Should You Electrolyte Load Before Exercise?

Exercise is hard.

I know, I know. News flash! But stay with me here. Exercise is hard and therefore it depletes the body’s resources. With this in mind, it only makes sense to jump into your race or training session with all of your nutrients—including the carbohydrates you burn and the water and electrolytes you sweat—topped off, right?

The first two are no problem. Carb loading is as easy as a few well-placed bowls of fettuccini and a strategically timed banana. And hyper-hydrating is as easy as, well, drinking water. But what about electrolytes? Will preloading these minerals before an intense physical effort give you an edge? The answer is a resounding and unqualified “maybe.” But to understand why, you first have to understand what you’re dealing with.

What Are Electrolytes?

Sodium, magnesium, potassium, calcium, chloride, phosphate, bicarbonate, and sulfate are the major electrolytes found in the human body. Like all electrolytes, they are minerals and dissolve in water, but by far their greatest attribute—at least as far as organic life is concerned—is that they can carry an electric charge. It’s that ability that allows them to play pivotal roles in a handful of bodily processes, including nerve function, neuron communication, blood pressure regulation, muscle contraction, and the transfer of nutrients into and out of cells.

As you can imagine, the efficiency of such processes has a huge impact on athletic performance, and many athletes try to stack the odds in their favor by preloading electrolytes before important races and tough training sessions. Their primary goals are to prevent cramps and delay fatigue, and a number of supplement companies are only too happy to support their efforts. But the question is, are those efforts worth the effort?

Cramping Your Style

Anyone who’s ever brought up cramping and electrolyte loading in the peloton knows that the anecdotal evidence is strong (and occasionally obnoxious), but the science? Not so much. The problem is that science is not 100 percent certain that electrolyte loss is a significant cause of exercise-induced muscle cramps. Even if it plays a part, so does dehydration, so you’re likely better off getting your pre-event electrolytes in liquid form as opposed to popping pills, as many athletes are wont to do. And even then, there are no guarantees. In a study published in the Journal of Athletic Training, 69 percent of participants experienced exercise induced muscle cramps even when they were well hydrated and chock full of electrolytes.

Another popular theory about cramps is that they result from neuromuscular fatigue. In short, your muscles and nerves not only get tired and stop cooperating, but also throw a fit. But the reality is that cramps probably result from a combination of all three factors (low electrolyte levels, dehydration, and neuromuscular fatigue), and possibly more, so focusing solely on electrolytes likely won’t tip the odds of avoiding them in your favor. Indeed, from a purely Vulcan perspective, as long as you eat a healthy, balanced diet and replenish electrolytes as you lose them during intense exercise, you’ll probably do just fine. But if you swear by preloading, I’m not going to get in your way. I’m all about pre-event rituals (if I don’t have a rice and bean burrito the day before an event, there’s really no point in me racing). Plus, there’s no harm in topping off your electrolyte tank before you start, which is why you’ll find electrolytes in Beachbody Performance Energize.

Will Sodium Get You to the Podium?

Another potential reason to electrolyte load is improved sports performance. In this case, sodium and chloride are the key players. People lose between 460mg to 1840mg of sodium (about 20 to 77 percent of the RDA for adults) and 710mg to 2130mg of chloride (31 to 93 percent of the RDA for adults) in a liter of sweat. Compare that to just 160mg to 320mg of potassium, 0mg to 40mg of calcium, and less than 5mg of magnesium in that same liter, and you can understand why the emphasis is on sodium and chloride, or simply NACL since they are often chemically paired (think: table salt).

With that in mind, a couple of studies suggest that taking a big sodium hit before a long endurance event can work to your advantage, performance-wise. The first study (published in Medicine & Science in Sports & Exercise) had a group of trained runners ingest a high-sodium drink (10ml of fluid and about 38mg of sodium per kg of bodyweight) in the 105 minutes leading up to a workout. They then ran to exhaustion—a point that took them considerably longer to reach than a second group of runners who drank a placebo. A study in the International Journal of Sports Medicine produced similar results with cyclists who were fed an electrolyte cocktail before a time trial.

Part of the strategy here is based on something called hypervolemia, or “fluid overload,” where the liquid portion of your blood is elevated. Normally, this is something you want to avoid—and if you’re sodium sensitive or have sodium-related issues, talk to your doctor before trying it—but the assumption is that you’ll sweat it all out while exercising. Of course, you should be hydrating and replenishing electrolytes during your event as well, but hypervolemia may give you a head start, especially if you’re going to be sweatin’ it up under a baking sun.

If you’re thinking about preloading with salt pills, I don’t recommend it. Salt and water work hand-in-hand in the body, and sodium plays a huge role in fluid regulation. While hyponatremia (low sodium levels) can happen during endurance events, dehydration is much more common. What’s more, research shows that going into an event hyper-hydrated, regardless of sodium status, benefits peak power output and extends time to exhaustion. In other words, there’s really no reason not to include fluids in your preload protocol.

There are reasons, however, why you shouldn’t preload with the other electrolytes, particularly magnesium, as ingesting excessive amounts of it can very quickly lead to gastrointestinal issues and panicked porta-potty searches. But beyond these general guidelines, there are really no hard-and-fast rules for electrolyte loading, which might be an indication that it doesn’t need to be a focal point of your nutritional strategy. You’re much better off eating a healthy diet, drinking plenty of water throughout the day, and hydrating strategically during your event or workout with a product like Beachbody Performance Hydrate.

That said, if you have a preload strategy that works for you, there’s no need to ditch it. You take your salt pills, I’ll have my bean and rice burrito, and we’ll meet on the race course.