As I write this, I am thinking about the running of the Boston Marathon just hours away with temperatures predicted to hover around the mid-eighties. The importance of hydration during this, or any intense workout, is more than likely on the minds of many individuals right now.  What are we losing when our bodies sweat?
Sweat consists of water and electrolytes.  Electrolytes are salts (ions) that are charged (+,-) and used for muscle contraction, heart beat,  fluid regulation and neural activity.  The electrolyte minerals lost through sweat primarily consist of sodium, chloride, potassium, magnesium and calcium.
Sports drinks are designed to replace both water and electrolytes lost through sweating.  They can reduce muscle cramping and spasms resulting in improved performance.  Many of the commercial sports drinks contain artificial color and flavor and refined sugar.  Basically, most are nothing more than sugar water marketed to us with the idea that, if consumed, we will perform like top athletes. Since the Boston Marathon inspired this post, I will go even further and equate commercial sports drinks with the Big Dig (a Boston highway project, the most expensive in the US, that resulted in charges of poor design, execution and leaks to name a few).  Poor quality construction materials resulted in a poor quality structure and eventual breakdowns.  We will pay for those breakdowns over and over until high quality materials replace inferior ones.  If you are not getting the necessary quality nutrients to replace the electrolytes lost through sweat, then your body cannot repair the cellular tissue that break down during exercise.  The result is less than optimal performance and longer recovery times.
So, what to do?  You guessed it, make your own!  Sports drink recipe.