fitness tracker keeps pausing

Hi Tcyarnall, 

Thank you for using Apple Support Communities. 

I see that you’re having an issue with the activity on your Apple Watch. The workout keeps pausing. You are also being asked to login your Apple Watch. I want to help. If you have not yet done so, update your iPhone and Apple Watch to the latest compatible software versions, starting with your iPhone. It is a good practice to back up your iPhone before updating. 

Here’s How to back up your iPhone, iPad, and iPod touch - Apple Support

Here’s how to: Update your iPhone, iPad, or iPod touch - Apple Support 

Here’s how to Update your Apple Watch - Apple Support

If everything is updated and the issue remains, I would recommend restarting your devices. 

Restart your iPhone, iPad, or iPod touch - Apple Support

How to restart your Apple Watch - Apple Support

Also, this article has the steps to Get the most accurate measurements using your Apple Watch – Apple Support

Reach back out with any questions.  

Best Wishes!