How important is it to hydrate yourself ?

July 15, 2014 ,

Hydration is a matter of utmost importance for sportsmen and is part of every sport in varying degrees, be it at the recreational or competitive level. Indeed, it is a given that no matter how competitive or not a sport may be, hydration will always play an important role in it.

The fluid needs of sportsmen vary greatly depending on the duration and intensity of the activity as well as the environmental conditions prevailing at the time. It is essential for the sportsman to be well equipped in order to control and optimize his fluid status so that it does not hinder his performance in any way.
More specifically, here are the different variables that affect the optimal amount of fluids to be consumed:

  • Exercise intensity
  • Exercise duration
  • Ambient temperature
  • Existing levels of hydration before exercise
  • Overall physical fitness
  • Individual characteristics (weight, sex, height…)


aerobic_exerciseObviously, it is possible that the water needs of several recreational sportsmen are relatively low. However, it is not uncommon to see some of them getting involved in a rather competitive way. In such a context, we can justify the importance of hydration. Most so-called “aerobic” activities such as long distance running and long bicycle rides are more likely to be adversely affected than interval and/or strength sports.


A body water deficit of about 2% of the sportsman’s weight generally leads to an inevitable drop in performance. Though such a drop is hard to quantify, a 10 to 20% reduction in performance is generally estimated. Furthermore, it is found to be regularly escalated by the additional stress of heat from the surroundings imposed on the body. Severe dehydration can cause nausea, confusion, weakness, etc. A considerable loss of body water inevitably leads to a reduction in our blood volume. Dehydration not only makes the body incapable of maintaining its temperature, it also overloads the cardiovascular system.


So as not to make matters too complicated, here are two simple elements that allow us to detect dehydration. First is the color of urine. The darker it is, the greater the extent of dehydration. The feeling of thirst is a qualitative tool and although subjective, it will help us in a state of rest to assess whether our body is entering a process of dehydration. However, during physical activity, you’ll only experience dehydration after a 2% loss of your body mass in water, by which time it will be too late to counteract it…but you should still drink to mitigate its adverse effect!



The American College of Sports Medicine indicates that approximately 150 to 300 ml of liquid per hour may be consumed during exercise. However, these are only general guidelines. A few studies have shown that participants whose fluid intake exceeded one litre per hour ran the risk of gastro-intestinal discomforts despite profuse sweating.

The following simple strategy can be applied in order to mitigate the problems related to hydration:

1. Drink 500 ml in the two hours prior to the exercise, then 125-250 ml a few minutes before the exercise.

2. Bring 700 ml of liquid in your bottle for a one-hour activity. Adjust the amount of liquid with the exercise duration by maintaining the same proportions

3. For every kilo lost after training, drink 1 liter of liquid or even a little bit more to optimize your fluid status. Tip: add a salt pinch to increase fluid retention in the body.


Shirreffs SM, Merson SJ, Fraser SM, et al. The effects of fluid restriction on hydration status and subjective feelings in man. Br J Nutr. 2004;91:951–958.

Cheuvront SN, Sawka MN. Hydration assessment of athletes. Gatorade Sports Science Institute: Sport Sci Exch. 2005;18:1–5.

Shirreffs SM, Taylor AJ, Leiper JB, et al. Post-exercise rehydration in man: effects of volume consumed and drink sodium content. Med Sci Sports Exerc. 1996;28:1260–1271.

Armstrong LE, Maresh CM, Castellani JW, et al. Urinary indices of hydration status. Int J Sport Nutr. 1994;4:265–279.

Cian C, Koulmann N, Barraud PA, et al. Influence of variations in body hydration on cognitive function: effect of hyperhydration, heat stress, and exercise-induced dehydration. J Psychophysiol. 2000;14:29–36.

Coyle EF. Fluid and fuel intake during exercise. J Sports Sci. 2004;22:39–55.

Sawka MN, Burke LM, Eichner ER, et al. American College of Sports Medicine position stand. Exercise and fluid replacement. Med Sci Sports Exerc.


Steven Couture
As the founder of and a trainer in nutrition at, Steven is a renowned sports nutritionist. Being recognized for his numerous talents and contributions in sports, Steven serves as a nutritionist for many athletes. He also helps with weight management.

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