Drink to This

From: Bicycling Magazine's Nutrition for Peak Performance: Eat and Drink for Maximum Energy on the Road and Off

During cycling, your muscles produce 30 to 100 times more heat than when you're at rest. The body extinguishes this inferno primarily by increasing sweat rate. In the summer, you can lose more than 2 liters (about 67 ounces) of fluid per hour on a hot day. If you don't replace it, power output declines in about 30 minutes. A study of trained cyclists found that they could barely finish a 2-hour ride at 65 percent max VO2 without fluids. According to Bicycling magazine's Fitness Advisory Board member Arnie Baker, M.D., in ultra-endurance cycling events such as the Race Across America, dehydration and saddle sores are the leading reasons cyclists drop out.

Studies by Edward Coyle, Ph.D., director of the Human Performance Laboratory at the University of Texas, reveal that cyclists who lose a quart of fluid experience a rise in heart rate of eight beats per minute, a decrease in cardiac function, and an increase in body temperature. Dehydration is also cited for increased metabolic stress on muscles and faster glycogen depletion. It wreaks havoc on your internal thermostat by decreasing bloodflow to your skin, slowing sweat rates, and increasing the time needed for fluids to be absorbed into your bloodstream. What's worse, by the time you feel thirsty, your body has already lost up to 2 percent of body weightabout a quart of fluid.

Is you mouth feeling dry just reading this? Here are several ways to beat the dehydration monster.

Drink more. Conventional wisdom calls for eight glasses of fluid daily (about 64 ounces), but that's for nonexercising couch potatoes. Cycling wisdom calls for 1 milliliter of fluid for every calorie you burn, according to Mitch Kanter, Ph.D., director of the Gatorade Sport Science Institute. "At about 3,500 calories a day, you'll need around 3 _ liters. That's almost 15 (8-ounce) glasses of fluid." He advises gauging hydration by monitoring these simple markers.

• Do you go to the bathroom less than three times during an 8-to-10 hour workday?
• Is your urine dark yellow and have a strong odor?
• Do you get headaches toward the end of a long ride or shortly after?
• Do you drink less than one water bottle per hour while riding?
• Do you lose more than 2 pounds during rides?

If you answer yes to any of these questions, your body is heading for a drought.

Prehydrate. Drink plenty of fluids every day, but before a race, long ride, or tour, start hyperhydrating at least 24 hours in advance. Smart cyclists keep a water bottle with them all day to stay hydrated. Avoid drinks containing alcohol or caffeine because both act as mild diuretics, causing the body to excrete more water. If you have trouble meeting your calorie needs, use sports drinks, recovery drinks, or other liquid supplements. If you're weight-conscious, quaff calorie-free or low-cal options such as diluted fruit juice, mineral water, or club soda.

Set a sipping schedule. To negate fluid lost to perspiration, practice drinking strategies during training. Determine your sweat loss per hour by weighing yourself before and after rides. (Every pound lost equals 16 ounces of fluid.) Then figure out how much fluid your stomach can tolerate per hour and the best drinking schedule to replace it. Dr. Kanter recommends that you set your sports watch to alert you to drink 4 to 8 ounces every 15 minutes regardless of whether you're thirsty. It takes practice to drink more than a quart per hour without intestinal discomfort. A backpack-style hydration system provides easily accessible water to help you drink more.

Rehydrate. After you've ridden for several hours, pump down fluids. What you drink makes a difference. In a study published in the International Journal of Sports Medicine, Dr. Coyle compared the effects of drinking nearly 2 liters of water, sports drink, or diet cola in dehydrated athletes 2 hours after exercising. Results revealed that diet cola replenished 54 percent of fluid losses; water, 64 percent; and sports drinks, 69 percent.

Munch on salty snacks. Sodium makes your blood spongelike so that you absorb more water and excrete less. "Each liter of sweat saps 500 to more than 1,000 milligrams of sodium," notes Lawrence Armstrong, Ph.D., of the University of Connecticut Human Performance Lab.

Dr. Coyle suggests that athletes drink plentifully with meals and snacks because food naturally contains many times more sodium than sports drinks or energy bars.

Eat "wet" foods. About 60 percent of your daily fluid comes from the food you eat, but some foods increase hydration better than others. For instance, fruits and vegetables are great fluid sources,they're 80 to 95 percent water by weight. Eating the recommended five-plus daily servings of produce means you'll get a lot of extra water in your diet. If you're downing protein supplements, you should drink more. Dr. Kanter warns, "You'll need more water to metabolize and excrete the extra protein." He adds that fat and water don't readily mix, so many high-fat foods provide little additional water.

Use sports drinks. Most popular sports drinks contain sodium, potassium, and other electrolytes. These are recommended for exercise lasting more than 1 hour. Whenever you plan to cycle for several hours, make sure you have two bottles of your favorite. Sports drinks are also useful for shorter workouts that include high-intensity riding such as sprints and intervals.

Make sure you like the way a drink tastes so that you'll be motivated to put down lots of it. Also, cool fluids taste better and may be absorbed more rapidly than warm ones. Ed Burke, Ph.D., an exercise physiologist and a member of Bicycling magazine's Fitness Advisory Board, tells cyclists to carry two bottles,one frozen. As you drink down the first bottle, the frozen one melts so that the liquid is cold when you need it.

Back to Top

Reprinted from: Bicycling Magazine's Nutrition for Peak Performance: Eat and Drink for Maximum Energy on the Road and Off © 2000 by Rodale, Inc. Permission granted by Rodale, Inc., Emmaus, PA 18098.

© 2006 Rodale Inc.
This selection of articles was paid for by Acura. The editorial staff of Rodale Publications was not involved in the production of this special section. We value your thoughts and suggestions. Please tell us what you think of this program.