GO Isotonic Energy Gel The world’s first isotonic gel Provides a quicker supply of energy to the working muscles than a thicker, more concentrated gel Clean taste and designed to be absorbed without needing additional water Easily digestible and light on the stomach What does isotonic mean? The tonicity of a solution refers to the concentration that affects water and carbohydrate transportation across cell membranes, most importantly the movement from the gut into the bloodstream. Ultimately this will affect how quickly the gel can be used as an energy source. Hypertonic: If a solution is hypertonic, it has a higher concentration than the fluid in the body. This means that water particles will have to be pulled from the cells into the gut to help it absorb and balance up this concentration. This slows down the availability of the energy from the gel and can bloat your stomach and be very uncomfortable. Hypotonic: If a solution is hypotonic, it will have a lower concentration than the fluid in the body. This means that it will empty quickly from the stomach, but it will not contain much energy. Isotonic: To be isotonic a solution must have the same concentration of dissolved particles as the fluid in the cells within the body, typically this means having a tonicity between 280-310 mmol/kg. The carbohydrate source in GO Isotonic Energy gels is maltodextrin which we specially select. We use one with a particular size of molecule, known as its’ molecular weight. This allows us to balance the amount of energy delivered versus how quickly it empties from the stomach. This means that you will feel the performance benefits of taking on a GO Isotonic Energy gel far more quickly than when a non-isotonic gel is consumed. The risk of upsetting your stomach is also much less. Energy gels with an osmolality close to the gastric content (i.e. isotonic) may promote high carbohydrate delivery to the small intestine compared to thick, concentrated hypertonic gels (1). What does the research say? A published study in the International Journal of Sports Nutrition & Exercise Metabolism compared a large range of gels that are currently available on the market (31 gels from 23 brands). It showed that there are huge variances in the concentration of gels across the market, and that the GO Isotonic Energy Gel was the only isotonic gel tested (2). The variations in energy density, carbohydrate content and source reflect the osmolality/ concentration of each gel. It is clear that the majority of sports gels (when consumed with insufficient water intake) are not aligned with promoting gastric emptying and optimum carbohydrate delivery (1). Compared to the Isotonic Energy Gel, 70% of the gels sampled were >2000 mmol/kg. Such osmolality values would not facilitate rapid gastric emptying and carbohydrate delivery to the small intestine (1). Evidence suggests that delivering carbohydrate in the form of gels (especially when isotonic in nature) in combination with consuming electrolyte-containing fluids (like that in GO Hydro and GO Electrolyte) allows for a more flexible approach to achieving both energy and hydration goals during exercise, helping to maintain endurance performance (3). REFERENCES Vist, G. E., & Maughan, R. J. (1995). The effect of osmolality and carbohydrate content on the rate of gastric emptying of liquids in man. The Journal of Physiology, 486(2), 523. Zhang, X., O’Kennedy, N., & Morton, J. P. (2015). Extreme variation of nutritional composition and osmolality of commercially available carbohydrate energy gels. International Journal of Sport Nutrition and Exercise Metabolism, 25(5), 504-509. Lee, M. J. C., Hammond, K. M., Vasdev, A., Poole, K. L., Impey, S. G., Close, G. L., & Morton, J. P. (2014). Self-selecting fluid intake while maintaining high carbohydrate availability does not impair half-marathon performance. International Journal of Sports Medicine, 35(14), 1216-1222. Written By Ted Munson (Performance Nutritionist) Ted is a Performance Nutritionist here at Science in Sport.