A deluge of sport beverages and "designer waters" are available to the physically-active consumer. Don't worry if the choices overwhelm you—there's no need to throw in the towel.
The one ingredient that these beverages all have in common is water. Water is a vital nutrient, with an average human requirement of at least eight 8 ounce (oz.) servings daily.
Bottled water may seem like a reasonable option compared to tap water, which may taste too much like the chlorine that is used to kill bacteria in it. But bottled water may not necessarily be safer than tap water, because the
U.S. Food and Drug Administration
(FDA) standards for bottled water are not the same as for municipal water supplies.
Americans guzzle millions of dollars worth of sports drinks each year. These beverages contain water, plus additional ingredients and some very promising claims on their labels. To decide if you need a sports beverage, consider two key factors—the level and the duration of exercise in which you plan to engage.
During exercise, muscles generate heat and the body responds by sweating. Along with water, sweat contains small amounts of minerals called electrolytes, such as sodium and potassium. You can replace the fluid lost as sweat during the first 45 minutes of exercise by drinking two to three cups of water as you exercise.
Working muscles rely on energy from carbohydrates, which is stored as glycogen in muscle tissue. However, one hour of continuous exercise whittles away muscle glycogen stores. The more intense your workout, the higher the demand. It takes approximately 90-120 minutes to completely exhaust the supply of glycogen.
After this time interval, you may need some help. Unless you replace fluids and electrolytes, you are turning off your body's cooling system. The result is increased cardiac rate, decreased cardiac output, and an increase in body core temperature. Muscles will also shut down without a replenished energy supply.
Sport beverages can be one solution, and are available in both high- and low-carbohydrate content.
Fluid replacements
The low-carbohydrate drinks are known as fluid replacements, and essentially flood your tissues and blood with water, small amounts of glucose (1 tblsp/cup), and sodium. They are designed to be consumed during exercise.
Carbohydrate-loading drinks
In comparison, carbohydrate-loading drinks are filled with sugar—three tablespoons or more per cup. They aren't meant to replenish fluids during exercise; instead they help build up energy stores before and after intensive exercise. High-carbohydrate beverages should not be used during exercise. Because they contain large amounts of sugar, they slow down the stomach-emptying process and can cause stomach distress during exercise.
Some of the advantages of sports beverages include energy, taste and convenience. According to Christina Economos, Ph.D., "Sport beverages are liquid fuel for the body, especially during the summer." Not coincidentally, the beverages are sweet, which promotes your drinking them. They also contain sodium, which stimulates your thirst signals, assuring adequate rehydration. They are convenient, and can be sipped on the run.
The carbohydrate-loading beverages can be used as a replacement for solid food before exercise to build up glycogen supplies, and after exercise to replenish the energy stores and help in muscle recovery.
These drinks are expensive, however. To save some money, you can make your own sports drink, using 16 oz. of apple or cranberry juice, 16 oz. of water, and 1/3 tsp. salt.
Be aware, too, that some manufacturers use exotic or superfluous ingredients to help distinguish their product in a very crowded marketplace. There is no evidence that royal jelly, minerals, or plant extracts are beneficial to the exercise or rehydration process. Beverages that contain caffeine might provide some benefit, however, as caffeine does have an ergonomic effect. However, too much caffeine can potentially cause heart problems.
Type of activity
If you exercise slowly or sporadically, you don't need a sports beverage, so the type of activity you are doing matters, too. Bob Arnot, M.D., medical correspondent for CBS news, says that sports drinks are poorly suited for stop-and-go activities such as soccer, basketball, tennis and squash, but are better for sports like cycling, inline skating, stairclimbing, and cross-country skiing. For most of us, though, drinking a free quart of water (32 oz) for every hour you exercise will do the job.
Length of workout
The longer you work out, the more you sweat, and the hotter the day, the more you will gain from a sports drink. Most studies have shown that you only start to benefit from carbohydrate loading drinks after an hour of continuous exercise. Remember that all sports drinks have calories, ranging from 50 calories per 8-oz serving up to 200 calories. The higher the carbohydrate content, the higher the calories. If you get into the habit of drinking these sweetened drinks without maintaining your physical activity level, you could find yourself putting on extra weight.
A trial run
Finally, it can't hurt to try sports drinks. Practice alternating water with a sport drink during workouts. Experiment with high-carbohydrate beverages before or after exercise. You might find the competitive edge you need!
