OUR MUSCLES HAVE CLOCKS BUILT IN

Many exercisers and athletes prefer to train at the same time every day. They may suggest a variety of reason for this: That's when they feel most awake, least hungry, most focused or least stressed. They may even say it seems easier to work out at a consistent times. They're probably right: But the reason is not merely psychological. It's biological, too. And it all begins with something that everyone has but most have never heard of: a collection of muscle clocks.

Muscles clocks are internal timekeepers that reside in muscles in the body, in much the same way that the master circadian clock resides in the brain. While the master clock monitors and regulates the rhythms of the body as a whole, muscle clocks are primarily responsible for synchronizing daily muscle activity with the rest of the body and the environment surrounding it. When skeletal muscles, biological systems and environmental events are synchronized, a rhythm is established that benefits the entire body, influencing sports and fitness performance, disease prevention, and overall health (Mayeuf-Louchart, Staels & Duez 2015).