By Chris Raymond
There are many people who prefer to run outside, especially when the weather gets nicer. The hot temperatures during the summer months, combined with humidity, can put runners at risk if they aren’t knowledgeable about proper precautions to take during this type of exercise. There are two important factors to consider when running outside during the summer: hydration and electrolyte balance. Fluid and electrolyte balance is a critical component of health and wellbeing, not just for runners. There is a high number of older adults that are sent to the emergency room every day for dehydration and a lot of these cases could have been prevented just by maintaining an adequate fluid balance.
Water affects athletic performance more than any other nutrient we consume. Drinking fluids in sufficient amounts is essential for normal cellular function. It is also very important to runners because of thermal regulation. A systematic approach to water replacement is necessary because thirst is not always a reliable indicator that the body is in need of fluid replacement (especially in the case of older adults). The Adequate Intake for water set by the Food and Nutrition Board for total water intake for men and women is 3.7L and 2.7L, respectively. This AI for water is a baseline of how much a person should drink on a daily basis, but sweat losses during exercise and running can increase fluid requirements even more.
In addition to thinking about water consumption during summer running, electrolyte balance is also something to consider. The major electrolytes lost when sweating are sodium chloride and potassium. People who are not acclimated to the heat, or who have low sodium intake can experience heat cramps from sodium depletion. Potassium loss in sweat can generally be replaced with a diet providing 2 to 6 grams per day. It is recommended to consume more potassium rich foods such as citrus fruits, juices, melons, strawberries, tomatoes, bananas, potatoes, meat, and milk.
The risk of dehydration can be very sudden without proper fluid balance. Unless the fluid in sweat loss during exercise is replaced, the body temperature rises leading to heat exhaustion, heatstroke, and even death. Sweat loss is tracked by decreased body weight. Fluid loss equals to as little as 1 percent of total body weight can be associated with an elevation in core temperature during exercise. A loss of 3 to 5 percent of body weight results in cardiovascular strain and impaired ability to dissipate heat. One pound of weight loss during exercise is equal to 1 pint (.5L) of fluid loss. A downward trend of weight loss is sometimes mistaken as fat loss. Although not as sensitive as weight change; dark, yellow urine, rapid-resting heart rate, and prolonged muscle soreness are other useful tools to monitor hydration status. Therefore, consuming adequate fluids before, during, and after your summer run is essential to prevent dehydration related complications
Chris Raymond B.S. NSCA-CSCS is a Certified Strength and Conditioning Specialist from the National Strength and Conditioning Association. Chris is a part-time instructor for the Personal Fitness Training program at MTTI in Seekonk, MA. He also is a personal trainer at Seekonk Total Fitness. Chris has over 5 years of experience helping people reach their goals as a Certified Lifestyle and Weight Management Specialist. He currently resides in Riverside, RI but is originally from Woonsocket, RI.