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Why choose the GO Isotonic Energy Gel?

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


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 effect 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. You’d need to take a considerable amount of water with this solution to help it digest.

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 290-310 mmol/kg. You do not need to consume water with this solution to help it digest.

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).

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 GO 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). With a concentrated, hypertonic gel like the market leader, to make the solution isotonic, an individual would need to have at least 7.8 oz of fluid with the gel to allow easy digestion. This is based on diluting the gel to make it 300 mmol/kg (isotonic).

1. 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.
2. 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.

Ted Munson (Performance Nutritionist)
Written By

Ted Munson (Performance Nutritionist)

Ted is a Performance Nutritionist here at Science in Sport.