Isotonic Sports Drinks - The Low Down




Isotonic Sports Drinks. The Low Down. 

Isotonic Sports drinks are sold as performance enhancing drinks that help the user to compete better and get better results. Often they are also sold as the perfect aid to hydration but before we discuss their effectiveness lets delve into the terminology. 

Isotonic, what does it mean?

In an isotonic solution the amount of solubles within the fluid match the concentration of the blood and the cells within. This means that where applicable the exchange or movement between the blood cell and solution happens easily. To put it into the context we refer to and in lay mans terms if the cell is deficient it will easily absorb what is needed from the solution provided the concentrations are correct (isotonic). 

The Theory

In light of the information above the theory behind isotonic sports drinks is that the right concentration of salt, sugar and other ingredients (often electrolytes flavours and preservatives) can replace what the body looses during sweating and therein aid performance by keeping the blood close to its natural state of balance. 

The Problem

Research from various sources suggests that unless an exerciser performs at a top level (to the degree of athletic performance) for no less than 1.5 and in some cases up to 4 hours there is no need to consume an isotonic sports drink and in fact evidence suggests consumption could have some of the following:

Excessive salt supplementation during exercise may lead to "gastrointestinal problems or cause further impairment of fluid balance" and may cause salt-induced cramps. ( Australian Institute of Sport )

Stretching The Truth

Now we must address the line we are sold by the drinks manufacturers.

 "[insert drink name] can help you perform better" 

Out of the majority of claims made by the drinks manufacturers most cite no evidence to back up their claim and with good reason. Studies performed on top athletes during prolonged exercise have yielded some positive results to back the claims but even then the improvement in performance has been deemed as almost irrelevant to the majority of the population due to the fact that they were performed on top flight athletes whose performance is a world apart from a normal member of the public. 

The Negative

Due to the sugary nature of isotonic sports drinks for the every day man or woman consuming isotonic sports drinks rather than the desired result which is some measure of either, increased performance, weight loss or weight control the results could actually be reduced performance or weight gain from drinking sports drinks with carbohydrates without prolonged exercise

A study presented at the Obesity Society's Obesity 2012 scientific meeting found people in their teens gained 3.5 pounds (1.6 kg) over two years for every bottle of sports drink consumed per day. The leading author of the study, Alison Field of Harvard Medical School, said she was surprised to find that "Sports drinks have an even stronger relationship than sugared fizzy drinks with weight gain".

Conclusion

Avoid isotonic sports drinks unless your a marathon runner or an elite athlete competing at a national level. For the rest of us water is a much better performance aid than high doses of either salt or sugar pre, post or during training.