Come On Man...

I know, we all love our morning latté...but what's the deal about caffeine?...everyone gives you a different story, and none of it makes sense.

Yes...it certainly raises the heartbeat.  But how does that enhance performance?

If it improves performance by 5% (as the infamous They say), what does that mean?  Can I run 5% faster, longer, lift 5% more weight or more often?

Come On Man...surely They don't mean I can do it all?  If Usain Bolt really thought he could run 5% faster and 5% longer, wouldn't he have a barista at the starting line?

The IOC banned caffeine in 2000 and then lifted the ban in 2004.  Now they test for excessive amounts (?).  It sounds like they are confused by it too.

All we seem to actually know is that caffeine does raise the heartbeat...tell me, in an athletic sense, precisely what does it do for you?