Every year, many of the planet’s fittest athletes converge in Kona, Hawaii, for the Ironman World Championship. It is a brutal triathlon: a 2.4-mile swim in the Pacific swells, followed by a 112-mile bike ride on a road flanked by lava fields, topped off by a marathon. You have to earn the privilege to race at Kona, and even that isn’t easy.
The 1,900 athletes competing in 2012 had taken the top few spots at qualifying triathlons all across the world. Most were jacked up on caffeine, the world’s most popular performance-enhancing drug.
Sarah Piampiano was among them. Though just a first-year pro, Piampiano had already won an Ironman race in New Orleans and was the second American woman at the 2012 Ironman U.S. Championship in Manhattan. The day before the Kona race, Piampiano was relaxing in a friend’s house, high above the endorphinated madness down in town, drinking a calorie-rich smoothie and telling me about her caffeine strategy.
Piampiano is not a caffeine addict. She has maybe two cups of coffee in a year, because she is sensitive to its effects. It makes her jittery. But on race day, she uses it thoughtfully and systematically to optimize her performance. She uses energy gels made by Clif Bar, one of her sponsors, to integrate calories and caffeine into her race-day nutrition plan. Before the race, she usually takes a gel with 50 milligrams of caffeine. Then on the biking leg, she takes 50 milligrams per hour. And that increases later in the race.
Piampiano uses Clif Shot Blocks, which are “kind of like gummy bears,” when it is easier to chew. She also has several energy gels—which have the consistency of thick honey and come in foil pouches—to use during the run. Throughout the day, she tries to take about 300 calories per hour and augments that with increasing doses of caffeine.
“As you get further into the marathon, your energy supplies are depleted and you just really start suffering; that’s why I start increasing the amount of caffeine I take. At the end of the marathon, you need that energy kick,” she said. And Piampiano said caffeine is an essential tool for an elite triathlete. “It’s critical, particularly if you want to perform and have any success at the top level.”
Like Piampiano, most of the super-fit endurance athletes at Kona used caffeine—but not everyone was on board.
Peter Vervoort, a physician from Belgium, has studied caffeine in athletes in Antwerp. He said for many athletes in his studies, doses of 200 to 350 milligrams were not helpful, especially in hot weather. He also competed in the Ironman and told me, “I’m not using caffeine. I do use Coca-Cola in the last 20 kilometers. But that’s caffeine in very small doses.” He said it’s actually getting hard to avoid caffeine on the race course. “There are more and more gel companies which only make gels with caffeine. So it is difficult.” Vervoort is an outlier. Most researchers have come to a different conclusion about caffeine’s ergogenic effects.
While in Kona, I tracked down Matthew Ganio, an exercise physiologist at the University of Arkansas Department of Health, Human Performance, and Recreation, and Evan Johnson, a University of Connecticut doctoral candidate. They have collaborated on caffeine research and were in Hawaii to study the effects of the triathlon on athletes’ physiology.
Ganio is soft-spoken but unequivocal about caffeine’s benefits for athletes. In 2009, Ganio and his colleagues published a systematic review of 21 studies on caffeine in timed performance. Most of the researchers looked at subjects cycling, but some also studied running, rowing, and cross-country skiing, and most of the tests were in the 15-minute to two-hour range. Looking across all the results, Ganio found consistent improvements in performance.
The improvements can be substantial, he told me, often as much as 3 percent. To put that into context, a 3 percent improvement would mean an 18-minute boost in a 10-hour race. Eighteen minutes was all that separated the top eight finishers in both the men’s and women’s pro races at Kona.
“There is always going to be some variability—some people won’t see as much of an effect as others; some people will see a large effect,” Ganio said. “Some people may not like it as much, or it may impair their performance a little bit. But on average, it does improve performance.”
For recreational athletes, too, the effects can be dramatic. A runner who is able to complete a 10K race in 40 minutes without caffeine could shave off 72 seconds with caffeine. And caffeine could allow a cyclist competing in a one-hour time trial to drop a minute and a half.