Hydration and Exercise: How Much Water Do You Really Need?

Water is arguably the most overlooked performance enhancer in existence. It costs nothing, is universally available, and yet the vast majority of people training in gyms are chronically under-hydrated. Even a modest level of dehydration — as little as 1 to 2 percent of bodyweight — significantly impairs strength output, reduces endurance capacity, impairs cognitive function, and increases the rate of perceived exertion during exercise.

How Much Water Should You Drink Daily?

General recommendations of 8 glasses per day are too simplistic for active individuals. A more accurate guideline is 35 to 45 millilitres per kilogram of bodyweight as a daily baseline. Add 500 to 750 millilitres per hour of moderate exercise and up to 1 litre per hour for intense sessions. Body size, sweat rate, climate, and intensity all significantly affect individual requirements.

How to Recognise Dehydration

By the time you feel thirsty you are already mildly dehydrated. Monitor urine colour — pale straw yellow indicates good hydration while dark yellow signals you need to drink more. Other signs include headaches, muscle cramps, fatigue, and dizziness. Develop a proactive hydration habit rather than a reactive one.

When to Use Electrolytes

For sessions under 60 minutes plain water is sufficient. For sessions exceeding 60 to 90 minutes — especially in hot conditions — electrolyte replacement becomes important. Sweat contains sodium, potassium, magnesium, and chloride. Consider a low-sugar electrolyte drink for extended training rather than sugar-heavy commercial sports drinks.