How much is too much?
Rest assured, caffeine is not taboo in the running world. “We know that it can boost performance and enhance alertness,” says registered dietician Kate Geagan.
But how much should you consume? Geagan recommends no more than 300 to 400 mg per day (an eight-ounce coffee has about 100 to 200 mg). In order to give your workout a kick, consume it beforehand and up to halfway through.
In addition to the obvious coffee and tea, you can buy many gels, chews and bars with added caffeine. It’s best to try them before race day to make sure your body reacts well.
People can respond differently to caffeine, and that can change at different points in your life. Geagan explains that many of her female clients have become more sensitive during menopause.
“I would steer people away from energy drinks,” Geagan says. “They aren’t regulated so their ingredient list isn’t necessarily accurate. While you may get a short-term boost for those, ultimately they make you feel less energy.”
Too much caffeine can overstimulate your system and lead to anxiety, stomach upset, feeling jittery and sleeplessness. Geagan says, “Sleep is so important for rest and recovery.” Caffeine can also be a diuretic so make sure you’re drinking enough water.