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H20 Lets Go! Now down to the Debate

Summer is abound in the southern hemisphere so what a great time to talk about water. Whether we are working out at our box, hitting the beach or playing some ball, we all need to stay fresh and hydrated.

So the question remains just how much H20 do we really need to survive and how much do we need for optimal, athletic performance? We’ve all heard the standard formula of 8 glasses a day but how much of this holds true? Amongst the sea of H20 recommendations, I remember a simple equation that also attempted to calculate required water intake, based on body weight. It went something like this:

Bodyweight (kg) x 0.0333= required daily water intake in litres

When I first came across this formula I was quite pleased to find that I came close to the required 1.6 litres of water I should be drinking each day. However, I knew this simple formula did not take into consideration the countless variables that an individual faces each day. So this week I set forth to unearth the mystery of how much water the human body really does require.

The European Journal of Clinical Nutrition states, an average sedentary adult should drink approximately 1.5 litres of water per day. Although like the other suggestions, the journal failed to provide any additional information and did not take into consideration various factors such as exercising, the environment, body weight and the list goes on. Unsatisfied with the European Journal’s prescription I made my way over to a trusted source.

There is no hiding the fact that we here at The Rx Review are big fans of KStar and in particular his website the [MobilityWOD]. I can remember earlier this year, Kelly Starrett posted a video on his site stating the recommended water intake for CrossFit athletes.

In his video, Starrett proposes an equation that first provides baseline water intake, based on body weight. He then offers a solution for replacing fluid lost from sweat, during a workout. So, to give you a general idea of how much water CrossFitter’s should be consuming, Starrett provides the following equations:

Body weight in lbs ÷2= baseline water intake in fluid oz

1 pound sweat= 16 fluid ounces lost (just under 500ml)

In lamens terms, a 100lb athlete should consume 50 fluid ounces each day (basically 1.5 litres). Under Starrett’s rule, CrossFitter’s are urged to weigh themselves before and after a WOD (this is so you know how much fluid was lost from the workout). So, if the same athlete weighed in at 100lbs before a workout and then weighed in at 99lbs after the workout, they should consume 16 fluid ounces (just under 500ml) to rehydrate, replenish and revitalise the body. I guess it goes without saying, but ill say it anyway, if you happen to lose a pound after a workout chances are it is water and sadly not fat.

While it is often hard to generalize issues that are specific to individual needs, Kelly Starrett does provide useful suggestions for staying well hydrated. Personally, I like Starrett’s recommendation because he emphasizes the need to replace fluid lost from perspiration, which is often forgot but always felt. You can watch his video below for further details and clarification.

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The Rx Review is an independent fitness website, reporting on the Sport of Fitness, functional fitness news, The CrossFit Games, health and diet related information, and also provides reviews on sports performance products.