FITNESS: You are what you drink

By LORNE OPLER

Walk around any gym, and you’ll see everyone carrying a water bottle.  We all know we're supposed to drink water when we exercise, but why?  Here are some of the most important reasons:

1)      Water is critical to maintain healthy joints.  Surrounding your joints is a thick, water-containing substance called synovial fluid, which lubricates the bones’ cartilage (shock absorbing material at the ends of the bone).  Synovial fluid ensures smooth movement of bones when they rub against each other.  When we exercise, we lose water through perspiration.   If we don’t hydrate sufficiently, there is less water in our synovial fluid to keep the joints healthy. 

2)       Water affects our digestive system.  Drinking adequate amounts of water helps to improve the transporting of nutrients from the bloodstream to muscle cells, and the excretion of waste products.   Typically, weight trainers consume more calories than the average person, making adequate water consumption even more important.

3)      Water helps reduce fatigue. Research has shown that a loss of 2 or more percent of  body weight from perspiration is connected to a drop in plasma volume (Plasma is the liquid which carries blood cells and is almost all water).   With less plasma moving through the body, the heart works harder to get blood and its nutrients circulated.  This can also cause muscle cramps, dizziness and fatigue.  With a 2 percent loss of water, the body is already in a state of dehydration.     And dehydration will always cause your exercise performance to suffer.   

4) As you exercise more, your body temperature increases.  Body heat needs to escape.  Warmed blood moves towards the skin, excreting water, potassium, sodium and calcium (i.e., electrolytes) as sweat. Sweat keeps the body temperature down.  The body cannot function if the internal heat can’t escape through the skin.

What to drink?

According to the American College of Sports Medicine, if you are working out for less than an hour,  plain water is sufficient. Sports drinks are good for high intensity exercises lasting 60 minutes or more.  The longer and harder you exercise, the more you’re sweating electrolytes, which the body needs for electrical impulse transmission.  Sports drinks contain electrolytes to replenish those lost through sweat.   

How much to drink?

A glass of water an hour or two before exercise. Have another glass about 20 minutes before your strength-training session starts.

·      Sip from a 1 liter bottle of water about every 15 minutes if you're exercising less than an hour.

·      After exercising, drink eight more ounces of fluid within 30 minutes after exercising. If you've exercised intensely for at least 60 minutes, also drink eight ounces of a sports drink.

Remember, the goal of drinking is to prevent dehydration.   The best way to determine whether you’re dehydrated after a workout is to weigh yourself before and after you exercise.    If you’ve lost 2 percent or more of your body weight (through fluid excretion), you know you need to drink.  Drink two cups of fluid for every pound of body weight lost after exercise.

ABOUT THE WRITER

Lorne Opler is a health educator and a certified personal trainer (American Council on Exercise) and also holds certification as a strength and conditioning coach through the National Strength and Conditioning Association (NSCA).  As a fitness educator since 1997, he has worked in health clubs,  and hospital and university settings in Austin, Boston and Atlanta.  He currently resides in Toronto, Ontario.