Water and Exercise

Water and exercise are important components of a sound health and wellness plan. Water is our most essential nutrient. It is especially important for active individuals.

About two-thirds of our body weight is water and even the slightest dehydration can cause significant problems. Sweating is one of our body’s ways of regulating our internal body temperature. It also results in a loss of water that must be replenished. We usually wait until we are thirsty before we replenish lost body fluid.

Thirst is one of the mechanisms that protects us from severe dehydration. However, by the time we experience the sensation of thirst we are slightly dehydrated. This is why we should constantly be drinking water. And exercise performed in cooler temperatures can be even more of a challenge. The reason is that we can be much more dehydrated before we are thirsty at all.

Although you may have read that you need to drink eight 8-ounce servings of water daily, some believe that is insufficient. In 2004, the Food and Nutrition Board of the Institute of Medicine released Dietary Reference Intakes (DRIs) for water and various electrolytes. The recommendation was 130 ounces for men and 95 ounces for women each day.

These numbers will vary depending on an individual’s activity level. Throughout the day you should be drinking water; and exercise will require you to increase you fluid intake.

In the 2-3 hours before your exercise session, you should consume one ounce of fluid for every 10 pounds of body weight. You can also drink an extra 8 ounces of water and exercise within the following hour will begin with you well hydrated.

Cooler water is more effective. The recommended temperature is 18-22 degrees C/59-72 degrees F. Water is the fluid of choice before, during, and after exercise sessions for most people. Unless the session is very long there is no need to replenish electrolytes. Commercially available sports drinks are not advised for sessions under ninety minutes.

During the exercise session you should drink 6-8 ounces of water each 15 minutes. You should not rely on your sensation of thirst. This becomes even more true as you get older. Research has shown that as we age the thirst sensitivity to body-dehydration status diminishes.

Hyponatremia is much less common than dehydration but is very serious. It occurs when the blood sodium level drops to deadly levels. This is caused by a combination of too much fluid and high levels of sodium loss during sweating. This is more common in exercise sessions that last longer than four hours such as a marathon.

If you are engaging in prolonged exercise sessions you will need to be careful not to drink too much fluid. This will result in your blood sodium level falling to life-threatening levels. A sports drink that contains sodium is helpful during these longer sessions.

A final consideration in your fluid intake is caffeine consumption. For years caffeine was thought to have a diuretic effect. This has been challenged recently by researchers who are finding that it has a diuretic effect comparable to water.

It is still wise to consume caffeine in moderation and not to overly depend on it for fluid replenishment. Nothing beats water for your body’s fluid needs.

Water and exercise in the proper amounts should be integral parts of your plan to fight disease, remain healthy, and obtain optimum wellness.