Barbell Shrugged - Talking Training W/ Crossfit Games Athletes, Strength Coaches & More

In this episode, Dr. Karen Esser Professor and Chair of the Department of Physiology and Aging at the University of Florida joins the crew to break down one of the most overlooked performance variables in human physiology: circadian timing. After a career spent studying muscle adaptation, Dr. Esser shifted her research toward the molecular clocks inside our tissues, uncovering how every cell in the body keeps its own time. She explains how these clocks govern fuel storage, protein repair, metabolic readiness, and ultimately the way muscle responds to training. The team digs into what these clocks do, how they synchronize, and why misalignment affects everything from daily performance to long-term health. The conversation dives deep into time-of-day effects on strength, endurance, and adaptation. Dr. Esser highlights that humans are consistently stronger and more explosive in the afternoon, a pattern reflected in Olympic records and decades of performance data. But her lab's animal research reveals something g