Whoop has expanded how it calculates strain by introducing muscular load across the platform. The update is live and works whether you manually log your workouts or not, letting strength-based sessions contribute more visibly to overall training stress.
Strain finally counts your actual effort
The core of this update is simple but important. Until now, Whoop mostly focused on cardiovascular strain. It was great at tracking how hard your heart worked, but not what your muscles endured. That led to issues when workouts involved heavy lifting, rucking, or even things like HIIT circuits where heart rate might not stay elevated throughout.
Now, strain reflects musculoskeletal fatigue as well. That means the app gives credit for the work you actually do, not just what shows up in heart rate data. You can go to the gym, skip tagging sets or reps, and still see meaningful strain added to your daily score.
What’s interesting is how this appears to be working even for activities that are not logged through the Strength Trainer. Weighted walks, bootcamp-style training, and general lifting routines now often show strain values that better match how they feel. There’s no need to break down every movement if you are not in the mood. Whoop fills in the gap based on motion patterns and duration.
How muscular load works behind the scenes
The new system combines several elements. Volume reflects how much total work was done. This includes not just reps, but also factors like bodyweight and the muscles involved. Intensity then looks at how hard you pushed, particularly during the concentric phase of the lift. It uses sensor data to gauge how fast and forcefully the movement was performed.
If you use the Strength Trainer, you can still log reps, sets, and weights manually. That gives more accurate results, especially for tracking progression or comparing sessions.
One thing to note is that muscular load does not replace cardio strain. It adds to it. So if you do a long Peloton ride followed by strength work, your total strain may spike more than expected. The benefit here is that recovery and readiness now reflect both systems.
Not everything works perfectly yet
There are a few quirks. Some users have noticed that logging a Strength Trainer session can sometimes reduce the strain that was already auto-assigned to the same activity. That’s likely a case of the system recalibrating the muscular load more conservatively based on the input data. It doesn’t always feel intuitive.
Others have pointed out that post-workout editing options are limited. If you make a mistake logging weight or reps, there’s no easy way to fix it later. That makes the automatic approach feel more appealing, even if it’s less precise.
Despite that, the update feels like a step forward. Workouts that used to be invisible in the strain score are now showing up properly. The app feels more in sync with how people actually train. And while it’s not perfect, it’s noticeably better than the older heart-rate-only model.
Subscribe to our monthly newsletter! Check out our YouTube channel.
And of course, you can follow Gadgets & Wearables on Google News and add us as a preferred source to get our expert news, reviews, and opinion in your feeds.
