Two Schools of Core Training: Anti-Extension vs. Anti-Rotation

Introduction

The word “core” has been used so loosely it’s almost lost its meaning. Crunches, planks, sit-ups, plank holds… which ones actually work? Stuart McGill, Canada’s leading authority on lower-back rehabilitation, offers a simple framework: the core’s job isn’t to create movement, it’s to resist movement — resisting extension, resisting lateral flexion, resisting rotation. This idea has completely reshaped how athletes approach core training.

What Is “Anti-Movement” Training

McGill argues that the spine’s essential job is stability, not repeated bending. Doing 100 crunches a day is actually repeatedly loading the intervertebral discs — a harmful habit, not a healthy one. Truly effective core training should train this instead: “An external force is trying to move my spine, and I use core strength to keep it still.”

Anti-Extension

This resists the spine being bent too far backward. When your foot strikes the ground while running, when you stand up out of the saddle while cycling, or when you pull a barbell off the floor, your lower back tends to hyperextend backward — and that’s exactly when you need anti-extension core strength.

Representative exercises:

• Plank
• Ab Wheel Rollout
• Dead Bug
• Hanging Leg Raise

Anti-Rotation

This resists the spine being twisted by outside forces. When you land on one foot while running, push off one side while cycling, or pull through the water on one arm while swimming, your pelvis and spine get pulled by a rotational torque — and the core has to resist that rotation.

Representative exercises:

• Pallof Press (standing anti-rotation press)
• Single-arm farmer’s carry
• Single-arm dumbbell bench press
• Bird Dog

Anti-Lateral Flexion

This resists the spine bending sideways. It’s often overlooked, but it has a huge impact on running posture stability.

Representative exercises:

• Side Plank
• Single-side kettlebell farmer’s carry
• Around the World (plate raise)

Suggested Training Schedule

Why You Should Stop Doing Crunches

The crunch’s movement pattern is repeated spinal flexion. According to McGill’s disc research, spines that flex more than 600 times a day show a significantly higher risk of disc herniation. For people already hunched from hours of cycling or slumped from sitting at a desk all day, crunches just add insult to injury.

Practical Tips

• Core training can be done every day: unlike squats, it doesn’t need 48 hours of recovery
• Short but consistent beats long and rare: 10 minutes a day beats one 60-minute session a week
• Add breathing work: intra-abdominal pressure (IAP) and diaphragmatic breathing are the foundation of core stability
• Stop immediately at pain: any sharp pain in the lower back means stop right away and re-check your form

Conclusion

The core isn’t a six-pack — it’s your spine’s stability system. Shift your training focus from “creating movement” to “resisting movement,” and your lower back will be healthier, your athletic performance more stable, and your posture will hold up better in the closing stretch of long-distance efforts. Three directions, six to nine exercises a week — that’s the full picture of modern core training.

Related Reading

• Anti-Rotation and Anti-Lateral Flexion Core Training for Endurance Athletes: From Plank to a Functional Force-Transfer Chain
• The Truth About Core Training: Endurance Athletes Should Train Anti-Rotation Stability, Not Just Abs
• Core Training for Runners: Anti-Rotation, Anti-Lateral Flexion, and Pelvic Stability
• Core for Swimmers: Why Anti-Rotation Matters More Than Flexion