We discussed the science of carbohydrate ‘hydrogels’ in a previous blog. Carbohydrate hydrogels are regular carbohydrate-containing sports drinks, with pectin and sodium alginate added. Pectin and sodium alginate have little effect until the drink reaches the high acidity of the stomach, where it forms a gel-like mixture. The gel-like mixture allows for a faster pass through the stomach into the intestine – what is called ‘gastric emptying’ – and speeds the rate at which the ingested carbohydrate is available for absorption across the intestine and, theoretically, utilisation as a fuel source by the working muscles.

When I wrote the blog in 2020, a handful of studies looking at the gastrointestinal and metabolic effects of carbohydrate hydrogels had been published. My conclusion at that point was that hydrogels might provide an effective means of accelerating gastric emptying, although the research did not demonstrate positive effects on exogenous...