Everybody knows the importance of drinking an adequate amount of water, especially during periods of high training volume or intense physical activity. However, less appreciated is the need to replenish lost electrolytes -- a critical component of proper hydration. Learn about what electrolytes are, how they function in the human body, and an easy way to integrate them into your daily life.
Very broadly, electrolytes are small, electrically charged particles in the body that are lost via sweat and must be replaced through food or beverage consumption. The four main ones are sodium, potassium, magnesium, and calcium, all of which have integral roles in proper body function during exercise. Importantly, pure water has no electrolytes. Athletes who over-hydrate with plain water may experience symptoms of hyponatremia, where the blood has been diluted so much that sodium levels dip abnormally low. This causes the cells in the body to swell, leading to muscle cramps, dizziness, nausea, and in extreme cases, a coma.
The symptoms that result from a depleted sodium supply help highlight how integral it is to the human body, especially during periods of heavy exercise. With this being said, the ideal amount of sodium intake varies significantly from person to person. Those who eat a diet made up primarily of processed foods likely consume around 4000 milligrams or more of sodium per day, despite the fact that the American Heart Association recommends decreasing intake to 1,500 milligrams daily. However, endurance athletes generally lose a significantly higher amount of sodium than their sedentary counterparts, especially when training in conditions resulting in heavy sweating. An intense two-hour workout could cause up to 2,000 milligrams of sodium loss, setting up the athlete for a bout of hyponatremia.1
Aside from working to maintain a normal fluid balance, sodium also aids potassium and calcium in promoting proper muscle contraction. Magnesium is a calcium antagonist and therefore helps the muscle relax; the absence of magnesium is associated with muscle cramping. Chloride is another important ion that has not been mentioned yet, and also has a role to play in muscle contraction. However, chloride is often obtained in the diet with sodium (in the form of sodium chloride), so they are typically viewed and assessed in tandem.
With all of this information, what are the best ways to ensure a proper electrolyte supply during exercise? Baseline levels can be obtained via a wholesome and balanced diet -- including milk products, nuts, whole grains, fresh fruits and vegetables, and animal proteins. However, two situations could arise that may necessitate additional electrolyte supplements, including 1) low dietary intake/high personal requirements or 2) heavy athletic activity.
Sports drinks like Gatorade® contain electrolytes, but they are often added to a base of sugar and carbohydrates intended to re-fuel lost energy stores during long periods of exercise. This can be valuable at certain times, but can be hard to digest for some athletes and is unnecessary for day-to-day consumption. Instead, a product like nuun® contains the four main electrolytes with no added sugar. Each tablet can be dissolved in any volume of liquid for hydration during races, meets, or games, or for post-workout replenishment if you’re feeling any symptoms of hyponatremia. Nuun® can also be beneficial for those who do not obtain adequate electrolytes through their diet and food choices.
Despite these facts, electrolytes are often overlooked, sometimes dangerously, in the sphere of hydration. Clearly, electrolytes are integral to maximizing athletic performance and maintaining peak health -- they should be given the attention they deserve!
1. Ryan, M. (2012). Sports Nutrition for Endurance Athletes. Boulder, Colorado: VeloPress.
Disclaimer: I am not a licensed nutritionist nor a registered dietician. The opinions expressed in this article are my own, and each individual is ultimately responsible for his/her dietary and nutrition practices. Please consult a physician before starting a new dietary program.