Close Banner Routines Ditch the Crunches — Here's What Actually Builds Core Strength Author: Ava Durgin March 04, 2026 Assistant Health Editor By Ava Durgin Assistant Health Editor Ava Durgin is the Assistant Health Editor at mindbodygreen. She is a recent graduate from Duke University where she received a B.A. in Global Health and Psychology. In her previous work, Ava served as the Patient Education Lead for Duke Hospital affiliated programs, focusing on combating food insecurity and childhood obesity. Image by JoJo Jovanovic / Stocksy March 04, 2026 Somewhere along the way, fitness culture decided that a strong core was built on a gym mat. We've been crunching, planking, and leg-raising our way to "core strength" for years, and yet lower back pain remains one of the most common complaints doctors hear, and most people still can't transfer their ab work into anything that makes real life easier. There's a reason for that. The core isn't a vanity muscle. It's a stability system, a 360-degree brace of deep muscle, fascia, and pressure that exists to protect your spine, transfer force, and keep you upright.  Crunches train almost none of that. And the sooner we acknowledge it, the sooner we can start building true strength. Your core is more important than you think  A strong core isn't about the six-pack you can see. It's about the strength you can use . Research consistently links core stability 1 to injury prevention, better posture, improved balance, and functional independence well into older age.  Think about the last time you lifted a heavy bag of groceries, caught yourself from slipping on a wet floor, or reached across a table to grab something. In every one of those moments, your core was the difference between control and chaos. It's the central link in every kinetic chain your body uses, the structural bridge between your lower and upper body that allows force to travel efficiently through movement. When that system is weak or imbalanced, the downstream effects are wide-ranging: Lower back pain : One of the most common complaints 2 in adults under 50, and frequently linked to poor core stability. Poor posture : A weak core lets the spine drift into compensatory positions over hours of sitting or standing. Hip and knee instability : Without a stable center, surrounding joints take on excess load they weren't designed to handle. Reduced balance and coordination : An issue that becomes increasingly important with age, when fall prevention directly impacts long-term health and independence. Building real core strength, then, is one of the most powerful investments you can make in your long-term health and longevity. RELATED READ: What Is Functional Core Strength? Pvolve's Head Trainer Explains The problem with traditional ab training Even with all their popularity, classic ab exercises are built around a very narrow definition of strength. The crunch, the sit-up, and most floor-based ab work primarily target the rectus abdominis , the long, superficial muscle that runs down the front of your abdomen and is responsible for spinal flexion (bending you forward). It's the muscle that creates the look of a six-pack. It is not, however, the muscle most responsible for functional core stability. Deep beneath the rectus abdominis lives a far more important cast of characters: the transverse abdominis (your body's natural weight belt), the multifidus (a series of small muscles running along the spine), the pelvic floor, and the diaphragm.  Together, these muscles create intra-abdominal pressure, essentially an internal pressure system that braces and protects your spine under load. Traditional crunches barely touch them. Worse, high-volume spinal flexion work can create real problems: Disc stress : Repeatedly rounding the spine under load places pressure on the intervertebral discs, which is compounded in people who already sit for most of the day. Hip flexor dominance : Crunches heavily recruit the hip flexors, the muscles connecting your thighs to your lower spine, pulling the pelvis forward and contributing to anterior pelvic tilt. Strength plateaus : Because crunches are so limited in the muscles they actually target, progress tends to stall quickly without meaningful carryover to real-world movement. Crunches do have their place, but they shouldn’t be the foundation of your core training.  What your core is designed to do Watch someone carry a heavy suitcase through an airport. Notice how their torso doesn't collapse sideways? That's their core resisting lateral flexion, keeping them upright against an asymmetrical load. Watch someone perform a powerful tennis serve or a golf swing. That rotational force doesn't come from the arms; it's generated and transferred through a braced, stable core. In real life, the core functions as a stabilizer and force transfer system , not a primary mover. It resists extension when you lift something heavy overhead. It resists rotation when a singl