Believe it or not, a lot of your favorite abdominal workouts may actually be working out your hip flexors more than your abs. Get the facts so you can maximize your ab exercises.
Hip flexors
The hip flexors are a group of muscles that help bring the thighs and torso together through flexion at the hip. These muscles include:
- Iliopsoas
- Rectus femoris
- Pectineus
- Sartorius
The hip flexors aren’t a part of the abdominal muscle group, but during ab exercises that utilize a greater range of motion, the hip flexors take over. Hip flexors are responsible for hip flexion, whereas the abdominal muscles work to allow rotation and flexion of the spine. In order to get the most out of your abs, you need to focus on exercises that require minimal involvement from the hip flexors while still allowing great abdominal muscular contraction.
Are you working hip flexors or abs?
The abdominal muscles flex the spine–bringing the torso to the thighs–up to roughly 45 degrees or until your shoulder blades have been lifted off the floor a couple of inches. After this angle, the hip flexors begin to take control in additional spinal flexion. For this reason full hip flexion, as is seen with sit-ups, is not a truly effective way to isolate your abdominal muscles. Additionally, sit-ups place a great deal of stress on your lumbar spine–especially when your feet are anchored–and are generally not recommended. Crunches on the other hand are more effective at isolating the abdominals and also minimize spinal stress and hip flexor activity. Hip flexor activity may also be dominant in the beginning stages of some exercises such as leg lifts or leg raises since the leg lifting motion requires flexion at the hip and not the spine.
Isolate your abs
If you really want to focus on your abdominal muscles, then consider some of the following exercises:
- Crunches/curl-ups
- Reverse crunches
- Standing side bends
- Oblique crunch
- Oblique twists
These exercises require little hip flexor activation and instead maximize abdominal contraction. Remember to go slow during your exercises and blow out forcefully at the top of the movement. This will ensure an extra squeeze at the top and force your abdominals to work harder. Keep your chin up and don’t pull on the back of your neck to avoid straining it.
Additional tips
- Don’t train your abdominals every day.
- Perform 10-20 reps of each exercise and avoid excessive reps. If you need to up the challenge, try adding a little weight and maintain good form.
