Oct 10, 2013

Nutrition During Cold-Weather Exercise


Athletes and exercisers who routinely use a sports drink while practicing or competing in the summer heat are much less likely to do so while enjoying winters sports activities such as snowboarding and snowshoeing. There is a tendency to assume that nutrition is not an important issue in cold-weather exercise. But in reality it is just as important. Failure to use a sports beverage carries the same risks in the cold as it does in the heat: dehydration, bonking, and even fatigue-related injury.

Three factors increase the likelihood of dehydration in the cold. First, cold air tends to be very dry, and in dry air more fluid is lost as vapor through breathing. Often you can see it when you exhale. Second, cold tends to suppress thirst, so even when a sports supplements are available, athletes are likely to drink less than they need when exercising in the winter. And third, the heavier clothing that is worn during cold-weather exercise has the same effect as hot air: it causes the body to sweat and thereby lose fluid.

As little as a 2% reduction in bodyweight through fluid loss results in impaired athletic performance. In one study, cross-country skiers experienced an average 3% reduction in bodyweight during a race.

As in hot-weather exercise, water is not sufficient for hydration. Along with water, electrolyte minerals (mainly sodium) are also lost in sweat. A good sports supplement contains electrolytes in the right balance to offset these losses.

Your Energy Needs

But hydration is just the first component of optimal sports nutrition. The second component is energy, which is essential for performance in all weather. Carbohydrate is the primary source of energy that powers the muscle during moderate- to high-intensity exercise in hot and cold conditions. Athletes become exhausted when they run out of a type of carbohydrate fuel called glycogen that is stored in their muscles. However, by consuming carbohydrate during exercise, they can get more of their energy straight from the bloodstream, in the form of glucose, and hold onto their precious glycogen supplies longer. This results in the ability to work at a higher level for a longer period of time.

In addition to the muscles, the central nervous system and the brain are largely dependent upon carbohydrate fuel for their energy needs. And athletes depend on a well-fueled brain for quick reflexes and decision-making. By consuming a carbohydrate drink during practices and games, athletes get more energy to their brain and are therefore less likely to make mistakes or get injured due to poor reaction time.

The Protein Factor

Most energy drinks contain no other useful ingredients besides water, electrolytes, and carbohydrate. But new research has shown that the addition of protein to a sports supplements carries additional benefits that apply equally to summer and winter exercise.

There first benefit of using a sports supplement with protein relates to the hormone insulin. The job of insulin is to transport glucose through the bloodstream and into the muscle cells, where it can be burned for energy. The pancreas releases insulin automatically when glucose and/or protein levels rise in the bloodstream.

Research has found that when a small amount of protein is consumed with carbohydrate, there is a stronger insulin response and glucose is delivered to the working muscles more quickly than when carbohydrate is taken alone. The result is greater muscle glycogen conservation and prolonged endurance. In other words, adding protein to a sports supplement is like adding a fuel injector to an automobile engine. A University of Texas study showed a special drink containing carbohydrate and protein increased endurance by 24 percent as compared to a conventional, carbohydrate-only drink and by 57 percent as compared to water.

Protein in a sports beverage also accelerates post-exercise muscle recovery. Proteins are the main structural ingredients of muscle cells. During hard play, many muscle proteins get damaged or broken down for energy, leaving the muscles sore and weakened. But when a little protein is consumed during exercise, fewer muscle proteins get broken down and afterward the muscles are able to rebuild proteins more quickly.

But be aware that too much protein will slow stomach emptying, delaying the deliver of nutrients to the muscles. The ideal ratio is 4 grams of carbohydrate to 1 gram of protein. This ratio provides the benefits of protein with no negative effect on stomach emptying.

Take It Along

For the maximum benefit, drink a few ounces of energy drink every 10 to 15 minutes during winter exercise. If the air temperature is below freezing, pour room-temperature beverage into an insulated container and carry it close to your body. You will feel the difference!