The raised leg crunch is a floor-based abdominal exercise that combines a straight-leg raise with a standard crunch, keeping the legs improved throughout to maintain constant tension on the rectus abdominis. It also recruits the hip flexors to hold the legs in position while the upper body curls up and down. Because the legs stay lifted rather than resting on the floor, it removes the lower back's ability to rest, making it more demanding than a basic crunch. It's a bodyweight movement that needs no equipment beyond a mat.
Muscles Targeted
- Primary: Rectus abdominis (upper and lower)
- Secondary: Hip flexors (iliopsoas), obliques
- Tertiary: Lower back stabilizers (erector spinae)
Starting Position
Lie flat on your back on a mat with your legs extended straight and pressed together, lower back in contact with the floor. Place your fingertips lightly at your ears or crossed on your chest - do not interlock your hands behind your head. Raise both legs straight up until they are close to perpendicular to the floor; this is your starting position before each rep.
Execution Steps
- Brace your core by pulling your navel toward your spine before initiating any movement
- Curl your upper body off the floor by contracting your abs, lifting your shoulder blades a few inches off the mat
- Reach your fingertips toward your raised feet as you crunch, keeping your chin off your chest
- Hold the top position briefly, squeezing the abs at peak contraction
- Lower your torso back down with control, keeping your legs vertical and stationary throughout
- Repeat for the desired number of reps without letting your lower back arch off the floor
Form Cues
- Keep legs vertical: Resist the urge to lower your legs as you crunch - they should stay near-perpendicular throughout
- Move from the abs, not the neck: Avoid pulling on your head or neck to generate momentum
- Press your lower back down: Keep the lumbar spine in contact with the floor to protect it and keep tension on the abs
- Exhale on the crunch: Breathe out as you curl up, inhale as you lower
- Short range, full contraction: The crunch is a small movement - focus on squeezing rather than sitting all the way up
Common Mistakes
- Pulling on the neck: Interlocking hands behind the head and yanking it forward strains the cervical spine; keep hands lightly at the ears instead.
- Letting the legs drop: Allowing the legs to sag toward the floor removes tension from the lower abs and adds lower-back stress.
- Using momentum: Swinging the torso up quickly reduces muscle tension; slow, controlled reps build more strength.
- Arching the lower back: A flat lower back protects the spine; if it lifts off the floor, the range of motion is too large.
- Rushing the eccentric: Dropping back down quickly wastes much of the exercise's benefit; lower with control instead.
Variations
- Reverse crunch: Removes the upper-body curl, isolating the lower abs by lifting the hips instead
- Weighted raised leg crunch: Hold a light plate or dumbbell against the chest to add resistance
- Twisting raised leg crunch: Rotate the torso toward alternating knees to bring in the obliques
- Stability ball raised leg crunch: Performing on a ball increases the range of motion and core stabilization demand
- Hanging leg raise: A more advanced hip-flexor-dominant progression using a pull-up bar
Tips for Progression
- Increase reps: Build toward 3 sets of 15-20 controlled reps before adding resistance
- Add resistance: Hold a light weight plate against your chest once bodyweight reps become easy
- Slow the tempo: Add a 2-3 second pause at the top of each rep to increase time under tension
- Progress to hanging variations: Once floor crunches are mastered, move to hanging leg raises for greater difficulty
Training Notes
Train raised leg crunches 2-3 times per week as part of a core-focused session, typically for 3 sets of 15-20 reps with 30-45 seconds of rest between sets. They pair well after compound lifts as a finishing core movement, since fatigued abs can still handle isolated flexion work without compromising bigger lifts.