There is a common myth that drinking water prior to and during exercise can cause an upset stomach and cramps. In reality, water intake is extremely important prior to, during and following exercising.
Two hours prior to exercise you should consume approximately 17 – 20 ounces of fluid. When possible you consume water over other sugar-sweetened fluids like sodas or juices.
During exercise you should be taking in 7 – 10 ounces of fluids for every 10 – 20 minutes of exercise. This is especially important during hot weather to help prevent dehydration. Drinking fluid during exercise helps to replace the body fluids lost through perspiration.
It’s possible to lose water weight during an exercise routine so following the exercise session you should drink 16 – 24 ounces of water for every pound lost. For workouts lasting longer than 60 minutes it is recommended that you consume a sports drink to achieve optimum rehydration for your body.