Athletes seeking a competitive edge through a few double-shot lattes may feel a little flat at new research on the links between caffeine consumption and performance.
University of Queensland exercise physiologist Tina Skinner has found that it is the timing of the coffee that matters, not the strength, and any more than two cups is unlikely to make much difference.
Skinner's study found that coffee consumed an hour before exercise invariably gave the best boost to endurance and alertness. And she said exercise buffs trying to tweak caffeine levels by waiting an extra couple of hours before they exercised, or by combining their coffee with a high-carb breakfast, were likely to be disappointed.
Her team found that caffeine consumed in a "fasting state" worked better because a high-carbohydrate meal delayed and diluted caffeine's entry into the bloodstream. The study found one to two cups were ideal for most athletes — particularly those aiming for alertness and accuracy rather than "arousal," such as archers; up to five could suit endurance competitors.
Anything over five cups could be "performance-decreasing," producing side effects such as irritability, gastro-intestinal stress and inability to focus.
"When you get those really high values, you get the jitters and too amped-up — that's where it all goes pear-shaped," Skinner said. "We haven't found any side effects at those moderate doses of two to five cups of coffee."
