Caffeine: the good, the bad and the athlete
by Dominique le Roux
You’d think I’d have known better than to choose a pharmacist as my Cape Epic partner. In 2004, he was banning me from drinking coffee at all. “A diuretic,” he said. Simply not good for endurance athletes. “An inspiration,” I said. “My body and soul crave it.”
We finished the race, downed a few celebratory cappuccinos, and soon found that caffeine restrictions had been lifted by the World Anti-Doping Agency. Fast forward to 2007 and many of us are slurping back energy gels that contain this previously banned 'stimulant'. But is all this caffeine good for us or our racing?
Caffeine was discovered over 1 000 years ago, and it is still considered the most widely used stimulant drug in the world. Until 2004, it was listed as a restricted drug: the National Olympic Committee of South Africa''s guidelines stated that the accepted level of caffeine was 12 micrograms of caffeine per millilitre of urine. This meant that for an athlete to be over this level they would have to drink more than six to eight cups of coffee or 10 cans of cold drink within two to four hours before being tested. (That’s a whole lot of Coke.) Which is why people were a little unbelieving when Elana Meyer tested positive during a marathon in Bali, and claimed she had had only one cup of coffee that morning. Meyer was suspended from racing just before the rules changed, despite the fact that she raised the issue that different people metabolise caffeine at different rates, and therefore they could possibly have higher levels of caffeine sloshing around their systems after much smaller doses than the doping rules suggested.
While there is a great deal of disagreement about the merits of caffeine and the extent to which it really is a diuretic, it’s clear that this ‘drug’ will not make you go faster, but there is general consensus that it could help with endurance. It was previously thought that this was because caffeine encouraged your body to use fat for energy rather than muscle glycogen.
“The critical time period in glycogen sparing appears to occur during the first 15 minutes of exercise, where caffeine has been shown to decrease glycogen utilization by as much as 50%. Glycogen saved at the beginning is thus available during the later stages of exercise,” reported one paper by a researcher from Houston’s Rice University in 1995. Though the writer did admit that the exact method by which caffeine did this was unclear, it was claimed that “caffeine caused sparing in all of the human studies where muscle glycogen levels were measured. The effect on performance, which was observed in most experimental studies, was that subjects were able to exercise longer until exhaustion occurred.” (Unless of course they succumbed to diarrhea and cramping – the potential side-effects cited by the same article.)
Though this fat-release thinking is now disputed, Lawrence Armstrong, a professor at the University of Connecticut, was quoted at the time of the raising of the restrictions on caffeine, saying that endurance sport performance improved by 20% to 50% for 32 to 77 minutes after ingesting an amount of caffeine roughly equivalent to two cups of coffee.
Those not quite as keen on coffee as I am might counter that caffeine’s effect is all in the mind – it’s a mental rather than physical stimulant. Even athletes who believe this is the case have used it effectively to their advantage: if it makes you feel better while training, why not use it to amp up your training sessions, but go easy on it during competition when you’re worried about dehydration?
On the diuretic issue, the good news is that Armstrong and other researchers concluded that less than 300 milligrams of caffeine per day, which they called moderate intake, does not have a significant enough diuretic effect to lead you to dehydration.
And on the legal side of things, realize that the World Anti-Doping Agency will continue to test for caffeine, but a positive result will not result in a penalty. Rather, the agency claims to be studying whether to introduce new caffeine thresholds.
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