Athlytic vs. Whoop

The following question has come up numerous times and in numerous places. Can the Apple Watch, using the app called Athlytic, replace the Whoop platform? Answering that question is complicated and not entirely clear cut. So rather than taking a definitive stand one way or the other, I’m simply going to provide a comparison of data from the two platforms from over the course of several weeks and try to draw some conclusion from it for you. Once that’s all said and done, I’ll leave it to you to decide which platform best fits your needs.

An important note to make is that I used a Whoop 3.0 for the first half of my data collection and a Whoop 4.0 for the second half. I point this out because the two devices have totally different sensors, with most reviewers agreeing that the Whoop 4.0 provides more accurate heart rate data. Additionally, the Whoop 4.0 contains sensors for skin temperature and blood oxygen, though the data from both of these sensors is not used in the calculation of Whoop’s recovery score.

Before I jump into the data, let’s walk through some key differences between the two platforms.

Athlytic

A major difference between Athlytic and Whoop is that Athlytic provides much more data than only Recovery and Exertion/Strain. In addition to these metrics, Athlytic also provides you with granular data about your individual workouts, giving you the following information.

• How much time you spent in each heart rate zone

• Heart rate recovery after your workout (tracked over the 10 minutes following your workout)

• Speed/Pace data

• VO2 Max estimate based on your workout

• Percentage of workout that is aerobic and anaerobic

Outside of individual workout data, Athlytic also provides three helpful charts that show your Training Adaptation. This helps you interpret how well your body is adapting or coping with your training regimen and can indicate possible signs of chronic fatigue.

Lastly, Athlytic makes an effort to provide you with specific advice for how to approach your day, based on your 7 day Recovery and Exertion scores. I always appreciate the effort that the developer makes to clearly indicate that the advice is a suggestion to consider in addition to how you feel. To me, this is an honest recognition that a consumer device cannot perfectly tell you what you should do. It’s not magic, and you’re not a robot.

Whoop

The biggest differentiator for Whoop is that the platform natively tracks your sleep and then uses that information to calculate your Recovery score.

Closely related to this, Whoop controls both the hardware and the software for their platform, which results in some big differences. Everything you see in the Whoop app is generated by Whoop, itself, except for route/GPS type data, as Whoop’s devices do not have GPS chips. Practically, this means that Whoop is better able to integrate what the hardware does and how the software uses it.

In terms of the sensor, you can also wear the Whoop 3.0 and 4.0 in places other than your wrist. This is especially true of the Whoop 4.0, which now works with various clothing items that Whoop sells. You can purchase compression sleeves, compression shorts, sports bras, etc., which all have the ability to store and use the Whoop 4.0 sensor.

The Data

Now on to what most of you are probably here to mainly see – the data. I gathered data from both Whoop and Athlytic for over two months, including both Recovery scores and Exertion/Strain scores. I had hoped to include the Exertion Target/Strain Coach information from the two platforms, but Whoop does not allow you to view this data historically. I don’t know about you, but I found that to be a little bit of a bummer. Athlytic allows you to see its Exertion Target Zone historically.

Recovery

Recovery scores between the Whoop 3.0/4.0 and Athlytic generally followed the same trend, but the specific score often varied by a lot. Considering the proprietary nature of both platform’s algorithms, I can only guess as to why the scores vary so much.

First, Whoop factors in sleep and respiratory rate when calculating a Recovery score, while Athlytic only uses Heart Rate Variability (HRV) and Resting Heart Rate (RHR). I doubt that this explains very much of the variation between the two platforms when it comes to recovery. Both platforms rely heavily on HRV to calculate a Recovery score, but again, it’s hard to know just how much (and neither side is likely to provide all the details).

Second, Whoop attempts to look only at HRV that is measured during the deep sleep stage. Athlytic, on the other hand, has two different options for how it uses HRV readings. The first option is to have the app prioritize HRV readings automatically taken during sleep or manually taken at wake. The second option is to use all HRV readings taken over the 24 hour period of the day. If you select the second option, your Recovery score will fluctuate throughout the day (something to which Athlytic alerts you).

(Important Disclaimer: I use the first option and tell Athlytic to prioritize sleep or wake HRV readings. For all the data you see here, I only used automatic HRV readings that my Apple Watch took during my sleep. I did not do any manually triggered readings with Mindfulness.)

In my opinion, there are pros and cons to both sides here. The pro for Whoop is that it has more HRV readings to go off of and they’re less random than the readings that the Apple Watch automatically takes. The con for Whoop is that its HRV readings depend heavily on the accuracy of its deep sleep time estimates. When it comes to consumer devices and sleep stage tracking, I’m not overflowing with confidence. According to a 2020 study, Whoop showed 68% similarity to polysomnography, which is a known as the gold standard for sleep studies. To be fair, things have changed since then and perhaps so have Whoop’s sleep algorithms. Here’s the bottom line though. If Whoop estimates your deep sleep incorrectly, it probably means that it estimated your recovery incorrectly.

When it comes to Athlytic, the pro is that you have options for how you want HRV readings to be handled. You can rely on the Apple Watch’s automatic readings throughout your sleep. You can take a manual reading each morning at wake by using the Mindfulness app, which is likely the most accurate method. Lastly, you can use the average of all Apple Watch HRV readings throughout the 24 hour day, which is likely the least accurate method. Whichever method you choose, at least you know how Athlytic is using your HRV and how the app obtained it. You can’t necessarily say that with Whoop. The con is that the HRV readings taken by the Apple Watch are infrequent and seemingly random, which doesn’t necessarily make for the most reliable sample.

One last thing to mention relating to Recovery scores is that the Apple Watch measures RHR based on readings taken during sleep and when you’re awake. That means that the figure changes throughout the day. It’s because of this that you’ll sometimes see your Athlytic Recovery score change after you’ve woken up. The developer attempted to account for this by creating an option that allows Athlytic to write its own RHR figure to Apple Health if you elect to allow it in Athlytic’s settings. Unfortunately, I still notice my Recovery score changing after I’ve woken up – sometimes by a good bit.

Whoop, on the other hand, calculates your RHR during sleep, and the calculated number does not change based on your HR during wake times. I prefer this, as it gives a more reliable baseline. Also, I believe that Recovery should be calculated during sleep, as so many changes can happen while you’re awake to skew the numbers.

The graphs below show comparisons of the Recovery scores from the Whoop 3.0 versus Athlytic and Whoop 4.0 versus Athlytic. In some ways, the Whoop 3.0 actually appeared to come close to matching Athlytic slightly more often.

Which one is accurate?

This is the hard part. It’s really difficult to know which platform is more accurate, if for no other reason than that the algorithms used by companies all differ and are all proprietary. The only thing I can really comment on is whether or not the Recovery score subjectively corresponded to how I felt on a specific day.

In all honesty, I’ve had days where both platforms gave me a recovery score that just didn’t add up with how I felt. There were also days where both platforms were spot on with how I felt. Overall though, I’d say that Athlytic edged out Whoop for me in this area. Whoop more frequently gave me a high Recovery score on days where I felt awful.

During times of actual sickness, both devices usually matched how I felt – which was like crap. For example, while sick (sadly on my birthday) on the weekend of April 2nd and 3rd, Athlytic gave me Recovery scores of 20% and 0%. Whoop gave me Recovery scores of 26% and 10%.

Exertion/Strain

A simple observation shows that the two platforms trend much closer when it comes to Exertion/Strain scores.

The two platforms use a different scale for Exertion/Strain. Whoop generates a score out of 21. Athlytic generates a score out of 10. In order to make the data comparable, I converted the scores to a percentage out of 100.

Based on my understanding, most platforms look at Exertion/Strain with a similar method, basing it on time spent in each Heart Rate Zone. Compared to the differing and more complex algorithms that are used for Recovery scores, this is far more simple (assuming that your Maximum Heart Rate is correctly configured).

My guess is that the differences in Exertion/Strain scores between Whoop and Athlytic have mostly to do with differences in Heart Rate readings during workouts and during normal, daily activities.

The following graphs show the differences in Average Heart Rate and Maximum Heart Rate during workouts. As you can see, there are several workouts where the Whoop 3.0 reported a lower Maximum Heart Rate for the workout. The same thing occurred when looking at the Average Heart Rate for the workout. As other reviewers have pointed out, this occurs mostly during workouts that involve frequent arm movement such as HIIT or strength training. It was less likely to happen with steady state workouts or workouts where my arm was mostly stable.

This appears to have improved with the Whoop 4.0, but it still occasionally (though less frequently) trends lower than the Apple Watch for Heart Rate. Interestingly, the Whoop 3.0 and 4.0 both on a couple odd occasions trended higher than the Apple Watch.

As before, I think that both platforms have pros and cons to them.

For Athlytic, the pro is that the Apple Watch has time and time again shown to be the most accurate Optical Heart Rate (OHR) sensor for a consumer device, especially during workouts. Specifically, it detects spikes and drops quicker and more accurately than other sensors. The con is that the Apple Watch doesn’t sample Heart Rate throughout the day nearly as frequently as the Whoop 3.0 and 4.0 sensors. The Apple Watch takes more readings now than it did in the past, but it’s still far from being every second. This means that it could potentially miss some Exertion/Strain from normal, daily life.

For Whoop, the reverse is true. The pro is that both the Whoop 3.0 and 4.0 sensors take Heart Rate readings every second throughout daily activities and workouts. Therefore, it’s likely to detect some physiological Exertion/Strain that stress and other routine activities may cause, which Athlytic may miss. The con is that the sensor is much more finicky than that of the Apple Watch, and you have to really be sure that you have it in the ideal position and at the ideal tightness to get accurate readings during workouts. If you get either of these wrong, it’s almost certainly going to mess up your heart rate readings.

Which one is accurate?

Overall, I think both platforms give a consistent and reasonable estimation for Exertion/Strain for cardiovascular activities. That’s an important distinction. There still just isn’t an activity tracker that monitors Exertion/Strain for strength training activities, at least not in any useful sense. If you’re someone that mostly does weights and strength training, you’re really only going to get benefit from the recovery side of things with a platform like Whoop or Athlytic.

Conclusion

As I said from the very beginning, it’s not quite clear cut enough to definitively say that one of these platforms is better than the other. Each one comes with its own pros and cons, and determining which one is right/best for you is a personal and subjective decision.

Here’s my subjective take on things. The cost of Whoop makes it hard to recommend over Athlytic based on the fact that in many cases Athlytic has more accurate data (as a result of it using the superior OHR monitor of the Apple Watch). On average, I also find that Athlytic more accurately reflects how my body feels compared to Recovery scores. A slight difference here would not concern me very much, but there are days where I don’t feel recovered at all and yet Whoop gives me a 97% Recovery score. My guess for why this happens is that Whoop is simply trying to do too much magic behind the scenes by attempting to weigh HRV heavier during deep sleep. Like I said, if the device estimates this sleep stage incorrectly it calls the final Recovery score into question.

At $29.99 a year for Athlytic, you’d be paying less than one month of the cost of Whoop (assuming that you pay Whoop on a monthly basis). In my opinion, that means Whoop really needs to excel and offer a massive advantage to warrant the price premium.

To be fair, there are some advantages to using Whoop.

1. You don’t ever need to remove the Whoop 3.0 or 4.0, which allows you to collect more data (though if you have more than one Apple Watch, this becomes less of an advantage).

2. The Whoop 3.0 and 4.0 sensors have the ability of being worn in more places, which is advantageous for certain types of exercise or just comfort preferences.

3. The Whoop platform is much more sophisticated when it comes to tags and statistical analysis of them via the Journal feature. The Weekly and Monthly Summary that Whoop generates from the Journal is very detailed and well done. (Whether or not it’s a useful feature for the average person…that’s another discussion.)

4. Whoop provides native sleep tracking that does a pretty good job at automatically detecting sleep and wake and makes an attempt to incorporate sleep data into its algorithms. (Of note here, I have noticed that automatic sleep detection is much less accurate when you where the device on a bicep band compared to the wrist band.)

5. The Whoop 4.0 has an additional sensor that captures changes in your skin temperature. (I almost didn’t list this though, as the Whoop platform currently doesn’t do anything with the data from the sensor.)

6. The Whoop app is cleaner and better designed. (Then again, it should be. Whoop has a lot more resources at their disposal than Athlytic, which is managed by one developer.)

Ultimately, after several weeks of using both platforms, here’s the bottom line. Can Athlytic replace Whoop? Not entirely, but it gets close enough for me (and I strongly believe the same is true for most people). I love a lot of things about how the Whoop devices are designed. I love the simplicity and cleanliness of the Whoop app. I love that the device can be worn 24/7. I prefer Whoop’s native sleep tracking over anything that the Apple Watch has available and typically find it to be much more accurate than any Apple Watch sleep tracking app. At the end of the day, these things just don’t come close enough to justifying the significant price premium that Whoop charges.