Personal Best: Exercising in the Heat Can Boost Performance

Of course you know this summer has been just unbearably hot and humid in most of the country. Of course you are tired of hearing people whine about how hard it is to exercise in the heat.

But there may be a bright side for athletes in this misery: Performance actually may improve as a result of their struggles with soaring temperatures.

The idea is straightforward. When you exercise on a hot day, the challenge for your body is to get blood to the skin ? to keep body temperature from getting dangerously high ? while at the same time delivering blood to the muscles.

At first, the body struggles. But after four or five days of exercise under these conditions, it starts to acclimate to the heat. Blood volume increases, less oxygen is needed to generate the same amount of power, the heart becomes more efficient, and muscles become more forceful and use less glycogen, their preferred fuel.

?Performance is dramatically altered by acclimation,? said Dr. Benjamin D. Levine, director of the Institute for Exercise and Environmental Medicine in Dallas.

In a way, it is analogous to what happens when people exercise at high altitudes. The body adapts by making more red blood cells that increase the amount of oxygen delivered to muscles, improving performance during training and races at lower altitudes.

Alberto Salazar, a former champion marathon runner who coaches for Nike, has said ?altitude training is absolutely essential? for any endurance athlete who wants to be internationally competitive. Indeed, the mantra for elite endurance athletes has become, ?live high, train low.?

Recently, one group of researchers wondered whether heat acclimation produce a similar performance boost.?If someone was to prepare for heat acclimation and then ended up in a cool condition, could there be a benefit to having trained in heat? Or would there be a detriment?? asked Christopher T. Minson, professor of human physiology at the University of Oregon.

He and his colleagues studied trained and experienced cyclists who knew how to push themselves and how to compete. They were divided into two groups. Both did hard speed and endurance workouts outside on cool mornings. In the afternoons, the experimental group then did an easy workout in a hot room ? 106 degrees ? that was kept dry so sweat could evaporate. The control group did the same afternoon workout but in a room at 55 degrees.

The results were striking. After 10 days of heat acclimation, performance in the experimental group improved by 4 percent to 8 percent when they rode as hard and fast as they could. That sort of increase ?is the difference between coming in first or 21st in a time trial event,? Dr. Minson said.

It was even better than altitude training, he added ? the performance advantage was slightly greater and more consistent than what athletes get when they ?live high, train low.?

So will those of us who have been running or cycling or doing other strenuous exercise outside in the summer heat and humidity be faster and stronger than ever on crisp fall days? That?s not clear, Dr. Minson said.

The problem is that to get faster you have to run or ride faster in your training workouts. And when it is hot ? and especially, hot and humid ? your body slows down to prevent dangerously high core temperatures. The result is that you simply can?t run or ride as fast. That?s why the cyclists in his study did their speed workouts in cool temperatures and used the hot room only to acclimate to exercise in heat.

But there may still be an advantage, Dr. Minson added. There is a large psychological component to performance, and those who do hard workouts outside on hot, humid days have to overcome mental barriers to push themselves. That sort of toughness can translate into improved performance.

Dr. Minson and others say they do not know of any rigorous studies asking whether people who do all their training in hot and humid environments get a performance boost. But ?there are real physiological changes that have been accrued,? Dr. Levine said. Dr. Minson suggests that if you really want to get the benefits of heat acclimation, you should do most of your workout outside and then go into a cool, dry gym to finish with a speed workout.

Dr. Levine thinks heat stress has been sadly neglected in athletes? search for a performance edge. Even with the paltry amount of research that has been done so far, the results are striking enough for him to suggest that elite athletes think of using heat in addition to altitude for their training.

The new mantra, he says, could be, ?live high, train low ? and hot.?

Source: http://feeds.nytimes.com/click.phdo?i=033d9ad2516ec4fb76eac09bd3d93820

celebration church new york auto show 2012 tulsa easter eggs pineapple upside down cake free ecards flying car