The YouTube video, entitled You’re Being Lied To About Electrolytes, follows a recent podcast episode Smith recorded with YouTuber and performance coach Adam McDonald, who shared his concerns about the popularity of electrolyte supplements given that most populations are consuming too much sodium.
Sodium is the primary ingredient in electrolyte supplements, yet the global mean intake of sodium in adults is 4.3 grams per day, more than double the World Health Organization recommendation, bringing into question whether the general population really needs to be supplementing their diet with more salt.
McDonald also raised important questions around whether sodium can improve exercise performance, how sweat and sodium loss varies from person to person, and whether electrolyte supplements can offer any additional benefits than a homemade concoction of table salt and water. But what do other sports nutrition experts think?
History of electrolyte drinks and the science behind sodium loss
Electrolytes, such as sodium, potassium, magnesium and calcium, are electronically charged minerals which are essential for many bodily functions. For example, sodium is responsible for maintaining extracellular fluid volume, potassium supports nerve function and muscle contractions, and calcium helps to regulate cardiac rhythm.
When electrolytes become imbalanced, i.e. the level of one or more electrolytes is too low or too high, symptoms such as fatigue, headaches and muscle cramps may arise. In severe cases, electrolyte imbalances can be life-threatening, although this is rare.
While all electrolytes are essential for various bodily functions, sodium is the primary ingredient in electrolyte supplements. This is because sodium is the most abundant mineral lost in sweat, with potassium, magnesium and calcium lost in much smaller amounts.
This was discovered in the 1960s after Dr. Robert Cade and a group of researchers from the University of Florida were tasked with helping football players avoid severe dehydration in hot weather.
The team identified that the players were losing critical minerals in their sweat and created a formula comprised primarily of water, sodium and sugar. This formula went on to become the world’s first commercially available electrolyte drink, known as Gatorade, which launched in 1967.
Since then, thousands of studies have been conducted on electrolytes in the context of sports performance, with results largely showing that, under certain conditions, both water and sodium need to be replaced to rehydrate the body and re-establish normal total body water.
Health guidelines which recommend low sodium intake are therefore not necessarily intended for individuals experiencing large, acute sodium losses, such as athletes or individuals exposed to heat stress (such as manual laborers or factory personnel), according to Dr. Andrew Jagim, director of sport medicine research at the Mayo Clinic Health and an associate professor of family medicine.
Dr. Jagim, who has authored more than 140 peer-reviewed publications largely focused on nutrition and exercise strategies, said there are certain circumstances where supplemental sodium may be warranted.
“These may include prolonged endurance exercise (generally lasting >90 minutes), high sweat rates (>1.5–2.0 L/h, which are likely in hot and humid environments), repeated daily training sessions (again, more so in hot/humid environments), and individuals with high sweat sodium concentrations (‘salty sweaters’),” he told NutraIngredients.
Sodium is the primary extracellular ion and is essential for maintenance of plasma volume, he added.
“Sodium is also involved with nerve impulse transmission, muscle contraction and glucose/fluid absorption via sodium-glucose cotransporters,” Dr. Jagim said. “Because of this, sodium restriction (or inadequate sodium intake) may impair thermoregulation, cardiovascular function and performance.”
What benefits might electrolyte supplements offer?
Low sodium intake can increase the risk of exercise-associated hyponatremia—a condition where there is too little sodium relative to water in the blood. Hyponatremia is common in hospitalized patients and older adults but can also occur in athletes when high levels of fluid are consumed during intense exercise and sodium intake is adequate.
However, research shows that blood sodium levels sometimes increase post-exercise. Adding more salt therefore seems counterintuitive, but Dr. Jagim said this rise reflects the concentration of sodium in the blood, not total sodium amounts.
“Sweat is hypotonic [less salty] relative to plasma, which is one of the reasons why more water than sodium is lost via sweat,” he said. “As a result, plasma volume decreases, which in turn means that serum sodium concentration transiently increases. However, this does not mean the body has excess sodium, as total body sodium is still reduced. And importantly, if rehydration occurs with plain water only, plasma sodium can continue to decline, increasing hyponatremia risk.”
Consuming sodium post-exercise can therefore help to restore total body sodium, support plasma volume recovery, enhance fluid retention by reducing urine output and stimulate thirst, which also improves rehydration.
However, whether sodium supplementation can improve exercise performance is up for debate. One systematic review published in the International Journal of Sports Science concluded that there is currently minimal evidence that sodium ingestion during exercise improves endurance performance.
This does not mean that electrolytes are useless but rather that they are only likely to indirectly support performance by minimizing decline during prolonged activity, said Michael Sawka, an adjunct professor of biological sciences at Georgia Institute of Technology who has authored more than 300 peer-reviewed papers related to exercise physiology.
“The electrolytes themselves don’t boost performance, but being able to sustain your total body water does,” he told NI. “Electrolytes are more likely to help sustain recovery and performance rather than boost it.”
Who really needs electrolytes? And are branded products superior to salt and water?
Whether electrolytes are needed is largely dependent on the individual, as well as the duration and intensity of the activity they are doing. The amount of sodium lost via sweat varies greatly from person to person, ranging from around 460 mg to 1,840 mg per liter of sweat, as does the amount of sweat lost. Heat conditions are also an important factor, Sawka said.
“Hydration is very important during warm/hot weather to sustain performance and avoid dehydration—which impairs performance—but is not much of a concern in cool/cold weather,” he said. “If fluid losses (sweating) incurs over an extended duration (2-3 hours, depending on sweat sodium content), sodium will need to be replaced to sustain extracellular fluid volume and avoid hyponatremia.”
In addition, while Sawka suggests that electrolyte drinks can be helpful when rapid recovery is needed, e.g., half-time at a football game, electrolyte replacement can also be achieved by normal eating and drinking practices post-exercise.
Dr. Jagim agreed, adding that since sodium is the critical component, any form of dietary salt can do the trick. However, branded products may offer advantages such as more precise sodium dosing and the inclusion of glucose to enhance absorption and palatability, helping with consistency of intake.
Finally, while Dr. Jagim stressed that electrolytes are not necessary for everyone, such as sedentary individuals or those partaking only in short, low-intensity exercise, they are likely to be beneficial during prolonged, intense, or heat-stressed conditions.
“Electrolytes are best understood as physiological tools and not performance hacks,” he said. “Their value depends on context, dose and need. If used appropriately, they can support hydration, cardiovascular function and recovery. However, used indiscriminately, they offer little benefit beyond flavored water, and if anything, may do more harm than good (e.g., a sedentary person with high blood sugar loading up on electrolyte packets because they think they are ‘healthy’) and could be considered a waste of money if purchasing expensive commercial brands.”
