If you want to work yourself out of a funk, exercise very hard or very gently, but forget about the middling stuff. It won’t help.
I notice that after I wrestle competitively or do a PACE workout for twenty or thirty minutes, I am both exhausted and exhilarated. More importantly, I get a surge of energy that lasts for hours.
When I jog or lift weights or do an aerobics class, I feel worse afterwards than I did before.
I’ve also noticed that I can recharge myself by meditating or napping for a half-hour. (I’m still not convinced that meditating is any better than napping, although everyone tells me it should be.)