Factsheet for professionals
- Water makes up about sixty percent of body weight. As every system in the body depends on the availability of fluids, even mild dehydration can impair bodily functions and performance.
- Fluid requirements vary greatly between individuals and can alter with climate and physical activity levels. Recommendations on specific fluid choices also vary between countries.
Coffee, caffeine and fluid balance
- It is commonly reported that drinking caffeinated coffee can lead to dehydration. Recent scientific evidence, however, does not support this commonly held belief.
- Coffee drinking in moderation contributes to our fluid intake and does not lead to dehydration or significant loss of body water1,2.
- Whilst caffeine may have a small diuretic effect, this effect is not strong enough to counter-balance the benefits of fluid intake from coffee drinking. Black coffee contains more than 95% water.
- During exercise, the evidence shows that, not only is moderate caffeine intake beneficial for endurance performance, it does not contribute to body dehydration3,4.
- Advice to abstain from drinking moderate amounts of caffeinated coffee in order to maintain adequate fluid balance is unfounded.