Energy gels

The body draws its energy from fats and carbohydrates. Fat is plentiful, but it is converted slowly and cannot keep up at high intensity. Carbohydrates, on the other hand, provide energy quickly, but in limited quantities: enough for about 90 minutes of running at a typical pace.

The gel is a concentrated carbohydrate syrup, often made with maltodextrin and fructose, in a single serving that is easy to swallow. It replenishes your reserves while you run.

It replenishes some of the carbohydrates the muscles burn and also nourishes the brain through the bloodstream, helping you stay clear-headed and stave off feelings of fatigue. Not all ingested carbohydrates are used immediately by the muscles, but the boost is often noticeable after a few minutes.

For an effort lasting an hour and a half or more, a first gel after 20 to 30 minutes is a good starting point, followed by another every 30 to 45 minutes. A gel containing 25 g of carbohydrates every 30 minutes provides 50 g per hour, a common benchmark. Highly concentrated gels (40 g per gel) mean you can carry fewer.

Yes for most gels, because their high sugar concentration can irritate the stomach if not diluted. A few sips of water (100 to 150 ml) are enough. So-called isotonic gels or gels with a liquid texture already contain water and are easier to take without drinking afterward.

Many brands offer versions with 25 to 100 mg of caffeine. These are generally reserved for the second half of an effort, when fatigue sets in. Sensitivity to caffeine varies widely. If you don't tolerate it well or get little sleep before a race, it's better to stick with the caffeine-free versions.

• Test the product during training at race pace.
• Increase the amounts gradually: your gut needs training too.
• Don’t take too many concentrated gels without water.
• Avoid switching brands during a race. Carbohydrate ratios vary.

Maurten offers hydrogel-based gels with a very neutral taste. Enervit, GU, Squeezy, and Precision Fuel & Hydration offer different carbohydrate doses and textures. Organic gels (Baouw, Meltonic, Atlet) focus on flavor. Browse the catalog below and filter by brand or carbohydrate content.