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Coffee and running

The good and bad effects of caffeine on running performance.

On a weekend morning before a long run, while the sky slowly lightens up, you can find me leaning on a kitchen counter in my running gear, with a steaming cup of coffee in hand. It is a ritual as certain as a run itself. Coffee wakes me up and warms me up, helping me prepare for the workout I’m about to start. But how much of it is real, and how much of this feeling is just in my head?

Coffee drinkers always claim they feel invigorated by the brew. Even the World Anti Doping Agency (WADA) believed caffeine can help boost performance in elite athletes and had it on the list of banned substances in sport until 2004. The reason for removing caffeine from the list was “presumably because WADA considered (caffeine’s) performance-enhancing effects to be insignificant,” said Mark Stuart, an editor at BMJ Clinical Evidence, who has worked with doping control for past Olympic Games and helped training medical staff for Beijing Olympics.

However, the notion that the “kick” we receive from coffee is “insignificant” can’t be more wrong, according to a recent article, “The Effects of Caffeine on Performance in Sports,” published by a team of medical researchers.

“Caffeine has been shown to increase speed and power output, improve the length an athlete can train, and assist the athlete in resisting fatigue,” the article said. In short, it makes you think quicker, last longer, sprint faster and recover more quickly. And, it’s legal.

A study on cyclists who were asked to cycle at high-intensity for an hour shows that a group given caffeinated energy bars generated 7.3% greater total power output than the non-caffeinated group. In another study done on sprinters in Australia, researchers gave half of athletes a 300-milligram dose of caffeine before running five sets of 6 x 20m sprints. They found that the runners who had caffeine ran faster than those who didn’t.

So, how does it actually work? So-called “metabolic theory” suggests that caffeine provides improved endurance by increasing the use of fat as a fuel, while at the same time lowers the use of carbohydrates. The energy from the fat cells burns slower, therefore providing the athlete with much bigger and longer lasting ‘fuel-tank’ than relying on carbohydrates alone. That explains why caffeinated cyclists had more energy. Second, caffeine may increase the calcium content of skeletal muscle and improve the strength of muscle contraction, which plays a role at anaerobic activities like sprints — being able to get more power from their muscle contractions made the caffeine-induced sprinters faster.

If that isn’t enough, caffeine also has direct effects on the central nervous system as a stimulant which can trick the brain to lessen the feeling of fatigue and increase alertness. Together with the metabolic effects it has on burning fat as fuel, it’s a powerful driver for endurance athletes.

Finally, caffeine also plays a significant role in recovery. As runners, we know we need carbs to restore the glycogen reserves after a workout. Glycogen is the body’s preferred fuel for muscles when exercising. A study on athletes who had caffeine with their meal after exercise shows that they had 66% more glycogen in their muscles 4 hours later.

Like everything else in life, too much of the good stuff can have its drawbacks. Caffeine may cause dehydration, although you can consume up to 550 mg without seriously affecting hydration — that’s an equivalent of five cups of coffee. There may also be some connection between caffeine and bone-mineral loss, though that isn’t certain.

So far so good, right? Well, not so fast, said Steve Magness, a running coach and author. Since caffeine as a substance is so readily available, Magness warns to exercise caution when using it. He points out that fatigue is the body’s signal that something is wrong — it’s either over-trained, not rested enough, or on the verge of getting injured. Using a drug which dulls the perception of fatigue can cause an athlete to push too far and cause serious damage to his own body. “Don’t use it for every workout,” says Magness in this article “because in the end it doesn’t matter if you hit your mile repeats one second faster, if the eventual drawback is some sort of chronic fatigue that comes back to bite you. Instead, save (coffee) for when it matters most: race day.”

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