H2O: Why Hydration Matters

Water plays a key role in nutrient transport through the blood, temperature regulation, and joint lubrication. Since the body cannot store water like it does fat, we need to hydrate regularly!

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When Should You Drink?

When you're thirsty! Despite marketing that encourages a strict hydration schedule, most people can simply rely on their thirst to know when to drink (Goulet ED). Urine color is also a great hydration indicator: the darker it is, the more water you likely need—simple as that.

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What About Endurance Athletes?

Exercise can alter your thirst mechanism. That’s why, during endurance activities, you shouldn’t wait until you're thirsty to drink. The best approach is to hydrate regularly, in small amounts, based on sweat loss and workout duration.

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How to Calculate Water Loss?

Weigh yourself before and after training. One liter of water equals 2.2 lbs. Don’t forget to include any fluids you consumed during the workout in your calculation!

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What Is Sweat?

Sweat is a fluid secreted by the sweat glands that helps regulate body temperature. As it evaporates, it cools the skin, keeping your body around 37°C.

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What’s in Sweat?

Mainly water, but also minerals, lactate, and urea.

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Are Electrolytes Essential?

It depends on the level of water loss. The longer and hotter the workout, the more electrolytes you lose.

Sweat is hypotonic compared to body fluids, so replenishing water is more important than replacing minerals. If you lose under 6 lbs of water, regular table salt is usually enough to restore your electrolytes.

That said, a small amount of salt in a glucose-based drink helps rehydration during hot-weather endurance training.

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Hot Weather Alert!

With summer in full swing in Quebec, many will head outdoors to stay active. But beware of heat stroke!

Heat stroke happens when the body’s temperature regulation fails—it's a medical emergency and needs immediate care.

Warning signs include:

• Headaches

• Muscle cramps

• Swelling in hands, feet, or ankles

• Heat rash

• Unusual fatigue or exhaustion

• General discomfort

Dehydration symptoms:

• Intense thirst

• Reduced urination

• Dark urine

• Dry skin

• Rapid heartbeat and breathing

Perceived heat (Humidex + temperature) and risk levels: