Monday, July 2, 2012

Myths about Hydration


In science, dehydration is defined as an excessive loss of body fluid. Dehydration usually has multiple symptoms: dizziness, fainting, headache, lowered blood pressure, etc. and can be treated immediately by drinking water or in the hospital, depending on the type of  dehydration. Types of dehydration are:
-          Isotonic (equal loss of water and electrolytes)
-          Hypotonic (primarily a loss of electrolytes, sodium in particular)
-          Hypertonic (primarily a loss of water)
When it comes to hydration and exercise I know for a fact that many people have misconceptions about hydration before, during, and after exercise. These misconceptions have not become popular belief because of any new scientific findings but because of very clever advertising campaigns by the bottled water industry and energy drink industry. Basically, we were told by these companies to ignore what Mother Nature gave us in order to maintain our body fluid balance: the thirst mechanism. Advertisers tell us that when we feel thirsty we are already dehydrated and that we need to start drinking lot earlier than when we become thirsty, every ten minutes during the workout, and of course to continue after the workout. Thus, we started buying very expensive bottled water (they want us to believe that tap water is not good enough) and many energy drinks. Tell that to my dog Fred, or any domesticated or wild animal. They would never buy that theory; they will drink only when they feel thirsty. Also, do not tell me or other retired athletes who were involved in a professional sport long before this avalanche of new energy drinks and bottled water mania. When I started my karate training and competition back in late 70’s, I had at least 400 workouts each year which translates to at least 800 of hours of training a year. The only one way to be a successful athlete was to push your physical and mental limits every single day. It was very hard work for decades but I have never drunk anything else but water and I drank water only when I was thirsty. I and many other athletes from the 70’s, 60’s, 50’s or 40’s have never trained in an air conditioned gym. We were working in extreme heat or cold, we were running 10 – 15 miles long routes either in the high mountains or at the sea level, but I cannot recall that I ever got dizzy or that I fainted. The reason for that is that I always drank water when I felt thirsty.
While on the subject of energy drinks, I believe that energy drinks such as Gatorade are necessary after long workouts when we sweat excessively. During long workouts when we are exposed to high temperatures for prolonged periods of time, we will lose a significant amount of fluid through sweat and a significant amount of electrolytes that must be replenished. But when we do a regular 60 – 75 minute workout, water is all we need. All we need to do is to maintain the electrolyte-water balance. In science, this balance is called OSMOLALITY. Many people drink a lot of Gatorade and similar drinks during short workouts because they believe that energy drinks will give them back what they lose through sweat but this is a wrong assumption because sweat contains significantly lower levels of sodium than the fluid in our bodies: 20 – 60 mM (millimoles) per liter of sweat versus 140 mM per liter of body fluids. It is important to know that the sweat of well trained and conditioned individuals have significantly lower sodium levels than the sweat of individuals who are not in good physical shape. So, we can conclude that well trained athletes really do not need energy drinks. And I suggest to everybody else that if you decide to use energy drinks, dilute your drink with three times more water.    
So, despite in what kind of conditions you work out in, do not spend money on energy drinks or bottled water. Fill your regular water bottle with tap water and follow your thirst. The thirst mechanism is nature’s invention that is millions of years old, if that mechanism is good enough for lions and chimpanzees in Africa then it is good for humans in the urban world.    

  

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