The Recommended Amount of Water Intake if Exercising

Replenishing water during exercise is important for your endurance and your health. Seventy-five percent of your muscles are water, and 60 percent of your total body weight is water, reports the MHealthy Physical Activity website. While exercising, your body uses water to regulate your temperature, lubricate your joints and regulate muscle contractions and responses. When water intake is not sufficient, you could experience decreased endurance, muscle cramps, loss of strength and concentration, all important when you exercise or engage in competitive sports. The recommended amount of water you should drink while exercising depends your gender, size, type and length of exercise and the environment.

  1. Quantity

    • Hydration needs vary from one person to another, with weight being a significant factor in determining how much water is enough for a given individual. When you are not exercising, a daily intake of 1/2-ounce of water for every pound of body weight is the rule of thumb. However, when you exercise, you lose up to a gallon of water in an hour in a hot climate, and half that amount in a mild climate, says Jeff Behrar on Bodybuilding.com. Behrar recommends drinking 8 to 16 ounces of water for every 15 minutes of exercise.

    Salt

    • Some individuals excrete more salt in their sweat than others. You are likely to have salty sweat if your sweat stings your eyes or open cuts, if your skin feels gritty after heavy perspiration or if you have white streaks on your skin after sweating. Excessive salt loss during exercise can lead to a condition known as hyponatremia, or not enough sodium in your blood. Consuming large amounts of water if exercising for longer than an hour can lead to sodium imbalance, even if you do not have salty sweat. During exercise bouts longer than hour, include consumption of sports drinks or electrolyte supplements to prevent this potentially serious or fatal condition.

    Hydration Before and After

    • Drink 17 to 20 ounces of water during the two hours before you exercise to hydrate your muscles, joints and vital organs. When you're doing exercising, consume an additional 16 to 24 ounces of water for every pound lost during exercise. Drinking more than enough to replace a pound provides replacement for the additional fluid lost during cool down.

    Considerations

    • Although thirst is a poor indicator of low hydration, it is an important guide to water intake, according to Alison Hamlett and Anita Bean in an article from "Runner's World." Anyone running for more than four hours should be guided by thirst and avoid drinking excessive amounts of water and consume sports drinks instead. Dark yellow or gold urine indicates dehydration. Drink water until the color is light yellow. Consult your physician before you undertake a new exercise regimen or if you have a medical condition that can be affected by exercise and excessive sweating.