If you want to exercise safely in the summer heat, you need to drink a lot of fluids during activity.
We used to believe plain water is absorbed faster than sugared drinks; cold drinks faster than warm ones, that carbonation delays absorption and special polymer sports drinks supply more energy than sugared ones.
Those theories are wrong.
If you exercise for more than 25 minutes, you can increase your endurance by drinking fluids. And if you exercise for more than 45 minutes, you can increase your endurance by consuming sugared drinks.
Furthermore, during exercise, the vast majority of drinks, such as fruit juices and soft drinks, can be absorbed as rapidly as plain water. Previous studies showing that conventional drinks need to be diluted with water have been discredited because the research involved people who were not exercising.
Polymer drinks offer no absorption advantage over regular sugared drinks. Prior research showing that warming and carbonating a drink delays absorption has not been supported by recent studies.
Drink anything you want during warm-weather exercise preferably, containing sugar. Make your own drink by adding 6 tablespoons of sugar to a quart of water. If you are a serious competitor, drink 1 or 2 cups of a sugared drink immediately before your competition and 1/2 cup every 10 to 15 minutes during exercise. Dr. Mirkin is a practicing physician in Silver Spring specializing in sports medicine and nutrition.