Hydration for runners, best practices

Why should you be sure to hydrate well during your running outings?

Every runner knows that hydration is crucial to their activity: water is crucial to many of your body’s functions, and is a vital element of cellular exchange. In other words, your cells depend on water to stay healthy.

Did you know ?

We’re made up of 60% water, which we can divide into metabolic water (created by enzymatic reactions in the body)—water that comes from both food and liquid refreshment.

This water allows the transport of nutrients and oxygen to cells, the elimination of waste (i.e. metabolites), in addition to playing a role in digestion and regulating the body’s temperature.

Your hydration level depends on various factors

• The climate
• The intensity of your effort
• The type of clothes you’re wearing
• Your intrinsic athletic ability

Dehydration: consequences on your health and performance

Dehydration disturbs numerous physiological attributes:

  • • Alteration of aerobic and anaerobic performance: 1% of your body weight leads to a performance loss of 10%
    • Increase of digestive, gastric, and intestinal issues
    • An increased risk of heat stroke, causing hemoconcentration
    • An increased risk of injury, especially tendon damage
    • A decrease in systolic ejection volume and a resulting increase in cardiac rhythm
    • An increased risk of kidney stones over time

In practice, how should you hydrate ?

Daily :

  • • Drink at least 1.5 liters of water regularly throughout the day
    • Avoid drinking too much at one time: 1 to 2 glasses maximum to optimize digestion quality
    • Favor tea over coffee, as it’s less of a diuretic and is richer in antioxidants
    • Limit “drainers” that can have a strong diuretic effect, not compatible with periods of intense training
    • Vary your choice of water as much as possible, prioritizing spring or mineral water

While exercising, it’s difficult to offset dehydration. The goal, therefore, is to minimize and delay its occurrence as much as possible.


To do so, you should: 

  • • Drink as soon as you start exercising
    • Regularly drink small quantities: drinking in small amounts promotes the emptying of the stomach and the resulting comfort level (one or two gulps every 7 to 10 mins)
    • Test your hydration strategy during training, under running conditions, and several times over

What’s the point of recovery drinks?

Recovery re-hydration has multiple goals:

  • • Restoring the hydroelectrolytic balance
    • Draining metabolites (wastes) that are produced during the effort of running
    • Neutralizing acidity

In practice:

  • • Drink water containing sodium bicarbonate (Vichy®, Badoit®, St-Yorre®), ideally combined with a recovery drink rich in minerals (sodium, potassium, and especially magnesium). Water containing sodium bicarbonate helps to neutralize the acids generated while exercising.
    • Eat easy-to-digest fruits and vegetables: very ripe bananas, dried fruits, applesauce, vegetable juice, cooked vegetables, and salted foods (salted oleaginous fruits, for example).

Written by:

Guillaume Boitel – Doctor in Physiology, Bio-mechanics, and Sports Sciences

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