Nutrition and staying hydrated are important for runners during all seasons. During the summer months, it is especially important to keep fluids in your body to run your best during those hot runs. "Being more than two percent dehydrated in warm environments causes a decline in performance," says Robert W. Kenefick, Ph.D., a physiologist with the U.S. Army Research Institute of Environmental Medicine.
- PRE-HYDRATE TO RUN FAST
In a study in the April 2010 Journal of Athletic Training, runners who started a 12K race dehydrated on an 80°F day finished about two and a half minutes slower compared to when they ran it hydrated. Dehydration causes your blood volume to drop, which lowers your body's ability to transfer heat and forces your heart to beat faster, making it difficult for your body to meet aerobic demands.
- GO COLD FOR LONGER RUNS
In a study published in 2008 in Medicine & Science in Sports & Exercise, cyclists who drank cold beverages before and during their workout exercised nearly 12 minutes longer than those who drank warm beverages. And in a study published this year, runners who had an ice slushy ran about 10 minutes longer than when they had a cold drink. In both cases, the drink that was colder lowered body temperature and perceived effort, allowing participants to exercise longer.
- STAY ON SCHEDULE
According to a study in the July 2009 Journal of Sports Sciences, when cyclists recorded their plan for hydrating during workouts—including exact times and amounts—they drank more frequently and consumed more fluid midworkout than their nonplanning peers. "Planning helps people remember how much and when they need to drink," says lead author Martin Hagger, Ph.D., of the University of Nottingham in the United Kingdom.