I had an email from a reader a few weeks ago that I unfortunately haven’t had the time to get back to as of yet, but it went something like this:
Dean, I want to be like you in every way. You bring sunshine to my life, and I’m going to name my first-born after you (I think, I kinda zoned out for the first few lines and just started thinking about puppies for a few minutes). Every time I do leg raises, I feel my legs working more than I feel my abs. What’s up with that?? Am I doing something wrong??
To answer your question as simply as possible…..ahem…….YES.
Leg raises, for those who are not indoctrinated with the advanced naming capacity of a personal trainer, is when you, uh, raise your legs. This is also called hip flexion, and is useful for training the abdominals. Pretty spiffy, right? Hells yeah!!!
When performing this movement, the abs have to work as dynamic stabilizers for the lumbopelvic region, in that they are resisting the mechanical propensity to go into an anterior tilt as you raise your legs up in front. Simple mechanics and something called Newtons Law show that if you have a downward force in the front of the center of gravity, it has to be balanced with the same force in the back to prevent movement, which in this case would be a pelvic tilt from weak abdominals and low back muscles. Commonly, this will result in the illiopsoas muscles and rectus femoris muscles having to do more work to flex the hip and have the abs just lie there like a lazy dog in the sunshine.
By performing a leg raise, either the hanging variety or the supine from the floor version, if the abs aren’t strong enough to resist this moment of force application, they wind up stretching out and not firing properly, relying on the hip flexors and back erectors to do all the work.
One of the best ways I’ve found to perform a leg raise without losing a pelvic tilt is to use a blood pressure cuff to tell whether the spine is moving away from neutral or posterior tilt and into anterior tilt as the legs lower to the ground. If the needle starts to go down, the pressure of the spine pushing down into the cuff is reducing, meaning the back is arching off the cuff and moving into anterior tilt. Keeping the needle within 5 mmHg through the entire movement.
Seriously, if you can do a set of 10 of these bad boys three times, you’re a core God!!!
One of the easiest ways to look at exercise is where you feel the muscle working hard, that’s what’s doing the most work. So if you feel your thighs and hip flexors scorched like Fergie’s halftime show review, and your abs feel like their fresh as a daisy, then your obviously working your legs and not your abs, so changing your position can make the biggest difference in the world.