In this series, Sword founder Scott Black reviews the changing tides of scientific thought. How did the founders of Sword arrive at their formula? Through careful analysis of past work in the study, and through their own work in the field.
Multiple studies performed since the development of the first sports drink in the late 1960’s / early 1970’s have provided new information that has created a blueprint for an optimized sports drink. New understanding of the mechanisms for carbohydrate absorption from the intestines (multiple carbohydrate transporters), physiologic effects of ingested sodium, electrolyte composition of sweat, and mechanisms of fatigue (central and peripheral) have clearly suggested that a more effective sports drink can be produced.
We believe that a sports drink should have the following qualities:
1. The drink should utilize carbohydrate as its primary energy source. The amount of carbohydrate in the drink should fall within the range of 40 – 80 mg / L with an estimated optimum amount of approximately 60 mg / L (6% carbohydrate solution).
2. The drink should utilize multiple carbohydrates (rather than a single carbohydrate source) in order to take advantage of the gastrointestinal system’s multiple pathways to move carbohydrate from the intestine into the bloodstream.
3. The drink should be palatable, with a light taste that reduces the development of taste aversion during prolonged use. Athletes should be able to consume the drink for over 24 hours without becoming fatigued of the flavor.
4. The drink should be hypotonic in relation to the osmolality of blood.
5. The drink should contain sufficient sodium to improve fluid retention and distribution within the extracellular space and to help maintain the thirst drive. A sodium content of 700 – 800 mg / L should be sufficient to accomplish that. Excessive sodium reduces the palatability of a drink and can lead to fluid accumulation within the interstitial space while reducing intracellular fluid content.
6. Additional electrolytes are not necessary due to their lower concentrations in sweat. In addition to being unnecessary, adding additional electrolytes to a drink increases the likelihood of gastrointestinal distress.
7. The drink should not contain any substances that are not absolutely necessary to support physical exertion. This includes artificial colors and sweeteners.
These are our beliefs as scientists, sports medicine physicians, and – most importantly –athletes who enjoy nothing better than testing our personal limits in a little friendly athletic competition. We believed that we could build a better sports drink. And we created Sword.