Like wine to the gods, water is the nectar of athletes. "Losing just 1 percent of weight from water loss can impair performance," says Colleen Cooke, a sports nutritionist at the Boulder Center for Sports Medicine. For the past 7 years, countless hikers and mountaineers have turned to her for advice on nutrition. Their #1 question: "How do I stay hydrated?" Here's what she says.
Drink early While you sleep, you lose as much as 1.5 pounds of fluid through sweat and respiration. Before breaking camp, replenish with 16 to 24 ounces of water, sports drink, or decaffeinated tea.
Sip often Some hikers walk for 3 hours, sip a few ounces on a rest break, and pay for it at the end of the day, says Cooke. Instead, drink 4 to 6 ounces of liquid every 20 minutes; it'll help you feel strong, even on the last hill.
Add Electrolytes "Sweat is made up of sodium and potassium, which need to be replaced," says Cooke. If they're not, you'll likely feel sluggish. Sip a sports drink (powdered versions work well in the field) or munch on salty snacks.
Eat carbs "Every gram of carbohydrate you eat pulls three grams of water into your digestive system, which helps keep you hydrated," explains Cooke. Cooke recommends a 60/20/20 carb-protein-fat ratio for backpackers on multiday trips.
Watch for signs Headaches, dizziness, or difficulty concentrating can signal dehydration. The fix: Rest, eat, and drink. Anxiety, a weak or rapid pulse, and clammy or hot, dry skin point to serious dehydration. Set up camp--a long rest, a good meal, and lots of water are your best bets for feeling stronger in the morning.