Energy gels: when to take them and how many
Gels are liquid carbohydrate in a tiny package, easy to carry and easy on the stomach. Used well, they are the simplest way to hit your carbs per hour.
Why gels work
Liquid fuel such as gels, chews and drinks causes fewer stomach problems than solid food such as bars, which contain more fat, fiber and protein. Late in a race, or when running, gels and drink are usually the easiest to get down.
How many do you need?
Start from your carbs per hour. Read the label to see how many grams of carbohydrate one gel has, then divide. For example, to take in 60 g per hour with one 500 ml bottle at 6 percent (30 g), you would add about one gel of 25 g or a little more. Our carbs per hour calculator does this sum for you.
When to take them
Start early and spread them across the hour instead of taking several at once. Do not wait until you feel empty. Take gels with water, because gels add almost nothing to your fluid intake. In a triathlon, a couple of practiced gels before the start can help when eating in the swim is hard.
Glucose and fructose
Look for a mix of glucose and fructose. A ratio of about 1 to 0.8 works for most athletes. Avoid products with polyols such as sorbitol, xylitol or isomalt, which can irritate the gut.
Caffeine gels
Caffeine blocks the feeling of tiredness, so it is most useful in events longer than three hours or ones that need focus. A cup of coffee has about 80 mg and an espresso about 50 mg. It takes 30 to 45 minutes to start working and peaks around 60 minutes. Caffeine can still disturb sleep for 6 to 8 hours, which matters for afternoon and evening races. Response differs a lot between people, so practice with the dose you plan to use.
The one rule: nothing new on race day
Use exactly the brands, gels and drinks you trained with and tolerated well. Switching to the race sponsor product, especially one with caffeine, is a common cause of stomach trouble.
General information for healthy adults, not medical advice. If you have diabetes, a gut condition, an eating disorder, or take medication, talk to your doctor or a sports dietitian first.
Common questions
How many gels per hour?
It depends on your carbs per hour and the grams in each gel. Divide the first by the second, and count any carbohydrate from your drink.
Why do gels upset my stomach?
Common reasons are taking too much too fast, a very concentrated gel without water, polyols, or a product you have not trained with. Build up in training.
Gel or banana?
Both work. Fresh food gives variety early in a long session, and gels and drink take over as it gets harder. Solid food more often upsets the stomach than liquid carbohydrate.
Want this planned around your own week?
The 2fuel app turns every training session into kcal, carbs per hour and protein, then into meals. With an AI coach or a sports dietitian. In beta now.