Leg-raised crunch

Muscles worked

Abs

Primary muscle

Upper abs

Equipment

Bodyweight

Movement pattern

Core

Difficulty

Intermediate

What it is for

Core strengthHypertrophyStabilityStrength

Watch the full tutorial

• Pulling on the neck with the hands. Hands behind the head end up doing the work and the neck flexes instead of the torso. Rest the fingers on the temples or cross the arms over the chest and look at the ceiling.
• Letting the lower back arch. With the legs low, the lower back lifts and the abs lose control of the pelvis. Press the lower back into the floor on every rep; if you cannot, raise the legs or bend the knees.
• Swinging the legs to help you up. That momentum comes from the hip flexors, and the abs just go along. Fix the legs at one height and keep them still; if they move, they are too low for your current strength.
• Coming up with momentum and dropping down. Half of the abdominal work is in the lowering, and letting go throws it away. Exhale as you curl, pause briefly at the top and lower in two seconds without fully resting the head.

Which muscles does the leg-raised crunch work?

The rectus abdominis curls the torso, and the upper part is felt most because the movement starts from the ribs. The obliques assist the flexion and keep the torso centered. The raised legs add intense isometric work for the hip flexors, mainly the iliopsoas and rectus femoris, and for the quads to keep the knees straight. That is why it tires you more than a regular crunch with the same range.

Leg-raised crunch or knees at 90 degrees: which one should you choose?

With the knees and hips at 90 degrees, the legs balance over the hips, the hip flexors work little and the lower back rests on the floor by itself: it is the base version for most people. With the legs straight and low, the hip flexors work hard and keeping the lower back down is harder: a progression for anyone who already crunches without arching. If the lower back lifts, go back to 90 degrees.

Is the leg-raised crunch effective, and how many reps should you do?

Yes, as long as the torso really curls and the legs stay still: then it is a more demanding crunch than the classic one. A common starting point is 3 sets of 12 to 20 reps, leaving 1 to 3 in reserve, with a two-second lowering. When 20 come out clean, add a plate on the chest before adding reps. It usually goes at the end of the session, two or three times a week.

How far should the torso come up, and how high should the legs stay?

The torso rises only a little: enough to lift the shoulder blades off the floor, with the lower back always down. Coming up to sitting turns it into a sit-up ruled by the hip flexors. The legs sit at 30 to 45 degrees; the lower they are, the harder the hip flexors work and the harder it is to keep the back down, so start high. Hands at the temples or crossed on the chest, never pulling on the neck.