Pre-exercise Fueling
Introduction
Paying attention to daily carbohydrate intake is crucial, but ensuring optimal fueling before training and competition is key to helping athletes perform at their best. It is important for female athletes to have knowledge of which types of foods are recommended to ingest before exercise, as well as which foods to limit.
Pre-exercise nutrition strategies should be developed with athletes on an individual basis. It is recommended that athletes practice these strategies prior to training so that they know what works for them when it comes to a major competition, match or race.
Practicing nutrition prior to training will help athletes to feel confident in their choices so that they feel ready to perform at their best. The information in this section will explain key nutrition considerations for pre-exercise fueling to promote optimal performance in training sessions or competition. It should be noted that currently, the recommendations for pre-exercise fueling do not differ between females and males.
Pre-exercise fueling: 1-2 days before
is stored in the body as glycogen, predominately in the skeletal muscles and liver, however the body can only store a limited amount. During exercise, carbohydrates (in the form of glycogen and glucose) are often the main energy source for working muscles, with the contribution of carbohydrate to energy metabolism increasing as exercise intensity increases.
It is important that athletes maximize their glycogen stores prior to exercise to provide working muscles with sufficient energy, which will help to delay fatigue and optimize performance. This is done by consuming carbohydrate-rich foods, and is particularly important prior to exercise that is of long duration and/or high intensity. The following information will discuss how athletes can optimize their glycogen stores prior to a key training session or competition (which will be referred to simply as ‘exercise’ from here onwards).
Two strategies which can help to maximize glycogen stores in the 24-48 hours prior to exercise, and promote high carbohydrate availability during exercise, are:
For most sports, carbohydrate intakes of ~6-8 grams per kg of body mass (g/kg BM) for 24 hours prior to exercise, combined with adequate rest and recovery, will be sufficient to promote high carbohydrate availability during key training sessions/competition. In some cases, carbohydrate intakes of >8 g/kg BM may be required, such as for endurance type events lasting >90 minutes.
Considerations for pre-exercise fueling: 1-2 days before
Achieving high carbohydrate intake can be difficult for some female athletes, in particular for those who have habitual daily energy intakes <2000 kcal. Some practical solutions to help athletes increase their carbohydrate intake include:
Consuming carbohydrate in liquid form e.g., smoothies, fruit juice, sports drinks, milk-based drinks
Consuming ‘simple’ carbohydrates which are more easily digested e.g., white bread/pasta/rice
Consuming small snacks often
as opposed to
large meals
Including higher carbohydrate vegetables within meals e.g., potatoes, corn, parsnips, peas, squash
Adding beans and legumes into meals e.g., lentils, black beans, pinto beans, kidney beans
Consuming high carbohydrate snacks e.g. granola bars, bananas, rice cakes
Considerations
Muscle glycogen storage
There is some research, albeit limited, to suggest that females have lower muscle glycogen storage capacity than males. In addition, there may be differences in muscle glycogen storage during different phases of the menstrual cycle (see diagram below). If carbohydrate intake is high, similar levels of resting muscle glycogen concentration can be achieved between the different phases. It is currently unknown whether different forms of hormonal contraception impact muscle glycogen storage.
See 
for more information.
Liver glycogen
Liver glycogen stores are reduced by ~50% after an overnight fast, which is a key consideration if exercise start time is earlier in the day. This highlights the importance of optimal nutrition preparation the day prior to exercise, as well as the morning of.
Pre-exercise fueling:
1-4 hours before
It is recommended for athletes to consume a carbohydrate rich meal containing 1-4 grams of carbohydrate per kg of body mass (g/kg BM) in the 1-4 hours before exercise begins. The upper end of the recommendations is most relevant for long duration (>90 min), high intensity endurance events where performance is the primary objective.
Carbohydrate content of different foods, which could be consumed in the 1-4 hours pre-exercise:
Sweet potatoes
Serving size: 1 cup
Carbohydrate: ~30 g
Fiber: ~4 g
Standard potatoes
Serving size: 1 cup
Carbohydrate: ~26 g
Fiber: ~3 g
Couscous
Serving size: 1 cup
Carbohydrate: ~56 g
Fiber: ~5 g
Pasta
Serving size: 1½ cups
Carbohydrate: ~50 g
Fiber: ~7 g
Gatorade Thirst Quencher
Serving size: 20 oz (1 bottle)
Carbohydrate: ~30 g
Fiber: 0 g
Rice
Serving size: 1 cup
Carbohydrate: ~46 g
Fiber: ~3 g
Banana
Serving size: 1 medium
Carbohydrate: ~30 g
Fiber: ~2 g
Oats
Serving size: ½ cup
Carbohydrate: ~30 g
Fiber: ~4 g
Bread
Serving size: 2 slices
Carbohydrate: ~30 g
Fiber: ~5 g
The pre-exercise carbohydrate recommendation of 1-4 g/kg BM encompasses a range, which allows for individual preferences
For example, if an athlete struggles to eat a large amount close to exercise then they may want to consume 2 g/kg BM carbohydrate ~3-4 hours before exercise. On the other hand, another athlete may prefer to have a large meal close to exercise, therefore they may consume 3 g/kg BM carbohydrate in the ~1-2 hours before exercise. Both strategies still meet the pre-exercise carbohydrate recommendations, while also catering to personal preference. Figure 3 shows how the carbohydrate content of a meal can be adapted. Meals containing 1-4 g/kg BM carbohydrate (based on a 60 kg female). To increase the carbohydrate content of this meal, click the plus button on the right
Considerations for
pre-exercise fueling:
1-4 hours before
Guide for plate portion
In practical terms, an athlete’s pre-exercise meal should have at least one source of good quality carbohydrate as a significant part (ideally at least 50%) of their meal. Some ideas for pre-exercise meals using this principle can be seen below:
Foods to limit or avoid?
High fat foods
Consuming high fat foods prior to exercise can cause stomach discomfort during exercise (e.g., bloating, gas, abdominal pain) because fat slows the rate at which food is emptied from the stomach. Encourage athletes to limit the amount of high fat food in their pre-exercise meal e.g., processed meats, fried foods, creamy sauces, cheese, and pastries.
High fiber foods
Consuming too much fiber prior to exercise may also cause stomach discomfort during exercise. This is because fiber is slow to empty from the stomach, which means that it takes the body longer to digest it. See below for examples of foods high in fiber.
Pre-exercise fueling:
60 minutes before
In the hour prior to exercise, some athletes may wish to consume an additional snack.
For example, this may be just before or just after their warm-up. It is recommended that this snack contains ~30-60 grams of easily digestible carbohydrates.
Click the items below for more details.
Gatorade Thirst Quencher (20 oz)
21g carbohydrate
Large banana
~25-30g carbohydrate
Gatorade Gx pod (mixed with water)
21g carbohydrate
Single serve Gatorade Thirst Quencher powder (mixed with water)
34g carbohydrate
2 slices white bread with jelly
~35g carbohydrate
3-4 rice cakes
with honey
~30g carbohydrate
Top tips
Top tips for pre-exercise fueling, click each for more details
Encourage athletes to practice competition fueling around training sessions or lower priority competitions
Provide education when athletes are travelling, as food options may not be as readily available
Focus on foods that are easily digestible to reduce the risk of gastrointestinal problems (e.g., bloating, discomfort, reflux)
Encourage athletes to consume familiar foods pre-exercise
Tailor meal and snack options to meet individual preferences
Pre-exercise Fueling
References
Burke, L. M., Hawley, J. A., Wong, S. H. S., & Jeukendrup, A. E. (2011). Carbohydrates for training and competition. Journal of Sports Sciences, 29 Suppl 1, S17-27.
Hargreaves, M., Hawley, J. A., & Jeukendrup, A. (2004). Pre-exercise carbohydrate and fat ingestion: Effects on metabolism and performance. Journal of Sports Sciences, 22(1), 31–38.
Hawley, J. A., Schabort, E. J., Noakes, T. D., & Dennis, S. C. (1997). Carbohydrate-loading and exercise performance. An update. Sports Medicine, 24(2), 73–81.
Jeukendrup, A. E. (2011). Nutrition for endurance sports: Marathon, triathlon, and road cycling. Journal of Sports Sciences, 29 Suppl1, S91-99.
Rehrer, N. J., McLay-Cooke, R. T., & Sims, S. T. (2023). Nutritional Strategies and Sex Hormone Interactions in Women. In A. C. Hackney (Ed.), Sex Hormones, Exercise and Women: Scientific and Clinical Aspects (pp. 87–112). Springer International Publishing.
Thomas, D. T., Erdman, K. A., & Burke, L. M. (2016). American College of Sports Medicine Joint Position Statement. Nutrition and Athletic Performance. Medicine and Science in Sports and Exercise, 48(3), 543–568.
