Jan

Sport hydration

By Hamish

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These days we’re told by television commercials that drinking the “sports drink” of your choice will enhance your performance as you train or play sports which has led many of us to to mistakenly believe that these drinks are a healthy choice. But what’s actually in these drinks? And what can they do for the weekend warrior?

When we exercise we sweat, and losing fluids inhibits our performance in any form of activity, from walking to weight training. In fact, during and after exercising rehydration is very important, with the simplest rule being keep drinking until you pee. But are these sports drinks better than good old H2O?

Sweat contains more than water, we also lose salt (NaCl or sodium chloride) and other trace minerals including potassium, calcium, and magnesium. Some of these, including sodium and potassium, are very important in all manner of biochemical reaction, for example sodium and potassium ions are important for nerve conduction.

However, while we lose these minerals, most of us don’t exercise enough to lose so much that we need immediate replacement. If training for a marathon and running for more than three hours you can lose so much sodium that hyponatremia is possible, and in that case a sports drink is ideal, but for those of us mere mortals training for shorter periods of time, water is just fine.

What many of us often forget about sports drinks is they contain quite a few calories, which offset the calories burned during exercise. For example, my last run of 7.7km burned 2650kJ after which I drank 750mL of fluid. Had that been Powerade Isotonic, I would have put 986kJ back into my system. Had I chosen Mizone Hypotonic it would have been 485kJ, either choice negates roughly 20% of my run, or 1.5km.

The other reason people often give for preferring sports drinks to water is a lack of stiffness the next day. Personally I always found that my legs were less stiff the following day if I drank sports drinks over water, but that’s hardly a scientific study.

Just a word on scientific studies of sports drinks, always look where they are carried out. The study cited in Powerade commercials was conducted at the NSW Institute of Sport, so was almost certainly carried out with elite athletes who were in the peak of physical condition, not weekend warriors trying to shed a few excess kg.

I’ll leave you with my sports drink of choice, Nuun. I find I’m not stiff the next day, recover quicker, and it tastes good, all with just 50kJ for 750mL.