How Much Water Should I Drink When Working Out?

During a moderate 60-minute workout, you need 500–1,000 ml of additional water on top of your daily intake. The exact amount depends on your body weight, exercise intensity, and how much you sweat.

Key Takeaways

Drink 500–1,000 ml extra during a 60-minute workout on top of your daily intake.
Pre-hydrate: 400–600 ml 4 hours before, 200–300 ml 2 hours before exercise.
During exercise: sip 150–250 ml every 15–20 minutes — don't wait until thirsty.
Post-workout: replace 150% of fluid lost (weigh before and after to measure).

Workout Hydration: Timing Is Everything

How much water you need during exercise depends on three things: how long you train, how hard you push, and how much you sweat. A gentle yoga session demands far less fluid replacement than an intense HIIT circuit or a long-distance run.

The American College of Sports Medicine recommends drinking 5–7 ml per kg of body weight at least 4 hours before exercise and 3–5 ml per kg 2 hours before. During exercise, aim for 150–250 ml every 15–20 minutes.

Before Your Workout

Pre-hydration sets the stage for performance. If you start dehydrated, no amount of mid-workout sipping will fully compensate. Here's a practical timeline:

4 hours before: Drink 400–600 ml of water.
2 hours before: Drink 200–300 ml.
15 minutes before: Take a few sips (100–150 ml).

This approach ensures your body is adequately hydrated without causing stomach discomfort during exercise.

During Your Workout

The goal during exercise is to replace fluid lost through sweat — not to overcompensate. Sweat rates vary enormously: from 400 ml/hour during light activity to over 2 liters/hour during intense exercise in heat.

For most workouts, follow this practical rule:

Low intensity (yoga, walking): 100–200 ml every 20 minutes
Moderate intensity (weight training, jogging): 200–300 ml every 15–20 minutes
High intensity (HIIT, sprinting, competitive sports): 250–350 ml every 15 minutes

After Your Workout

Post-exercise rehydration is where many people fall short. The goal is to replace 150% of fluid lost during exercise over the next 2–4 hours. The simplest way to estimate loss is to weigh yourself before and after — each kilogram lost equals roughly 1 liter of fluid.

If you lost 0.5 kg during a workout, drink about 750 ml over the following hours. Include sodium-rich foods or a pinch of salt in your water to improve fluid retention.

Workout Type Matters

Not all exercise dehydrates equally. Outdoor running in summer generates far more sweat than an air-conditioned gym session. Swimming masks dehydration because you don't feel yourself sweating. Pay attention to environmental factors and adjust accordingly.

Use the calculator above to enter your specific exercise type, duration, and intensity for a precise recommendation.

Frequently Asked Questions

Should I drink water during my workout?

Yes — drink 150–250 ml every 15–20 minutes during exercise. Don't wait until you're thirsty, as performance declines before thirst kicks in.

Is it bad to drink too much water while exercising?

Overhydrating during exercise can dilute sodium levels (hyponatremia). Stick to 150–250 ml per 15-minute interval and don't exceed 800 ml per hour unless you're in extreme heat.