What Drives Muscle Growth & What Doesn't | Dr. Mike Roberts

In this episode, I sit down with Dr. Mike Roberts, Professor in the School of Kinesiology at Auburn University, and one of the most respected muscle physiologists, to explain how muscle actually grows. Mike shares that mechanical tension—not hormones, metabolic byproducts, or muscle damage—is the primary driver of hypertrophy. We cover why testosterone and androgen receptors don't necessarily predict muscle growth, what separates high responders from low responders, and how these “low responders” should train to best get results. We also work through training volume, load versus reps, lengthened partials, aging and anabolic resistance, and the interference effect between strength and endurance training. If you want to understand the real science of building muscle, this conversation is for you.

Sponsors

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Chapters

(00:00:00) Introduction

(00:03:15) How Muscle Grows

(00:17:39) What Drives Growth: Tension, Stress & Damage

(00:24:08) Responders vs. Non-Responders

(00:29:54) Hormones, Receptors & Genetics

(00:48:01) Cell Signaling, mTOR & Myostatin