The Core Lie We Keep Believing: Why Crunches Still Won’t Die

Let’s Get One Thing Straight: Crunches and sit-ups aren’t the core training gold standard. In fact, if your goal is real strength, injury prevention, and long-term health, they’re probably the worst place to start. Yet, somehow, they just won’t go away.

Despite decades of science, real-world application, and evolving knowledge, crunches and sit-ups continue to show up in workouts, magazines, bootcamps, and influencer videos like they’re the holy grail of ab training. But let’s call it what it is: outdated, overhyped, and wildly misunderstood.

So, why are we still stuck doing them?

A History of the Crunch Obsession

Let’s rewind. The idea that doing crunches leads to six-pack abs dates back to the '70s and '80s when bodybuilding and aesthetic-focused fitness took center stage. Everyone wanted to “spot reduce” belly fat, and the crunch was the go-to move for carving out a chiseled midsection.

But here’s the problem: spot reduction is a myth. You can’t crunch your way to a leaner waistline. Body fat is reduced systemically—not in isolated pockets—through a combination of calorie deficit, strength training, cardio, sleep, and stress management. Period.

Worse yet, the mechanics of crunches and sit-ups are fundamentally flawed when it comes to spine health and real-world core function.

Enter Dr. Stuart McGill: The Spine Doesn’t Lie

Dr. Stuart McGill, a world-renowned spine biomechanist and professor emeritus at the University of Waterloo, has spent over 30 years studying spinal mechanics. His conclusion? Repeated spinal flexion—the very motion used in sit-ups and crunches—is one of the fastest paths to disc herniation and chronic low back pain.

According to McGill:

"The spine has a limited number of flexion cycles before it becomes damaged. Performing sit-ups and crunches puts unnecessary stress on the lumbar spine."

In fact, his research demonstrated that repeated flexion leads to a loss of disc height and function, and over time, increases the risk of disc bulges and herniations—especially under load or poor movement patterns.

So why are we still doing them?

The Real Purpose of Your Core

Your core isn’t just there to look good on the beach. Its real function is to:

• Stabilize the spine

• Transfer force between limbs

• Control movement (anti-extension, anti-rotation, anti-lateral flexion)

Crunches and sit-ups? They don’t train any of that. They create movement at the spine, rather than controlling it—which is the exact opposite of what your core is designed to do.

The world’s top strength and performance coaches, from Dr. McGill to Mike Boyle, agree: if your goal is performance, longevity, and spinal integrity, your core training needs to focus on bracing, resisting, and controlling—not curling up like a shrimp on the floor.

The Crunch Addiction: Why They Keep Coming Back

So why are crunches still around?

1. They're Easy to Teach and Do Crunches are simple. No equipment. Easy to demonstrate. Accessible for all fitness levels. But just because something is simple doesn’t mean it’s effective—or safe.

2. Aesthetic Obsession People are still chasing the six-pack, and crunches feel like they target the abs. The burn is real. But again, the burn doesn’t equal effectiveness. The visible abs you’re chasing? That’s made in the kitchen and supported by full-body strength and conditioning work—not ab circuits.

3. Fitness Myths Die Hard We live in a copycat culture. When one person shows crunches in a viral video, a thousand others follow. Without context. Without science. Without results that matter.

4. No Immediate Pain Doesn’t Mean No Damage Most people don’t feel pain during crunches—until the damage has already begun. Herniated discs don’t happen overnight. They build slowly, silently, through years of faulty mechanics. That’s why smart programming is about prevention, not reaction.

What to Do Instead: Core Training That Works

Want abs that not only look good but function at an elite level? Focus on anti-movement patterns, not spinal flexion. Here’s what that looks like:

1. Anti-Extension

Your spine wants to overarch. Your job is to resist it.

• Dead Bug

• Stability Ball Rollouts

• Ab Wheel

• Plank Variations (RKC Plank, Long Lever Plank)

2. Anti-Rotation

Rotational forces from lifting, running, or daily movement? Your core has to stay locked in.

• Pallof Press

• Single Arm Farmer’s Carries

• Landmine Anti-Rotation

3. Anti-Lateral Flexion

When something pulls you to the side, your core must resist.

• Suitcase Carries

• Side Planks with Reach-Throughs

• Offset Loaded Squats

4. Rotation and Diagonal Patterns (When Controlled)

When you're ready, integrate controlled rotation to mimic sport and life.

• Cable Chops

• Med Ball Rotational Throws

• Standing Band Rotations

The Numbers Don't Lie

In a 2009 study (Journal of Strength and Conditioning Research), athletes who incorporated anti-movement core exercises improved performance metrics (sprint speed, jump height, rotational power) significantly more than those relying on traditional ab routines.

In contrast, a 2013 analysis from McGill’s lab showed that subjects performing repeated sit-ups over six weeks had increased spinal stiffness and decreased hip mobility—two red flags for athletic performance and injury risk.

Let’s Get Practical: What You Should Be Doing

Ditch the floor crunches. Instead, build your week around:

Day 1 – Stability Core

• Dead Bug – 3x8/side

• RKC Plank – 3x20 seconds

• Pallof Press – 3x10/side

Day 2 – Carry Day

• Farmer’s Carry – 3x40 yards

• Suitcase Carry – 3x30 yards/side

• Overhead Carry – 3x20 yards

Day 3 – Power Core (Rotation Focused)

• Med Ball Rotational Slams – 3x8/side

• Cable Chops – 3x10/side

• Plank Reach with Shoulder Tap – 3x12

These movements don’t just work the muscles around your spine—they build a bulletproof system that keeps you moving, lifting, and living without pain.

Train Smarter, Not Louder

It’s easy to fall for exercises that make you feel like you’re working hard. Crunches will do that. But they’re not the path to real core strength. They’re not the secret to a six-pack. And they’re definitely not a ticket to a pain-free back.

Let’s stop chasing fads and start chasing function.

Your core deserves better. So do your results.

It’s time to leave crunches where they belong—in the past.

Want to Learn What Core Training Actually Looks Like?

Book a free training assessment with our team. We’ll break down your current routine, identify weaknesses, and build a custom program designed to make you stronger, safer, and more capable—no gimmicks, no nonsense. Call or text 973-352-0933 to get started. Because your body isn’t average. Your training shouldn’t be either.