Can Caffeine Help Marathon Runners

This past Sunday morning, 35,000 runners got up at the crack of dawn to arrive at Staten Island by the 8 a.m. deadline before the New York City Marathon .

Many of these groggy athletes will be tempted to get a quick pick-me-up from a cup of coffee -- or a caffeine pill or two.

Should runners be downing jolts of java or popping pills before a 26.2-mile race?

That depends on who you ask .

Lawrence Armstrong, a professor at the University of Connecticut, said that endurance sport performance improved by 20% to 50% for 32 to 77 minutes after ingesting an amount of caffeine roughly equivalent to two cups of coffee.

"Caffeine certainly does have ergogenic properties," Armstrong said. "It allows you to exercise longer, and the outcome of the exercise will be better in terms of competition."

However, elite athletes like Marla Runyan aren't convinced.

"I definitely don't think it has much of an enhancement value, especially physically," said Runyan, a two-time Olympic distance runner. "The negative consequence of drinking too much coffee would far outweigh any possible benefit."

Americans in general are attached to their morning coffee. According to Armstrong, Americans consume 200 to 400 milligrams of caffeine per day -- between two and four cups. The world average for daily caffeine intake is 70 milligrams.

In addition to coffee, other sources of caffeine include teas, soft drinks, some over-the-counter medicines and chocolate.

"I have only run one marathon in the last 3 years, but I did drink coffee before the marathon," Armstrong said. "As with every morning, there's no question that I feel more alert and more vigorous. I imagine it's both psychological and physiological."

Armstrong would not rule out the possibility that caffeine's effect on runners is purely psychological. Athletes ingesting caffeine say they feel less exhausted while exercising, but the physiological effects have yet to be thoroughly researched.

Armstrong and other researchers concluded that less than 300 milligrams of caffeine per day, which they called moderate intake, does not have a significant diuretic effect, leading to dehydration. Some athletes disagree.

"The concern with caffeine for a marathon is the dehydration," said Runyan. "Being dehydrated is far more of a disadvantage than the mental awareness coffee might give you."

Most experts agree that caffeine is a central nervous system stimulant. Its purported diuretic effect and role in dehydration are in contention.

"Caffeine mobilizes free fatty acids for energy," said David Martin, an exercise physiology professor at Georgia State University. "This seems to be the reason that people are interested in having a cup of coffee before the race."