Q: Work out app issue

Ignore.

It's possible you locked the screen ...

Lock your Apple Watch while you work out

You can lock your Apple Watch screen, so nothing can accidentally tap the screen, change your metrics, or end your workout. Just firmly press the display and tap Lock.

When you want to end your workout or make changes, firmly press the display again and tap Unlock. 

Hi

The following steps may help:

• Check whether there is a workout in progress (whether active or paused) within the Workout app on your watch. If there is, end the activity.
  • Use the Workout app on your Apple Watch - Apple Support

• If you have ever (but not necessarily recently) previously used any third-party fitness tracking apps (such as Strava) to record workouts on your watch:
  • On your watch: check whether there is presently a paused activity within any of those apps. If there is, end that activity from within that app on your watch (not on your iPhone).
  • If in doubt, it may help to remove the third-party fitness app from your watch:
    • On your iPhone, in the Watch app, go to: My Watch > scroll down and tap on the app name > turn off Show App on Apple Watch.

It may also help to close all open apps on your iPhone and then to restart both your iPhone and your watch:

• To close all open apps on your iPhone: double-click the Home button, then swipe up on each app preview.
• Turn both off devices off together, then restart your iPhone first:
  • Restart your iPhone, iPad, or iPod touch - Apple Support
  • Restart your Apple Watch - Apple Support

If you have not yet done so, consider updating your iPhone and Apple Watch to the latest software, starting with your iPhone:

• Update the iOS software on your iPhone, iPad, or iPod touch - Apple Support
• Update the software on your Apple Watch - Apple Support

You're most welcome - thank you for following up!