Have you ever woken up early in the morning to go for a ride, skipped breakfast, and thought, “I wonder if that was bad for my training? Or maybe it was good?!” In today’s episode, we try to decipher if there are any advantages or disadvantages to occasionally riding, or exercising in general, in a fasted state. What does “fasted” actually mean, in this context? How’s that help, or hurt, my training? How conclusive is the evidence? And how often should I do it? Those are just some of the questions we’ll try to answer today.
Fasting is one of those subjects that many of you have likely heard mentioned in passing, but whether or not it can lead to true performance gains is another matter. To fast or not to fast, that is the question. Today, we go particularly deep into the details of fasting, from the different types of fasting you can use for both health and performance benefits, to the genetic and cellular mechanisms which could play a role in adaptations.
In essence, there are two overriding questions: Does fasting have health benefits? And does it help in training and performance? The science is pointing towards clear health benefits, but performance and training are less clear. We’ll explore all of that and much more today on Fast Talk.
Our primary guest is someone who has spent his research career looking into these very questions. Dr. Brian Carson, of the University of Limerick, in Ireland, is a leading expert on the effects of exercising in a fasted state, as will become patently clear when we dive into the science.
We’ll also hear today from longtime USA Cycling coach Jim Miller, pro roadie Petr Vakoc and pro mountain biker Payson McElveen, leading physiologist Dr. Iñigo San Millan, and neurologist Dr. Dale Bredesen.
Put down that cookie. Let’s make you fast.
- Aird, T. P., Davies, R. W., & Carson, B. P. (2018). Effects of fasted vs fed-state exercise on performance and post-exercise metabolism: A systematic review and meta-analysis. Scandinavian Journal of Medicine & Science in Sports, 28(5), 1476–1493. Retrieved from https://doi.org/10.1111/sms.13054
- Burke, L. M., Ross, M. L., Garvican‐Lewis, L. A., Welvaert, M., Heikura, I. A., Forbes, S. G., … Hawley, J. A. (2017). Low carbohydrate, high fat diet impairs exercise economy and negates the performance benefit from intensified training in elite race walkers. The Journal of Physiology, 595(9), 2785–2807. Retrieved from https://doi.org/10.1113/jp273230
- Hawley, J. A., & Burke, L. M. (2010). Carbohydrate Availability and Training Adaptation. Exercise and Sport Sciences Reviews, 38(4), 152–160. Retrieved from https://doi.org/10.1097/jes.0b013e3181f44dd9
- Hawley, J. A., & Leckey, J. J. (2015). Carbohydrate Dependence During Prolonged, Intense Endurance Exercise. Sports Medicine, 45(Suppl 1), 5–12. Retrieved from https://doi.org/10.1007/s40279-015-0400-1
- Jeukendrup, A. E. (2017). Periodized Nutrition for Athletes. Sports Medicine, 47(Suppl 1), 51–63. Retrieved from https://doi.org/10.1007/s40279-017-0694-2
- Lane, S. C., Camera, D. M., Lassiter, D. G., Areta, J. L., Bird, S. R., Yeo, W. K., … Hawley, J. A. (2015). Effects of sleeping with reduced carbohydrate availability on acute training responses. Journal of Applied Physiology, 119(6), 643–655. Retrieved from https://doi.org/10.1152/japplphysiol.00857.2014
- Mattson, M. P., Allison, D. B., Fontana, L., Harvie, M., Longo, V. D., Malaisse, W. J., … Panda, S. (2014). Meal frequency and timing in health and disease. Proceedings of the National Academy of Sciences, 111(47), 16647–16653. Retrieved from https://doi.org/10.1073/pnas.1413965111
- Volek, J. S., Noakes, T., & Phinney, S. D. (2014). Rethinking fat as a fuel for endurance exercise. European Journal of Sport Science, 15(1), 13–20. Retrieved from https://doi.org/10.1080/17461391.2014.959564
- Zouhal, H., Saeidi, A., Salhi, A., Li, H., Essop, M. F., Laher, I., … Abderrahman, A. B. (2020). Exercise Training and Fasting: Current Insights. Open Access Journal of Sports Medicine, 11, 1–28. Retrieved from https://doi.org/10.2147/oajsm.s224919
(Please excuse any typos as this transcript is generated automatically through A.I.)