Electrolytes are made up of four electrically charged minerals: sodium, potassium, magnesium and calcium—which we lose through sweating. For endurance runners, excessive loss of electrolytes, primarily sodium, along with inadequate hydration could lead to muscle cramping—it’s the body’s first indication, along with salt streaks, that you’re low on these essential minerals.

“Electrolytes are essential for chemical reactions, muscle contraction and transport of fluid into the blood and cells to maintain  equilibrium of fluid balance in the body,” says Liz Broad, a USOC senior sports dietitian. “The amount of electrolytes an individual loses during exercise depends on their sweat rate and a range of other factors.”

Broad adds that most people don’t need to replenish their electrolytes if they’re working out for less than an hour. Otherwise it’s recommended to drink 500 to 750ml of water with 200 to 500mg of electrolytes per hour during exercise, especially in hot conditions and if you’re a particularly aggressive sweater. For this summer’s peak temps when you’re sweating buckets, drinking only water might not cut it, and these electrolyte supplements will do more than just quench your thirst.

Photos: Oliver Baker

Herbalife 24 CR7 Drive, $32 for 29-ounce container
Tailwind Endurance Fuel, $16 for pack of 7 sticks
Glukos Energy Gel, $24 for case of 12
Nuun Energy, $7 for a single tube of 10 tablets
GQ-6 Flooid, $40 for 33-ounce container
Clif Hydration Electrolyte Drink Mix, $20 per 15.5-ounce pouch