Sweat, Sun and Fun Pt. 3
What does water have to do with this anyway?
Water is something I hold near and dear to my heart…73% of it to be exact (1)…and my lungs, muscles, blood, skin…
Countless hours (years) spent swimming through the awe-inspiring open blue, the permanently attached water bottle at my hip and a rather unusual adoration of a quality sweat-sesh. This only begins to explain the depths of which my heartfelt conviction for water expands. Call me obsessed, but soon you’ll see why you should be as well.
Water makes up 60% of our body, 70% of this earth, 80% of our brain…and should be 100% by your side
Can you guess what the most popular beverage in the US is? I’ll give you a hint it’s not water! (9)
Water comes in second behind soft drinks. If we were meant to drink soda, then it would make up 2/3 of our body! Soda is not only a health hazard, but it contributes to our increasing stroke rate, heart issues and obesity epidemic. All of this could be avoided with a simple beverage swap.
Being that water influences every process in our body, the benefits are endless. Whether you are looking for commercial clear skin or maximal brainpower – water is the answer. Most importantly, you have nutrients to be transported, temperature to be regulated, and food to be digested. Water maintains all these processes.
Just a reminder of how smart we are – our body is one massive, synchronic army constantly sending cues for combat. The sensation of thirst is a concert of tiny, specific cues precisely timed together. Our brain, organs, hormones, kidneys, glands…EVERYTHING…work in tune to monitor the amount of water coming in verse going out (2).
Most of the time our body has it all under control. It’s only when we are losing more water than we can replace (think Part 1 with some super sweat sesh or Part 2 trapped in a full body suit running a marathon) that we are dehydrated and left completely helpless.
Let’s back up to Part 1 – when are body temperature rises from a butt-kicking workout, we cool it down a notch by sweating. Sweat evaporates from our skin and takes the heat with it. However, if you don’t have water, then blood can’t flow to the skin to make this possible (3). Exercise and heat are the two big culprits in jacking up our sweat output. It’s easy for us to not realize how much we are sweating, and before we know it we aren’t matching that with water intake.
In efforts to reduce the risk of thermal injury and impairment of performance during exercise,
“fluid replacement should attempt to equal fluid loss” being that the “requirement for fluid replacement becomes greater with increased sweating during environment thermal stress” (4).
So what does this mean…
For those who don’t catch every exact ounce of individual sweat droplet and measure how much water they should consume, how do you know how much water to drink?
Many, many, MANY factors contribute to our water needs. Breathing, sweating, peeing, crying – water is leaving us all the time, at different rates through many ways. Most of the time we can rely on our simple thirst mechanism to keep us hydrated (5). However, the dangers of dehydration can be just as important as overhydration. I’m all about water…but in moderation of course!
In efforts to avoid or combat dehydration, hyponatremia can occur when people drink way too much water that it dilutes their blood. The kidneys have all the water, salts and other solutes under control. Start forcing water down our mouths and our kidneys won’t be able to flush it out fast enough. All this water has to go somewhere – so off it flows into any place that will take it (it won’t be the toilet) (6)!
Understand your optimal balance by paying attention to urine color, energy levels, satiety, and general feel. Only YOU know how your body handles special circumstances like exercise and heat. The invariability based on our individual factors and lifestyle make it impossible to prescribe a perfect number, but a daily water intake of 3.7 L for adult men and 2.7 L for adult women meets the needs of the vast majority of persons (2).
The multitude of factors, important symptoms and how we respond to dehydration (and even overhydration) is worthy of it’s own article – check back next week for the last article of this series!
References:
- The chemical composition of the adult human body and its bearing on the biochemistry of growth Mitchell, H.H. et al. 1945. The Journal of Biological Chemistry. 158: 625-637
- Water, Hydration and Health. Popkin, B. M., D’Anci, K. E., & Rosenberg, I. H. (2010). Nutrition Reviews, 68(8), 439–458.
- Hydration effects on thermoregulation and performance in the heat. M. N. Sawka, S. J. Montain, W. A. Latzka. Comp Biochem Physiol A Mol Integr Physiol. 2001 April; 128(4): 679–690
- American College of Sports Medicine position stand. Exercise and fluid replacement. V. A. Convertino, L. E. Armstrong, E. F. Coyle, G. W. Mack, M. N. Sawka, L. C. Senay, Jr, W. M. Sherman. Med Sci Sports Exerc. 1996 January; 28(1): i–vii.
- Human water needs.Michael N. Sawka, Samuel N. Cheuvront, Robert Carter, 3rd. Nutr Rev. 2005 June; 63(6 Pt 2): S30–S39. Fatal water intoxication. Farrell, D. J., & Bower, L. (2003). Journal of Clinical Pathology, 56(10), 803–804.