How Many Electrolytes Should I Consume?

We know that electrolytes are critically important to hydration and that hydration is critically important to performance. For this reason, people at all levels of sport trying to maximize their performance should take care to maintain adequate levels of hydration by consuming fluids with electrolytes before, during, and after exercise. Easy enough right? In reality though, this begs other questions: how many electrolytes should I be consuming? And how much is enough? Is there such a thing as too much?

These are deceptively simple questions with somewhat complex answers.

The high-level response is that the average person should consume, at minimum, 400mg of sodium per hour of strenuous exercise. This is a well-established minimum that allows the scientifically average person to replace enough of the sodium that is lost through sweat to stay hydrated and function at peak performance. As for other essential electrolytes--think magnesium, potassium, and calcium--they are much more abundant inside our cells and are lost in sweat at far lower levels than sodium.

In reality though, few people are “scientifically average,” meaning it’s quite possible that 400mg of sodium is nowhere near enough for you.
There are two principal factors that drive the calculus governing how many electrolytes you need per hour of work: 1) how much you sweat and 2) the composition of your sweat. Perspiration rates, or how much you sweat, vary widely from person to person; some people are very efficient sweaters and perspire just enough to moisten their skin, thereby harnessing the benefits of evaporative cooling without losing lots of fluids and dehydrating themselves. Others will soak through a shirt within ten minutes of setting out on a run. The wide range of perspiration rates means that a heavy sweater will have to push much more fluid than an efficient sweater--up to four or five times as much!--to stay hydrated.

However, as we have previously discussed, fluids are only half of the battle. Understanding what you sweat is just as important as determining how much of it you lose during exercise. If you’re a “salty” sweater, you intuitively understand that some people purge sodium at a much higher rate than others during exercise. The flaky, white sweat rings and briny taste left behind by a salty sweater’s perspiration are hallmarks of someone who loses sodium at a far higher rate than the average person. Like perspiration rates, the composition of one’s sweat varies widely, from 400mg to 2 grams or more per quart of sweat, and it’s important to replace a portion of that loss during exercise.

Bringing these two ideas together, to truly answer how many electrolytes you need to consume, you must divine an understanding of the quantity and composition of your sweat during exercise. Interestingly, you can be an efficient sweater but purge electrolytes at a very high rate, or a heavy sweater that conserves electrolytes. Furthermore, while these functions are driven by genetic predisposition, they are not hardwired and unchangeable. They are influenced by heat acclimatization and overall fitness, so the more fit and more heat tolerant you become, the sooner you will sweat, the more widespread your perspiration will be, and the lower the sodium content of your sweat will be as your body holds onto sodium to help protect blood volume.

While understanding this concept is great, how do you put it into action? In other words, how do you determine how much and what you need to replace during exercise?

Dialing It In

This is a two-pronged question that is best answered through a combination of trial-and-error and intuition. The best method for determining how much fluid your body requires during exercise is to periodically weigh yourself before and after your workout. If you are hydrating adequately, you should not lose more than a pound or two; if you’re losing more, that’s a clear indication that you need to drink more. By tying the quantity of fluids you consume to your weight change during exercise, you can dial in exactly how much you should be drinking to keep weight loss--and dehydration--to a minimum. In turn, this will help ensure you are replacing enough of what you lose during exercise so as to not jeopardize your health and overall performance.

In terms of electrolytes, it is best to start with the well-established minimum--400mg of sodium per hour of exercise--and build from there. For Stage, this is somewhere between Level 7 and Level 8 on the dial, but you can take it all the way up or all the way down to key in on exactly the amount of electrolytes that work best for you. As discussed above, if you know you’re a salty sweater, it’s a safe bet you will find your sweet spot is well-above 400mg, while your running mate’s hydration might be well-maintained with nothing more. One note: the risks of consuming too many electrolytes--namely, gastrointestinal distress--are far outweighed by the risks of dehydration, so if you’re going to miss during this period of trial and error, miss high.

As you continue to tweak these two variables--fluid and electrolytes--and get closer to your perfect fit, you will begin to feel the difference. This is where intuition takes over; when you are well-hydrated you will feel it in all aspects of performance, from endurance to strength to speed. It’s akin to the first time you saddled the perfect bike in your local bike shop--you just knew it was the right rig for you.

In other words, this process of trial and error should not be focused solely on getting you to the right number, but to the right feeling.

How to Hydrate.

Finally, like all aspects of training, you will reap more of the benefits of hydration if you approach it methodically. Once you’ve dialed in the right mixture of pure water and electrolytes for your body, it’s important to implement a hydration protocol that prescribes when and how you consume fluids and electrolytes. Following a hydration plan tailored to your specific needs (i.e., for a long run, consuming 4 ounces of water with electrolytes every fifteen minutes) will keep dehydration to a minimum and allow you to work hard and feel good. It’s also important to remember that during strenuous, sweaty exercise, your sense of taste will gradually change and you’ll start to desire saltier beverages, a craving that Stage is perfectly designed to accommodate.