Does your child know his sweat rate? Turns out it is the key to replacing fluids lost during exercise, according to several studies presented at the 2010 annual meeting of the American College of Sports Medicine in Baltimore, with experts recommending that athletes replace 150% of the weight loss from sweating in the first four hours after sports.
- Knowing sweat rate is critical to rehydration. Ironman triathletes lost 1.5 liters of sweat during a 1 hour simulated bike race but drank about a liter too little fluid to replace that loss. The experts' advice for endurance athletes: learn their sweat rate by weighing themselves naked before and after 1 hour of race-pace work. Each pound equates to a loss of 16 ounces of fluid.
- Rehydration: Gulping or sipping makes no difference After hard exercise, it doesn't matter whether the athlete drinks a large amount of fluid to replace sweat losses or drinks smaller amounts every 30 minutes over a four hour span. Either works. The trick, say experts, is to be sure to consume 150% more than is lost in sweat. Once again, the research indicates the importance for athletes of learning their sweat rate!
- Winter athletes get dehydrated too. Winter athletes often need to be taught to drink more fluids throughout the day. Urine samples of high school alpine skiers found that 11 of 12 were dehydrated before they even began racing. A survey of NCAA hockey players found that that they arrived for practice dehydrated and ended practice with an even bigger hydration deficit.
Created July 10, 2010
© Nancy Clark
Nancy Clark, MS RD CSSD, is MomsTeam's sports nutrition expert, a Certified Specialist in Sports Dietetics and best-selling author. She counsels active people in her practice at Healthworks, a fitness center in Chestnut Hill, Massachusetts. Her new book, Food Guide for Soccer: Tips & Recipes from the Pros and other books, including her Sports Nutrition Guidebook and food guides for new runners, marathoners, and cyclists are available at www.nancyclarkrd.com and www.sportsnutritionworkshop.com.
Editor's Note: Calculating the amount of fluids to consume to rehydrate after sports based on urine color or weight lost through sweat is easy with a new iPhone application called iHydrate TM!