Dietitian's Dish: Exercise, hydration and summer heat
By Katherine Klingle, R.D., L.D.
The summer of 2011 will be noted in the record books as one of the hottest that we have experienced. Add the unmerciful drought to it, and you can't help but feel thirsty and exhausted. Staying hydrated is hard enough during this time, but anyone who tries to continue his or her exercise program in this heat has to have determination and savvy to avoid dehydration and stay safe.
One may think that it's simple enough to avoid dehydration by obeying your thirst signals. However, thirst is not always an accurate indicator to avoid dehydration. And without adequate fluids, the body's core temperature rises and can affect exercise performance or worse - threaten your very life.
Especially in this weather, it is crucial to drink before, during and after exercise. Monitor urine color for hydration and remember that clear to lemonade colored is the goal. If possible, exercise during the cooler parts of the day. Weighing before and after exercise is a good way to estimate fluids lost during exercise to know the minimum you need to replenish losses (1 pound lost = minimum 16 ounces fluid needed). Water is the replacement beverage of choice for the first 60 minutes, but longer exercise may require fluids that provide carbohydrate and electrolyte replacement. But what do you look for in a sports beverage?
It's important to distinguish the difference between a sports beverage and an energy drink. Most sports beverages provide water, carbohydrate and electrolytes. A sports drink with approximately 60-80 calories and 110-170 mg sodium per 8 ounce serving is usually appropriate to replace water, carbohydrates and sodium. The "plus" of a sports beverage is that it is flavored and contains some sodium, both of which may trigger you to drink and hydrate more. Most contain some potassium to replace some lost in perspiration. A few may provide negligible amounts of vitamins.
A diet including healthy foods and beverages can provide all the nutrition and fluid you need before or after an event. But, sometimes, sports beverages are convenient and typically easily tolerated during exercise lasting more than 60 minutes when stores start depleting. Energy drinks, on the other hand, may contain additional ingredients such as taurine, guarana and ginseng, to name a few. It is important to remember that herbs and supplements are not regulated by the U. S. Food and Drug Administration, so there is no guarantee they do what they claim, are even safe or won't interact with medications you may be taking. And remember, no energy drink will be a quick fix for a poor diet.
A nutritious way to get fluids at mealtime is by consuming fruits and vegetables with high water content. Watermelon, oranges, peaches, lettuce, cucumbers, tomatoes and apples are some examples of juicy fruits and vegetables that provide fluid along with carbohydrates, vitamins and minerals naturally. With a little planning and care, you can stay hydrated and continue to exercise even during the dog days of summer.
Katherine Klingle is a registered and licensed dietitian. Send questions or comments to firstname.lastname@example.org.