Dehydration due to coffee consumption? Another myth!

No, But what a lot of talk there is about coffee! We've been fighting for years to debunk the famous myth that coffee must be kept in the fridge or freezer (yes, you read that right, it's a myth too), that's how much we've been doing! Here's another one we're volunteering to debunk!

A recent meta-analysis (a statistical approach combining various research and results from independent studies focusing on a hypothesis X), encompassing some 16 studies, evaluated caffeine-induced diuresis (urine output) in adults at rest and during physical activity. The average caffeine dose ingested was 300 mg (equivalent to two small filter coffees or six short espressos). The study demonstrated that caffeine ingestion increased the average urine volume by 109 ml, or 16.0%, compared to the unexposed group, but the effect varied considerably across studies. Exercise reduced this loss by more than 80%, and women were significantly less sensitive to the diuretic effects of caffeine than men. The authors concluded that caffeine has only a minor effect on diuresis and that this effect is negated by exercise. Therefore, concerns about unwanted fluid loss after caffeine consumption are unfounded, especially during physical activity. Furthermore, the myth surrounding the rumor that caffeine enhances athletic performance is true!

Caffeine is one of the most widely used ergogenic substances (used to increase and support muscle capacity during endurance events or activities). Indeed, caffeine intake has demonstrated positive effects on performance in endurance sports of all kinds, as it increases the time before the onset of fatigue or exhaustion.

Caffeine is also effective in team sports because it increases concentration. However, during short, intense physical exercise, such as sprinting, its effects are more variable and difficult to assess. The effects of caffeine depend on the dose ingested, but remain the same for both sexes.

However, we regret to inform you that alcohol, unlike alcohol, is dehydrating, and this is no myth… Fortunately, coffee quickly revives those who have overindulged. Hooray for coffee, that faithful ally!

- Valérie Verhoef

Source :

• Institute for Nutraceutical and Functional Food Research, 2014.
• Daignault Gélinas M., Lavallée Côté L., Online clinical nutrition manual, Professional Order of Dietitians of Quebec, 2003-2007.