Water impacts blood volume, temperature control, nutrient transport, and recovery. Underhydration increases fatigue, slows pace, and lengthens recovery time.
How much?
A simple starting point: ~35 ml per kg body weight per day. Use the Hydration Calculator for a personalized liters/day target.
Practical rules
- Hydrate early and consistently through the day.
- Add electrolytes for long/hot sessions.
- Weigh pre/post workout; 1 kg lost ≈ 1 L water.