Sideways Lifts Vertical Straight Legs

Body Part: Waist

Muscle: Abs

Equipment: Body Weight

Sideways Lifts Vertical Straight Legs is shown here as a supine core drill: lie on your back, keep both legs straight up over the hips, and use your abs to curl the pelvis off the floor in a short, controlled range. The movement is small, but the lever from the straight legs makes it demanding, so the quality of the pelvic tuck matters more than how high you lift.

The main training effect comes from the rectus abdominis, with the obliques and deep core helping keep the ribcage down and the pelvis aligned. Hip flexors assist in holding the legs vertical, but they should not take over the rep. If the low back arches or the legs drift toward the face, the set becomes more about balance and hip flexion than about clean abdominal work.

Set up by lying flat with the arms along your sides, palms down, and the legs together. Stack the feet above the hips, then gently flatten the lower back into the floor before the first rep. That starting position is important because it creates the posterior pelvic tilt that protects the spine and makes the abdominal curl effective.

During each repetition, exhale, brace, and curl the tailbone upward a few inches without swinging the legs or pushing through momentum. Keep the shoulders relaxed on the floor and let the pelvis move as one piece. Lower under control until the sacrum returns to the mat, then reset before the next rep.

This exercise works well as bodyweight core accessory work, a finisher, or a lower-ab focus drill when you want controlled tension instead of load. It is a useful choice for athletes and beginners alike, but only if the range stays short enough to keep the torso stable and the neck relaxed. If the movement feels like a hip-flexor strain or the lower back starts to arch, reduce the range and slow the tempo.

Instructions

• Lie on your back on a mat with your arms straight along your sides and your palms pressing lightly into the floor.
• Bring both legs together and extend them straight up over your hips so your feet are stacked above your pelvis.
• Set a small posterior pelvic tilt so your lower back is gently pressed toward the floor before you start.
• Inhale to prepare, then brace your abs and keep your ribs down as you begin the rep.
• Exhale and curl your tailbone and hips a few inches off the floor without swinging your legs or bending your knees much.
• Keep the legs vertical and move the pelvis as one controlled unit instead of kicking upward.
• Pause briefly at the top when your hips are lifted and your shoulders stay relaxed on the mat.
• Lower slowly until your sacrum returns to the floor and your lower back stays controlled.
• Reset your brace before the next rep and repeat for the planned set.

Tips & Tricks

• Keep the legs stacked over the hips; if they drift forward, the hip flexors take over and the abs lose tension.
• A slight knee bend is better than locking out so hard that your lower back arches.
• Press your palms into the floor to stabilize your torso and stop the chest from flaring up.
• Lift only a few inches; this is a pelvic curl, not a big leg swing.
• If you cannot keep the low back controlled, shorten the range before you try to increase reps.
• Keep the neck long and relaxed so you do not turn the movement into a crunching strain.
• Use a slow lowering phase of about two to three seconds to keep tension on the abs.
• Stop the set when the pelvis starts rocking or the feet can no longer stay directly above the hips.
• Exhale through the effort phase to help keep the ribcage down and the core braced.

Frequently Asked Questions

What muscles do Sideways Lifts Vertical Straight Legs work most?

They primarily train the rectus abdominis, with the obliques and deep core helping stabilize the pelvis.

Is this more of a leg raise or a reverse crunch?

It is closer to a reverse crunch with the legs held vertical, because the main action is a small pelvic curl.

Should my lower back stay on the floor the whole time?

At the bottom, yes, it should stay controlled and close to the floor. The rep starts with a solid brace, then the hips lift without losing lumbar control.

Can beginners do this bodyweight exercise?

Yes, but beginners should keep the range short and may need a slight knee bend until they can hold the pelvis steady.

Why are the legs kept straight up?

The vertical lever makes the abs work harder to control the pelvis, so the exercise stays focused on the trunk instead of becoming a momentum drill.

What is the most common mistake?

The biggest mistake is swinging the legs or lifting too high and letting the lower back arch off the floor.

Why do I feel this in my hip flexors?

If the legs drift toward your face or the pelvis stops moving, the hip flexors start doing most of the work. Keep the feet stacked over the hips and shorten the range if needed.

How can I make this exercise harder without adding weight?

Slow the lowering phase, pause longer at the top, or reduce the range only if you can still keep the pelvis controlled.