This is an excellent review paper on all of the facets of pre-exercise nutrition.
Conventional (or dogmatic) wisdom states that carbohydrate loading (or fasting) are universally useful in all types of training.
- For most athletes, carbohydrate loading before exercising is unnecessary and impairs fat burning (oxidation), so should not be performed. According to the review, protein/fat before exercise is fine in this regard
- The authors note a placebo effect – people who think they’ve eaten calories/carbohydrates (even though they haven’t) perform slightly better
The image above and review provides more context to different situations where carbohydrate loading is useful, for longer, higher intensity exercise sessions typically.
Data over dogma
A reminder that I am not anti-carbohydrate. I am pro-science :).
Reference
Rothschild JA, Kilding AE, Plews DJ. What Should I Eat before Exercise? Pre-Exercise Nutrition and the Response to Endurance Exercise: Current Prospective and Future Directions. Nutrients [Internet]. 2020 Nov 12;12(11):3473. Link: https://www.mdpi.com/2072-6643/12/11/3473