Studies demonstrate that training after consuming calories yields more strength gains.
Last updated on March 6th, 2025
Fasting is common during religious observances like Ramadan and Lent. Intermittent fasting is a relatively common diet technique to lower calorie intake and is often effective, but are there performance benefits to training fasted versus fed?
A recent study conducted on athletes during Ramadan explored how fasting impacts strength training. The research compared athletes training in a fasted state to those training after eating to determine performance differences.
This 2024 study, published in the Frontiers in Nutrition journal, examined how training during Ramadan’s fasting window compared to the eating window impacted key metrics such as muscle mass, strength, and hormone levels.
Both groups maintained the same intake of calories, water, and macros (protein, carbs, and fats), ensuring a controlled comparison. Participants followed an identical resistance training program. (1)
Results
The study found no significant differences between groups in body fat loss or lean mass growth. However, the fed group showed notable improvements in 1RM for squats and deadlifts. Both groups experienced similar results with the bench press.
The fed group saw increased testosterone levels, whereas the fasted group exhibited higher cortisol levels.
Interpretation
The study results suggest that participants who train during their feeding window gain greater strength. Dr. Layne Norton recommends scheduling workouts within the eating window while following an intermittent fasting routine.
Research comparing intermittent fasting and other diets shows similar effects on body composition and training outcomes. (2)
The fasted group trained in the afternoon instead of the morning, which may have influenced the results since they had not eaten since the previous evening. Dr. Norton noted that they could have had a better workout performance if the training session had been in the morning since they would have had more fuel.
“It’s hard to know we don’t have that data,” Dr. Norton said. “This suggests being fed is more conducive to an anabolic environment and building strength than a fasted state.” However, dr. Norton acknowledges this doesn’t necessarily mean training in a fed state is better for hypertrophy.
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References
- Triki, R., Ben Abderrahman, A., Salhi, I., Rhibi, F., Saeidi, A., Almaqhawi, A., Hackney, A. C., Laher, I., Granacher, U., & Zouhal, H. (2024). Effects of time-of-day resistance training on muscle strength, hormonal adaptations, and sleep quality during Ramadan fasting. Frontiers in nutrition, 11, 1439738. https://doi.org/10.3389/fnut.2024.1439738
- Moro, T., Tinsley, G., Bianco, A., Marcolin, G., Pacelli, Q. F., Battaglia, G., Palma, A., Gentil, P., Neri, M., & Paoli, A. (2016). Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males. Journal of translational medicine, 14(1), 290. https://doi.org/10.1186/s12967-016-1044-0
Featured image via Shutterstock/Ground Picture
