Just bumping this thread with a very tiny detail:
When you gather, the stamina timer resets to 3 minutes again.
Effectively, this means that if you go gather when there's just 5 seconds left on the stamina timer, that you effectively lost 2 minutes and 55 seconds of stamina regeneration.
If the stamina ticks over while you're gathering, you may notice that stamina shown (you can just see it above the gather screen) + stamina gathered does NOT add up.
So, to get the most out of your stamina and gathering practices, start your gather right
after your stamina ticked over. On a daily basis, this can save you several minutes of stamina regeneration (upto 8 points worth of stamina if you do the A-hunting daily). No, it's not that much, but it's something.