Exercise time wrong on Apple Watch

Hey there Milton,

We'd like to help understand why you're only seeing 15 minutes worth of exercise credit for the 40 minute walk you had.

While you may need to contact Apple Support, we'd like to rule out a few basics first:

1. If you have a compatible model, the latest version is watchOS 7.2. You can verify which version number is installed within Settings > General > About. Here's a link that'll show how to Update your Apple Watch.
2. For the iPhone that's paired with your watch, if it's a compatible model, the latest version is iOS 14.3. You can verify which version number is installed within Settings > General > About. Here's a link that'll show how to first back up, then Update your iPhone, iPad, or iPod touch.
3. If you already have both up to date with those version numbers, this link shows how to Restart your iPhone, whereas this link shows How to restart your Apple Watch.
4. After confirming you're signed into the same Apple ID on both devices, check out the section 'Update your apps manually' here: Update apps or use automatic downloads

If you need more help, we recommend reaching out to Apple Support here: Get Support

Cheers.

To earn 1 minute of exercise credit(green ring);

Travel a full minute at a brisk walking pace 3.3 mph or 18 minutes per mile approx.

or

5.3kph or 11.3 minutes per kilometer.

Raise your heart rate to approx 75% of your maximum.

When you're at around or above this heart rate and speed for the entire minute you'll receive 1 exercise minute credit.

If you pause or slow down during this minute then you won't get any exercise credit for that minute.

Source;phone call I had with apple support.