How many carbohydrates per hour based on your distance? The practical guide

The amount of carbohydrates consumed during exercise is probably the variable most underestimated by endurance runners and cyclists. Too little, and you are guaranteed to "hit the wall" (or at least experience a crash). Too much, or poorly timed, and digestive issues will take over. Here are the current scientific benchmarks, distance by distance.

The basics: what research says

The current sports consensus (based on the work of the ASICS Institute of Sport Science and numerous exercise physiology studies) distinguishes three levels based on the duration of the effort:

• Less than 75 minutes: carbohydrates are generally not necessary, unless you feel hungry.
• 75 minutes to 2h30: aim for 30 to 60 g of carbohydrates per hour.
• More than 2h30: aim for 60 to 90 g of carbohydrates per hour, provided you use a multi-transportable carbohydrate blend (glucose:fructose, ideally in a 2:1 ratio) to maximize intestinal absorption and avoid digestive saturation.

Distance by distance

5 km and 10 km: the effort is too short to justify carbohydrate intake during the race. The priority is intake before the start (a carbohydrate-rich meal 2 to 3 hours beforehand).

Half-marathon: depending on your pace, the effort lasts between 1h20 and 2h30. Aim for 30 to 60 g/h, which is the equivalent of one serving of ELIXYR Endurance Fuel diluted in your soft flask, taken from the 30th or 40th minute.

Marathon: with an effort lasting 3 to 5 hours, the 60 to 90 g/h window becomes the standard. This is exactly where the 2:1 glucose:fructose ratio of the ELIXYR formula makes a difference: it allows you to increase the dose without multiplying the risk of digestive issues.

Ultra-trail: beyond 6 to 8 hours of effort, individual digestive tolerance takes precedence over theory. Many ultra-runners top out around 60 to 80 g/h and alternate between liquid carbohydrates (Endurance Fuel) and solids to avoid taste and digestive fatigue.

How to apply this practically with ELIXYR

A serving of ELIXYR Endurance Fuel diluted in your soft flask gives you a controlled intake of carbohydrates, with the 2:1 ratio already calibrated and 500 mg of electrolytes included. No need to calculate each gel or bar separately: you simply adjust the number of servings according to the planned duration of your session.

Common mistakes to avoid

• Waiting until you are hungry or tired to start fueling: it is already too late.
• Testing a new product or a new dosage on race day rather than during training.
• Neglecting electrolytes during efforts longer than 2 hours, especially in hot weather.

The right carbohydrate strategy is not improvised: it is built during training, session after session, until it becomes second nature on the big day.