concentric contraction, a common form of muscle contraction that occurs in rhythmic activities when the muscle fibers shorten as tension develops. Compare eccentric contraction. See also isotonic exercise.
1 Multiply by 2/3: Next you want to multiple your weight by 2/3 (or 67%) to determine how much water to drink daily. 2  For example, if you weighed 175 pounds you would multiple that by 2/3 and learn you should be drinking about 117 ounces of water every day.
In short, the equation tells you to take half your body weight, and drink that amount in ounces of water. In the example, notice that you should be drinking more than 12 glasses of water, not eight! Your exercise habits affect the amount of water you should be drinking, as well. The American College of Sports Medicine recommends adding 12 ounces of water to your daily intake for every 30 minutes that you plan to work out. If you are exercising outside and it is very hot, you may need to add more.