Right. I run 5 days a week, but I don't attend to performance enough to be really aware of any difference there. I suspect differences due to caffeine, if any,

Right. I run 5 days a week, but I don't attend to performance enough to be really aware of any difference there. I suspect differences due to caffeine, if any, would be swamped by the already pretty significant day to day variations. But that's just a guess.