In April, the president of PepsiCo Beverages U.S. stood behind a sentence that most people would read past without blinking. Gatorade, he said, has spent sixty years studying hydration and turned that work into "products proven to hydrate better than water alone." Five weeks later, a putative class action landed in the Southern District of New York arguing that the sentence is unsupported for the way most people actually drink the stuff. And this month, a peer-reviewed study built specifically to separate the water in a sports drink from the salt in it produced a result that neither side is likely to frame on the wall.
The water won.
The short version
If you are training hard in the heat for something under about three hours, the thing protecting your performance is how much fluid you replace, not how much sodium rides along with it. Sodium earns its keep later, in the hours after you stop, by helping you hold onto what you drink. Those are two different jobs, and the marketing around electrolyte drinks has spent a decade blurring them into one.
A study designed to settle an argument
Most hydration research has a built-in problem. When you compare a sports drink to plain water, you change two things at once, the fluid and the salt, and then you cannot say which one did the work. A team led by Sam Sage, publishing in the August issue of the European Journal of Applied Physiology, went at it differently. Eleven trained male cyclists, average age 35, rode three hours in a chamber held at 32 degrees Celsius and 50 percent humidity, then hit a time trial. Both trials gave riders a personalized sodium prescription, deliberately calibrated so that blood sodium stayed matched between conditions. The only variable left standing was water: one trial replaced 60 percent of sweat losses, the other 80 percent.
Blood sodium held steady across both, exactly as designed. Core temperature ran lower in the better-hydrated trial from the two-hour mark onward. And the time trial came in about 8 percent faster when riders had drunk more, roughly 1,793 seconds against 1,968. The paper's own conclusion is blunt: fluid replacement during exercise that lets body mass loss pass 2 percent impairs both temperature regulation and cycling performance, and it does so despite no difference in blood sodium.
The funding line is where it gets strange. The study was co-funded by Precision Fuel and Hydration, an electrolyte company, and two of its authors are founders and owners of that company with a declared financial interest. They helped design the study and approved the manuscript. They did not collect the data, analyze it, or write it up, and the paper says so in a competing-interests statement that is worth reading in full. A company that sells sodium paid for a trial that found sodium was not the lever. That does not make the result true, but it is not the direction industry money usually pushes.
The caveats belong in the same breath. Eleven riders, all men, all trained, one temperature. The 8 percent average carried a standard deviation of 10, which is wide. Nobody should read this as settled physiology for a 45-minute lunchtime run in October.
The second finding nobody is talking about
A separate paper in the August 1 Journal of Applied Physiology, from a Loughborough-led group, found something that should bother anyone who spends money on gels. Nine trained cyclists rode 160 minutes taking in 60 grams of glucose per hour, tagged with a carbon isotope so the researchers could track exactly how much of it got burned. Dehydrated by 2.8 percent of body mass, riders oxidized an average of 0.51 grams per minute. Properly hydrated, 0.61. At the sixty-minute mark the gap was wider still, 0.33 against 0.49.
Read that as a consumer, not a physiologist. You paid for the carbohydrate. You carried it. You choked it down mid-effort. And under-drinking quietly shaved something like a sixth off your ability to use it. The authors' recommendation is unglamorous and correct: adequate fluid intake should be considered part of any carbohydrate absorption plan, not a separate box to tick.
What sodium is actually for
None of this makes electrolytes decorative, and the honest counterweight arrived in June. Akira Takamata's group at Nara Women's University ran fifteen young adults through a two-by-two design, carbonation crossed with electrolytes, drinking freely for three hours after losing about 1 percent of body weight. Plain water won on volume, people simply drank more of it. Carbonated water was the clear loser, suppressing intake and leaving people less recovered at the end. But the electrolyte arms, at a modest 19 milliequivalents of sodium per liter, held onto more of what went in, and electrolytes largely rescued the carbonation penalty.
That study was funded by ITO EN, and seven of its authors are ITO EN employees, which the paper discloses alongside a note that the primary statistics were run independently by the academic authors. Take it with the same grain of salt you take the other one.
Put the two together and you get the cleanest teaching point in this whole area, and it is one we have made here before in a piece on electrolytes versus plain water. During the session, water. After it, sodium retention. A drink that is heavy on salt and light on volume is solving the second problem while you still have the first one.
What the label is claiming
Gatorade's April announcement introduced what it calls an Advanced Hydration System, a portfolio sorted by whether a product hydrates "Better," "Faster," or "Longer" than water. It launched Gatorlyte Longer Lasting, described as the brand's highest-electrolyte ready-to-drink offering, with a limited release later this year and national rollout in 2027. It also led with a headline number: 150 million Americans feel dehydrated. That figure carries an asterisk defined only as "mild to moderate dehydration," and the release does not disclose the survey, the sample, or the method behind it. The same release invokes sixty years of research without citing a single study.
Damian Browne, PepsiCo Beverages U.S. senior vice president of research and development, framed the everyday case this way: "One of the biggest misconceptions about hydration is that it only matters for elite athletes or extreme situations. In reality, mild to moderate dehydration can build gradually across the day for most people, often without realizing it, and thirst is not always a reliable signal." That is a defensible statement about physiology. It is also, precisely, the usage pattern the litigation says the superiority claim was never tested against.
Two lawsuits, one theory
The federal case is Leam v. PepsiCo, Inc., No. 1:26-cv-04258, filed in the Southern District of New York on May 21, 2026, with Blake Hunter Yagman of Yagman PLLC as counsel. It runs on New York General Business Law sections 349 and 350 alongside California and Illinois consumer statutes. The complaint accuses the company of "health-washing" its products to justify a higher price, and it makes a narrower argument than the headlines suggest: that replacing electrolytes "does not equal better hydration unless the consumer drinks Gatorade in conjunction with physical exercise." It also alleges that regular Gatorade carries 48 grams of added sugar in a 28-ounce bottle, and that citric acid, the third listed ingredient on the Lower Sugar line, is more than 99 percent synthetically manufactured in commercial practice, which sits awkwardly beside a "no artificial flavors, sweeteners, or colors" label.
A second, separate case, Kononenko v. PepsiCo, No. 26CV493594, was filed a week earlier in Santa Clara County Superior Court on the citric acid theory alone.
Both were pending as of the most recent public reporting in June, and PepsiCo has not publicly responded to the allegations. Nothing has moved on the docket that we could verify, so treat this as a live claim, not a finding. Separately, the company has been removing artificial colors across the Gatorade portfolio, with three flavors reformulating this year and the full lineup targeted by the end of 2027. That is context, not a concession, and it should not be read as one.
The precedent Gatorade helped create
In February 2024, the National Advertising Division took up a challenge to BodyArmor's claim that its Flash I.V. product was "The Rehydration Champ." The challenger was Stokely-Van Camp, the Gatorade entity. NAD found the claim unsupported, and its reasoning was that the quantity of electrolytes in a sports drink is not, by itself, substantiation for a claim of superior rehydration. Flash I.V. did contain more electrolytes than Gatorlyte. Without comparative performance testing in the record, that did not matter.
Gatorade asked a self-regulatory body to hold a competitor to a rule about sports drink marketing claims. Two years later, plaintiffs are pointing that rule back across the table.
What to do with this on Saturday morning
Weigh yourself before and after a hard session in the heat, once, in similar conditions to what you normally do. Every kilogram you are down is roughly a liter you did not replace, and that number is yours alone, which is the whole argument for a personalized sweat rate rather than a generic bottle count. If that number is landing past 2 percent of your body weight, you have found your ceiling, and adding salt to a bottle you are not finishing will not raise it. Fix the volume first.
Then, and only then, worry about what is in the bottle. For anything under about ninety minutes in mild conditions, plain water is not a compromise. For long, hot, salty efforts, or for the recovery window afterward, sodium has a real and measurable job. Buy it for that job. A sensible hydration strategy for exercise in the heat is mostly a logistics problem, where the bottles are and whether you will actually drink them, and only secondarily a chemistry problem.
And when a label promises it will hydrate better than water, the fair question is the same one NAD asked in 2024, and the one a federal judge may get to ask next year. Better at what, measured how, against whom?
