One of my old trainers told me during a session that he drinks 1.5 litres of water during the workout. This was a bit of a shock, and it’s not necessary to hit these numbers. Instead, consider all the factors determining your hydration: the weather, the type of workout you’re doing (sports or heavy lifting, plyometrics etc), the timing of day, and how much you sweat. Most research suggests that you can drink between 400ml to 1 litre of fluids in a 60-minute workout. Anything less than that could be problematic. “The potential for dehydration to impair cognition appears small and related primarily to distraction or discomfort. The impact of dehydration on any particular sport skill or task is therefore likely dependent upon the makeup of the task itself (e.g., endurance, strength, cognitive, and motor skill),” says a research paper titled, Dehydration: physiology, assessment, and performance effects published by the National Library of Medicine.
