Yesterday I tried running with the AOD disabled during activity. It's horrible!
I am not very surprised because Garmin is not good in gestures, even in the watchface it doesn't really work (usually I have to move my arm 2 or 3 times, or touch the screen to wake it up) but at least there's a way to wake it up!
During running the gesture did not work in 90% of the times I tried, nor the touch (touch is turned off for activity, but I mean, if gesture doesn't work, then at least make it possible to wake it up with a touch!)