Honestly, most people treat core training like they’re trying to win a laundry-folding contest with their own torso. We’ve been told for decades that the path to a "strong back" is paved with 500 crunches and those weird twisting machines at the gym.
It’s total nonsense.
If you’ve ever felt that sharp, electricity-like twinge in your lower back after a set of sit-ups, you’ve met the consequences of "spinal flexion" firsthand. Dr. Stuart McGill, basically the godfather of spine biomechanics, spent decades in a lab at the University of Waterloo proving that our spines have a finite number of bends in them before the discs start to look like a squashed jelly donut. He didn't just guess; he used cadaver spines and high-tech sensors to see exactly what makes a back "break."
The result? The Stu McGill Big 3.
These aren't "ab exercises" in the way you think of them. They are stability drills. The goal isn't to move; the goal is to not move while your limbs try to pull you out of alignment. If you do them right, they’re exhausting. If you do them wrong, they’re just another way to waste ten minutes on the floor.
1. The Modified Curl-Up (Not Your 80s Gym Class Crunch)
The biggest mistake I see? People trying to touch their elbows to their knees. Stop it.
📖 Related: How to get rid of a hangover quick: What actually works vs. what's just a myth
In a traditional crunch, you’re crushing your lumbar discs. McGill’s version is different. You lay on your back with one leg straight and one knee bent (foot flat). This little tweak keeps your pelvis from tilting and protects your lower back. You slide your hands under the natural arch of your spine.
Why? Because your hands are the "canary in the coal mine." If you feel your back flattening against your fingers, you’re cheating.
You only lift your head and shoulders about an inch or two off the floor. Gaze at the ceiling. Imagine your head is sitting on a scale and you just want to make the scale read "zero." You hold that for 10 seconds. It feels like nothing at first, then you realize your deep abs are actually screaming.
2. The Side Bridge: The Forgotten Stabilizer
Most people skip the sides of their body, which is why they "throw their back out" when they reach for a grocery bag. The Stu McGill Big 3 includes the side bridge because it hits the quadratus lumborum (QL) and the obliques without the crushing load of a front plank.
You can start from your knees if you’re hurting or just getting back into it. If you’re a bit more advanced, go from the feet. The key is the "stiff board" look. No sagging hips. No rotating your chest toward the floor.
Dr. McGill is big on the 10-second hold. Why 10 seconds? Because research shows that shorter, high-quality holds build endurance without depriving the muscles of oxygen or causing the "shaky" fatigue that leads to injury.
3. The Bird Dog: Finding Your Center
This one looks easy until you try to do it without wobbling like a drunk toddler.
You’re on all fours. You extend the opposite arm and leg. Most people try to reach as high as possible, arching their back like a mountain range.
Don't do that. Think "long," not "high." Push your heel toward the back wall and your fingertips toward the front wall. If I put a glass of water on your lower back, not a drop should spill. To really "McGill" this, make a fist with the reaching hand. That "radiation" of tension helps lock in the spine.
The Secret Sauce: The Descending Pyramid
You don’t just do 3 sets of 10. That’s boring and inefficient. McGill suggests a descending pyramid to manage fatigue.
It looks like this:
- 6 reps of each (10-second holds)
- Short rest.
- 4 reps of each (10-second holds)
- Short rest.
- 2 reps of each (10-second holds)
This way, you’re doing the most work when you’re the freshest. As you get tired, the volume drops so your form doesn't go to crap.
Is This Enough to Fix Your Back?
Kinda. But also, no.
The Stu McGill Big 3 are tools, but they won't fix a back that you're constantly "re-injuring" throughout the day. If you do these exercises perfectly for 15 minutes but then spend 8 hours slumped over a laptop or picking up heavy boxes with a rounded spine, the exercises won't save you.
McGill calls this "spine hygiene." It’s about how you move 24/7. These exercises "stiffen" the core so that your hips can do the heavy lifting. You want a stiff torso and mobile hips—most people have the opposite.
Actionable Next Steps
If you’re ready to stop the "stretch and pray" method for back pain, start here tomorrow morning:
- Audit your "Cat-Camel": Before you do the Big 3, do some gentle Cat-Camels to lubricate the joints. But don't push to the end range. Just move through the "painless" middle ground.
- The 10-Second Rule: Never hold a rep longer than 10 seconds. If it’s too easy, increase the tension (squeeze harder), not the time.
- Check your neck: During the Curl-up, if your neck hurts, you’re pulling with your chin. Keep your tongue on the roof of your mouth behind your front teeth. It sounds weird, but it stabilizes the neck muscles.
- Walk more: McGill is a huge fan of "fast walking" with swinging arms. It’s the perfect natural reset for the spine after doing your stability work.
The goal isn't to have "6-pack abs." The goal is to have a spine that stays still while you live your life. Start the pyramid tomorrow. Your future self will probably want to buy you a beer for it.