Physiological effects of caffeine
Caffeine was on the list of banned substances, where a maximum of 12 micrograms/ ml in urine was permitted. However, it was removed from the WADA (World Anti-Doping Agency) list due to certain studies that documented the performance-enhancing effect of caffeine.
Caffeine increases muscle contractility. This was used alongside the fact that caffeine increases the amount of adrenaline in blood, which is the body's stress hormone. However, this theory is still in question. More recent knowledge has shown that caffeine generates signals within some cells, releasing intracellular calcium in muscle cells, which, in turn, creates the possibility of a muscle contraction. The problem with this theory is that this is only found at extremely high, toxic doses of caffeine. However, at lower, non-toxic doses, there is no release of intracellular calcium and thus there is no promoting effect.