For the purpose of crediting the hourly Stand achievement, your Apple Watch aims to identify when you have stood up and moved around for at least one minute during that hour.
Apple Watch uses an accelerometer to identify movement, so arm movement equivalent to changing from a seated to a standing position followed by a minute's walk around with your arms swinging naturally should help to register this.
If you believe that you have met this requirement, but Stand credits are still not being awarded, it may help to follow these steps, which have previously resolved the same issue for other users:
If you have not yet done so, update your iPhone and Apple Watch to the latest software, starting with your iPhone:
On your iPhone in the Watch app, go to: My Watch (tab) > Passcode > check that Wrist Detection is turned on.
- Note that Wrist Detection can be affected by temporary or permanent skin changes, such as by some wrist tattoos.
- Stand credit will not be awarded unless Wrist Detection is enabled.
If Passcode is enabled, check that you are unlocking your watch each day after placing it on your wrist and that you are wearing your watch sufficiently snugly (neither too tightly nor too loosely).
On your iPhone, in the Watch app, to go: My Watch > Health.
- If the setting for Wheelchair currently states "Not Set", then tap on Edit (upper-right) > tap on "Not Set" and change it to "No" (options are shown in the bottom area of the screen) > tap on Done (upper-right).
On your iPhone, in the Watch app, go to: My Watch > Privacy > Motion & Fitness - turn Fitness Tracking off.
Restart both devices by turning both off together, then restarting your iPhone first:
Re-enable Fitness Tracking.
It may also help to calibrate your Apple Watch, including resetting any existing calibration data:
Calibrating your Apple Watch for improved Workout and Activity accuracy - Apple Support
Activity-related estimations also depend, in part, on your personal information. To check that this is accurate - and to update it over time:
On your iPhone, in the Watch app, go to: My Watch (tab) > Health > Edit - tap and adjust items, then tap on Done.