Athletes sometimes feel as though they are “hitting a wall” during prolonged efforts. Among the possible causes, hydration may play a role, regardless of the sport. Here are some tips to hydrate properly and ensure optimal performance and recovery.
In brief
- Start your effort well hydrated: lemonade-colored urine is a good sign.
- During exercise, drink small amounts frequently, generally 400 to 800 ml per hour depending on the heat and how much you sweat.
- Water + carbohydrates + sodium: the winning trio for efforts lasting more than an hour.
- The goal: avoid losing more than 2% of your body weight through sweat during exercise.
- Coffee consumed in moderation does not dehydrate you.
1. Start well hydrated
Optimal hydration before exercise helps limit increases in heart rate and body temperature. Being well hydrated before, during and after exercise is therefore essential! In practice, drink approximately 5 to 7 ml per kg of body weight (that is, 300 to 450 ml for a 60 kg person) about 4 hours before exercise.
2. The winning trio
Water + carbohydrates + sodium is the winning trio for more effective hydration than water alone during prolonged efforts. Carbohydrates provide energy, while sodium helps the body retain water and replaces the sodium lost in sweat. How much should you consume? Aim for 30 to 60 g of carbohydrates per hour and approximately 50 to 70 mg of sodium per 100 ml of beverage.
3. Small amounts
The strategy of small sips, short intervals limits the risk of gastrointestinal discomfort while promoting better hydration. Drinking 150 to 250 ml every 15 to 20 minutes is a good example, although this varies from one athlete to another depending on the heat, intensity and sweat rate.
4. Just water?
Water and sports drinks remain the best choices during exercise. What about coffee or tea? Good news: consumed in moderation, they hydrate almost as well as water. One study showed that 4 cups of coffee per day did not cause dehydration in habitual coffee drinkers. Energy drinks, on the other hand, are often very high in sugar and caffeine: consume them judiciously, according to your digestive tolerance.
5. Drink your carbohydrates
It is necessary to consume carbohydrates during prolonged efforts to replenish your energy stores. Why not drink them and kill two birds with one stone? Sports drinks or carbohydrate gels can be a great option. You can also try Zenit powdered electrolytes, which contain no sugar, and add a little maple syrup or juice for energy.
6. Weigh yourself to hydrate better
The simplest way to determine your needs is to weigh yourself before and after a typical workout. Each kilogram lost corresponds to approximately 1 litre of unreplaced sweat. The goal is not to lose more than 2% of your body weight during exercise. After exercise, drink approximately 1.25 to 1.5 litres for every kilogram lost, in several servings. For a personalized hydration plan, consult a sports nutritionist.
More than just “hitting a wall”
The effects of dehydration should not be underestimated. Nausea, palpitations and headaches can occur with moderate dehydration. More severe dehydration can cause extreme fatigue, dizziness and confusion. In a performance setting, this can even put the athlete’s health at risk. Conversely, drinking much more than you lose (especially only water during very long events) can dangerously lower blood sodium levels (exercise-associated hyponatremia): drink according to your thirst, not excessively.
Psst! How can you tell whether you are well hydrated? Look at the colour of your urine! Aim for a lemonade-like colour. If it is darker, you need to drink more.
Frequently asked questions
How much water should I drink during sports?
Generally, 400 to 800 ml per hour, in small sips every 15 to 20 minutes. Your needs increase with heat, intensity and sweating.
Should I take electrolytes when I exercise?
For an effort lasting less than an hour, water is enough. For a longer effort, in hot conditions or with heavy sweating, a beverage containing sodium helps you hydrate more effectively.
Does coffee dehydrate you?
No, not when consumed in moderation. In habitual coffee drinkers, approximately 4 cups per day hydrate almost as well as water.
Can you drink too much during exercise?
Yes. Drinking much more water than you lose through sweat, especially during events lasting more than 4 hours, can dilute the sodium in your blood: this is exercise-associated hyponatremia. Signs include nausea, headaches, swollen hands and, in severe cases, confusion. To avoid it, drink according to your thirst, do not gain weight during exercise and add sodium during long efforts.
How can I tell if I am dehydrated?
Dark urine, thirst, headaches or losing more than 2% of your body weight during exercise are signs of dehydration. Lemonade-coloured urine indicates good hydration.
This article was written by the registered dietitians and nutritionists at Équipe Nutrition. Their team of health professionals offers nutrition counselling services, virtually or in person, throughout Canada. Discover their approach combining health, performance and the pleasure of eating on their KoalaPro portal or by booking an appointment with a sports nutritionist and dietitian.
Reviewed and updated in October 2026 by Danielle Dubois, nutritionist.
References
- American College of Sports Medicine; Sawka MN, Burke LM, Eichner ER, et al. American College of Sports Medicine position stand. Exercise and fluid replacement. Med Sci Sports Exerc. 2007;39(2):377-390. PMID: 17277604
- Thomas DT, Erdman KA, Burke LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. Med Sci Sports Exerc. 2016;48(3):543-568. PMID: 26891166
- Killer SC, Blannin AK, Jeukendrup AE. No evidence of dehydration with moderate daily coffee intake: a counterbalanced cross-over study in a free-living population. PLoS One. 2014;9(1):e84154. PMC3886980
- Hew-Butler T, Rosner MH, Fowkes-Godek S, et al. Statement of the 3rd International Exercise-Associated Hyponatremia Consensus Development Conference, Carlsbad, California, 2015. Br J Sports Med. 2015;49(22):1432-1446. bjsm.bmj.com