FITNESS TIP Ok, so here is your Double Jeopardy question for the week: Sodium, Potassium, Chloride, Calcium, Magnesium, Bicarbonate, Phosphate, and Sulfate are what in the human body and what is their function? If you guessed "the major electrolytes in the body" you are correct. If you got stumped on their function, you are not alone. Basically, electrolytes are what your cells (especially nerve, heart, and muscle) use to maintain voltages across their cell membranes. Electrolytes carry electrical impulses (nerve impulses, muscle contractions) across themselves and to other cells. Proper balance is critical not only for athletic performance, but also activities such as heart function, fluid absorption and excretion, nerve function, and concentration. Exercise (or any activity) that produces heavy sweating can result in (usually) limited electrolyte loss (principally sodium and potassium) so replacement can be advisable for some people to ensure they keep their electrolyte balance in check. An electrolyte imbalance can also be caused (or exacerbated) by poor diet, dehydration, medication, and disease. So, for example, a combination of poor hydration and heavy sweating could definitely lead to an electrolyte imbalance and possible effects on performance and/or general health condition. The good news, however, is leading sports physiologists agree that for most of us running short on sodium or potassium is unlikely as both of these nutrients are plentiful in the American diet. Plain water, which is easily absorbed by the body, is not only adequate but is the best beverage for most to drink for rehydration. Especially for those focused on weight loss (or even maintenance), sugar in commercial sports drinks can add unwanted (and unnecessary) calories. On the other hand, for athletes who compete in endurance events or notice high amounts of sodium in their sweat, a wisely-chosen electrolyte replacement can be advisable (eg: the SaltStick now at Fleet Feet). The important thing to remember is that for most of us electrolyte loss and successive health risk is probably unlikely. Being aware of the facts can help you make the best choices for your individual training and health needs. Alongside fluid replacement guidelines from last week, here are a few things to keep in mind: If you exercise vigorously for less than one hour, or moderately for less than two hours, water is probably all you need. Add a squeeze of lemon or lime for taste. If you exercise strenuously for more than one hour or moderately for more than two hours, you can benefit from an energy drink. Be sure to watch the sugar content; diluted concentrations can help in controlling calorie intake. Refuel your muscles within two hours after exercise (as in "eat" - energy drinks don't count as food). Carbonated drinks tend to make you feel full and can make it difficult to drink enough (fluid). Always make fluids a part of your exercise routine and never restrict fluids during exercise (especially if you are feeling thirsty - remember, your body needs fluid WAY before you feel thirsty). Train hard, Train smart, and HAVE FUN! Nancy Maia is a 20+ year veteran in the fitness industry and owns CustomFit Coaching and Training. She is a world-class triathlete and does personal and group fitness coaching and instructor training here in Savannah. She would love to hear from you on your fitness questions! Email her at customfit@bellsouth.net