Whoop 4.0 Test TL; DR: Top tier fitness tracker for athletes who train too hard and too often. However, the data is not going to be cheap.
I can’t remember the last time I was so dedicated to wearing a heart rate monitor (which is also a fitness tracker) as I was when testing the Whoop 4.0. I wore the band day and night and only took it off for showering (nobody likes a soaked band wrapped around their wrist). I was curious to see how the data would stack up over time and whether the Whoop 4.0 could determine my fitness readiness every day.
As far as I can tell, it really can. I still have to finally determine whether the Whoop 4.0 is the most precise fitness tracker in the world, but based on a month-long test, the heart rate data agrees with other fitness wearables such as the Polar Verity Sense or the Coros Pace 2.
Should you buy one? Can you even buy a Whoop 4.0 tracker? Let’s find out.
Whoop 4.0 test: price and availability
Whoop 4.0 is available now, but you cannot buy it directly, only part of the Whoop subscription. Included in the membership fee, you get Whoop 4.0 free of charge and access to the Whoop App.
You can sign up with Whoop, membership costs start at $ 18 / £ 18 / AU $ 18 a month.
(Image credit: Whoop)
Whoop 4.0 Review: Design
At first glance, the Whoop 4.0 band looks like a pretty simple fitness wearable: it’s an optical heart rate sensor unit attached to a band. Of course, the actual technology is more complicated, but Whoop 4.0 is a straightforward device from a daily wear point of view.
However, the Whoop 4.0 introduces an improved sensor configuration that now includes three green, one red, and one infrared LEDs (five total), four photodiodes, and advanced algorithms to improve accuracy and heart rate measurements (more on accuracy soon).
Overall, the new Whoop 4.0 is 33% lighter than the Whoop 3.0. Despite the lighter case, the Whoop 4.0 has even improved battery life thanks to the new Whoop Battery Pack 4.0 technology that uses Silas silicon anode battery materials. The battery life isn’t too bad (around four days on average), especially when you consider that the fitness band uses an optical heart rate sensor.
The vibration motor, which is used for the alarm clock, is also new. It works well as advertised and is a nice touch, especially given the emphasis on sleep tracking in the whoop ecosystem. The Whoop 4.0 can also measure skin temperature, blood oxygen levels, heart rate variability and resting heart rate.
(Image credit: Whoop)
Whoop 4.0 Review: Accuracy
Although people liked the Whoop 3.0, it has been widely criticized for not being particularly accurate. Fortunately, Whoop addressed this with the new sensor, which in my experience is considerably more accurate. Only occasionally did the heart rate measurement go off the diagram; the Whoop 4.0 even did well on strength training sessions, which are generally harder to follow.
Speaking of workouts, I’ve tested the Whoop 4.0 for a lot of these workouts, mostly strength workouts. I think about the ten or so activities I followed just when Whoop 4.0 lost the plot and said my heart stopped. It was on the ball most of the time and I could clearly see the pattern of my heart rate rising and falling as I did my sets.
As for running tracking, I took the Whoop 4.0 out for a couple without a phone to see if I could sync the band to the app afterwards (you can add workouts manually). It was a similar experience to the previous one and I didn’t see any signs of abnormalities on the heart rate graph. Admittedly, I didn’t use the Whoop 4.0 for really long runs, but I could imagine that it will do just fine as long as the battery is sufficiently charged.
The Whoop 4.0 also records sleep. And since sleep is a fundamental part of recovery, the whoop system places great emphasis on monitoring and analyzing sleep. The accuracy was great here too, I only had to manually edit the sleep data twice (I had to sleep lazily on the sofa in the evenings).
Daily sleep statistics are compared to the 30-day average to identify any abnormalities. Similar to all other fitness wearables that track sleep, most of the breakdown is absolutely useless because it is quite difficult to fix the lack of REM sleep, for example. However, sleep quality does feed into your strain score, which is admittedly the main characteristic of the whoop ecosystem.
(Image credit: Whoop)
Whoop 4.0 Review: The Whoop App
In the World of Whoop, every single amount of data collected has something to do with exposure. So the most important part of the Whoop app is your strain score. It can be between 0 and 21. Depending on your recovery and workload, Whoop recommends the right amount of exercise for each day.
Just existing every day increases your stress score, but exercise (obviously) also contributes to it. Each activity has its own stress score, but these activity stress scores are not simply added to your daily result. A few activities with a score of 9-10 won’t suddenly push your Daily Strain Score above 21.
As Whoop explains, the exposure uses a “non-linear calculation” and the algorithm aggregates your raw data and then scales the final results to get your overall exposure score.
Remember, just because the Whoop app recommends a certain amount of exposure for the day doesn’t mean you have to do everything possible to achieve that exposure goal. The Whoop app evaluates your body’s readiness for action and recommends you if you want to do sports. It’s not an obligation, just a recommendation.
This is not exclusively a problem with Whoop; Most fitness wearables follow a similar pattern. Some even go so far as to say that if you don’t exercise as much as recommended, you will “detrain”, causing people to massively overtrain and injure themselves.
I use it to check out the whoop app on the day I was going to work out anyway to see how much I can push myself. If my rest and sleep weren’t great, I wouldn’t be trying to crush my deadlift or 5,000 PBs that day.
Whoop 4.0 Review: Verdict
The Whoop 4.0 is an excellent fitness tracker, but especially for those who prefer to train hard and know when to slow down a little. It could also be useful for people who are generally interested in how well their bodies are recovering from daily stress.
However, I would be surprised if people who are just a little interested in their performance are willing to pay the monthly cost of accessing their stats. The cost of whoop membership can add up over time and even if you don’t use the band you still have to pay the monthly fee.
Another threat to whoop is fitness wearable brands including Garmin and Fitbit, which are adding similar features to their ever-growing functional arsenal and making the subscription-based fitness wearable market more competitive.
For my part, I really enjoyed using the Whoop 4.0 tape and I enjoyed keeping track of my strain score. If you are interested in fitness and sport, the Whoop 4.0 can help you achieve the optimal balance between rest and training. As long as you are happy to pay the price.
Whoop 4.0 review: also take into account
The Polar Verity Sense is a fantastically versatile, feature rich, and affordable heart rate monitor that is very similar to the Whoop 4.0 in terms of physical design. There are no monthly costs, but admittedly the free Polar Flow app is not as user-friendly as the Whoop app.
The Fitbit Charge 5 provides you with a Daily Readiness Score, which essentially corresponds to the Strain Score in the Whoop app. To access it, you need a Fitbit Premium subscription, which also costs you a monthly fee, only in the case of the Whoop app.
I would also recommend buying just a running watch. The best running watches are versatile fitness wearables that – unlike the Shoop 4.0 – often have GPS. Top-quality running watches can train you to run better, faster and more efficiently. simply that way.