lunch hour woes

Frustrating day today. I've been sleeping badly, which isn't doing anything to increase my patience level, but training sessions like the one I had at lunch push me over the edge. Lunch time classes used to be fairly advanced. Lately, there have been alot of beginners. Which I'm all for - the more beginners the better. But when I'm lacking patience, and want a good workout, I don't want to train with them. I know, as an advanced student, I should be patient and help them hold pads correctly. But it means that I don't get a work out at all during the hour. And now, I'm just frustrated and pissed off. I want to go back later this evening to get in a hard workout, but I probably shouldn't and should just simply go for a run. It won't do my foot any good to go and pound on the bag in frustration.