I expirimented with caffeine before racing tonight.
I attacked a lot, I wasn't able to react as fast as usual. I attacked once and crumbled. When the field caught me a counter attack went, which I regained strength for, I flew up the inside track, into the first turn, and completely crumbled again.
My heart rate went up way too high and I couldn't recover. I think this was a direct result of the caffeine.