Physical function may hang in the balance if electrolyte levels remain low after a workout. Resulting symptoms can include muscle fatigue, dizziness, and nausea. But the right food or sports drink can get those electrolytes back in the body, no sweat. Yet when and how much to eat or drink depends on factors like exercise intensity, weather, and individual differences in sweatingRehydration after exercise in the heat: a comparison of 4 commonly used drinks. Shirreffs, S.M., Aragon-Vargas, L.F., Keil, M., et al. Sport and Exercise Sciences Faculty, Loughborough University, UK. International Journal of Sports Nutrition and Exercise Metabolism, 2007 Jun;17(3):244-58.Fluid and electrolyte balance in ultra-endurance sport. Rehrer, N.J. School of Physical Education and Department of Human Nutrition, Otago University, Dunedin, New Zealand. Sports Medicine, 2001;31(10):701-15..
The Threat of Sweat — Why It Matters
Dig up that high school chemistry book for an electrolyte refresher course. Electrolytes are minerals that break into small, electrically-charged particles called ions when they dissolve in water. Found in blood and cells, electrolytes are essential to physical activity because they regulate bodily fluids. Sodium and chloride, which maintain normal blood pressure and support muscle and nerve function, may be the most well known of the bunch. But the supporting cast includes calcium, which aids muscle contraction; magnesium, which aids healthy cell function; and potassium and phosphate, which help to regulate energy and pH balance.
During exercise, the body’s electrolyte balance can begin to shift. Finding a stick of deodorant may not be the only post-workout problem— as the body loses electrolytes through sweat, the imbalance can result in symptoms like muscle cramps, fatigue, nausea, and mental confusion. And if the electrolyte supply stays low, muscles may continue to feel weak during the next workout sessionFluid and electrolyte needs for preparation and recovery from training and competition. Shirreffs, S.M., Armstrong, L.E., Cheuvront, S.N. School of Sport and Exercise Sciences, Loughborough University, Loughborough, UK. Journal of Sports Science, 2004 Jan;22(1):57-63.. Long-term risks include kidney failure, seizures, and disturbances in heart rhythm— a high price to pay for skipping a few sips.
During longer workout sessions, the plan for electrolyte replacement depends on a few factors. Though gender differences are small, guys tend to sweat more than gals doA review of comparative responses of men and women to heat stress. Kenney, W.L. Environ Researhc, 1985 Jun;37(1):1-11.. And research suggests larger athletes may need more sodium than smaller teammates, since they usually get sweatier. In general, more intense exercise (e.g. an hour of kickboxing vs. a stroll in the park) depletes more electrolytesFluid and electrolyte balance in ultra-endurance sport. Rehrer, N.J. School of Physical Education and Department of Human Nutrition, Otago University, Dunedin, New Zealand. Sports Medicine, 2001;31(10):701-15..And check the thermometer, since warmer weather can mean more sweat. Endurance athletes, get the calculators out: Weigh in before and after exercise and consume 16 to 24 ounces of fluid for every pound of body weight lostRehydration and recovery of fluid balance after exercise. Shirreffs, S.M., Maughan, R.J. Biomedical Sciences, University Medical School, Foresterhill, Aberdeen, Scotland. Exercise and Sports Science Review, 2000 Jan;28(1):27-32..
There are several food and drink choices that can help replenish electrolytes. One common way to restore the balance is swigging on a sports drink, or even milkRehydration after exercise in the heat: a comparison of 4 commonly used drinks. Shirreffs, S.M., Aragon-Vargas, L.F., Keil, M., et al. Sport and Exercise Sciences Faculty, Loughborough University, UK. International Journal of Sports Nutrition and Exercise Metabolism, 2007 Jun;17(3):244-58.Milk as an effective post-exercise rehydration drink. Shirreffs, S.M., Watson, P., Maughan, R.J. School of Sport and Exercise Sciences, Loughborough University, Loughborough, UK. British Journal of Nutrition, 2007 Jul;98(1):173-80. Epub 2007 Apr 26.. But watch out for drinks with too much sugar, which can add unnecessary calories. Look for drinks that have four to nine percent carbohydrates per eight ounces, and 120 to 170 mg sodium. Gatorade is a well-known choice that offers a good supply of electrolytes and minimal sugar, too. A quick snack is another way to get back electrolytes. Salty foods (think peanut butter, pickles, and tomato juice— maybe not all together) should top the list, since the body loses sodium in higher amounts than it loses other electrolytes. Leafy greens, tomatoes, celery, bananas, yogurt, nuts, and beans can help restore the rest of the electrolyte team. They’ll get the body back on track and ready for its next challenge.