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...

- By Dr. Dan Plews & Ed Maunder

From time-to-time, there is a flurry of research interest into a new product in sports nutrition, as researchers seek to determine if they have discovered the next great ergogenic aid. Recently, that product seems to be carbohydrate-hydrogels (1, 2, 7, 8, 10). In this blog, we are going to review what is a growing literature on this product, and assess if hydrogels are something you should consider adding to your race-day bottle.

What is a hydrogel?

First things first, what is a hydrogel, and how does it work? A carbohydrate-hydrogel is a regular carbohydrate-containing sports drink, only 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. Supposedly, the gel-like mixture allows for faster pass through the stomach into the intestine – what is called ‘gastric emptying’ – and speeds the rate at...