I have been catching up on my scholarly reading and came across a very interesting study on the effects of carbohydrate consumption, timing, and performance. Definitely worth breaking it down and sharing it here on the blog!
Over the years I have worked with many athletes who are simultaneously trying to train to perform but also want to lose weight or improve body composition. This is tricky because some of the nutritional steps that need to be taken to lose weight could potentially impact training status and outcomes. This is why I found this “train high, sleep low” concept intriguing. It might have potential for those who are training to perform but also for those who are working to improve body composition.
The concept of “train high, sleep low” basically refers to manipulating carbohydrate consumption throughout the day so as to promote fat utilization but at the same time make sure that performance won’t be impacted.
- The “train high” component means that an individual would consume ample carbohydrate at the right time so as to provide enough glucose and glycogen availability allowing for them to perform a high intensity training session.
- “Sleep low” refers to limiting carbohydrate consumption after the high intensity workout sessions (and subsequently throughout the night while sleeping).
The small study referenced here involved three different groups with three different approaches:
- High-intensity training with high carbohydrate availability.
- Those who “slept low” with carbohydrates having been restricted.
- Fasted exercise.
- Decreased RPE by sleep-low group during submaximal exercise.
- Improved cycling efficiency during submaximal exercise by the sleep-low group.
- Decrease in heart rate by the sleep-low group.
- Decreased carbohydrate oxidation (i.e. used more fat as fuel) by the sleep-low group.
Although this study is small, it does present some interesting consideration for manipulating carbohydrate timing. This might bode well for active people who are trying to work on increasing fat utilization as a fuel source or to improve body composition. Caution would still need to be used for those training for performance over extended periods of time because lack of carbohydrate availability can impair energy production. It would make sense to have an athlete with body composition concerns address that during post or off-season. But for the recreational fitness enthusiast, this may have some potential to help with improving body composition.
A final note: If or when I do work with anyone who is looking to make nutritional changes to pursue their goals, I refer them to a registered or licensed dietitian. While it is important for me to understand these concepts, I also recognize my scope of practice.
Marquet, L., Brisswalter, J., Louis, J., Tiollier, E., Burke, L. M., Hawley, J. A., & Hausswirth, C. (2016). Enhanced Endurance Performance by Periodization of Carbohydrate Intake. Medicine & Science in Sports & Exercise, 48(4), 663-672. doi:10.1249/mss.0000000000000823