In this episode of The Rucker’s Edge, Dr. Ryan Peebles, Doctor of Physical Therapy and founder of Core Balance Training, unpacks what’s really happening to your spine when you ruck under load.

Dr. Peebles explains why rucking back pain is rarely about having a “weak core” and is more often tied to poor core endurance, breathing mechanics, and loss of spinal stability as fatigue sets in. Rather than chasing sit-ups or isolated ab exercises, he introduces the concept of core connection (the ability to maintain intra-abdominal pressure and spinal support for long periods of time).

You’ll learn how added ruck weight increases the same forces already acting on your spine, why posture tends to break down when the core fatigues, and how common patterns like anterior pelvic tilt show up during long rucks. Dr. Peebles also hi ...