Running for a mind-boggling 155 miles is grueling — keeping one's energy up and pushing past physical and mental blocks is not for the faint of heart. To reach the finish line, endurance athletes frequently use tools that are tried and (now debatably) true: Electrolyte supplements and sports drinks.
According to a new study on 266 ultramarathoners, electrolyte supplements and sports drinks actually do little to keep electrolyte levels balanced, boost performance, or prevent illness from hitting — upending common wisdom on athletic recovery.
“These electrolytes that people take are not protective,” Grant Lipman, study co-author and researcher at Stanford University, tells Inverse. “They don't stop cramps; they don't stop the distress or gnawing in your gut from nausea or vomiting; they don't help performance and they don't protect against dangerously low or high salt levels.”
Lipman’s study, published Tuesday in the Clinical Journal of Sports Medicine, adds to an ongoing debate over whether sports drinks and electrolyte supplements are overhyped for their ability to give athletes a much-needed edge. Previous research has shown these add-ons can help replace vital electrolyte levels after vigorous workouts.
And while this study specifically examined how well electrolytes served elite athletes, these findings also have implications for weekend warriors and 5K enthusiasts. There’s little reason to add electrolyte supplements on top of drinking water and eating a nutrient-rich diet if you're a casual athlete, Lipman explains — an opinion shared by Stavros Kavouras, a hydration expert and professor in the College of Health Solutions at Arizona State University, who was not a part of this study.
“The average American consumes double of sodium you need, and if you need a little extra, you add extra salt in your diet,” Kavouras tells Inverse.
Electrolyte imbalance is not an issue unless you're an ultra-athlete who is on a low sodium diet, he says. From his perspective, sports drinks and electrolyte supplements aren't totally useless. They do provide sugar and carbs, which can be helpful to keep athletes from "hitting the wall" during an intense workout or long race. But for everyday activity, they probably aren't necessary.
"You don't need to go overboard and take electrolyte supplements every time you go to the gym for 20 minutes. You don't need to take salt pills to work for half an hour in your garden."
To test if electrolyte supplements make a meaningful difference, Lipman and his team ventured far from the controlled conditions of their labs to the deserts of South America, Mongolia, or Namibia. They set up camp at five different Racing the Planet ultramarathons, weeklong athletic events where people run 155 miles over seven days across rough terrain. Physically straining ultramarathons also push athletes to see how well they can survive natural elements: They compete in extreme weather conditions, from freezing temperatures to 120 blazing degrees.
Overall, researchers recruited and analyzed an international group of 266 ultramarathoners. They took note of the athlete's weight, took blood samples, and asked them to share if they used electrolytes — whether they be gels, powders, drinks, or chews — in an effort to influence their performance or avoid illness.
Broadly, electrolytes are essential minerals like sodium, calcium, and potassium, which regulate muscle contractions and keep one hydrated. People can get the electrolytes they need through a nutritious diet — and a common source of sodium is salt. Meanwhile, products like Gatorade claim they can replenish needed electrolytes.
The team was careful to note how many milligrams of salt people were taking per hour, per their body weight. They also documented which electrolyte supplements the athletes planned to take throughout the race along with how much water or sports drinks they planned to drink, before the races began. They asked whether the athletes planned to drink on a regular schedule or whenever they got thirsty. The athletes weighed in and reported their training programs leading up to the competition.
Then, after completing the first 50-mile leg of the race, instead of resting or hydrating, the athletes checked in with the researchers, reporting how closely they followed their drinking and supplement plans. They also gave blood samples so the research team could analyze the sodium levels in their blood. They weighed in again because weight is a metric that signals how their hydration levels may have fluctuated after the 50-mile run.
"It was the heat that dictated everything."
Out of the total group of 266 athletes, 41 of the athletes had sodium imbalances by the end of their race. Eleven were also found to have exercise-associated hyponatremia (EAH) due to too little sodium, while 30 were dehydrated, with too much sodium in their blood.
This was despite the fact that all of the ultramarathoners consumed some type of electrolyte supplement. No matter the type, amount and manner of ingestion, the supplements showed little to no effect on sodium levels.
This high rate of supplement consumption is mirrored in other studies of endurance athletes: It’s estimated 90 to 96 percent of ultramarathoners take electrolyte supplements or sports drinks when competing.
Lipman is careful to note that the majority of people in the study had "totally normal salt levels after running 50 miles." The point is more so that salt levels appear unaffected by whether or not someone consumes electrolytes.
Eighty-eight percent of the sodium imbalances recorded occurred during the hot races, indicating that heat and hydration levels were far more predictive of sodium imbalances than either the manner or type of electrolyte supplements taken.
“It was the heat that dictated everything,” Lipman said.
Salt, sweat, and supplements
Lipman and his team focused on one electrolyte — sodium — which maintains healthy blood pressure and regulates the function of muscles and nerves. Keeping sodium levels in check while exercising can prevent nausea, muscle cramping, dizziness, and fatigue, and in turn, thought to have a strong impact on exercise performance, Kavouras explains.
Hypernatremia (when sodium levels are too high and often comes along with dehydration) and exercise-associated hyponatremia (EAH) (which is caused by a drop in sodium levels) can emerge as a result of out-of-whack sodium levels. EAH can lead to altered mental status, seizures, pulmonary edema, and even death. There have been over a dozen documented fatalities since 1985, according to previous studies, during activities like hiking, canoeing, triathlons, and summer sports training.
"There's this false paradigm that dehydration is super dangerous."
These potentially fatal conditions can also arise when people overhydrate.
“There's this false paradigm that dehydration is super dangerous, and you need to drink all these sports drinks and water, but you have to listen to your body,” Lipman says. “You can actually cause serious harm by doing this false approach.”
Still, these conditions are relatively rare — the average jogger or biker isn’t likely to run into electrolyte depletion to the point that it would cause severe medical issues. Only people exercising at high-intensity or working long hours in the heat need to worry about electrolyte imbalances, Kavouras says, and replenishing electrolytes doesn't mean one has to turn to electrolyte supplements or drinks.
After a long, intense workout, you can go home and have a regular dinner and drink something and replenish those electrolytes, Kavouras says.
"If you drink just a glass of milk, you get approximately as much sodium as you get from a glass of Gatorade," he says.
Racing without electrolytes
Instead of reaching for a Gatorade during a long race, Lipman suggests eating potato chips as a way to balance salt levels.
“Drink when you're thirsty and eat salty snacks,” he suggests. “If you're feeling nauseous and dizzy and fatigued and feeling bloated and you're not thirsty, you might be over-hydrated and have salt levels are too low.”
Still, Kavouras cautions "drink to thirst," isn't an effective strategy to optimize performance.
"We have beaten the dead horse for years," Kavouras says. "Some people like to give these guidelines, 'Drink whenever you're thirsty,' which probably works for most people. But it's not the optimal way if your outcome is the best performance or if you're an elite athlete."
Drinking whenever you're thirsty can actually cause you to under or over-drink, Kavouras says. He suggests creating an individualized hydration protocol: Learn how much you sweat and how much you need to drink to feel good, energized and not overloaded.
On this point, Lipman and Kavouras agree. Everyone is different, and staying adequately hydrated is critical for performing athletically — and staying healthy.
"It might be a good idea to develop a taste for water," Kavouras says. "Water it doesn't come with anything — no calories, no sugar, no nothing. It comes full of benefits."
Lipman says that the take-home message is a classic one: Everything needs to be done in moderation. Athletes should listen to their body, respond accordingly — and maybe skip the purchased electrolytes. Ultimately, it could be a good idea to drink an electrolyte drink simply as a way to stay hydrated or get an energy boost — but these types of products likely won't spark any athletic advantages.
"When you're drinking, realize that that the sports drink is not a panacea," Lipman says. "It's not going to be protective. But it might minimize your performance degradation. So just drink to moderation.”
Objective: Analyze the effect of sodium supplementation, hydration, and climate on dysnatremia in ultramarathon runners.
Design: Prospective observational study.
Setting: The 2017 80km (50 mile) stage of the 250km (150 mile) 6-stage RacingThePlanet® ultramarathon in 2017 Chilean, Patagonian, and 2018 Namibian, Mongolian, and Chilean deserts.
Participants: Two-hundred sixty-six runners were enrolled, with post-race sodium on 174 (74%), and 164 (62%) participants with both blood sample and post-race questionnaire. The mean age was of 42.2 years (+ 9) with 61 (23%) females.
Intervention: Weight change and finish line serum sodium levels were gathered. Main outcome measures: Incidence of dysnatremia by sodium ingestion and climate.
Results: Eleven (6.3%) of runners developed EAH and 30 (17.2%) developed hypernatremia. Neither total ingested sodium nor rate of sodium ingestion were correlated with dysnatremia. Neither differences in drinking behaviors (p = 0.72), type of supplement (p=0.66), or amount of total ingested sodium (p=0.08) were associated with dysnatremia. Hypernatremic runners were more often dehydrated [8 (28%), -4.7 kg (+ 9.8)] than EAH [4 (14%), -1.1 kg (+ 3.8)] (p < 0.01); EAH runners were more frequently overhydrated [6, 967%)] than hypernatremic runners (1, 11%) (p < 0.01). There were 98 (56%) runners from hot races, with hypernatremic OR = 8.7 (95% CI 2.9 to 39.5) and EAH OR = 3.5 (95% CI 0.9 to 25.9).
Conclusions: Sodium supplementation was not responsible for development of EAH or hypernatremia in ultramarathon runners. Hot conditions increased the odds of EAH hypernatremia by 3 – 9 times greater than cold races.