The pre-workout window has traditionally been viewed as the 4 hours before training and competition and serves to:
- Prevent or delay fatigue,
- Improve performance,
- Setup for a faster recovery,
- Limit immune suppression, and
- Support adaptations from training.
Carbohydrate availability gets identified as a limiting factor for performance as muscle glycogen stores in the body are limited.
2-hours of moderate-intensity and 1 hour of high-intensity aerobic exercise can deplete muscle glycogen levels up to 70%, and during high volume resistance training, glycogen levels get reduced by 40%.
Athletes beginning training and competition with low or sub-optimal glycogen stores due to limited rest or inadequate carbohydrate between events are likely to benefit more from pre-exercise carbohydrate intake than those with extensive rest while consuming adequate carbohydrate.
For athletes competing in a tournament, playing games daily or multiple times in a week, undergoing early morning training, or undergoing multiple training sessions within the same day, pre-exercise carbohydrate intake becomes crucial in the preparation and recovery cycle and in supporting performance.
Another benefit of pre-exercise nutrition is its impact on immune function. Before exercise, carbohydrate intake limits immune suppression and sets up for faster recovery from training and competition by decreasing inflammation and sparing glycogen stores.
The amount of carbohydrate before training and competition will depend on your current glycogen levels (are the low or depleted) and the type, intensity, and duration of the training session.
Carbohydrate intake recommendations can vary from 0.5-4 g/kg within 4 hours before the commencement of training or competition.
Check out Part I and Part II of our Pre-Workout Nutrition series for more on how to properly prepare for key training sessions and competition in the hours prior and how and if you need to carbohydrate load.
If you are limited on time or find it easier to consume smaller quantities of meals, we recommend you check out some of our portable options below!
References
Gollnick, P.D., Piehl, K., & Saltin, B. (1974). Selective glycogen depletion pattern in human muscle fibres after exercise of varying intensity and at varying pedalling rates. Journal of Physiology, 241, 45–57.
Haff, G.G., Lehmkuhl, M.J., McCoy, L.B., & Stone, M.H. (2003). Carbohydrate supplementation and resistance training. Journal of Strength and Conditioning Research, 17, 187–196.
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, 48, 543-568.
