How to fuel your body for endurance training - Women's Health and Fitness magazine

Get the low down on how to fuel your body for optimum performance when it comes to endurance training.


While carb loading (eating carbs in high enough quantities that they will be stored for use later) is a popular notion when it comes to running a marathon, Cox says it may not be for everyone. 

“Some people can convert glycogen (sugars) from protein more effectively than others. The best example being indigenous Eskimos – due to their geographic location, they only have access to fish and hardly any vegetation, which means their diet is pure protein and fat. So how then do they supply enough glycogen to their cells to stay alive?,” says Cox.

“Through glycogenic amino acids, is the answer. This can apply to many people around the world. So if you’re one of those types who do better with a higher protein and fat meal either pre- or post-workout, you will actually replenish glycogen stores via your correct food choice!”

That said, the main concerns for endurance athletes pre-workout is ensuring fuel availability, preventing the onset of gut disturbances and minimising fluid losses. 

“Events lasting more than 90 minutes are the most likely to challenge the body’s glycogen stores. Newer research confirms that less extreme carb loading practices provide similar benefits without the negative factors (fatigue, ketosis) that were associated with the original protocol,” says Turner.

“Interestingly, many athletes are now following paleo diets, or low carb and high fat eating plans. It’s a topical area.”

For events lasting longer than 90 minutes, Turner suggests eating complex, lower GI carbs such as rice salad or wholegrain pasta with lean chicken breast. Eat 10 to 12 grams of carbs per kilogram of body weight within the 36 to 48 hours before your event, and then 1 to 4 grams per kilogram of body weight within 60 minutes before you get to the starting line. 

Intra-workout snacks might also help to delay fatigue – think 30 to 60 grams per hour of exercise, or 90 grams per hour for activities lasting longer than 2.5 hours. Just be sure to ditch the fruit. 

“The exception is fructose which appears to be oxidised at a lower rate, and can cause digestive problems if consumed in large amounts (more than 50 grams),” says Turner.


Higher GI carbohydrate-rich foods provide a good option for rapid glycogen replenishment following your long distance run or cycle. Both endurance athletes and resistance-training athletes appear to have increased requirements for protein, so ensure you eat enough to support your lean muscle mass. Aim for larger amounts of complex carb sources, and moderate fat and protein in the 12 hours following your exercise bout.

“Muscle glycogen replenishment is greatest during the first 24 hours of recovery, with the highest rate of storage occurring during the first hour post-exercise,” says Turner.

“But be sure to consider total energy needs, specific training needs and feedback from training performance.”

Turner suggests 1.0 to 1.2 grams of carbs per kilogram of body weight per hour for the first four hours following an endurance event. 

Words by Katelyn Swallow. 

Model: Paola Marquez.