Did you know the human body at rest produces 100W of electricity? Shocking jokes aside, electrolytes – substances like sodium and potassium that conduct electricity when dissolved in water – enable homeostasis, hydration, muscle contraction and other critical functions. Electrolyte levels change for various reasons, a big one being decrease due to fluid loss, e.g. sweat during normal exertion or diarrhea due to sickness. This can lead to any number of symptoms from cramps to convulsions. Aside from suffering the symptoms of imbalance you can also see your electrolyte levels in the results of blood tests, e.g. a comprehensive metabolic panel or CMP.
A few things to keep in mind: first, it's important to know you can overdo electrolytes as well, and if you have any doubts consult your doctor. Also, keep an eye on those sports/energy drinks: they love to advertise their electrolyte levels, but they frequently pollute it with high levels of sugar, caffeine, and other crap that pumps up the calories. Not that carbs are bad, especially for endurance activities, but take the time to figure out your individual carbohydrate needs and your own fluid replacement plan. On a very rough average, you can expect to lose about 800mg of sodium, 195mg of potassium, 20mg of calcium and 10mg of magnesium per hour. Finally, you can make your own electrolyte drink by combining 32oz water with 1/4 teaspoon salt, 1/4 cup lemon juice (fresh squeezed lemons and limes are a great source of natural electrolytes), and sugar to taste. Replace one cup of water with coconut water and/or juice if you want.
If you're on the go and need something easy to add to water, electrolyte supplement powders, tablets, chews, and gels are available. We're not going to go into taste, because that's pretty personal and you can always find people who like or dislike the taste or consistency of a particular product. We've used all of the products in the table we provide above, and besides taste you want to look at cost, format (powder, gel, tablet, or chewable), and electrolyte balance. Also keep in mind a lot of these vendors offer different formulations of their products for endurance, recovery, energy, vitamins, etc., but here we concentrate on the basic formulations.
So on to the actual advice; as always it's free and it comes with a money-back guarantee! If you're looking for the big electrolyte hit for less money, it's hard to beat the powder, which in our example also includes BCAAs. You have to pre-mix it of course, so while powder is great for home use, if it's convenience you're after, gels and tablets are the ticket. Gu gels and SaltStick FastChews are nutritionally comparable except for format and carbs, so if you want the carbs go for Gu, which are spendy but hard to beat for chugging on the move and also include BCAAs. If not SaltSticks are great, if light on the electrolytes – and chewable, in case you're in between water stations, and although less costly than Gu they are a bit more than powder and Nuun, and you can use a single tablet for kids or a small boost for adults. Finally, for an in-between hit of electrolytes, Nuun is a great option, easily portable and added to whatever you're drinking at the moment; we like Nuun tablets for hiking to add to our liter bottles of filtered water.