I must agree with the list – and I’m truly happy to see sit-ups mentioned as useless. (I’d add regular crunches or anything where the work is done by flexing the abdomen.) While sit ups are not the strangest of the exercises, it is one that too many people still believe they MUST do to get a strong and flat stomach.
This is a belief that I wish would go away as quickly as the concept that lifting heavy will make a woman all bulky.
Anyway, why am I anti- sit-ups and crunches? Mainly because Dr. Stuart McGill is. McGill is the University of Ottowa (Canada) world-known expert on the lower back. I read a quote from him once that suggested we have “x” number of flexions in our lower spine. And we can choose to use those to bend over and tie our shoes when we’re 80, or we can do 100 crunches/day damage it that much sooner.
In a T-Nation interview, he explained:
Also among the misperceptions that I hear out there about the rectus abdominis, and upper vs. lower abdominals, is that you’ve got to work the rectus throughout its range of motion. Again these might be muscle physiologists speaking but not people who are cognizant of spinal mechanics. For example, when you look at the architecture of the rectus, it’s a muscle with four heads, four contractile components each separated by a lateral tendon.
If it was a muscle designed to work through its full range of motion it would be one long continuous muscle—but it’s not. It anchors the obliques and transmits the hoop stresses laterally through those lateral tendons. If it wasn’t beaded, the oblique forces would rip it apart laterally. In many elite performances the abdominals contract isometrically. Too many bad backs are created by misinformed people thinking they need to train the rectus with repeated full flexion exercises. There are much better and safer ways to do this.
If you shouldn’t be doing crunches/sit-ups to work your abs, what should you do?
- Planks. And all plank variations. This will strengthen the muscles of your posterior chain, teach these muscles to work as a unit, and teach them to stabilize your spine.
- Bridges. The opposing motion to the plank, bridges strengthen the anterior chain and pelvic floor.
- Bird dogs. Kneeling on all fours, then extending one arm and the opposite leg teaches the core to stabilize with transverse motions.
- The side plank. Again integrates stabilization of the abdominal/core muscles.