Feeling parched or dizzy after your hot-weather workout? These could be signs you're not drinking enough. In fact, dehydration can restrict your exercise performance and muscle strength, and can even contribute to life-threatening heatstroke by inhibiting your body's ability to regulate its temperature through sweat. When it comes to hydrating, it's best to stay ahead, according to Laura Anderson, RD, a specialist in sports dietetics in Colorado Springs, Colorado. “Recovery needs to be an all-day, everyday thing — not just what you do post exercise,” she says. Here are the experts' top hydration tips.
Begin hydrating long before your workout to give your body a chance to absorb the liquid. “Most people can easily go for an hour run, walk, or bike ride at a moderate pace in a moderate temperature without taking fluids with them,” explains Melinda M. Manore, PhD, RD, a nutrition and exercise sciences professor at Oregon State University in Corvallis. “Longer or harder workouts, especially if it's hot, require more fluids.” In general, Anderson recommends drinking 20 ounces three to four hours in advance of exercise, then another 10-15 ounces two hours before exercise. “Just make sure your urine is a light lemon-yellow color and you are good to go,” Manore adds.
The amount of fluids you sweat out during exertion depends on intensity, climate, and individual metabolism. One thing is universal: When you sweat, you lose minerals such as salt and potassium along with water. When well stocked, these electrolytes keep your body's fluids in balance and help maintain normal heart rate, muscle contraction, and brain function. For most low-intensity workouts, you may not need the extra carbohydrates and electrolytes in sports drinks, says Anderson. For intense workouts, however, especially in hot climates or if you sweat profusely, electrolyte-enhanced drinks can help replace lost sodium, potassium, and chloride. And remember: If you wait to drink until your brain registers thirst, chances are you're already dehydrated.
Good old H2O, combined with foods naturally high in moisture, such as fruits and vegetables, should be enough to replace lost liquids and electrolytes after most workouts, according to the American College of Sports Medicine. Salty foods such as nuts work double duty by replacing sodium and stimulating you to drink more. But if you've lost a lot of fluids, you may need to be more aggressive. The surest way to measure fluid loss is to weigh yourself before and after your workout (naked, to avoid weighing sweaty clothes). For each pound lost, replenish with 20-24 ounces of liquids, says Anderson.
As a general rule, experts recommend drinking water above all other liquids. However, we all know that can be, well, boring. Beverages with a little zing may encourage you to drink more. Liven things up by adding a slice of citrus to your water or, for something a little different, try fresh mint and cucumber slices.
Not to be confused with its fatty cousin coconut milk — derived from the nut's flesh — coconut water is the nearly clear, slightly sweet juice inside young, green coconuts. Available in packaged form at many natural products stores, coconut water is a natural electrolyte-replacement drink: An 11-ounce serving can contain up to 60 mg of sodium and more potassium than a banana.
Energy drinks can provide your body with a quick burst of ready-to-go energy in the form of simple carbs or sugar. Plus, they can help replenish minerals lost in sweat. Look for options without artificial colors or high-fructose corn syrup, and be sure to factor the calories of your energy drink into your regimen if you're trying to lose or maintain weight.
In moderate amounts (less than 180 mg per day, or about two 8-ounce cups of coffee), caffeine does not cause dehydration. In fact, caffeine may even make your brain think your workout is easier than it actually is, according to Melinda M. Manore, PhD, RD, a nutrition and exercise sciences professor at Oregon State University in Corvallis. But don't overdo: Too much caffeine can increase heart rate and blood pressure and cause the shakes.