This post has been escalated to our Support team. If you have a similar question please submit a support ticket and we will investigate further.

Update from our support team: The error we are seeing on our end is 'the file has too few data points', meaning that there was insufficient data written to the activity file for our system to actually process it. This usually occurs when the watch can write neither GPS nor heart rate data to the file during the recording process.

Settings app > Health > Data Access & Devices > Strava

Heart Rate should have a green toggle to indicate that we are allowed to read this data. I have provided a screenshot of how this should look:

If these settings have been enabled,

• Please force close the Strava app on your Apple Watch and iPhone; confirm the applications are closed.
• From there restart your Apple Watch and iPhone.
• When your devices have restarted, can you see if this behavior persists when you record different activity types on the Strava Watch app?
• Lastly, when you're recording with the Strava Watch app, is the heart rate icon just grayed out or are you seeing two dashes?
• If you have Workout Power Saving mode enabled, please disable this feature as it can affect how often your Watch collects hr data. Watch app on the paired phone > Workout > Power Saving Mode(toggle should be off, no color)
• Please note: during a recording, the iPhone and Watch apps behave independently. Activity stats will not appear on your phone if you're recording with the Strava Watch app and vice versa. If you're using your Apple Watch as a heart rate monitor, you'll need to record your activities with the Strava Watch app.
  If you'd like to connect a heart rate monitor to the Strava iPhone app you can learn more about pairing a Bluetooth device on our support page here.

Unfortunately we aren't able to fix or add in missing data for these activity files, but the above should provide the solution so that this doesn't happen with new workouts.