Electrolytes: what are they for?

It’s the time of great heat and sweat! Speaking of sweat and if you know anything about sports drinks, you’ve probably heard the word ELECTROLYTES.

What is an electrolyte?

Electrolytes are chemical compounds that, once in water, allow current to flow through our body.  Their balance is important for the proper functioning of cells, the maintenance of pH and nerve transmissions through different fluids and tissues. The best known are sodium, potassium, magnesium and calcium. In sweat, the concentration of sodium is most important. Losses of potassium and calcium are less and those of magnesium are rather minimal.

Sodium and potassium

Sodium and potassium play a role in muscle contraction and nerve transmissions while working together to maintain body fluid balance. If you have salt residue on your sweaters, shorts, cap and you sweat profusely (often white in color), it is important to replace this loss when exercising for more than 90 minutes. You can add 300 to 500 mg of sodium per liter of liquid. People who sweat profusely will even go up to 700 mg per liter (a pinch of salt is usually enough!).

Potassium, for its part, hides inside the cells and its concentration in sweat is much lower.  Too little consumption of vegetables and fruits is the cause of the potassium deficiency observed in many Canadians. So eat a variety of fruits and vegetables such as bananas, vegetable juice, oranges, potatoes, as well as milk and almonds for example.

Salt capsules

But is it necessary to add electrolyte tablets (sodium and potassium) to our favorite sports drink? Adding sodium via electrolyte capsules is generally not necessary, unless the physical activity is very intense and takes place in a hot environment (e.g. a summer day of cycling or at an outside temperature of 30 degrees Celsius). In fact, the daily sodium consumption among Canadians is very high, approximately 3,400 mg/day compared to the average loss of 820 mg of sodium per liter of sweat during physical activity outdoors. In addition, commercial sports drinks contain between 500-700 mg of sodium/liter, which is enough to make up for sodium losses. The addition of other minerals such as magnesium and calcium during physical activity is not necessary due to the minimal loss of these minerals through sweat.

Aside from consuming sports drinks, it is also possible to meet our electrolyte needs with a varied diet.

Source: Nutritional values ​​of some common foods. Health Canada and products.

In conclusion, for activities lasting more than 90 minutes and carried out in a hot environment, the consumption of electrolytes (sodium and potassium) can be beneficial.