Biostrap vs. WHOOP Review and Comparison

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Last Updated: Oct 06, 2020

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After having worn WHOOP every day for about 18 months, I decided to purchase the Biostrap wristband and write an in-depth, side-by-side comparison to determine which device is the better fitness and sleep tracker.

Like WHOOP, Biostrap’s goal is to measurably improve your sleep, recovery and performance. But despite their similarities, there are plenty of differences between these two wearables.

So let’s take a look at those differences, starting with their hardware.

Hardware (Wrist Strap and Sensor)

WHOOP vs. Biostrap
Biostrap and WHOOP sensors.

Both Biostrap and WHOOP are wrist-worn devices that rely on hardware sensors to keep tabs on your heart rate, HRV and other important biometrics.

But before we discuss the actual sensors, let’s briefly talk about the piece of hardware that’s supposed to keep the sensor in close contact with the skin: the strap.

Strap Comfort and Fit

Biostrap uses an elastic silicone strap that doubles as the housing of the removable sensor. 

I found the strap’s material to be comfortable against my skin. However, I didn’t like the pin-and-tuck closure, because it makes it difficult to tighten the strap with one hand. As a result, I never seem to achieve the right amount of tightness, ending up with a strap that’s either too tight or too loose. 

I had the same issue with the first-generation Apple Watch, until Apple decided to offer the Sport Loop instead of the traditional Sport Band.

FeaturesBiostrapWHOOP
Strap materialSiliconePolyamide, polyester, elastane
Closure mechanismPin-and-tuckClasp
Adjustability★★★☆☆★★★★★
Elasticity★★★★☆★★★★★
Comfort★★★★☆★★★★★
Alternative wearing options
Biostrap vs. WHOOP strap comparison.

The WHOOP Strap 3.0 ships with what the company calls the ProKnit strap. 

I love the ProKnit because it doesn’t rely on a pin-and-tuck closure, which means I can get just the right amount of tightness. Additionally, the ProKnit strap is even more elastic than Biostrap’s silicone band — and incredibly comfortable. 

Apple’s Sport Loop is my absolute favorite strap of any wrist-worn wearable I’ve ever owned.

Overall, I’d have to say that between the Apple Watch, Biostrap and WHOOP, I like my Apple Watch strap the best, followed by WHOOP’s ProKnit strap. 

As far as Biostrap’s implementation of the closure mechanism is concerned, I wish the company would take a cue from Apple and make it easier to adjust the strap.

By the way: I’m so picky about the strap of wrist-worn wearables because the accuracy of these devices depends on a good and tight fit. Without that, you won’t get good data. Check out my article about the accuracy of WHOOP for more information on that topic.

Also, unlike WHOOP, you can’t charge Biostrap without taking the strap (or at least the sensor) off your wrist. So the convenience and usability of the closure mechanism are even more important for those who use Biostrap than for those who wear WHOOP (which can be charged without having to take the sensor off your wrist).

Wrist-Band Alternatives

What I like about Biostrap is that the company offers alternative methods to keep the sensor in close contact with your skin while exercising.

For example, you can wear Biostrap on your forearm, which could provide more accurate HR readings during exercises that involve wrist movements (such as push-ups or kettlebell swings). Just be aware that Biostrap’s armband is not meant for sleep and recovery tracking. In a way, it’s an alternative to the chest strap that you can wear on your forearm.

WHOOP offers a dedicated bicep band that some athletes prefer over the wrist strap — especially those who have to wear gloves or grips (such as martial artists, CrossFitters, etc.).

I’ve also heard that doctors and other medical professionals prefer the bicep strap so they don’t have to worry about contaminating the strap with germs.

Sensors and Biometrics

Biostrap vs. WHOOP - sensors
Biostrap and WHOOP sensors.

By looking at the table below, you can tell that both Biostrap and WHOOP include several advanced sensors that allow the straps to capture a variety of biometric data.

BiometricsBiostrapWHOOP
Heart rate
Heart rate variability
Wrist movement
Ambient temperature
Electrodermal activity
Calories burned
Respiratory rate
Blood oxygen saturation
Sample frequencyEvery 5 or 10 minutes100x per second
Comparison of the biometrics collected by Biostrap and WHOOP.

In a nutshell, both devices have a similar set of core sensors for measuring heart rate, HRV, movement and respiratory rate. However, WHOOP packs in two additional sensors that enable the device to detect sleep and stages of sleep much more accurately than Biostrap.

The second big difference between WHOOP and Biostrap is the sample frequency.

Out of the box, Biostrap samples your heart rate (beats per minute), heart rate variability (HRV), blood oxygen saturation and respiration rate only once every 10 minutes. This is meant to conserve battery life, but you can increase the sample frequency to every five minutes via the mobile app.

In comparison, WHOOP samples biometric information 100 times per second. This leads to a significantly more accurate picture of the information it tracks. 

Optical Heart Rate Sensor

Of course, the core of both wearables is an optical heart rate sensor that uses light-emitting diodes (LEDs) to detect both how fast your heart beats and the variability between heartbeats (HRV).

Biostrap and WHOOP both rely on two LEDs to shine light onto your blood vessels, and one sensor between the LEDs that captures the reflected light.

I can easily tell if WHOOP is capturing data by lifting up the sensor with my finger. If I see green light from the LEDs, I know the sensor is working and has battery power.

I have never seen any light being emitted from the Biostrap sensor throughout the day. That’s probably because of how infrequently it captures data. The only time I saw the sensors capturing data was while capturing biometric data “on demand,” one of the features that Biostrap has but WHOOP doesn’t. 

To my surprise, I realized that Biostrap’s LEDs emit red light rather than green light. That’s unusual, because most photoplethysmography (PPG) sensors built into wearables use green LEDs (including WHOOP). 

Green LEDs are so prevalent because they’ve been around longer and manufacturers have a lot of expertise making them. Plus, they offer a better signal-to-noise ratio and are more resistant to motion artifacts. Practically, that means that, for example, wrist-movement or ambient light impact PPG sensors less than pulse oximeters.

On the other hand, the skin absorbs green light easily, which reduces the amount of light that gets reflected back from your blood vessels.

Sensors that emit red light are called pulse oximeters, and they use near-infrared spectroscopy to deeply penetrate the tissue to obtain biometric signals like hydration, muscle saturation and total hemoglobin — things that green light can’t measure. 

Note: Apple just introduced the Apple Watch Series 6, which uses green, red and infrared LEDs.

Red light is also not impacted by tattoos, freckles or darker skin tones (melanin).

The downside to red light is that it has a higher signal-to-noise ratio and is more susceptible to motion artifacts. The latter can significantly impact heart rate readings during physical activity.

The bottom line is this: there are pros and cons to both types of light.

Accelerometer

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

Both straps also include an accelerometer (or gyroscope) that detects wrist movement, which can be useful for activity and workout tracking.

The accelerometer is also used in combination with the optical HR sensor to capture heart rate data. Much like you can feel your heartbeat with your fingers, wearables can detect the force of a beating heart to improve their readings.

Additionally, Biostrap appears to use the accelerometer to detect whether or not the wearer is sleeping. In other words, it interprets a lack of movement as being asleep. That’s a major design flaw, as I explain in the sleep tracking section of this article.

Ambient Temperature

WHOOP’s body temperature sensor enables the device to accurately detect both when you fall asleep and in what stage of sleep you’re in. That’s because your skin and body temperature both change during certain phases of sleep. 

You can learn more about that in my review of the best sleep trackers.

Electrodermal Activity

Much like your temperature, your skin conductance (a measure of how much electricity flows through your skin at a given time) changes as you fall asleep (as well as during certain stages of sleep).

This sensor is the second reason why WHOOP is so much better at detecting sleep and sleep stages.

Respiratory Rate

The respiratory rate reflects how many times per minute you breathe. Knowing what your normal respiratory rate is can help you detect and diagnose pulmonary issues (or even COVID-19 infections) if you see sudden changes in your breathing rate.

My respiratory rate is usually around 14 breaths per minute at night. If that were to rise to 16 or higher, I’d know that something was wrong. In fact, WHOOP analyzed the data of members that contracted the new coronavirus, and the common denominator was a sudden increase in respiratory rate — which occurred even before the wearers showed other symptoms.

Blood Oxygen Saturation (SpO2)

Biostrap-Oxygen-saturation
Biostrap: Blood oxygen saturation.

Blood oxygen saturation is another indicator of how efficient your pulmonary system is at extracting oxygen from the air you inhale. It’s also an indication of the ratio between oxygen-carrying and non-oxygen-carrying hemoglobin.

A normal reading is somewhere between 94% and 100%.

Biostrap can keep tabs on your SpO2 readings, while WHOOP cannot. While that’s not a problem for healthy individuals, knowing your night-time SpO2 readings can be incredibly useful for those who suffer from sleep apnea or other sleep disorders. 

Plus, any deviation in your blood oxygen saturation can tip you off to potential infections in your airways (similarly to changes in your respiratory rate, as discussed previously).

WHOOP doesn’t provide SpO2 readings because it lacks the sensor hardware (and the oximeter) to capture that data.

Software (Mobile App)

Biostrap and WHOOP took vastly different approaches to mobile app design, including with regard to how they expose the captured data.

Overall, I’d say that WHOOP has the more sophisticated app. It not only provides more details, but also more actionable information.

Biostrap’s app offers a lot of high-level information and is easy to navigate. But I don’t feel like the information it provides is particularly helpful in making better lifestyle choices that lead to improved recovery and sleep — at least, not to the extent that WHOOP does.

FeaturesBiostrapWHOOP
Today’s view
On-demand biometric recording
Activity timeline
Recovery analysis
Impact of lifestyle factors on sleep and recoveryBasicDetailed (Performance Assessments)
Sleep analysisBasicDetailed
Data comparison with other platform usersDaily (basic)Weekly, monthly, yearly (detailed)
Actionable information
Usability★★★★★★★★★☆
Track other users
Workout detectionYes (unreliable)Yes
Third-party integrationHealthKit, NoonlightHR broadcast (generic), Strava
Feature comparison of Biostrap and WHOOP mobile apps.

Initial Setup

Biostrap - Setup
A bold claim right on the initial setup screen.

Both Biostrap and WHOOP are fairly easy to set up. In a nutshell, you have to create an account, and enter some personal information (such as date of birth, weight and height, etc.).

That information helps the wearable guesstimate your basal metabolic rate (BMR), which is used for calorie tracking. Then you have to pair the strap with your smartphone via Bluetooth.

Once the initial setup is complete, both devices start capturing data. For each, it takes a couple of days to establish a baseline and provide a recovery analysis.

What got me super excited during the setup of Biostrap was that it asked me if I wanted to store all captured data in Apple’s Health app. Integration with HealthKit has been on my wishlist for WHOOP since I got the device. 

Overview and Usability (Dashboard)

Both Biostrap and WHOOP offer a dashboard screen that shows up when you open the respective app. The dashboard gives you an overview of the day’s biometrics, an indication of how recovered you are, and insights into how you slept the previous night.

From there, you can drill down into individual biometric categories to get more details.

While Biostrap offers a dedicated menu on the bottom of the screen and a few clickable items on the main dashboard, WHOOP allows you to swipe left and right, click, and swipe up and down.

As a result, some users find Biostrap’s app to be more intuitive than WHOOP’s. I tend to agree with that assessment, at least when you’re just getting started. Once you’ve figured out how to navigate WHOOP’s user interface, it becomes second nature.

Activity and Fitness Tracking

WHOOP - Activity Tracking
WHOOP detected a functional fitness workout.

As I explained in detail in this article, wrist-worn fitness trackers have limitations when it comes to tracking active calories burned and rapid changes in heart rate — especially when compared to HR monitors you can wear around your chest.

Considering the fact that Biostrap measures your biometrics only once every 5 to 10 minutes, and uses red light to do so, I didn’t expect much from the device. Remember, red light is more prone to noise and motion artifacts than green light!

Biostrap has acknowledged these issues by offering a separate armband and chest strap, which you can use in combination with the wrist band. 

I didn’t order the chest strap because I don’t care about activity tracking, as I explained in the article linked above. I’m not a professional endurance athlete (I do CrossFit) and thus heart rate zones don’t matter much to me.

Biostrap - Chest strap
A chest strap is the best way to get accurate HR data during certain types of workouts.

That said, I think it’s awesome that Biostrap offers more reliable options for those who need accurate heart rate data from their workouts.

As you might already know, WHOOP can only broadcast its own HR data; it cannot receive data from a third-party chest strap. That’s a clear limitation as far as activity tracking is concerned, but not one that influences its quality as a sleep and recovery monitor. 

Regardless of the usefulness of wrist-worn activity trackers, you should know that most devices only automatically recognize physical activity as a workout if it lasts longer than 15 minutes or so. 

By that, I mean that your heart rate has to be elevated above a certain threshold (compared to your baseline) for 15 minutes or longer. So any activity that doesn’t raise your HR long enough (such as short weightlifting sets) won’t be automatically tracked as a workout.

To give you some context around that, my CrossFit workouts usually include a 10-12 minute warmup, a 12-15 minute strength or weightlifting portion, and a 5-25 minute metabolic conditioning segment.

As a result, my WHOOP only occasionally detects those sessions as workouts, because my HR doesn’t always stay elevated for long enough. Biostrap has never detected any of these workouts — even on days when WHOOP has.

Again, I don’t care about that at all. But if you do, you can always add those workouts manually in either the Biostrap or WHOOP app. Both applications have extensive lists of workouts to choose from, so I’m sure you’ll find your exact type of physical activity there.

Tracking Different Types of Movement

Biostrap - Shoe pod
Biostrap – Shoe Pod.

Aside from accurately tracking your biometrics during physical activity, the second challenge wrist-worn devices face is identifying the type of movement you’re performing. 

To improve the reliability of its detection algorithm, Biostrap offers Shoe Pod, which is a separate sensor you can attach to your shoe.

The Shoe Pod enables you to track leg movement during sleep, and also helps Biostrap to better track the cadence, velocity and reps of any movements that involve your legs.

The downside to Biostrap’s Shoe Pod is that it has a battery. That means you’ll have to charge it every two days, much like the wrist strap.

So while I like the idea of leveraging additional sensors to better track complex movements involving my legs, I didn’t order it because, as I said above, I don’t really care about activity tracking.

Recovery Tracking

Recovery and sleep monitoring are the two features you should care about the most, because they can help you make better decisions that lead to a healthier life and improved mental and physical performance.

Both WHOOP and Biostrap rely on a handful of biometrics to calculate your recovery score every morning, including:

  • Heart rate variability (HRV)
  • Resting heart rate (RHR)
  • Duration of sleep
  • Quality or efficiency of sleep

HRV is arguably the most important of those factors, because it’s an indirect indication of how your nervous system is performing. You can learn more about the relationship between HRV and recovery in this video and my in-depth WHOOP review.

I won’t repeat everything I’ve previously said about HRV, but the higher your HRV is (compared to your baseline), the more recovered you are.

The need to establish a baseline is the reason why neither Biostrap nor WHOOP shows you a recovery score during the first few days of use. That’s how long it takes for the devices to figure out what a “normal” HRV looks like for you.

Biostrap uses a score from 0 to 100 to indicate how recovered you are. Based on this number, the Biostrap app changes the color and style of its indicator icon.

While the numbers shown make sense, the iconography is super confusing as it changes from an orange ring (Go Easy) to a blue ring (Ready) to a solid greenish circle with an upward-facing arrow when you’re fully recovered.

If you click on the recovery icon on the dashboard, you’ll see your score, your relative improvement as compared to the day before, your total sleep time, your resting heart rate, and any contributing factors as percentages of how much each of the biometrics affected the final score.

What the detailed recovery analysis screen doesn’t show you is your nocturnal HRV (you can see that on the dashboard) or which lifestyle factors might have impacted the contributing factors that Biostrap relies on.

For example, alcohol consumption impacts deep sleep (and thus your overall sleep quality). It might also increase your resting heart rate. As a result, if you drink too much — for me, that’s more than one glass of wine — you might get lower recovery scores. 

That’s the stuff I need to know, as it allows me to actually do something to improve my recovery. Unfortunately, Biostrap doesn’t show any of that information. As a result, I find the recovery score shown by Biostrap to be much less impactful. 

WHOOP, on the other hand, is much more data-driven in the sense that it provides me with actionable intelligence that I can use to make better choices throughout the day.

I also find the red, yellow and green recovery indicators more impactful. Those are the primary colors that most humans associate with stop, warning and go. 

Obviously, a red recovery indicator doesn’t tell me that I should stay in bed all day and not work out. But seeing red does make me think about the factors that could have contributed to a low recovery score.

If I can’t identify any obvious culprits — such as poor sleep due to alcohol consumption, elevated stress levels or injury — it might be a sign that my body is fighting off an infection. 

As I mentioned in my WHOOP review on YouTube, I’ve seen my recovery score drop and then bounce back suddenly as I cycled in and out of a mild cold while traveling.

The bottom line is that I prefer how WHOOP has implemented recovery monitoring and I also think it’s more accurate. But more on that later.

Sleep Tracking

Besides keeping tabs on my body’s ability to recover, sleep tracking is the most important feature that I care about. I strongly believe that if you don’t sleep well, nothing else matters.

By that, I mean that it doesn’t matter how well you eat or how much you exercise if you consistently get insufficient and/or low-quality sleep.

However, as you might already know (if you read my article about the best sleep trackers), detecting the onset and stages of sleep is incredibly difficult for most wearables.

Going into this review, I suspected Biostrap might struggle with sleep detection for two reasons:

  1. Biostrap lacks some of the extra sensors that WHOOP has.
  2. Biostrap records your HR in much longer intervals than WHOOP.

However, I tried to keep an open mind and let Biostrap’s technology surprise me. 

Unfortunately, I was disappointed by the device on the first morning I woke up after having worn both devices (one on each of my wrists).

To give you some context, my wife and I usually watch TV from 7 to 8 P.M. in the family room, before we get ready for bed. However, on the evening I put on Biostrap, we sat on the couch until 8:15 P.M. before heading to the bedroom.

When I looked at Biostrap’s sleep analysis the next morning, I noticed that it recorded I was falling asleep (sleep onset) at 7:18 P.M. 

Looking at Biostrap’s detailed sleep analysis, I noticed that the device thought I was cycling in and out of sleep at a time when I wasn’t sleeping but rather watching TV.

When the same issue happened almost every evening that followed, it became clear to me that Biostrap was only relying on the accelerometer and my HR to detect sleep — a highly flawed (and evidently error-prone) concept.

The problem is that if Biostrap can’t figure out whether I’m sleeping or not, I can’t trust that it can differentiate between deep and light sleep. And if it can’t reliably detect deep sleep, then it can’t know when to effectively measure HRV (which only makes sense to measure during slow-wave sleep if the goal is to calculate a recovery score).

Update: I spoke to Biostrap about this issue. They recommend putting the wrist strap on when you go to bed, and wearing the armband or chest strap during the day, to track active calorie burn. I’m currently awaiting the new Biostrap Evo and will update this article again with my findings.

Accuracy issues aside, Biostrap can only differentiate between three stages of sleep, including:

  • Awake
  • Light sleep
  • Deep sleep

Here’s where it gets interesting: Biostrap doesn’t show REM sleep in its app. Instead, according to their FAQ and this knowledge base article, Biostrap lumps REM sleep in with slow-wave (deep) sleep and just calls it all deep sleep.

While both REM and deep sleep are certainly the restorative phases of sleep, they’re vastly different from each other — as you could tell if you looked at an analysis of brain waves of someone who went through those stages of sleep.

But the differences even show on a regular HR analysis. During deep sleep, your resting HR tends to be low and doesn’t show a lot of ups and downs. REM sleep is much more volatile and you can expect changes in HR (and even spikes), as it’s an active phase of sleep during which memory consolidation and dreaming occurs.

Brainwaves during different stages of sleep.
Brainwaves during different stages of sleep.

So, in my opinion, lumping them together as “deep sleep” doesn’t make any sense.

In addition to its lack of detailed reporting and its accuracy issues, Biostrap also fails to provide insights into which lifestyle factors might have influenced my sleep and quality of sleep. As a result, I can’t take any corrective action.

WHOOP, on the other hand, provides much more accurate and detailed sleep tracking — including differentiating between deep and REM sleep. Plus, the WHOOP app provides important information about how the previous day’s actions impacted that night’s sleep quality.

From a purely technological perspective, I think WHOOP has a massive advantage over Biostrap because of its two additional sensors. 

WHOOP never misidentified me sitting still on the couch or lying in bed (while being awake) as being asleep, even though my heart rate might have been below 50 (i.e., close to or at my resting heart rate).

Biostrap Sleep Lab

Sleep Lab is Biostrap’s paid upgrade for its basic (and inaccurate) sleep tracking functionality.

With Sleep Lab, you get additional features such as arm and leg movement tracking. What’s more, Biostrap allows you to capture and track any snoring using the microphone on your phone.

To understand how your snoring impacts your night’s rest, Biostrap can overlay your oxygen saturation. That way, you can see if episodes of snoring align with low SpO2 measurements, which likely hurts your sleep quality and prevents you from entering deep sleep.

In addition to snore tracking, Sleep Lab also enables you to track arm and leg movement by leveraging an additional product Biostrap calls a Shoe Pod. While that feature isn’t meant to diagnose or treat sleep apnea, restless leg syndrome or other sleep-related conditions, it might give you and your doctor additional data.

Subscribing to Sleep Lab also increases Biostrap’s biometrics sampling frequency from every 10 minutes to every two minutes. That’s five times better than without the subscription, but still nowhere near as often as WHOOP.

What’s worth noting is that Sleep Lab sessions have to be entered manually; they cannot be captured automatically. 

The bottom line is that I trust WHOOP’s sleep data much more than I trust Biostrap’s, just based on the latter’s consistent accuracy issues during my tests.

Third-Party Integration

Both platforms offer limited integration with third-party apps. 

Biostrap integrates with Apple’s HealthKit (on iOS devices) and with Noonlight, a 24/7 emergency service.

WHOOP offers a feature called HR Broadcast that, when enabled, broadcasts the sensor’s heart rate data via Bluetooth for any other app to pick up. I used that feature to capture WHOOP’s HR data while writing an article about WHOOP’s accuracy during workouts.

Additionally, WHOOP recently announce an integration with Strava, a popular app for runners and cyclist. The integration enables you to track your running/biking route in Strava and to automatically upload your WHOOP data and GPS route to Strava.

Biostrap Insights vs. WHOOP Performance Assessments

As I mentioned several times throughout this article, Biostrap doesn’t correlate my input from the brief questionnaire I answer every morning after waking up with sleep quality or recovery. 

As a result, I can’t take any corrective action to improve these important lifestyle factors.

All that Biostrap offers are “insights,” which allow you to compare your data with the general Biostrap population. So you can see how your core biometrics are in comparison to other genders and ages.

While that’s neat to see, it’s irrelevant because it doesn’t help you get more sleep or improve your recovery.

WHOOP heavily relies on its WHOOP Journal to collect as much information about your lifestyle choices as you feel comfortable sharing for the purpose of correlating this information with your sleep and recovery data.

WHOOP Journal - Magnesium Supplement
One of the over 50 data points WHOOP can correlate with sleep and recovery scores.

Additionally, you get weekly, monthly and annual performance assessments that report on all the data and lifestyle choices WHOOP collected (and that you shared via the WHOOP app).

As a result, WHOOP can tell you if getting a massage that lasted more than 30 minutes improved your recovery score, or if supplementing with magnesium improved your deep sleep.

WHOOP also tells you how your biometrics compare to the rest of the WHOOP population, but that’s just an entertainment factor.

Battery Life and Charging

Biostrap recommends charging its device daily. That’s because the built-in battery won’t last much longer than a day or two.

Based on my experience, I can confirm that Biostrap’s battery won’t last much longer than a day and a half.

I’m used to taking my Apple Watch off for bedtime and charging it overnight. So you might think that Biostrap’s relatively short battery life shouldn’t be an issue.

The thing is that Apple Watch doesn’t capture any biometric data that I care about; I simply use it as a timekeeper and for viewing notifications. 

I wear Biostrap and WHOOP to keep tabs on my strain, recovery and sleep. Any gaps in that data might influence the device’s ability to accurately report on those metrics.

Update: Biostrap recommends using the wristband for sleep tracking only. By doing so, you can significantly increase the time between charges.

The good news is that I care much more about recovery and sleep tracking than I do about activity tracking. So having to take Biostrap off my wrist for two hours to recharge the battery won’t cause any issues in those areas.

Biostrap - Low battery warning
I see this notification more often than I care to.

But data quality aside, it’s super annoying to have to take off the strap every other day, charge it, and then remember to put it back on. At least with the Apple Watch, I’ve made charging the device part of my evening and morning routine — I just place the watch on its charger before bedtime and put it back on in the morning.

With Biostrap, those charging events happen at random times throughout the day, whenever the mobile app sends me a notification that the battery level is below 20%. 

WHOOP’s battery lasts about five days. But the major difference between WHOOP and Biostrap is that I don’t have to take WHOOP off for charging. Instead, I can slide the battery pack on without having to take the strap off my wrist. 

That ensures continued data capturing. And it’s so much more convenient, because it doesn’t matter when I get low on battery. If it happens at bedtime, I just sleep with the battery pack attached to the sensor.

From a usability perspective, it’s worth noting that neither Biostrap nor WHOOP has a display or buttons you can use to interact with the sensor. However, WHOOP has battery indicator LEDs on the side that allow you to quickly check how much battery you have left by simply tapping on the sensor. 

Biostrap doesn’t have that, which means the only way to check the battery status is via the “Settings” tab inside the mobile app. 

Accuracy of Biostrap vs. WHOOP

Unless you skipped most of what I wrote above, you’ve probably realized by now that there are major differences in accuracy between WHOOP and Biostrap.

Ignoring my findings and hands-on experience for a moment, I’m intrigued that Biostrap decided to use a pulse oximeter with red LEDs instead of green LEDs like pretty much every other wrist-worn HR monitor does.

There’s a reason why medical pulse oximeters (such as the ones you’d see during your annual physical exam) use red light: they can penetrate your skin better and gather additional biometrics, such as blood oxygen levels.

However, there’s also a reason why virtually no other consumer-grade device (including the FDA-approved Apple Watch) uses red lights: it’s prone to interference and noise, especially when the wearer isn’t completely still.

But if you like Biostrap and want to use it to track workouts and other physical activity, you can wear a chest strap and get accurate HR readings, regardless of what the wrist strap reports. 

Having the ability to use a separate chest strap gives Biostrap a leg up when it comes to activity tracking. There’s no question about that. 

Unfortunately, Biostrap’s accuracy falls short in all the other areas that I care most about, including sleep and recovery tracking. The problem is that not even a chest strap can easily fix that — even if you wear it overnight.

Biostrap simply relies on the “wrong” biometrics to detect sleep. And it doesn’t have the necessary sensors to improve its reliability and accuracy.

What makes the situation worse is that effective recovery tracking relies on accurate sleep data. As a result, Biostrap falls short in both areas.

As I mentioned in this article, multiple validation studies have confirmed that WHOOP is a highly accurate sleep and recovery tracker. 

Accuracy of Biostrap’s HRV Data

Below is a snapshot of Biostrap’s nocturnal HRV readings compared to WHOOP’s, taken from some of the nights that I wore both devices.

DateBiostrapWHOOP
June 1592 ms88 ms
June 1664 ms62 ms
June 1850 ms59 ms
June 1948 ms55 ms
Comparison of nocturnal HRV readings.

As you can see, the two devices range by as much as 9 milliseconds of each other, which is an 18% spread that could mean the difference between a red and yellow recovery (in WHOOP terms).

However, it’s worth noting that HRV changes constantly and the discrepancies I noticed could be do to different recording times. The good news is that both devices showed similar HRV trends and that is what matters most.

Pricing

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

Biostrap and WHOOP follow different pricing models. The former requires an up-front payment of at least $175 (for the biometric set), whereas WHOOP requires a six-month membership that costs $30 per month.

BiostrapWHOOP
Minimum Cost$175$180
Base pricing comparison.

In addition to the biometric set, which includes only the strap and an inductive charger, Biostrap also offers a “total health set” and a “fitness set w/ armband” that come with extra hardware, such as the Shoe Pod and an arm wrap.

WHOOP offers only one type of product but with different subscription lengths. The longer you commit, the lower your monthly payment is.

Biostrap SetsPrice
Biometric Set$175
Total Health Set$250
Fitness Set w/ Armband$320
Biostrap kits and pricing.

In addition to the up-front fee, Biostrap also offers a Sleep Lab subscription that starts at $9.99 per month ($47.99 for six months or $83.99 for 12 months).

Buy Biostrap*

WHOOP’s monthly subscription fee is determined by how long you want to commit:

WHOOP SubscriptionPrice
6 Months$30 per month ($180 total)
12 Months$24 per month ($288 total)
18 Months$18 per month ($324 total)
WHOOP subscription options.

If you’d like to give WHOOP a try, you can use this link* to get a $30 discount on the monthly fee. The discount will be automatically applied during checkout.

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Frequently Asked Questions

What’s the difference between green and red LEDs for heart rate and other biometrics?

In a nutshell, green light doesn’t penetrate the skin as deeply as red light, and thus can’t measure certain biometrics (such as blood oxygen saturation). 

On the other hand, green light is less prone to noise and interference. That means devices that use green LEDs are more accurate in some situations.

I think Biostrap’s decision to use red light is a bold move that might pay off in the future, if the company can figure out its accuracy issues. 

Does Biostrap’s chest strap make it better than WHOOP?

The ability to use a separate chest strap makes Biostrap the more accurate heart rate monitor during certain types of exercises, such as CrossFit.

As I wrote in my in-depth article about WHOOP’s accuracy, wrist-worn devices have trouble during activities that involve wrist movements and a rapidly changing heart rate.

Does Biostrap or WHOOP count steps?

Biostrap counts steps using its accelerometer. WHOOP doesn’t count steps, even though it could. 

WHOOP’s strategy is to make biometric data actionable and to help you make better lifestyle choices. In that context, the number of steps you’ve taken on a given day is somewhat irrelevant.

Biostrap follows the same strategy as most other fitness trackers by providing you with a lot of (more or less) accurate raw data, leaving you to draw your own conclusions from it. 

Personally, I care about steps taken as much as I care about my weight: not at all.

Does Biostrap offer different silicone strap styles?

While Biostrap offers different wearing mechanisms, including a wrist band, an armband and a chest strap, there’s only one type of wrist band and closure. However, you can select from several different colors.

Does Biostrap require a membership?

When purchasing Biostrap, you pay for the device upfront. From there, you can sign up for an optional subscription (Sleep Lab) that unlocks additional sleep-related analytics.

In comparison, with WHOOP you don’t pay for the device upfront but through a membership with a six-month minimum commitment.

Can I return the Biostrap if I don’t like it?

Biostrap offers a very generous 100-day return policy. I’ll be taking advantage of that policy after publishing this review and the associated YouTube video.

Can Biostrap or WHOOP help detect coronavirus infections?

Possibly! Both companies have started doing research in the area of COVID-19, and based on early findings it appears as if sudden changes to your respiratory rate (and perhaps your blood oxygenation) could be early indicators of COVID-19 infections.

You can check out WHOOP’s work around COVID-19 here and Biostrap’s here.

Do Biostrap and WHOOP work on Android?

Yes, both companies offer apps for iOS and Android.

Are Biostrap and WHOOP better than regular smart watches?

Neither Biostrap nor WHOOP are smart watches, and thus fall into a different device category. So whether or not they’re “better” depends on the functionality you want to compare. 

I wear an Apple Watch and I like it for what it is — an excellent time keeper, and a convenient way to get notifications and keep tabs on my calendar and other important data.

However, the Apple Watch is a poor sleep and recovery tracker and, based on what I learned from Apple’s WWDC 2020, that won’t change much with watchOS 7.

Are Biostrap and WHOOP waterproof?

Yes, both devices are waterproof and you can safely wear them in the shower or while swimming. Note that WHOOP’s battery pack is not waterproof!

How are Biostrap and WHOOP different from the Oura Ring?

I compared WHOOP and the Oura Ring in my WHOOP review, but I might do a more in-depth comparison if enough people ask for it.

How long does it take to get a recovery and sleep score from either device?

Assuming that your smartphone was in Bluetooth range while you slept, you should get a sleep score shortly after getting out of bed.

I usually open the apps right when I wake up, and I have noticed that while WHOOP is usually synced up, Biostrap always takes a few minutes to transfer a few hours worth of data from the strap to my iPhone.

I’ve also noticed that Biostrap crunches the data really quickly — usually within a minute or two. WHOOP takes a little longer — around five minutes or so before the sleep and recovery scores become available.

Can you buy Biostrap or WHOOP on Amazon?

No, I haven’t seen either device being sold on Amazon. 

Conclusion: WHOOP vs. Biostrap

I haven’t had Biostrap for nearly as long as I’ve had WHOOP. But based on everything I learned over the past few weeks, it’s become clear that the two gadgets pursue different strategies when it comes to activity, recovery and sleep tracking.

Biostrap is more like Fitbit on steroids, focusing on daily activity goals, steps taken and basic recovery and sleep tracking.

While that approach produced a lot of data (with mixed accuracy), it doesn’t provide the same level of insights and actionable intelligence that WHOOP delivers.

I think it’s irrelevant how many steps I’ve taken or how many calories I’ve burned in a given day. Instead, I want to understand how my lifestyle choices — such as alcohol consumption, medication or a consistent bedtime — influence the quality of my sleep and recovery the next day.

WHOOP does an outstanding job of correlating the choices I make throughout the day with sleep performance and recovery. Biostrap does some of that but with much less accuracy.

The biggest issue I have with Biostrap is it’s inconsistent sleep tracking. That doesn’t inspire any confidence in the other data the wearable device captures and presents.

So I plan on returning the Biostrap and continuing to use WHOOP.

Have you tried either of these devices — or something completely different, like a Garmin? If so, let me know what you like and dislike about your gadget by leaving a comment below!

4 thoughts on “Biostrap vs. WHOOP Review and Comparison”

  1. Great and in-depth review.
    I would buy a WHOOP if not for their exorbitant subscription fee. I may buy a Biostrap as the aforementioned sleep tracking issue is not a big deal to me plus I have an Oura ring.
    Professor Matthew Walker PhD (Author: Why We Sleep) stated that both Oura and WHOOP are not 100% accurate when tracking sleep stages vs. a Polysomnography however he said they are good at tracking the iterations in your sleep once a baseline is established.

    Reply
    • Same… If I were training for events, rather than just for fitness, the Whoop may make more sense. I’d love to have the data, but I just can’t justify the $30 a month. I already have enough fitness related subscriptions going. Strava, TrainingPeaks, Zwift… It all adds up.

      Reply

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