StrongLifts for Apple Watch

You can log your full workout with Apple Watch, without using your iPhone

  • Work sets and warmup sets will show on Apple Watch
  • Timer between sets works on Apple Watch (with haptic feedback)
  • Once finished, workout duration, avg heart rate, estimated calories, etc will sync to Apple Health/Activity

Do Not Use The Apple Workout App

When you use two apps on an Apple Watch that both access Apple HealthKit data, only one app can access the data at a time. This means that if you start a workout with one app, and then start a workout with another app, the first app will stop.

This limitation is set by Apple to prevent conflicts and ensure data accuracy. However, if you use Stronglifts for your workout, it will send the same information to Apple Health as the Apple Workout app. Stronglifts workout data will fill up your activity circles and show up in Apple Health. We will send your workout duration, estimated calories burned, avg heart rate, etc

Therefore, there is no need to use the Apple Workout app if you use Stronglifts on your Apple Watch. This makes your workout flow easier since you don't have to switch between two apps that cannot work simultaneously.

Here's an example of one workout logged by the Apple Workout app and one logged by Stronglifts. You can see that the same information is sent to Apple Health.

Why are the estimated calories higher when using the Apple workout app? Because the Apple Watch overestimates the calories burned. See this study: https://pubmed.ncbi.nlm.nih.gov/34957939/

"The Apple Watch 6, Polar Vantage V and Fitbit Sense showed poor accuracy for energy expenditure during 5 different physical activities.... proceed with caution on the clinical utility of energy expenditure of these devices during the implementation of an exercise training or nutritional programme."

Lifting weights burns about ~300kcal/hour. See: https://pubmed.ncbi.nlm.nih.gov/34977570/ We're using our own formula which gives a more realistic estimated calories burned.

Our formula is used when you log your workouts with your iPhone without using your Apple Watch. When you log your workouts with your Apple Watch using Stronglifts, the calorie formula from Apple Watch will be used. We cannot change the formula used when logging your workouts on your watch (Apple doesn't allow us to change that). That means you'll see different estimated calories burned if you log with or without your watch. For consistency, it's best to log your workouts the same way each time.

For questions, email us at support@stronglifts.com