How much fluid should one drink before and after exercise? You probably can’t drink enough water before and after exercise, as long you can tolerate it and have a chance to eliminate before you exercise.
At a minimum, you should drink three to four ounces of water every 15 to 20 minutes during exercise. If you’re exercising hard, you may require eight ounces of water every 20 to 25 minutes. To determine if you’re taking in enough fluid to match your sweat losses, weigh yourself before and after each workout. Your after-workout weight should match your pre-exercise weight.