Performance Hydration

Image: Stuart Miles /

Image: Stuart Miles /

Balancing fluid in athletes’ daily diet is crucial to their performance. Water makes up 60% to 75% of the body. Drinking too little water and losing hefty amounts of it through sweating can inhibit an athlete’s ability to exercise and perform at their optimal level. Therefore, on daily basis, athletes are encouraged to monitor their hydration status in order to improve their performance and win in their competitions.


Did you know?

For every 1% of body weight loss due to dehydration (a state of having insufficient amount of water :

  • Heart rate increases by 5-8 beats per minute?
  • Cardiac output decline significantly?
  • Core body temperature increases by 0.2°C – 0.3°C

Hydration is important. It helps to:

  • Delay physical and mental fatigue.
  • Keep the mood stable and motivation intact.
  • Avoid injuries and muscle cramps.
  • Satisfy thirst and promote quick recovery from training and competition.

Hydration Strategies for the athlete and you

It’s hard to make a one-size-fits-all recommendation as fluid needs vary greatly from person to person.

Here is an easy-to-follow guideline:

  1. Pre-exercise Hydration
    Start exercising when the body is in water balance (euhydrated state). Good hydration habit during the day would be consuming water and foods containing water (fruits and vegetables).

  2. Hydration During Exercise
    The goal for hydration during exercise is to prevent excessive dehydration (defined as more than 2 percent body weight loss from water deficit) as it can negatively impact your performance.

  3. Post-exercise Hydration
    After exercise, the goal is to fully replenish any fluid and electrolyte deficit back to normal before the next workout. The aggressiveness of rehydration depends on how quickly you need to recover before the next exercise session.

Take-home message

For the athlete, hydration strategies during training and competition are highly individualised in which it should be customised to the athlete and the sport. Thus if you are a serious athlete, do make an appointment with a sports dietitian to develop a personalised hydration plan that meets your fluid needs.


  1. American College of Sports Medicine (ACSM). 2007. ACSM position stand on exercise and fluid replacement. Med Sci Sports Exerc 39(2):377-390.
  2. Sawka, M.N., Montain, S.J. and Latzka, W.A. (2001). Hydration effects on thermoregulation and performance in the heat. Comparative Biochemistry and Physiology, 128, 679-690.
  3. Sports, Cardiovascular, and Wellness Nutrition (SCAN)
  4. The International Olympic Committee Consensus on Sports Nutrition