To learn how to get rhythm and flow in doing a video, you watch movies. To develop rhythm in a real-time performance, you watch live performances and it wouldn't hurt to go to the theater now and again.
Allow me to put on my nerd pants for a second and recommend you see Avatar if you haven't already. James Cameron has many faults as both a filmmaker (his ham-fisted approach to dialog) and as a person (kind of a prick), but if there's one thing he does extremely well it's directing action sequences. And Avatar is probably the best action sequence he has ever directed in his entire career. Seriously, the aerial dogfight sequence is a masterpiece of how to put action on screen.
Really good action directors are great to learn pacing for short sequences with a lot of activity. Their task is to keep things moving while also giving you time to process what's happening on screen without getting lost. It's a delicate balance, but a good director knows how to pull it off.
You have the advantage that you only have to keep track of one person; that is, yourself. But the trade-off is that you can't also use "fights are chaotic" as an excuse to fall back on when things get too messy.
