Performance & Nutrition

There are different approaches to fueling for exercise. These guidelines focus on carbohydrates as the primary fuel source.

Every athlete is different. These guidelines should be a starting point to find a way to fuel that works best for you.

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The ACSM and AND recommend:

• 30g to 60g or more of carbohydrates (120-240 calories) per hour of exercise.
• Source has less than 5g of fat, 5g of fiber and 5g of protein.
• Ultra-endurance athletes can require more carbohydrates.
• Easily digested, low-fiber complex carbohydrates in the 60 minutes prior to a workout are best.

The most important fuel source for exercise is carbohydrate in the form of glucose.

Glycogen is the storage form of glucose in muscle and because glycogen storage is limited, it can be depleted. The depletion can occur in 1-2 hours of intense activity and can significantly compromise endurance exercise performance.

To help maintain a steady supply of energy, the ACSM and AND recommend that athletes consume 30g to 60g or more of carbohydrates (120-240 calories) per hour of exercise. It is suggested the source has less than 5g of fat, 5g of fiber and 5g of protein. Ultra-endurance athletes can require more carbohydrates.

In addition, when pre-fueling for endurance, easily digested, low-fiber complex carbohydrates in the 60 minutes prior to a workout are best.

These are general guidelines. To calculate guidelines that are specific to you and the type of exercise you do, scroll further down the page.

Carbohydrates are the first source of fuel that the body goes to; they are the quickest to absorb and metabolize, and therefore the most immediately available as energy. Fat can also be an important source of energy and, to a lesser extent, so can protein, and there are fueling approaches that prioritize these nutrients.

Hydration and recovery are just as important as fueling properly. We won’t cover either subject now, but will at some point in the future. If you’re interested in learning more, the ACSM & AND have published guidelines for both in a paper that can be viewed here.

The following information is from the 2016 paper titled “Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance”. It is a table from pg 508 of the paper titled “Summary of guidelines for carbohydrate intake by athletes”. The full paper can be viewed here.

1. The following targets are intended to provide high carbohydrate availability (ie, to meet the carbohydrate needs of the muscle and central nervous system) for different exercise loads for scenarios where it is important to exercise with high quality and/or at high intensity. These general recommendations should be fine-tuned with individual consideration of total energy needs, specific training needs, and feedback from training performance.
2. On other occasions, when exercise quality or intensity is less important, it may be less important to achieve these carbohydrate targets or to arrange carbohydrate intake over the day to optimize availability for specific sessions. In these cases, carbohydrate intake may be chosen to suit energy goals, food preferences, or food availability.
3. In some scenarios, when the focus is on enhancing the training stimulus or adaptive response, low carbohydrate availability may be deliberately achieved by reducing total carbohydrate intake, or by manipulating carbohydrate intake related to training sessions (eg, training in a fasted state or undertaking a second session of exercise without adequate opportunity for refueling after the first session).

Comments on type and timing of carbohydrate intake:

• Timing of intake of carbohydrate over the day may be manipulated to promote high carbohydrate availability for a specific session by consuming carbohydrate before or during the session, or during recovery from a previous session
• Otherwise, as long as total fuel needs are provided, the pattern of intake may simply be guided by convenience and individual choice
• Athletes should choose nutrient-rich carbohydrate sources to allow overall nutrient needs to be met

* These guidelines should be a starting point to find a way to fuel that works best for you. Every athlete will have different nutrition requirements depending on body weight, exercise duration and a number of other factors. Any athlete whose demands go beyond a single serving can consume additional quantities, or combine with a carbohydrate drink, using the ACSM/AND guidelines as a reference.