Isolating Abdominal Muscles
If you are my client or have taken my classes before- you know how picky I am about how to properly train your abdominal muscles. You may have heard me say- “stay out of your hip flexors…”. What does that mean? And how can you do it?
First of all, the hip flexors are a group of muscles that bring the thigh and your torso closer together. You use your hip flexors in many daily activities like walking, stepping up, and bending over. In technical terms, the hip flexors are the illiacus, psoas major, pectineus, rectus femoris, and sartorius muscles. Obviously, we need our hip flexors. But we usually don’t need them as much as we use them in abdominal exercises.
Here is the problem: When we exercise to target the abs we do movements that decrease the distance between our thigh and trunk: think sit-ups, roll-ups or leg lifts. The hip flexors are a strong group of muscles, and tight on most people. This causes them to be over-facilitated, which means they take over the movement and we end up working our hip flexors more than our abdominal muscles! You can literally do 500 sit-ups and not have a single one of them truly target your abs.
For example: the old fashioned exercise where you put your feet under something to hold them down and then do a whole bunch of sit-ups with an almost flat back? Guess what? The hip flexors are doing most of the work. (Not to mention that your sacrum is being slammed against the floor). Another example is doing leg lifts on the Roman Chair in the gym. If the only thing you are lifting is your legs and your tail bone stays on the pad… all of the work is being done with your hip flexors. Reverse crunches where you are only moving the legs but not the spine are targeting hip flexors as well. Not to say that the abs aren’t involved, but they are only involved isometrically, which means that they are only stabilizing the torso and not responsible for the primary movement. In Pilates, we run the same risk with the many flexion (forward bending) exercises we do.
“So how do I get out of my hip flexors?”
The answer isn’t simple. A lot of us have to work on the hip flexor habit constantly. For one thing, you can’t really leave the hip flexors entirely out of most ab exercises. They are still an important part of the picture. The idea is to get the abs involved as much as you can and to keep the hip flexors from taking over.
The first line of defense is always awareness. When you do any type of focused abdominal work, put your attention on your abdominal muscles. Start to figure out for yourself what feels like abs and what feels like hip flexors. It might help to familiarize yourself with the abdominal muscles and their functions. That way you will know if they are actually doing the movement. The primary function of the abdominals is to flex the spine (think of your tail bone coming toward your head). So-when you are doing a reverse crunch: observe whether or not your hips are actually lifting off the floor. Are you swinging your legs up to create the movement? Don’t mistake excess motion for abdominal contraction. When you take the legs out of the movement by keeping your knees into your chest and your feet down by your hips, you are forced to make the abs do the work, not your hip flexors…and yes it will be much harder!
Knowing how to isolate your abs is important not just for having a toned mid-section but also to loosen up your low back and prevent injuries. Low back pain and soreness in the groin area may be signs that you are weak in the abs and over-using your hip flexors. Another clue is not being able to keep your feet and legs down when you do a sit up or roll up. Do you see the logic in that one? What’s happening there is that the abs aren’t strong enough to do their up-and-over contraction, but we’ve told the body to get the trunk and thigh closer together, so the hip flexors take over and the feet fly up. (Tight hamstrings play a role too)
Stretching the hip flexors is also going to be very important in prevent them from firing when they shouldn’t.
As you work with increasing your awareness of the relationship between the abs and the hip flexors, you will discover that there is reciprocity in terms of one set of muscles doing the stabilizing of the trunk or pelvis while the other set moves. What we want to achieve is muscular balance, better functionality, and ultimately more choices about how we move.