There is little doubt that caffeine can have a beneficial effect on endurance running performance. But there’s more to getting a performance boost than glugging down a pre-race coffee. “A dose of around 3mg of caffeine per kg body weight is needed to have an ergogenic effect in endurance exercise,” says sports dietician Ruth McKean. That’s around 175mg for me - and a quick internet search suggests the average cup of coffee contains between 70-130mg. “It’s not always easy to equate mg of caffeine to cups of coffee, as it depends on size and strength,” says McKean. And besides, most of the research showing performance benefits has been done on caffeine in its pure form, not coffee, suggesting you might be better off with caffeine tablets rather than a cup of Joe.
Another factor to bear in mind is that to get the best effect, you’ll need to ‘taper’ your customary caffeine intake. McKean recommends cutting down by one drink a day until the final three days, over which you should abstain completely. “You could either take a caffeine dose about an hour before your race or training run, and ‘top up’ later in the race (without exceeding the 3mg/kg dose), or you may prefer to take the whole lot in the latter stages of the race when you feel you are hitting a low,” she says. “Caffeine has been shown to enhance the uptake of glucose during exercise.” Experiment in training to see what works for you. I generally take a caffeine gel, which contains 80mg, an hour beforehand and top up with a second gel in the second hour of racing.
As a triathlete (of sorts) I race Olympic distances and I thought that caffeine was only to be taken in the last 30-45 minutes of a race and I use carb gels early with a caffiene gel 30 mins prior to the finish. Is this correct? Henry
Hi Henry, No you’ll do better to take your caffeine earlier on to get the full benefit. It takes 60-70 mins for it to peak in bloodstream. Try taking a caffeine/carb gel early in the race and see how that goes. Cheers.