Review | Whoop 3.0 Technology

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Wearable health & fitness trackers are everywhere these days and the business is booming with options from Apple, Garmin, Polar and a plethora of others. But most devices track and focus on the fitness or basic health components of our daily lives. So when I found Whoop 3.0 and its focus on the recovery side of training, I did some homework and became fascinated at the breadth of data I could use to peak my athletic performance on the water. So the review below is based on almost 6 months of ownership and daily use, and how it integrates into my daily training.

So first off, we should address why a wearable should focus on recovery and how that data might be useful. In short, training creates a stress on our bodies. We’re actually breaking ourselves down during training. When we rest and sleep at night, our bodies rebuild and recover from that stimulus to become stronger and more efficient. So optimal stress combined with optimal rest and recovery is the balance we should all be striving for. I’ve recognized the importance of sleep, good nutrition, stress management and other healthy habits a long time ago, and yet until now, I only planned, executed and monitored my training. What if I could attach metrics to my recovery as I do to my training and find ways to optimize my recovery to become a better athlete?

There’s a bunch of reviews and videos out there covering Whoop 3.0, so I am not going to go into too much detail here. Here’s one of my favorites that helped me make a purchasing decision. Most are produced by sponsored or hooked up athletes (like the one below), so the content does seem biased as one would expect, but you’ll gain a great understanding of the product nonetheless.

The Whoop 3.0 app has three primary screens that present the data collected from the wrist strap. They are Day Strain, Recovery and Sleep Performance. There are also some summary screens and the ability to jump off the app to review weekly and monthly performance assessments.

Cardiovascular strain in measured thru heart rate. Basically, the harder you work, the higher the heart rate and the strain you are putting on your body. It uses a scale of 1 thru 21 to present your daily accumulated stress. Your training sessions will show here as activities. Average heart rate and calories burned also show here and you can also use the Whoop app as your primary activity tracker by using its Strain Coach.

However, it’s here that I find Whoop 3.0’s largest weakness. The activity tracking thru the optical heart rate sensor on the wrist is hugely inaccurate compared to the chest strap I wear when using my Garmin Fenix watch. Optical heart rate measurement (like Whoop 3.0) is based on photoplethysmography (PPG), whereas the heart rate sensor with a chest strap (like my Garmin Fenix) measures the electrical activity of your heart (ECG). There’s lots of information on the web and the papers I’ve read largely support the fact that ECG is more accurate than PPG. In an effort to try and improve its data, I tried several things. Firstly, I made sure the Whoop strap was above my wrist so any flexion of the wrist during the kayak paddle stroke does not affect it. I was using the strap on my paddle control hand where there should be little to no flex anyway, but I did try moving it to the other wrist and the data remained wildly inaccurate. I also tried a bicep strap which quickly proved not to be an option for kayaking. Finally, I also tried it on my ankle, where there is zero movement during kayaking as my feet are flat on the foot plate of my surfski. I felt like the data improved marginally, but it was still well off from the ECG data collected from the Garmin. The collected activity data from Whoop does seem a little more accurate when I use it biking or for other more mainstream activities. Therefore, I can only conclude that as many other papers have found out, ECG measurement is more accurate than PPG and that future inaccuracies are probably a result of water interfering with the optical sensor interface on my wrist. Additionally, as kayakers, we are also moving our arms at 50-120 strokes per minute and I wonder whether that could possibly compound the inaccuracy of the data.


The heart rate images above are from the same workout on the same day. The workout was a 10 minute warm up plus 4 x 8′ on/2′ off at a comfortable aerobic pace, plus a 10 minute cool down. Whoop data on top. Garmin data on the bottom. As you can see, the Whoop PPG data shows very little resemblance to the Garmin ECG data, in fact it shows very little detail as a whole. Peak heart rates are off by nearly 20 bpm too with Whoop average HR of 141 and maximum HR of 183 compared to Garmin’s 125 average and 151 max. Recovery heart rates do not go as deep in Whoop and the general pattern of the workout is simply missing.


Overnight, Whoop 3.0 is recording how restful and restorative your sleep cycle was. In addition to the quality of sleep (more on this later), it’s two significant metrics are Resting Heart Rate (RHR) and Heart Rate Variability (HRV). RHR should be familiar to most folks. Back in the day, you’d wake up and press your finger to your pulse and measure your RHR. Increases in RHR could be an indication of over training or sickness. While an increase in RHR still means the same thing today, the Whoop 3.0 makes sampling of the data super easy. RHR should also drop as we get fitter. But more interesting is Heart Rate Variability (HRV). HRV is the beat to beat difference in heart beats, measured in milliseconds. In simple terms, if your heart is beating at 60 beats a minute, it is not beating exactly every second. There will be small differences between beats. We’ve known about HRV for centuries by more recently, sports physiologists have tied HRV to athletic performance. (I believe it was weight lifters that noticed they could lift more when their HRV was elevated.) In short, an elevated HRV indicates you are primed for high stress in training or are ready for a great competitive outcome, where as a lower HRV suggests you are still recovering. Once again, there are lots of peer reviewed papers out there to read on HRV and athletic performance and if you geek out on this stuff like I do, head down that rabbit hole.

So with Whoop 3.0 measuring RHR and HRV and knowing how well you slept, it can give you a recovery score as a percentage (1-100% recovered) at the beginning of each day, so you can fine tune your training load for the day ahead.

As mentioned above, Whoop 3.0 is collecting data 24/7, so overnight it can gauge how well you slept and therefore how restorative that sleep cycle was. This of course contributes to the RHR and HRV Recovery scores detailed above. Whoop will suggest the amount of sleep needed for optimal recovery, but I have always found that I need an hour on top of its recommendations for optimal recovery. Upon waking up, you can review your sleep cycle and look at the heart rate data while also reviewing time in bed, disturbances, your sleep efficiency (basically sleep time divided by time in bed) and your respiratory rate. This high level data gives you an overview of how well you slept and therefore, recovered. Respiratory rate was recently added to the Whoop app in response to Covid-19. While respiratory rate doesn’t really change that much day to day, an elevated rate could be an early indication of a respiratory infection. Nice job Whoop! You can also dive deeper into your sleep performance by looking at the time spent in sleep stages, which include how much time you were awake, in light sleep, in REM sleep and SWS / Deep sleep. These last two are significant as REM (rapid eye movement) sleep in known to be important for mental alertness and promotes learning, while SWS (slow wave sleep) or Deep sleep is important, as this is where the majority of the hormones are released for muscle regeneration and recovery.

So after nearly 6 months of use, how do I feel about Whoop 3.0? From a recovery perspective, I am 100% sold on Whoop 3.0. By trying to maximize my sleep performance and monitoring my recovery score, I have reinforced good sleeping habits from as simple as getting enough sleep to removing electronic devices from the bedroom, making sure I’m sufficiently hydrated, eating several hours before bedtime, having a cool bedroom and plenty more. Bottom-line, I feel like the bio-hacks I’ve been able to play with have helped improve my over night recovery leading to better training performance the following day. The recovery score itself has been very useful in identifying days when perhaps I need to reduce my training load or days when I can take on even great training stimulus than my training plan suggests. This day to day fine tuning of the training load should lead to greater gains over time. While all competitions have currently been cancelled as a result of Covid-19, I am pretty thrilled to use this data to optimize my recovery to peak for a major competition.

As a training tool, Whoop 3.0 leaves me disappointed and underwhelmed by its hugely inaccurate data collection, especially in a kayaking environment. It is not a replacement for a ECG chest strap heart rate monitor and as a result, all stress scores the Whoop 3.0 app present to me are taken with a good dose of skepticism. These inaccurate Stress Scores clearly impact the recommended sleep need, but it does not seem to impact the Recovery Scores the next day … although I do wonder. Perhaps a question better answered from Whoop themselves.

If training data and analytics are your thing, you’ll appreciate the ability to dive deep into your recovery performance for the optimization of your training and competition. HRV as part of a larger overview of your athletic recovery simply works and should be a good indicator of your ability to perform. But as a fitness tracker? We suggest looking elsewhere for a trusted ECG chest strap heart rate monitor from a known player like Garmin, Polar, etc. If Garmin would purchase Whoop and integrate this technology into its platform, that would be AMAZING, but until then, I’ll have my Garmin Fenix on my left wrist and the Whoop 3.0 on my right.

For more info on Whoop 3.0, check out their website at