0, your total strain score is likely lower than the sum of both (15.0).

WHOOP does that so it can top out at 21 — the maximum strain you can achieve.

Consequently, increasing your strain from 10 to 11 is much easier than from 11 to 12.

Does WHOOP integrate with Strava?

Yes, WHOOP recently announced an integration with Strava, a popular app and social platform for bikers and runners.

The integration enables athletes to track running/biking routes in Strain Coach and to upload your WHOOP data and GPS route to Strava automatically.

Can I use WHOOP for swimming?

Yes, you can use WHOOP for swimming or triathlons but I recommend getting the Hydrosleeve to prevent water from getting between the sensor and the skin and to ensure that the sensor remains in tight contact with the skin. See https://shop.whoop.com/products/hydrosleeve

How can I upgrade my WHOOP tracker?

While WHOOP doesn’t have a dedicated upgrade program, the company has offered discounts and incentives to get members to upgrade to the latest version. I don’t recall the details of those incentives from when I upgraded from the WHOOP Strap 2.0 to 3.0, but I remember it was pretty much a no-brainer.

When I asked, WHOOP didn’t provide any details on what the upgrade pricing might look like for the next generation of the WHOOP fitness tracker, so we’ll have to wait and see.

Can stress impact my HRV?

Definitely! Stress, and chronic stress in particular, can have a huge impact on HRV and overall cardiovascular health. Check out this study on the subject for more information.

How can I increase my HRV?

You can increase your HRV by adopting certain lifestyle changes, including avoiding alcohol, exposing yourself to sunlight, protecting your circadian rhythm and others. For more information, check out my YouTube video about the 10 hacks I’ve implemented to increase my HRV.

Does HRV and sleep tracking work for people who suffer from irregular heart beats or AFib?

WHOOP offers a special algorithm that can be enabled to provide accurate sleep and HRV tracking for people who have irregular heart beats. Once you’ve signed up for WHOOP and notice issues, reach out to membership services immediately to get on the new algorithm. If that doesn’t work, you can always cancel (within the first month).

WHOOP Review – Final Words

I have become a huge fan of WHOOP, and I’m thankful to the folks at CrossFit Alpharetta who introduced me to the platform. However, there is one thing I’d like WHOOP to fix: the lack of integration with Apple’s HealthKit, which is the central hub for all my fitness and health data.

When I buy a new smart home gadget, such as a security camera or light switch, I make sure it supports HomeKit, Apple’s home automation platform. The same goes for fitness devices.

By having a copy of all my data in HealthKit — which third-party devices and apps can feed into — it’ll be much easier in the future to make it available to doctors and other care providers.

I know that Apple is already working with medical facilities to enable them to get secure access to your medical records via HealthKit. So I’m hoping WHOOP will enable that integration with a future software update.

Do you use WHOOP? If so, I’d love to hear your experience with it. So leave me a comment below, regardless of whether you’re a health-conscious consumer or one of the many elite athletes using the strap.

Medical Disclaimer

The information shared on this blog is for educational purposes only, is not a substitute for the advice of medical doctors or registered dieticians (which we are not) and should not be used to prevent, diagnose, or treat any condition. Consult with a physician before starting a fitness regimen, adding supplements to your diet, or making other changes that may affect your medications, treatment plan or overall health. MichaelKummer.com and its owner MK Media Group, LLC are not liable for how you use and implement the information shared here, which is based on the opinions of the authors formed after engaging in personal use and research. We recommend products, services, or programs and are sometimes compensated for doing so as affiliates. Please read our Terms and Conditions for further information, including our privacy policy.

109 thoughts on “WHOOP STRAP Review (WHOOP 4.0 Updates)”

  1. Do you have any idea if hrv works well if I have an irregular heart beat – not afib? I tried the Oura ring but it had large gaps that took about 2/3 of fmy sleep time.

  2. I would not recommend the Whoop. Although it does recognize activity of sleep and exercise I have found the results to be wildly inconsistent. I referred to heart rate during exercise and the corresponding algorithm results for calories burned, HRV, strain etc. I have tested it against other competitive products which has led me to this conclusion. Initially the customer support was attentive however when requesting a refund, as I had prepaid, there were crickets. This conversation started several months ago during which I was quite patient however when the refund was requested the correspondence ceased.

  3. Michael,

    Thank you for a very well written and informative review. I am not an athlete, I am in my early 60’s, out of shape, work too many hours sitting on my tail and have terrible sleep habits. Suffice to say I have a lot of work to do.

    I have started initial training to be able to work up to real, age appropriate exercise and making better life/work decisions on my time and activities. I’ve shed 17 lbs in the last 2 months and building more walking stamina. I am looking for a fitness monitor that is accurate enough for my profile (not a competitor/athlete) the will provide a more fully featured range of health metrics and the Whoop sees to fit the bill. I have read many reviews over the last week on a spectrum of fitness monitors and yours stands out as convincing me that I should give the whoop a trial run.

    One thing nagging me are the very poor reviews this product gets on the Google Play store. Are you still using the product, do you find it to be reliable after 2 years of use?

    Regardless of the feature set in the software or data, if the thing is not reliable, it is worthless. Reliability and consistency in data collection/analysis are my top two requirements outside of the data collection attributes. Accuracy/Precision follow fast but being accurate but unreliable is a deal breaker.

    Thanks in advance,

  4. Thank you for this very detailed and comprehensive review. As much as I love my Apple Watch, I prefer to wear my regular time piece when I’m not working out. Problem is I love metrics! Came down to Whoop vs. Oura Ring. This review did it for me. Went ahead and ordered the Whoop.

  5. I just took my pulse manually after reading all previous comments while seated in front of
    of my laptop, HR 30. I am an elite athlete with Heart Block second degree, type 1.
    The HRV measurement, daily strain and recovery scores are very appealing to have,
    but could they still be accurate?

  6. I swim laps in a 25yd pool. Will it track my distance and any other info since it doesn’t have gps? I don’t have any type of fitness/smart watch so trying to find something that best suits me better than my lap counter.

    Thank you

  7. Hi Michael,
    Thanks for writing such a succinct review. I’m a review-aholic when it comes to purchasing new gadgets, or anything, really. So cheers to your review.
    I have a couple of questions that you may or may not be able to answer, and I will also direct the questions to Whoop, but it’s good to get a unbiased opinion.
    I’m wondering if you know how Whoop performs in ‘hot’ gyms. So, hot everything – HIIT, cycle, yoga, pilates, weight sessions, etc etc. My thoughts are that the band would loose contact or its performance hindered by copious amounts of sweat, regardless of the type of band and where it’s worn. Do you have any thoughts on this?
    Also, do you know how Whoop performs for people with unusual heart rhythms? Does it adapt to the wearers own unique heart rhythms, or does it match the wearer according categories at what’s expected of people in those categories (age/sex etc)? I’m not sure if I’ve asked that very well. For example, I have a very low average and resting heart rate (pro athlete-type heart rate – and I’m definitely not a pro-athlete). When exercising, my heart rate shoots to maximum HR zone regardless – it’s near impossible to stay in a medium to high intensity zone. And the moment exercise stops, HR drops to normal/resting HR very quickly. It’s either maxed out, or average/resting. Not much in-between. Does Whoop adapt to individual biometrics that fall outside the ‘norm’?
    Due to the HR irregularities I find it really difficult to know how to train and if I’m helping or hindering myself. That, and now throw menopause in the mix, I have no idea how to train anymore. I was hoping that Whoop might give me some insights.

    • Hi Melissa,

      Thanks for your feedback, I appreciate it!

      Re WHOOP: You always want the strap to be in close contact with the skin, with or without sweat. If the strap is not tight enough, you’ll get inaccurate readings.

      As far as unusual heart rhythms are concerned, I’m not aware that WHOOP has been pre-calibrated for a “normal” rhythm but that’s something you’d have to confirm with WHOOP directly. But based on your example given, I can tell you that all wrist-worn devices have problems detecting rapid changes in HR (in comparison to chest straps). That’s less an issue with the calibration as it is with the technology those devices use to read HR data from the wrist.

      To be perfectly honest, I’d completely ignore HR data during workouts and simply rely on the recovery data WHOOP provides. That data is not related at all to strain or HR data captured during exercise. Instead, it’s based on HR data during sleep and WHOOP can capture that very accurately. See https://michaelkummer.com/health/whoop-accuracy/ for more information on that!


  8. Regarding the Oura ring, it is really not a fitness tracker in the same vein as the Apple Watch or Whoop. I know many that only wear their ring at night and just have it synced to Apple Health to get their activities included in the Oura app.

    • Exactly: the Oura ring only tracks HRV, temperature, &c when it detects a lack of movement. The rest of the time, it’s just an accelerometer being used to determine how active a person is, and there’s no data lost by not wearing the ring during a workout, especially if that workout is tracked by something else that integrates with Apple Health or Google Fit (Garmin, Suunto, &c).

      Workouts that are written to Apple Health (or Google Fit) are automatically imported, but more as a journalling feature: the ring makes its prognosis primarily based on data it captures while sleeping, or being still (it’ll automatically detect a nap, and show change in HRV if one medidates.

      Oura writes to Apple Heatlh (or Google Fit), and has an API that allows that data to be pulled into other services, such as HRV4Training.

  9. Hi M,

    Great review. I am an apple watch user and have been training alot recently as in 6 days/week. These involve lots of crossfit and hiit. However, recently have been feeling very tired and thought the whoop maybe a good tool to have. I do have a few concerns:
    1) I am not allowed to wear a wrist band or strap due to infection control measures so will a bicep strap work to wear for a full day?
    2) If so, will a bicep band accurately track my heart rate since the easiest place to read heart rate is on the wrist?

    • Hi Zee,

      based on everything I know, the biceps band appears to deliver more accurate HR tracking results because it stays in better contact with the skin — especially during exercises that involve wrist movements, such as CrossFit. So yeah, I think the biceps band would be an excellent choice for your needs.

  10. Thanks for the extremely thorough review! You said you found out how IF effected your sleep, but I didn’t see the actual results of what you found out. I’m very curious what you found.

    • Hi Michael, many thanks for your article. I would agree with your conclusions, except that integrations are crucial and will kill Whoop unless they grow and mature the offer. It is impossible to gain a truly accurate picture of total health and wellbeing without blood sugar, hydration, weight, muscle mass, body fat, basal metabolism and many other factors which need to be measured and analysed constantly as part of the holistic health equation. Whoop’s lack of adequate integration is, therefore, I conclude, its ultimate failure. I certainly love the Whoop band and its metrics but this lack of integration is leaving a glaring hole in my metrics. They need to fix their lack of integration swiftly if I am to continue, certainly. And the Strava integration is ultimately flawed.

  11. None of this interests me whatsoever until they have (reasonably) accurate oxygen sensors. If/when, the biceps band (but wider) would be my choice. In pink or gold – the dark colors get lost in my home…. I am a f/77, have COPD so won’t be breaking a sweat but will meet/exceed my max HR just thinking about exercise!

  12. Not a fan anymore. There is no way to get access to your data (or your trainer), you only get what Whoop thinks you should see. The automatic detection of activities used to be way better in the past. This was a huge plus for me, but having to add or manually start my workouts is a bit cumbersome. The bluetooth issues you already mentioned.

    It also looks like the support has access to your data, which is think is a big Nono, which might not bother a lot to people. You can also not download the data to do your own calculations on.

    I still like it, the band is superior to most other trackers and having sensitive skin there is no other tracker I can wear so well. Also like that it does not have a display.
    As a long time user I am just not that wowed anymore and I came here to see if there is a good alternative. Which seems like there isn’t.

  13. Thank you for the review. How does Whoop’s sensors react to tattoos? Apple Watch and some sensors have difficulties with this and causes me to be unable to use specific features especially those with wrist detection.

    • Hi Heath,

      Based on what I know, all optical HR sensors that use green light can be affected by tattoos. But I don’t have any hands-on experience because I don’t have tattoos :)


  14. I have used all three-Whoop, Biostrap and Oura. I logged data for several weeks for sleep to see what the differences were. Whoop always showed more deep sleep than Oura-every night. Biostrap only characterizes Deep Sleep, not a breakdown of REM/Slow wave. Overnight HRV was somewhat consistent between the three. I let my Whoop expire as the strain algorithm never meant much to me as I only do Peloton cycling and it always desired more strain for some reason. I still use Biostrap for sleep and Oura 24/7 although I am suspicious of the sleep data as it shows 5-30 minutes per night of deep sleep every night. I love new wearable tech and try most platforms and ultimately think it will become very reliable and significant to healthcare.

  15. I was really excited to get my Whoop…..but right out out of the box my charger did not work, and I was thankful I ordered a second one. But the unit would not hold a charge. I visited their website, was greeted by an auto message telling me they are experiencing a high volume of calls, and was directed to send an email. I did, and am now on my 7th attempt to get any kind of a response – all the while I am paying $30 a month on top of what I paid for the equipment, and am locked in until they choose to let me out of it. I’d like to discuss why I have to keep paying when my equipment doesn’t work…..but I am able to contact them and they seemingly have no interest in contacting me. Even months later, they are still receiving too high a volume of calls to respond……let that be your warning.

    I rely on and this equipment and am very familiar with other similar products. I have passed my units around to other professionals and they all agree that I have received a lemon. Now just to receive a response to tell Whoop that!

    • Hi Annely,

      I’m sorry to hear about your troubles! I never had to call in for support but I submitted a couple of requests via email — actually via the WHOOP app — and always got a response within a day or two.

      Either way, I hope you’ll get your defective unit replaced asap and won’t end up paying for the time you couldn’t use it.


  16. Great review! Just received my WHOOP 3.0 and have not found in any literature what is the preferred hand to wear the device. Most videos I see has it on the right hand which I assume is the dominant hand for most.

    Do you have an opinion on this?

    thank you

    • If I remember correctly, most of the testing WHOOP has done in terms of fit and accuracy where done on the right hand. Practically, I don’t think it makes much of a difference. But I’ll reach out to my contact at WHOOP to confirm and will send you an email.


      • Hi Michael,

        Thank you for your in depth review. It makes me even more excited to try Whoop. My dominant hand is my left-hand. I also wear my Polar watch on my left hand so when my Whoop arrives tomorrow I plan to wear it on my right hand. With your experience would that be an issue?

        Kind regards


    • Hi, I saw whoop website that the 3.0 watch just compares hrv during the first 5 minutes of your last sleep wave to establish a baseline for day to day comparison. Do you know if other measurements in the day happen or are considered.

      • Hi Edward!

        That is correct! HRV is highly volatile and random readings don’t mean anything because they’re influenced by your activities. For example, if you drink a glass of water, your HRV might change in response. That’s why it only makes sense to measure HRV during a time where your body isn’t influenced by any outside factors — and that’s deep sleep.


  17. So is the $30/mo just basically a payment plan for the band, or does this subscription continue indefinitely? If you have to pay a membership fee to where a fitness tracker—that’s utterly insane.

    • Hi Julius,

      The monthly payment covers the hardware (sensor/strap) and the service (ongoing reporting, algorithm updates…). It’s not much different to paying a subscription fee for an app. There are pros and cons to that approach for both the provider and the user.


      • Hi Michael,
        what happens if my subscription expires?
        Will the app shut down and I cannot get readings anymore?`
        Or will I still have rudimental access?

        I find $30 quite a heavy price tag for this service…


        • Hi Nikolas,

          without a subscription, the strap is useless as all the data crunching happens in the cloud. You might still see the accumulated strain and maybe calories burned (never tried it) but you definitely won’t see any recovery scores or sleep analysis.


  18. Michael,
    Ausgezeichnet! I share similar passions..technology, health, sports performance.. Former US National Cycling Champ and World Champ (in St Johann) (Masters) turned Crossfit competitor. Also speak fluent German..lived there 4 years..several cities. I must say you hit some decent wattage numbers on the Carol bike 20 sec sprint.

    I have been extremely healthy and very competitive in sports my whole life, but recently had a very unexpected, first time ever AFIB occurrence…confirmed by my Apple Watch 4.0 last week. My cardiologist believes it was the ‘perfect storm’…Bang Energy Drink, hot Crossfit session, 40 mins in sauna at 190 F. AFIB began in the sauna. He believes not likely to happen again if I minimize the ‘triggers’. I have cut out all caffeine and alcohol (huge sleep improvement) and have become obsessed with monitoring my sleep quality..poor sleep/sleep apnea are triggers for AFIB. Have been using Apple Watch with Pillow app for decent results. Would you expect me to be able to better monitor my sleep with Whoop than Pillow? Also in your experience, have you noticed better performance with crossfit workouts on the days Whoop scores your recovery as high and conversely poor performance on low recovery score days? Thanks for taking the time to answer. Ich wuerde sehr gern Sie einmal kennenlernen.

    • Hey Allen,

      Thanks for sharing your story, I really appreciate it!

      I just finished drafting an article that goes into more details about the technology used by sleep trackers and why I think WHOOP is one of the best consumer-grade devices out there – so stay tuned for that.

      But in a nutshell, yes, I believe that WHOOP will provide you with better and more reliable data than the Apple Watch + any app. Maybe once Apple turns its Beddit acquisition into a new product that combines the Apple Watch with a contactless sleep tracker we’ll see better results. For now, WHOOP and its additional sensors (skin conductance, ambient temperature) is your best bet imho.

      Lower recovery scores don’t always translate into bad performance, especially if I slept well — at least not on the level that I’m on (performance wise). But I usually take it easy or easier on those low-recovery days to give my body a chance to…well…recover.

      So if I’m in yellow, I might not perform noticeably worse that day. If I’m in red, I can usually feel it and don’t even bother trying to push it.

      Hope that helps!


  19. I wear my Oura ring for most workouts, unless it involves gripping a bar or kettlebell. I have worn it during those and do okay, but would prefer to be safe and protect it. It doesn’t track workout intensity during those kind of movements particularly accurately anyway, so I just use the app’s manual activity entry to enter the time/duration/intensity level of those types of workouts so some data is there rather than none or inaccurate data.

  20. So I got a whoop and have been testing it against my Apple Watch and honestly I think it’s kind of a gimmick. The Apple Watch series 4 or 5 have battery life long enough for sleep tracking and with a fast charger can get you from 25% to 80% in 15 minutes, enough to fit into a shower routine. Combine it with a good 3rd party sleep app like AutoSleep that detects your recovery using HRV, and you get legitimately great feedback on recovery and how much you can push yourself every day. I hate having to wear multiple devices and don’t think the Whoop is for long..

    • Hi Chris,

      the Apple Watch isn’t a good sleep tracker for numerous reasons. I’ve had all models, including the Series 5 using the latest apps and none worked reliably. I’m about to publish an article that goes into the technology (sensors) and other reasons why most sleep trackers aren’t good enough. So stay tuned for that.


  21. Great review! If I have a subscription for a while and then stop, is there anything I can still do with the whoop band? Or does it require a subscription to function?

  22. Dear Michael,
    how does one take shower after the Workout? Do you take Whoop off just for the shower? or leave it be on your wrist? Because the wrist band gets all wet and salty and most of all will get stinky if you don’t wash them or dry them properly. How did you manage yourself around These Problems?

    • Hi Eumin,

      WHOOP is water-proof (just the battery pack isn’t), so I leave it on when taking a shower. I might just open the clasp so I can wash the inside of the sensor and the band. All bands I’ve had so far, including the latest ProKnit dry really quick. So I never experienced any issues.


  23. Hi i use actually a Garmin but ay the past i used WHOOP
    Garmin sais me i burn 1500-2000 caloier
    And WHOOP near 3500-4000 caloies
    What of two its correct

    • Hi Raquel,

      that’s hard to tell. Calorie tracking is based on your HR reading and the quality of that depends on how well a contact the sensor has with your skin. For a woman, 3-4k calories seem high – but of course, it depends on your level of activity.

      For reference, I’m 6 feet tall and weigh 190 pounds. On days I workout, I burn 2.8k – 4k calories in total.


    • I have the same issue! My Apple Watch shows a far greater calorie burn than my whoop, some days a 700 calorie variance. I don’t know which to trust!

  24. I’m a competitive athlete with several international level coaches in my team. My sleep doctor coaches NHL players and he expressed very strictly that none of these devices can actually track your sleep. What they do is that they use algorithms to model your sleep based on certain metrics but to track your sleep you need to have a polysomnography :) so wearables are not accurate with sleep metrics. Remember that all models are wrong while some models are useful. :)

    Now, here’s the caveat: the more you have sleep disturbances the more these models get wrong. Having been twice in real polysomnographic test (you sleep with over dozen medical grade sensors around your body) I can ensure that these gadgets are wrong, quite much wrong indeed.

    Why do I still use my Oura then? Two reasons: a) these gadgets are useful is collecting HR and RHR data during my sleep (I’m still in the process of analyzing if the data is useful itself though) and b) they guide me to give more attention to the sleep and recovery ☺️

    Albout the gym, (or sports), I’ve come to notice that optical HR monitors are really bad when tracking HR during the sports. They don’t come even close of a real HR strap. They are so unreliable that a real athlete cannot base her training on these and I have used different top models from Polar and Garmin. As the optical sensors are pretty standard stuff I highly doubt Whoop cannot make any difference.

    I encourage you to make a test: wear garmin/polar with HR strap and compare the results with Whoop. Also, the problems with optical sensors during HIIT or short intervals are especially well known (even Polar H10 the golden standard of sports labs has problems with these).

    Thus going gym without Oura is not a problem for me as none of these wearables are something that gives me useful data and during the sports I always wear a HR real strap. 🙂

    My point here is that while new tech is awesome and it can help you many ways, you still have to use your judgement and not become “slave” – because oour technology still fails us quite often. It’s easy to become fascinated by reducing our lives into a couple of numbers but unfortunately human bodies are way more complicated than one could possibly understand.

    I recommend studying undergraduate level exercise physiology to grasp a bit how complicated and fine machines we are. You might get surprised. 🙂

    • Hi Frnkr,

      I appreciate the time you took to draft such a detailed comment.

      Your sleep doctor reminds me of my primary care physician, who still thinks saturated fat intake increases my risk of developing coronary heart disease — despite meta analysis of numerous clinical trials stating the opposite. I consider that an opinion that’s not based on actual, scientific evidence.

      I’ve linked a study in my article showing the accuracy of certain wearables for sleep tracking and how they compare to the equipment used in sleep labs. Speaking of sleep labs — have you ever tried that? The stress alone of being hooked up to monitors while trying to sleep in a lab-environment renders the results pretty much useless.

      Outside of the lab studies WHOOP has performed, they also published a real-life study with college athletes – you can check it out here: https://www.whoop.com/the-locker/study-rhr-hrv-sleep-collegiate-athletes/

      Besides that WHOOP has the data to proof its accuracy (which very much depends on how tight the strap is), I’ve compared HR readings of a chest strap, my Apple Watch and the WHOOP during CrossFit workouts. I couldn’t find any significant discrepancy.

      My recommendation would be to read up on the latest scientific evidence and to ask your sleep coach what studies he bases his opinion on.


      • I have been reading through the comments and I believe your reply here is not on target. I have used Whoop for a couple of years and have benchmarked it with chest straps and/or Apple Watch for Crossfit, running, and cycling and the Polar OH1 HRM against the temple and on the goggle strap for swimming. The Whoop does give me highly variable data vs what I consider more gold stand measurement of chest straps and the aforementioned OH1. The Apple watch is probably the preeminent OHR monitor. Whoop overestimates by around 20 bpm for swimming and cycling and is fairly close running. In Crossfit the Whoop can go crazy. Given that, the Whoop strain is off and can give inaccurate advice. Regarding sleep and in line with the post you replied to, Whoop gives me far less sleep than the Oura ring, much higher deep sleep, so I do not know which one is right. So, I consider the data as relative information. I also wear an Oura ring btw. I also agree that the more advanced lab studies are the truly only real indicator even though all these sleep devices want you to think differently. I do have a bicep strap on order for the Whoop and will benchmark again versus the bicep strap. I do feel wrist geometry may play into the accuracy of the Whoop.

        • Hi Fred,

          I recently performed some more accuracy tests and documented my findings in this article — check it out: https://michaelkummer.com/health/whoop-accuracy/

          I’ve also gotten an Oura Ring and Eight Sleep to compare sleep tracking data. Eight Sleep and WHOOP agree most of the time. Oura is always wildly off and I’m not entirely sure why that is. I’m currently performing some more tests and then write up my findings in a blog post.

          • Thanks for the link to your comprehensive evaluation. Your method of benchmarking is quite similar to mine in that I use my Apple Watch connected to a chest strap and your findings are similar to mine. Swimming is the big wild card and and the wrist movement you mention is likely the culprit along with the rapidly moving arm. I do try to put the Whoop Strap underneath my wrist where it is more fleshy but that really does not help that much. I equate the swimming to what I can do at my desk; move my arm overhead in circles and watch the HR on Whoop go up artificially. As a result, I just tend to ignore the HR and rely on my Apple Watch. If I want really good data in the pool, Polar Beat with OH1 on my temple in memory mode does the trick and I just accept Whoop for what it is. I am not a pro athlete either :) and just like the guidance. I will read through more of your articles. Thanks Fred

  25. I have been using the whoop and i like it a lot but i sweat a lot during my workouts. Unfortunately the band is still soaking wet after i shower and get ready to go about my day. I have the band that came with the whoop 3.0 but i was wanting to know if you know if any of the other whoop bands are more plastic or rubber type that will dry off a lot easier. Thanks you for your post if was very informative.

    • Hi Rene,

      I just got out of the shower and paid attention to the strap. My 3.0 strap dried within a few minutes. Before I read your comment, I never noticed it and so I never paid attention to the other straps I used before. However, just based on the fabric, the Lux Kit might dry a little faster. Not sure if it’s worth a try, though.

  26. It’s hard to believe we have such opposite experiences. Unfortunately the whoop 3 just does not meet the mark. From missing nights data to not recognizing activities, and an inability to correctly record sleep (even after manually updating it to correlate to my other devices). This is a good idea very badly executed. Two other huge issues, which ultimately would be the reason for purchasing: 1) on days where I literally do nothing it has me showing as having a strain level higher than 91% of users, and days where I run 21 miles it barely notices a difference. 2) it references a new metric “HRV” but does not give any insight into how to address it and what is good or bad. The stress of having the device tell me I am way behind on sleep and recovery (when in reality I know I am well above average in both) actually has been quite stressful. So many deal breakers this is not ready to be in market and certainly not at the price point.

    • Hey Pippen,

      Thanks for the feedback, I appreciate it! Have you considered that your strap might be defective? Many of my friends and fellow CrossFitters use WHOOP and none of them have reported any of the issues you’re having.

      Coincidentally, I listen to episode 31 of the WHOOP podcast yesterday in the car in which John Capodilupo — their CTO — talked about some users who have gotten a 3.0 strap with bad electronics. He recommended to reach out to support via the app (which sends a diagnostics file). If your strap is bad, you’ll get it replaced.


  27. Hi Michael, First, thanks for the accurate review and comparisons, truly appreciated!
    My question is how do you use it for Crossfit? and how durable is the Woop strap for CF? :) as if in the wrist we commonly sometimes do Kettlebell, that can endanger seriously the device (and anything in our wrists, as the wrist itself…) so I guess you use a arm strap… if so which one and how does it go for you?

    • Hey José,

      I usually just keep WHOOP on my wrist during CF workouts – but I move it back a bit, so that I have enough room to close my grips, if I use any. Otherwise, I don’t do anything special. However, I’ve banged KBs a few times both against the WHOOP and my Apple Watch, so far without breaking anything. A few times, the clasp of the WHOOP opened and I had to close it again. No big deal.

      However, if that happens more often, I suggest to use the biceps strap or to wear something protective over your WHOOP. I have the biceps strap that I showed in the photo and it works really well – you just have to take it on and off before/after the workout. I’m lazy and prefer keeping WHOOP on my wrist :)

      Hope that helps!


  28. Hi. Interesting deep dive. I am a Crossfitter and a runner. For my running I use a Garmin Forerunner 235 which has the built in HR monitor. Is there any ability to integrate the two platforms? Any benefit of Whoop over Garmin? Anyone discussion of the two?

    • Hi Geoff,

      I’m not aware of such an integration and I’ve never used Garmin. But based on what I know, it doesn’t look like Garmin offers the same sleep and recovery tracking capabilities as Whoop.


  29. I received the white not grey Whoop 3.0 on Friday and it is nothing like the 2.0. It will not stay up to date in app unless it’s open……rendering it useless for me. I liked the 2.0 so much better. Are others reporting this issue?

    • Amy, can you elaborate on the issue with the app updating? Maybe it’s due to more processing happening in the 3.0 strap or the BLE connection.

  30. Hi Michael, so I have been interested in getting a Whoop but the issue I keep having is I not a huge gym rat. I do BodyPump one day a week but then do a 3 mile morning walk 5 times a week. I also work at costco so I’m always moving and lifting TV because work in the sales dept.Do you need to be a gym rat for the whoop to be worth the money. I wear an Apple Watch 4 right now. If anyone could help me out would appreciate it.

    • Hi Jason,

      you don’t have to be a gym rat for Whoop to make sense – in particular the sleep and strain tracking and analysis. The only limitation I see is around automatic workout detection. Whoop only detects activities automagically if your HR is above average for 15 minutes or longer. So if you go for a slow walk and your HR doesn’t go up, you might have to tell Whoop (via the app) that you exercised.

      Hope that helps!


  31. Really great article, thank you for posting. Out of curiosity have you tried the Oura band? I was torn between Oura and Whoop.

    • Hey Derek,

      Thanks, I really appreciate your feedback! I haven’t tried the Oura yet, but it’s on my todo list :)
      Meanwhile, I don’t think you can go wrong with WHOOP — I really like it.


  32. How does the membership incorporate device upgrades? Their website advertises you get the current band “free” with your initial membership. If they come out with the 4.0 in two years, would I be able to to get an upgraded device as part of my monthly membership fees or would I have to pay an extra couple hundred dollars to upgrade?

    • Hi Matt,

      this is what Whoop has told me regarding upgrading from 2.0 to 3.0: “Current subscribers are receiving a $120 offer for 3.0, which includes a 4-month membership extension.”


    • Hi Gen!

      I saw this option when I tried to upgrade my membership to the new WHOOP 3.0 strap. Maybe it’s only an option for existing lifetime members. I’ll ask WHOOP and let you know when I have an answer.


    • Hi Gen!

      The lifetime option is only available to founding members, meaning those who purchased the strap before WHOOP introduced subscription pricing.


  33. Hi,
    I’m considering getting a whoop – but any ideas how it would be affected by my occasionally working overnight shifts? I Know they hurt me, but they are a necessity of my job a couple of times a month. I’m just wondering how the Whoop algorithms would handle that and if it would just negate the whole effectiveness of their platform. Any thoughts?

  34. Hi Michael,

    A question about the accuracy. I currently have a Fitbit Versa as my main watch. I am aware of the lack of accuracy on wrist worn devices during exercise. I strap on a Wahoo TickerX for my HRM during my Crossfit workouts. I am looking to consolidate into one device. In your opinion, if I were to switch from wrist worn to biceps worn during the workouts, would that increase the accuracy enough to consider making the switch? It would stand to reason that the biceps would give it a more consistent contact with less flexion during the workout. Just looking for your thoughts. Thank you in advance and thank you for a great review.

    • Hi Michael,

      I too have a Wahoo TickerX that I started using for Ticker Training at our Crossfit box. I do see some minor discrepancies between my Apple Watch, WHOOP and the chest strap but I’m not sure which device is most accurate. I say that because my chest strap tends to move around a bit as well.

      I’d say with a biceps band, like the one I started using two weeks ago, you should be perfectly fine.


  35. Does the whoop need constant radio contact with your phone or can I go for a run without the mobile? Also concerned about sleeping with RF next to my skin. Can I turn off the bluetooth in the whoop during sleep?

    • Hi Hannah,

      no, it doesn’t need constant radio contact with your phone. I stores all data on the band until it reconnects to the phone to transfer it. You cannot turn off BT. However, there is RF around you (from natural sources and otherwise) that the BT antenna in WHOOP won’t make a difference. Plus, there isn’t any [credible], scientific evidence to show that RF is bad for your health.


  36. Great review. Appears there might be some accuracy deficiencies that no product has resolved. I’m wondering why no chest strap. I can’t imagine a woman wearing this device. Seems like a chest strap would attract that segment of the population.

    • Hi Curt,

      I know several women wearing Whoop, some even with the fancy-looking gold strap. However, I agree that a chest strap would offer an excellent alternative for those who won’t like the wrist strap.


    • ^women wear bras and just the thought of adjusting chest straps and bra bands makes me irritated! Perhaps some women do it, but I certainly would not. Ouch!

  37. Excellent review. I’ve been wearing Whoop for about 16 months and it’s impressive looking back at a years worth of data. Can’t imagine life without it. Really keeps me healthy and injury free. Not overloading on poor recovery days are so important. Another eye opener is if I have any drinks the night before. And I don’t mean getting drunk. Just a couple of beers. Wow, my body doesn’t recover well at all. Sleep cycles are terrible. Low HRV and high RHR. And that’s with no strain the day before. Opens your eyes to the reality of daily life, stress, and other things that impact your health. I, too am an Apple guy and was contemplating the upgrade to the newer version of the watch, hence why I stumbled on your review. But it doesn’t look like it’s where I want it to be for me to upgrade quite yet. Again, great review! Enjoy the whoop!

    • Try out an Apple Watch 4 or 5 with autosleep. Does the same thing. I got the whoop based on a rec from a friend but honestly don’t see the benefit of it when the Apple does the same thing with a 3rd party app

  38. Hey Mike!

    This is a very detailed and comprehensive review of the product and services offered by Whoop. I have been debating between products such as Whoop, Fitbit, and the Apple watch. The biggest selling point for me is the sleep tracker and sleep coach Whoop has to offer.

    Have you utilized the Whoop Bicep Band yet? If so, what are your thoughts on that?

    Thanks again for the great review!

    • Hey Warren!

      Thanks for stopping by! I haven’t tried the biceps band yet, but it’s on my list! I’ll update my review in a few weeks, once I have had a chance to try it!


      • I have the biceps band and it’s wonderful. Also a Crossfit guy and it’s a must when doing kettlebell snatches and other movements similar. A little cumbersome getting it on and off the device but I think there are newer versions now. I also like the sleeve idea. I may dive into that next.

      • Michael,

        You said “that you have seen”–unless you’ve looked, you’d be unlikely to run across such evidence, because it’s a fairly unpopular position.

        But there is plenty of independent, peer-reviewed evidence to suggest EMFs from cellular devices, smart devices, household electricity, and appliances (“dirty electricity” or electrical noise) have biological effects. It’s really not up for debate.

        That’s leaving aside the very well known, widely acknowledged biological effects of light (including electrical sources of visible light, visible sunlight, and non-visible frequencies like UV and IR) which are technically EMFs, but we don’t usually include those in the discussion. However, keep in mind that all EMFs do have biological effects. That is a certainty.

        The question then becomes, are these effects potentially harmful? And again, credible perspectives (such as a Lancet paper you’ll find below) suggest the answer is yes (again, for AC electricity in the Hz range, Khz, and Mhz/Ghz radiofrequency radiation).

        Why might we not hear about this more often? Similar to how big tobacco used to operate in its heyday, industry sponsors studies and also funds advertising for outlets that may report on the harms, creating conflicts of interest everywhere.

        For example, here’s a paper showing that industry funding in wireless safety studies significantly influences outcomes, in the favor of showing wireless is safer compared to independent studies: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1797826/

        The first successful lawsuit against a tobacco company was in the year 2000, which means an analogous situation went on for decades before they were held accountable. Except the tech and wireless industries are far more entrenched, and are orders of magnitude bigger than the tobacco industry/lobby ever got.

        The 1996 telecommunications act in the US sets very high exposure limits based on tissue heating (like a microwave oven). That’s the only official, regulatory standard for harm.

        Keeping in mind what we now know about other mechanisms for EMFs that take effect at lower exposure levels (altered glucose metabolism, activation of voltage-gated calcium channels, altered melatonin activity, impaired mitochondrial function, red blood cell aggregation called Rouleaux formation, sympathetic-dominant changes in autonomic nervous system activity, and more), that’s a recipe for harm.

        Here’s some reading to get you up to speed:

        * RF EMFs produce widespread neuropsychiatric effects including depression https://pubmed.ncbi.nlm.nih.gov/26300312
        * Cell phone use alters human brain glucose metabolism with unknown clinical effects: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3184892/
        * RF-EMFs affect the activity of melatonin and voltage-gated calcium channels https://www.sciencedirect.com/science/article/pii/S2213879X17300330
        * Pulsed cell phone EMFs suppress REM sleep in humans https://www.karger.com/Article/Abstract/119247
        * NTP RF EMF toxicology study funded by NIH shows tumors in rats https://www.nih.gov/news-events/news-releases/high-exposure-radio-frequency-radiation-associated-cancer-male-rats
        *Lancet paper on the effects of EMF pollution on humans and the planet https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(18)30221-3/fulltext

        Unfortunately, many people who haven’t looked at the evidence or have personal biases still view this position as paranoid and unfounded, and are unwilling to acknowledge the potential for harm until they or someone they know develops symptoms caused by overexposure to wireless tech.

        If that ever happens to you, as an apparent gadget lover, there’s nothing wrong with admitting you initially overlooked the potential for harm.

        If you feel curious and want a deeper look into this whole issue, I highly recommend the book “Going Somewhere” by Andrew Marino, a PhD biophysicist and JD who’s been involved in successful legal action against power companies and wireless companies.


        • Hi Corey,

          Thanks for the detailed information! Since I wrote the comment you are referring to back in April of 2019, EMF has become an area of interest for me and there appears to be a good amount of research on the topic.

          While I’m still not too concerned about the Bluetooth LE (Low Energy), I’ve been thinking about practicals ways to limit my exposure (i.e., no cell phone on my nightstand…).

          However, I realized that unless I move away from the city and put a Faraday cage around my house, there isn’t a whole lot I can do to limit the exposure of the big EMF emitters.


          • Hey Michael,

            Thanks for publishing the comment and your thoughtful reply.

            That’s awesome to hear you have the issue on your radar (pun mostly intended). Maybe if influencers like you can help tactfully spread some awareness on this issue among tech users and companies, demand for truly safe tech could grow. I honestly think it’s possible, maybe even using current technology, or not a big leap.

            Here are some more thoughts, since you also seem to enjoy nerding out…

            I would partially agree with you that moving to a vetted rural area can be good (and that’s what I did ultimately, as a person who was experiencing mast cell reactions from EMFs–undiagnosed for about 4 years).

            But a lot of times the biggest sources really are the ones near us, on our bodies or in our living environments, due to what’s called the inverse square law. The intensity of these types of EMFs scales proportionately to intensity divided by distance squared. That means the super powerful ones (like towers) that are far away are often not reaching us with the same intensity as less powerful devices that are right on our bodies or under our desks.

            So similar to what you are already doing, disabling, turning off, and unplugging personal devices when not in use can really make a huge difference in your daily exposure levels. For devices that can’t be turned off for whatever reason, each time you double your distance, the exposure scales down exponentially.

            A “consumer level” EMF meter for about 200 bucks can be a very eye-opening way to mitigate hidden or otherwise overlooked sources, and I’d strongly recommend it before getting into shielding since all shielding is directional to some degree, meaning it can also bounce EMFs back.

            Sometimes people living in cities even get really lucky and their sleeping quarters are acceptably low EMF, at least when they do the basic work to not contribute EMFs at home. Hard to know without a basic meter.

            But the “secret” method that’s nearly as good as all that, better in some ways, is…take a device-free camping trip (or at least devices off as much as possible) in a low-EMF natural area. For someone who seems as healthy as you, maybe a week or two to get a good idea of how much better you might feel. But someone who’s dealing with environmental sickness, even a couple of nights can be incredibly eye-opening to how much their environment makes them feel bad.

            All right, thanks again.


  39. Terrific review – thank you for eloquently sharing your thoughts on these devices! I currently have an Apple Watch 4, but love the way Whoop integrates your physiological measurements into actionable recommendations (i.e., sleep more tonight, hold off on working out right now, etc.).

    As I debate joining Whoop and wearing both devices, is the Apple Watch’s ability to perform what Whoop does just a software upgrade away? Or do you think there are enough differences in the hardware such that the current Whoop band will always have an edge above the Apple Watch 4?

    Appreciate your thoughts, and thanks again for your insight!

    • Thanks Jeff and good question! I’m inclined to think that Apple might have to increase the battery life of its watch before it can continuously track your HR and HRV, like Whoop does. That likely means a chance in hard- and software. WWDC is around the corner, so we’ll learn more about the next version of watchOS soon.

  40. I’ve worn Whoop for 18 months now and while I love the concept, I don’t feel the accuracy of the device is close enough yet for me to trust the recommendations. If it can’t measure heart rate accurately, then how can I trust any of the other measurements? It frequently tells me I’m sleeping (REM or light sleep) when I’m actually just reading in bed.

    I also don’t understand how professional athletes trust the accuracy of the device, for example, when the heart rate data is so obviously wrong. Are people really that unaware and so determined to believe what a device is telling them?

    • Hi James!

      Same as with the Apple Watch (or any other wrist-worn device), proper contact with the skin is crucial for its accuracy. The latter often suffers during exercise (i.e. when you move a lot). I started Ticker training about a week ago and have been wearing 3 heart rate monitors during exercise: Apple Watch, WHOOP, and a chest-strap that connects to my iPhone. Comparing the readings from all three devices, they are pretty much in line (+/- 5BPM). But I can tell both Apple Watch and WHOOP suffer in accuracy when I do exercises that make me bend my wrist, because it breaks the device’s contact with my skin. Another study I found on a similar subject confirms the accuracy of wrist-worn devices when there is no movement involved – check it out: https://www.researchgate.net/publication/323417048_Can_Wearable_Devices_Accurately_Measure_Heart_Rate_Variability_A_Systematic_Review

  41. The review is appreciated. As a long time user we do however know that whoops HR accuracy is questionable to say the least. If the user is moving his//her arm the HR is erratic, while at rest however it is pretty good

    • Hey John!

      Based on the technology WHOOP uses and the sleep lab testing the company has done, it’s seems to be relatively accurate. As I mentioned in my article, I expect their accuracy to be around 86%. WHOOP claims 95%, but I think it’s too high based on their technology and lack of EEG.


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