From today’s New York Times
By GINA KOLATA
Published: March 25, 2009
WELDON JOHNSON first tried caffeine as a performance enhancer in 1998. He was not a coffee drinker but had heard that caffeine could make him run faster. So he went to a convenience store before a race and drank a cup of coffee.
For the first time in his life, he ran 10 kilometers in less than 30 minutes.
“I remember being really wired before the race,” he said in an e-mail message. “My body was shaking.”
From then on, he was a convert.
Mr. Johnson, a founder of LetsRun.com, would avoid caffeine, even in soft drinks, for a few weeks before he competed in a race, wanting to have the full stimulant effect.
“It may have been a huge placebo effect, but I swore by it,” Mr. Johnson said. “Having a cup of coffee exactly one hour before the race was part of my routine.”
Or maybe it was not a placebo effect.
Caffeine, it turns out, actually works. And it is legal, one of the few performance enhancers that is not banned by the World Anti-Doping Agency.
So even as sports stars from baseball players to cyclists to sprinters are pilloried for using performance enhancing drugs, one of the best studied performance enhancers is fine for them or anyone else to use. And it is right there in a cup of coffee or a can of soda.
Exercise physiologists have studied caffeine’s effects in nearly every iteration: Does it help sprinters? Marathon runners? Cyclists? Rowers? Swimmers? Athletes whose sports involve stopping and starting like tennis players? The answers are yes and yes and yes and yes.
Starting as long ago as 1978, researchers have been publishing caffeine studies. And in study after study, they concluded that caffeine actually does improve performance. In fact, some experts, like Dr. Mark Tarnopolsky of McMaster University in Canada, are just incredulous that anyone could even ask if caffeine has a performance effect.
“There is so much data on this that it’s unbelievable,” he said. “It’s just unequivocal that caffeine improves performance. It’s been shown in well-respected labs in multiple places around the world.”
The only new questions were how it exerts its effects and how little caffeine is needed to get an effect.
For many years, researchers thought the sole reason people could exercise harder and longer after using caffeine was that the compound helped muscles use fat as a fuel, sparing the glycogen stored in muscles and increasing endurance. But there were several hints that something else was going on. For example, caffeine improved performance even in short intense bursts of exercise when endurance is not an issue.
Now, Dr. Tarnopolsky and others report that caffeine increases the power output of muscles by releasing calcium that is stored in muscle. The effect can enable athletes to keep going longer or to go faster in the same length of time. Caffeine also affects the brain’s sensation of exhaustion, that feeling that it’s time to stop, you can’t go on any more. That may be one way it improves endurance, Dr. Tarnopolsky said.
The performance improvement in controlled laboratory settings can be 20 to 25 percent, Dr. Tarnopolsky said. But in the real world, including all comers, the improvement may average about 5 percent, still significant if you want to get your best time or even win a race.
For years, researchers believed that you needed about 5 to 6 milligrams of caffeine per kilogram of body weight. An 80-kilogram, or 176-pound man, for example, would need about 400 milligrams of caffeine, or 20 ounces of coffee.
Now, Louise M. Burke, the head of sports nutrition department of the Australian Institute of Sport in Canberra, reports that athletes get the full caffeine effect with as little as 1 milligram of caffeine per kilogram of body weight. Instead of 20 ounces of coffee, a 176-pound man could drink 4 ounces of coffee, or about two 12-ounce cans of Coke.
It’s also possible to get diminishing returns.
Terry Graham, chairman of the Department of Human Health and Nutritional Sciences of the University of Guelph in Canada, found that at 9 milligrams per kilogram, athletes actually did worse.
Many athletes and coaches are not caffeine fans. Mr. Johnson said he has tried to spread the word and gets frustrated when runners don’t use caffeine — so much so, he said, that when he sees the team his brother coaches at Cornell, he thinks, why aren’t they all going to Starbucks?
Mike Perry, a friend who is a sculler who has competed nationally and internationally, said that, with one exception, the rowers he knew did not use caffeine.
“People would have psychological issues with using it,” he said. “They would see it as against the spirit of the law, even though it’s not against the law.”
Still, Mr. Perry wondered whether caffeine would help him. When he retired from rowing last July, he decided to do a randomized, blinded, placebo-controlled experiment on himself.
He noticed that the 200-milligram caffeine pills look exactly like vitamin C pills, allowing him to code the pills so that he would not know which one he had taken. For eight months he tested himself once a week, taking two pills an hour before working out on a rowing machine. Then he worked as hard as he could for an hour, recording the results, also recording his guess about whether the pills he took contained caffeine. Mr. Perry, who also is a runner, said that an hour on the rowing machine is the equivalent of an hour of very fast running on the road.
When he finished his study and broke the code late last month, he was astonished to see how much the caffeine had affected him. He was stronger — his power output was 3 percent greater — and faster. In fact, he said the average speed for his tests when he used caffeine was faster than his fastest speed when he was not using caffeine.
He also guessed right most of the time about whether the pills he took were caffeine or vitamin C. Mr. Perry said he is now sorry that he never used caffeine when he was competing. “It would have been a pretty harmless way to do better,” he said.
Others, including my son Stefan, disagree. I urged Stefan to try caffeine and he did. Once.
He took a caffeine pill before a track workout that involved running a mile very quickly, resting briefly, and running a mile again, repeatedly. Like Mr. Johnson, he was wired and shaking. But, Stefan said, he could not recover between miles. His heart was pounding and just would not slow down. He said he has no desire to experience that again.
Then there is the problem my running partner Jen Davis and I have. We love coffee and probably have caffeine in our blood all the time except during the middle of the night (it lasts for hours).
SO would we do better if we weaned ourselves from caffeine and then took a pill or two before a race?
I asked Dr. Tarnopolsky. It turns out, he said, that you get habituated to two of caffeine’s effects right away. Caffeine can make you urinate, but only if you are not used to it.
“Athletes do not get dehydrated from caffeine,” he added, “contrary to popular myth.”
And caffeine does increase the heart rate and blood pressure in people who are not regular uses. “But after three or four days, that potentially negative effect is gone,” Dr. Tarnopolsky said.
The beneficial effects on exercise, though, remain. Even if you are a regular coffee drinker, if you have a cup of coffee before a workout or a race, you will do better, Dr. Tarnopolsky said. “There is no question about it,” he added.
He puts the caffeine research to use when he trains and competes. Dr. Tarnopolsky is an elite triathlete, ski orienteer and trail runner who has competed at national and international levels. And, he said, he loves coffee: “I love the smell. I love the taste. It’s heaven.”
And before a race? He always has a cup.