Understanding the Pectoralis Major: Anatomy, Function, & Training Tips

In this “NASM-CPT Podcast,” host Rick Richey gets personal and practical, diving deep into the anatomy and significance of the pectoralis major—better known as the “pecs.” Rick opens up about his own childhood experiences and how a formative (and embarrassing) classroom moment inspired his obsession with building his chest muscles. Through relatable stories and a few laughs, Rick connects personal transformation with anatomical education. Listeners will learn the etymology of the pectoralis major, the Latin roots of its name, and why understanding muscle attachments is foundational to good training. Rick expertly breaks down the pec’s structure—including its multiple points of attachment on the sternum, clavicle, and ribs—and explains how its fan-shaped muscle fibers allow for various directional movements. He demystifies key joint actions like horizontal adduction, flexion, and internal rotation, and highlights how certain exercises, such as bench presses at different angles, target upper, middle, or lower pec fibers. Rick also busts some common gym myths, clarifying why you can’t “isolate” just the inner or outer pecs, and emphasizes the importance of proper technique and functional anatomy for trainers. With practical insights and memorable rules for muscle function, this episode is a must-listen for fitness professionals and enthusiasts alike. If you like what you just consumed, leave us a 5-star review, and share this episode with a friend to help grow our NASM health and wellness community! Introducing NASM One, the membership for trainers and coaches. For just $35/mo., get unlimited access to over 300 continuing education courses, 50% off additional certifications and specializations, EDGE Trainer Pro all-in-one coaching app to grow your business, unlimited exam attempts and select waived fees. Stay on top of your game and ahead of the curve as a fitness professional with NASM One. Click here to learn more. https://bit.ly/4ddsgrm