Both these documents are mandatory.
Your fitness screenshots help us know that you are preparing for the trek and are fit to go.
These also help you gain confidence to do the trek successfully.
You can install a fitness app ( Eg- Nike run club ), go for a jog.
Cover the distance as per your trek’s eligibility criteria and upload the screenshot on your dashboard.
Here is a screenshot on where you have to upload the screenshot on the dashboard.
The medical certificates have to filled by a certified doctor. This certificate has all your vital readings which helps the trek leader understand your health better.
And yes, you do not have to upload the medical certificate. You have to take a hard copy of it to the basecamp. Your trek leader will be verifying this at the basecamp.
Click here for the downloadable pdf of the medical certificate