Spanish health experts urge two liters of water daily to sustain performance in heat

Longevity specialist Manuel de la Peña and physicians at Hospital Clínic de Barcelona recommend that people drink about two litres (eight large glasses) of water each day, especially during heat waves, to keep physical strength and mental focus. They explain that even a 2 % loss of body water can cut muscle power by 5‑10 % and slow cognitive processing.

The experts advise hydrating before, during and after exercise: a glass of water 30 minutes before activity, small sips every 15‑20 minutes while training, and roughly two litres in the three hours after a session. They also suggest planning workouts for cooler times of day, wearing breathable clothing, and avoiding alcohol or diuretic drinks around exercise. Proper hydration helps maintain blood volume, reduces heart strain, and prevents early fatigue.