If the app is crashing on your Apple Watch this can generally be solved using one of the following methods:
Ensure that you are only recording your workout with a single app
The Apple Watch is only able to support one active workout on the Watch as one time. This means that you cannot track the same workout with multiple apps. This will cause one or both of the workout apps to crash. To record your workout while using multiple apps please record with only one workout app on the Apple Watch then save the workout and sync the completed workout between devices.
Restart the Apple Watch
Restarting the Apple Watch can solve a variety of problems involving the app crashing upon first launch. Generally this particular type of crash is caused by an incomplete update to the Apple Watch or app software. In this case the crashing issue should immediately clear up once the device is restarted.
If you are having other crashing issues or have any other question please email firstname.lastname@example.org