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.
Note: I initially wrote this article comparing the classic Biostrap with the WHOOP Strap 3.0. Since then, I’ve been using the Biostrap EVO and I’m currently awaiting the WHOOP Strap 4.0. The latest version of this comparison post reflects the newest hardware available from both brands.
So let’s take a look at those differences, starting with their hardware.
Hardware (Wrist Strap and Sensor)
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 of my original Biostrap, which made it difficult to tighten the strap with one hand. As a result, I never seemed to achieve the right amount of tightness, always ending up with a strap that was 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.
Interestingly enough, I haven’t had that issue with the newer Biostrap EVO. Maybe that’s because Biostrap changed the distance between the holes in the strap (or maybe the size of my wrists has changed).
|Strap material||Silicone||Polyamide, polyester, elastane|
|Alternative wearing options||✔||✔|
The WHOOP Strap 4.0 ships with what the company calls the SuperKnit band, whereas the WHOOP Strap 3.0 featured the ProKnit band.
I love both the SuperKnit and ProKnit because they don’t rely on a pin-and-tuck closure, which means I can get just the right amount of tightness. Additionally, the WHOOP 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 SuperKnit 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).
However, I use the Biostrap predominantly for sleep tracking and I take it off when I get up in the morning. In other words, it doesn’t bother me that I can’t charge Biostrap without removing it from my wrist.
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
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.
|Biometrics||Biostrap EVO||WHOOP 4.0|
|Heart rate variability||✔||✔|
|Blood oxygen saturation||✔||✔|
|Sample frequency||Every 5 or 10 minutes||100x per second|
In a nutshell, both devices have a similar set of core sensors for measuring heart rate, HRV, movement and respiratory rate. But WHOOP packs in two additional sensors that enable the device to detect certain sleep stages, like REM sleep.
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.
If you sign up for a Sleep Lab subscription (see below), Biostrap can increase the sample frequency to every two minutes.
In comparison, WHOOP samples biometric information 100 times per second. This should lead to a significantly more accurate picture of the information it tracks during physical activity.
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 LEDs to shine light onto your blood vessels, as well as sensors between the LEDs that capture the reflected light. The Biostrap EVO features two LEDs and and sensor while the WHOOP Strap 4.0 has five LEDs and four photodiodes for improved accuracy.
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 and at night.
It’s also worth noting that Biostrap relies exclusively on red LEDs while WHOOP uses a combination of both red and green (much like the Apple Watch does).
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 photoplethysmography (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 and I appreciate that WHOOP uses a combination of both.
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 if the wearer is sleeping. The previous generation of Biostrap interpreted a lack of movement as being asleep. That was a major design flaw, as I explain in the sleep tracking section of this article. The Biostrap EVO seems to be smarter and more accurate in that regard.
However, based on the “time awake” data I get every morning from the Biostrap app, I don’t think the issue has been completely fixed yet. Biostrap reports that I’m awake for about 20 minutes each night on average, but WHOOP claims I’m awake for 40-50 minutes. I believe the latter is more realistic based on my own assessment.
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.
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 better at detecting sleep and certain sleep stages.
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 viral 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 COVID-19, and the common denominator was a sudden increase in respiratory rate — which occurred even before the wearers showed other symptoms.
Blood Oxygen Saturation (SpO2)
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 couldn’t until the release of the WHOOP Strap 4.0.
While knowing your nighttime SpO2 readings is also important for generally healthy individuals, it’s crucial 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).
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.
|On-demand biometric recording||✔||✘|
|Impact of lifestyle factors on sleep and recovery||Basic||Detailed (Performance Assessments)|
|Sleep analysis||Detailed (with Sleep Lab subscription)||Detailed|
|Data comparison with other platform users||Daily (basic)||Weekly, monthly, yearly (detailed)|
|Track other users||✔||✔|
|Workout detection||Yes (unreliable)||Yes|
|Third-party integration||Noonlight||HR broadcast (generic), Strava|
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.
Unfortunately, Biostrap appears to have discontinued its integration with HealthKit (as I recently found out).
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
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’ve been using Biostrap’s chest strap for my CrossFit workouts and have found it to be incredibly accurate and comfortable to wear!
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
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 Activity Pod, which is a separate sensor you can attach to your shoe.
The Activity 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 Activity Pod is that it has a battery. That means you’ll have to charge it every two days, much like the wrist strap.
I have the Activity Pod but haven’t used it for activity tracking. Instead, I used it in combination with Biostrap’s Sleep Lab to learn how much I move my legs while sleeping. Fortunately, I don’t move them very much at all.
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. (Here are some tips for improving your HRV.)
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.
Besides the different ways of visualizing the recovery data, I should point out that I’ve been getting very similar scores from both devices on most days. In other words, if you’re only concerned about your score and aren’t interested in any contributing factors, Biostrap is just as good as WHOOP.
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:
- Biostrap lacks some of the extra sensors that WHOOP has.
- Biostrap records your HR in much longer intervals than WHOOP.
When I first started using Biostrap, I wore it 24/7 to simulate how I’ve been using WHOOP. Unfortunately, that led to some issues with Biostrap’s sleep tracking capabilities.
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.
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.
Once I had realized that Biostrap wasn’t doing a great job at detecting when I was sleeping, I decided to change my approach and only put the strap on when I was ready to go to bed. Additionally, I signed up for Biostrap’s Sleep Lab, which required me to manually start and stop sleep sessions.
By doing so, I’ve been getting significantly more accurate sleep data from Biostrap that matches those of WHOOP during most nights.
The only thing Biostrap doesn’t support is REM sleep tracking, because the company believes that without an EEG (which measures brainwaves), you can’t reliably track REM sleep. I tend to agree with that assessment. Check out my review of Muse S (a brain-sensing headband) to learn more about REM sleep tracking using an EEG.
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.
Based on my findings, that doesn’t seem to add up because the deep sleep that Biostrap reports is pretty much in line with the numbers I get from WHOOP, Eight Sleep and Muse S. In other words, these devices appear to agree on how much time I spend in deep sleep (usually between 90-120 minutes per night). Additionally, I spend another 90-180 minutes per night in REM sleep (as per WHOOP, Eight Sleep and Muse S).
So to me it appears as if Biostrap lumps together REM with light sleep — both of which are active phases of sleep as far as heart rate and brain activity are concerned.
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.
So, in my opinion, lumping them together as “deep sleep” doesn’t make any sense.
The other thing about Biostrap is that it’s not incredibly accurate at differentiating between light sleep and being awake without moving. That leads to some inaccuracies as far as the “time awake” data is concerned, as I mentioned above.
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 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 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.
I knew that I snore after consuming alcohol but thanks to Biostrap I realized that I also snore after consuming dairy. That’s likely because dairy increase the product of mucus that can you to a tightening of the nasal airways.
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 the Activity 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.
Both platforms offer limited integration with third-party apps.
Biostrap integrates 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 compared to other genders and ages. Additionally, the monthly Biostrap report allows you to compare your basic biometrics and activity levels month to month.
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.
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.
However, as I mentioned above, Biostrap’s battery life hasn’t been an issue for me because I only wear it to sleep and can charge it during the day. If you plan on wearing Biostrap for both activity and sleep tracking, you’ll have to find time during the day to recharge the device.
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 between WHOOP and Biostrap.
Overall, I’d say that both WHOOP and Biostrap are relatively good at detecting deep sleep. But WHOOP is arguably better at detecting sleep onset and awakenings as well as differentiating between REM and light sleep.
The clear downside of Biostrap is that you need to get a Sleep Lab subscription to get the most accurate information the device can provide. Without Sleep Lab, the sampling rate is much too long while the automatic sleep detection is unreliable.
As far as activity tracking is concerned, you definitely want the separate chest strap to get accurate heart rate information while working out. That’s because Biostrap uses pulse oximetry to capture heart rate data which is inherently unreliable during exercise as I’ve explained above.
However, there is no question that Biostrap in combination with a chest strap is significantly more accurate and reliable at tracking your heart rate during workouts.
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.
|June 15||92 ms||88 ms|
|June 16||64 ms||62 ms|
|June 18||50 ms||59 ms|
|June 19||48 ms||55 ms|
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.
Biostrap Biometric Report and Real-Time HRV Tracking
Two things I really like about Biostrap that I haven’t seen in any other device are the on-demand Biometric Report and live HRV tracking.
The Biostrap app allows you to capture your biometrics and visualize the findings in a detailed report you get via email. Besides the classic biometrics — such as heart rate, heart rate variability and blood oxygen saturation — you also get an indication of your arterial and peripheral elasticity. Both are independent predictors of cardiovascular disease.
You also get an indication of how your sympathetic and parasympathetic nervous systems are doing. For example, a relative increase in the LF/HF ratio may indicate decreased vagal (parasympathetic) activation or increased stress (as you can see in my report).
Additionally, the report provides you with an estimate of your artery age. Mine is 13 years — pretty good considering that I’m almost 40 years old. I guess my healthy lifestyle has been paying off.
The other thing I like about Biostrap is that I can get real-time updates on my heart rate variability (HRV) when using the chest strap. That’s incredibly useful if you want to find out how meditation, deep breathing or exercise influences your HRV.
For example, I’ve noticed that any physical activity, including walking, makes my HRV drop to below 10 milliseconds. But as soon as I rest, it bounces back. While that might seem like useless information, it helped me understand how engaged my sympathetic nervous system is during physical activity.
Biostrap and WHOOP follow different pricing models. The former requires an up-front payment of at least $319.00 (for the Recovery Set plus a six-month subscription for Sleep Lab and Meditation Plus), whereas WHOOP requires a six-month membership that costs $30 per month.
|Biostrap EVO||WHOOP Strap 4.0|
It’s worth noting that Biostrap used to sell a Biometric Set that included only the strap without a subscription. However, in October 2021 the company changed its pricing model and you can no longer get the hardware only.
So as of this writing, Biostrap offers the following sets:
The Recovery Set includes the EVO wristband only. The Move Set also includes the Activity Pod and the Active Set includes the Activity Pod and the Armband Heart Rate Monitor (HRM).
All three sets include a six-month subscription to Sleep Lab and Meditation Plus. After six months, you can choose to continue paying for these subscriptions individually at the following rates:
Sleep Lab Pricing
- Monthly: $9.99
- 6 months: $47.99
- 12 months: $83.99
Meditation Plus Pricing
- Monthly: $4.99
- 6 months: $26.99
- 12 months: $47.99
Personally, I preferred the old pricing, where you could get the EVO wristband only for $179.00 and then decide which subscription you wanted to get. As far as the Active Set is concerned, I would have preferred the inclusion of the chest strap over the Armband because the former is significantly more accurate.
WHOOP offers only one type of product but with different subscription lengths. The longer you commit, the lower your monthly payment is.
WHOOP’s monthly subscription fee is determined by how long you want to commit:
|6 Months||$30 per month ($180 total)|
|12 Months||$24 per month ($288 total)|
|18 Months||$18 per month ($324 total)|
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.
Frequently Asked Questions
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 WHOOP made the right decision in using both green and red LEDs in the WHOOP Strap 4.0 to improve accuracy.
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.
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.
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.
When purchasing Biostrap, you pay for the device along with a six-month subscription to Sleep Lab and Meditation Plus. After the initial term, you can decide if you want to continue paying for Sleep Lab and/or Meditation Plus.
In comparison, with WHOOP you don’t pay for the device upfront but through a membership with a six-month minimum commitment.
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.
Yes, both companies offer apps for iOS and Android.
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 2021, that won’t change much with watchOS 8.
Yes, both devices are waterproof and you can safely wear them in the shower or while swimming. Note that WHOOP’s latest battery pack is now waterproof too!
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.
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 less accuracy.
What I do really like about Biostrap are the snoring and leg movement features of its Sleep Lab and the super-accurate chest strap.
Going forward, I’ll continue using the chest strap for CrossFit workouts and I’ll likely give my EVO wristband to my 8-year-old daughter because I’m really curious to learn how much deep sleep she gets on average and what her nocturnal HRV is.
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!
I’m a healthy living and technology enthusiast.
On this blog, I share in-depth product reviews, actionable information and solutions to complex problems in plain and easy-to-understand language.