Fitness Fact: How much water do you really need when working out? This answer varies depending on the person and elevation of routine, but the following is a great rule of thumb to follow if you workout in a climate controlled environment and doing a non-vigorous workout. Before your workout (15 minutes prior) 16oz, during your workout 8oz every 20 minutes (24 per hour), after your workout 24oz immediately. Remember if you are doing a vigorous workout or in elevated temps or climate the water intake will increase! If you have specific questions please post!