At times you might find that your Apple Watch does not connect with your Stryd. If Stryd works without problems within the Stryd app on your iPhone and you only have issues with the Apple watch, try the following steps:
1. Restart your Apple Watch and see if you can record a run after the restart.
2. If step 1 does not work, uninstall and reinstall the Stryd app from your Apple watch from within Watch app on your iPhone. Afterward, you will need to hit the "Pair Apple Watch" link within the settings menu of the Stryd app on your iPhone. Try again to record a run.