Can someone explain wood and mining offline energy?

[itsme]

I've been having this issue for awahile and I just don't understand. I currently play with two accounts and right before I log off or leave it to idle for a long period of time I always use up all my woodcutting and mining energy. I assumed that it comes back even when you're offline, but I'm not so sure, but my results aren't adding up.

1. Sometimes i'll come back and both are back to full energy.
2. Somtimes I'll come back back and neither will have any energy.
3. Lastly other times I come back one has full energy, but the other one is empty.

I have seen it once or twice where I spent all my energy, but then I had it back. I'm not sure if I kept my progress/resources and basically glitched to get free energy or not, I may have even assumed I only did it on one toon, Idk. Anyways, how is it supposed to work? I'd like to at least understand what's suppose to happen so I know what's not normal. Thanks!

[Ragekai]

I'm pretty sure the timer is constantly ticking, and energy constantly slowly refilling towards max rather you are online or off for both cutting and mining..