Study Spotlight: Sleep "LOW", Perform Better but Don't Worry About Elevation

By: Andrew Jagim

People often use the phrases "Train low, live high" to describe a style of training that utilizes the benefits of our body's ability to adapt to living at altitude as a result of several physiological adaptations. However, recently investigators have taken this same catch phrase and applied it to the idea of training or sleeping in a "low carb" state or more specifically a glycogen-deleted state.  Typically our bodies rely on digested carbohydrates with are stored within the body as muscle and liver glycogen for energy during periods of training and recovery.

So when our bodies have low carbohydrate availability it is then forced to look elsewhere for alternative fuel sources.  By forcing the body to use alternative fuel sources it may stimulate some physiological and metabolic adaptations (i.e. increase aerobic enzyme content, increase mitochondrial density etc.) to occur that better allow the body to utilize fat as a fuel source for example which could provide a performance advantage during competition.

Recently a team of investigators sought out to determine when was the best time to train, in regards to the availability of carbohydrates for fuel.

What did they do?

The researchers divided 21 triathletes into two groups: A diet manipulation group which underwent a 3-week training/diet intervention and a control group. The diet group completed a 3-week training/diet period which consisted of train-high interval training, overnight carb restriction "sleep low" and 3) "Train-low" sessions with low endogenous and exogenous carb availability. The control group followed the same training program but with high carb availability throughout the training sessions.

What did they find?

The researchers found a significant improvement in delta efficiency during sub-max cycling in the "Sleep low" group versus the control.  They also found an improvement in the supra-maximal cycling to exhaustion test at 150% of peak aerobic power and 10 km performance in the "sleep low" group.  Not to mention, the "sleep low" group also experienced a significant reduction in fat-mass.

Conclusions

The authors concluded that short-term periodization of dietary carbohydrates around periods of training may positively influence performance in cycling energy efficiency and time to exhaustion during a maximal cycling test.  Try completing some HIIT training first-thing in the morning before you have breakfast to take advantage of this apparent "sleep low" phenomenon.  WARNING, this may take several weeks for your body to adapt and your first couple of training sessions may be a struggle as you get accustomed to the "low-carb" state.

Reference Article Here