I’ve always trained in the morning after a big breakfast. My thought process was simple; I’d be providing high quality fuel for maximum muscle building. There is at least some degree of truth to my methodology.

Recently, however, I’ve found that my larger meals consisting of five whole eggs, a giant sweet potato and several cups of black, organic coffee have not led to my best workouts. I’ve actually been feeling somewhat sluggish during my sessions. On my recent road trip, I sprinted before breakfast and found my head to be clear and my body filled with ample energy. Additionally, I was likely burning fat more efficiently, according to a study reported in the New York Times:

For one, as has been known for some time, exercising in a fasted state (usually possible only before breakfast), coaxes the body to burn a greater percentage of fat for fuel during vigorous exercise, instead of relying primarily on carbohydrates. When you burn fat, you obviously don’t store it in your muscles. In “our study, only the fasted group demonstrated beneficial metabolic adaptations, which eventually may enhance oxidative fatty acid turnover,” said Peter Hespel, Ph.D., a professor in the Research Center for Exercise and Health at Catholic University Leuven in Belgium and senior author of the study.

If you’ve been following the blog, you’ve likely seen our posts devoted to the value of trial and error. It’s certainly the way I learn best and how I encourage folks I care about to learn about training. I’m putting the philosophy into practice on this one. Tomorrow, I’ll be running my sprints before breakfast.

I don’t necessarily have a specific plan in mind. This experiment came about simply from an anecdotal feeling of sluggishness. The research, however, suggests that I could experience better muscle development and recovery from my sessions. From a study published in the European Journal of Applied Physiology:

…training in the fasted state, compared with identical training with ample carbohydrate intake, facilitates post-exercise dephosphorylation of eEF2. This may contribute to rapid re-activation of muscle protein translation following endurance exercise.

Contrary to my concerns about my body not having enough fuel to fire in an optimal fashion, training in the morning while still fasted may lead to more power. From the Journal of Strength and Conditioning Research on a study on cyclists:

In addition to aerobic endurance and anaerobic capacity, high power-to-weight ratio (PWR) is important for cycling performance… exercising after fasting overnight can improve a cyclist’s PWR without compromising endurance cycling performance.

I don’t know if a study on endurance athletes will apply to my sprints, but it is worth finding out. I’m not going to put a time limit on my trial. If I don’t have ample energy, I’ll go back to my old style. That result would represent the error, and I will have learned something. If I’m feeling strong, perhaps I’ll stick with it.

To science,

Kap