Hello ZedC13,
Thanks for coming to the Apple Support Communities for help with your Apple Watch battery issue. We understand that your battery drains faster when you're running or working out.
Which iPhone model, and iOS version are you pairing with your Apple Watch? Settings > General > About.
You've mentioned that you're running the latest watchOS version on your Apple Watch. Let's make sure you're running the latest iOS available on your iPhone as well. If not, please back up, and update your iPhone by following the steps in these links:
How to back up your iPhone, iPad, and iPod touch
Update your iPhone, iPad, or iPod touch
If your iPhone and Apple Watch are already updated, let's restart both devices normally:
Restart your iPhone, iPad, or iPod touch
How to restart your Apple Watch
We have a handy article here that explains how to Maximize battery life, and lifespan of your Apple Watch so you’ll get the most out of it:
Maximizing Battery Life and Lifespan
Under: "Tips for Apple Watch"
Hope this helps. Kind regards.