There is an advertisement on TV where a man is just walking down the street on a hot day. He stops, pulls out his water bottle and adds a pack of Liquid I.V., mixes it and drinks it down. He’s replenished, ready to go. A case just costs $180. Such ads for electrolyte supplementation are everywhere, but especially on social media, where TikTok influencers have submitted more than 460,000 posts on electrolytes. They swirl the colorful drinks, suggesting enhanced energy, hydration, and performance. Unfortunately, TikTok influencers are not the scholars of science education. This man who has apparently only walked a block or two needs nothing more than a drink of water.
Most of the recent articles promoting electrolytes suggest that such supplements actually began with the advent of Gatorade in the early 1970s. A quick search will inform you that as early as the 1920s workers in South Africa’s gold mines swallowed salt tablets prior to working in the hot mines. World War II soldiers in the tropics were regularly administered salt tablets. Gatorade (Pepsi) and Powerade (Coca Cola) are the two most popular fluid beverages but electrolyte powders are now the rage. Others have tried; most interesting was a beverage called S.W.E.A.T., designed to imitate sweat. Let’s just say the taste was a problem. Basically, they all provide electrolytes plus some form of glucose. The glucose sweetens the beverage, supporting one to drink more. Drinking more is a good thing since glucose is lost as well as electrolytes when exercising.
While the miners and soldiers were given ample water, football coaches in the 1950s and 60s got the strange idea that water restriction was one key to fitness. Salt tablets were often administered but without water. A salt tablet is toxic in a dry stomach. Twice a day workouts to untrained athletes in August was harsh, especially without water, moreover wearing a heavy uniform and helmet. Many coaches were brutal, labeling athletes as sissies if they drank any water. The result of this practice was not better trained athletes, but the occasional death, athletes struck down in the prime of life. The incidents were labeled as accidents and no coaches were prosecuted for malpractice. Today, athletic organizations mandate hydration as well as early training to become acclimatized. Unfortunately, abuse still occurs.
August is upon us and athletes will be training for fall sports. We used to think of these as fall and winter sports but August is brutally hot in many areas. Some teams even have competitions before school starts. Athletes must have time to acclimatize to the heat and the only way to do this is by exercising in the heat. Hydration before, during, and after training must be part of practice. The result is better performance and athletes who can weather the heat without a heat illness. In the recent World Cup, we watched athletes exercise vigorously for almost two hours, often in the heat. What we observed was athletes who were well trained and acclimatized to the heat.
One question is whether individuals need to supplement with electrolyte beverages. Intense sweating for long periods results in water and electrolyte loss. Electrolytes such as sodium, potassium, and calcium function to carry electric charges, also helping to maintain fluid balance, and maintain blood pressure. During exercise, water is the predominant need. Electrolyte loss is not a problem unless vigorous exercise lasts longer than 90 minutes. Drinking an electrolyte beverage helps with fluid and electrolyte replacement, but mealtime is critical for recovery. Salt is easy to replace as it is usually within reach when you eat. Eating fruits, vegetables, and dairy restores potassium and calcium. Expensive powders are unnecessary, just eat.
Recreational athletes may need electrolyte replacements, especially if the intensity of the task, the duration, and the environmental challenge meet the criteria–vigorous exercise longer than 90 minutes in a hot environment. If there is not considerable sweating, supplementation is not needed. Electrolyte supplementation is unnecessary otherwise and does not improve performance. Recreational athletes need to acclimatize. You must exercise in the heat to acclimatize. It is important when assessing the environment challenge to take humidity and sunlight in addition to temperature. Sweating is supposed to cool one but only if the sweat evaporates. When humidity is high, sweating doesn’t help much. Accordingly, some young footballers have died with temperature only in the 80s but high humidity. Checking the heat index helps but it does not take into account solar heating.
Jim Johnson is a retired professor of exercise and sport science after teaching 52 years at Smith College and Washington University in St. Louis. He comments about sport, exercise, and sports medicine. He can be reached at jjohnson@smith.edu.