Twist Crunch (leg-up)
- Target muscle
- Iliopsoas, Obliques, Rectus Abdominis
- Synergist muscles
- Quadriceps, Tensor Fasciae Latae
- Equipment
- Body weight
- Body part
- Waist
- Type
- Strength
The Twist Crunch (leg-up) is a bodyweight core exercise that targets the rectus abdominis, obliques, and iliopsoas simultaneously while the legs are raised, increasing the demand on the abdominal wall. The rotational component activates the obliques to a greater degree than a standard crunch, making it an efficient choice for building both core strength and rotational stability.
How to do the Twist Crunch (leg-up)
- 1Lie on your back on an exercise mat. Raise both legs to roughly 90° so your shins are parallel to the floor or your legs are fully extended toward the ceiling.
- 2Place your hands loosely behind your head with your elbows wide — fingertips touching, not interlaced, so you don't pull on your neck.
- 3Engage your core by pressing your lower back gently into the mat.
- 4Exhale and curl your upper torso up and across, rotating your right elbow toward your left knee while your left leg may draw slightly closer.
- 5Hold the peak contraction for a moment, feeling the squeeze through your obliques and abs.
- 6Inhale and slowly lower your torso back to the mat with control — do not drop down.
- 7Repeat the movement to the opposite side, bringing your left elbow toward your right knee.
- 8Continue alternating sides for the target number of repetitions.
Form tips
- Keep your chin slightly tucked and leave a fist's worth of space between your chin and chest to avoid straining your neck.
- Initiate the movement from your core — think of bringing your ribcage toward your hip rather than pulling your head with your hands.
- Maintain steady leg position throughout the set; letting the legs drop reduces abdominal tension and shifts load off the target muscles.
- Control the descent on every rep — slow lowering keeps tension on the abs and makes the exercise more effective than fast, bouncy reps.
Common mistakes
- Pulling the head and neck with your hands, which strains the cervical spine and takes work away from the abdominals.
- Letting the hips rock or the lower back arch away from the mat, which reduces core engagement and places stress on the lumbar spine.
- Using momentum to swing the torso up rather than contracting the abs, which shortens the effective range of motion.
- Dropping the legs between reps — the legs-up position is part of the exercise load; keep them stable to maintain iliopsoas and lower abdominal activation.
- Rotating from the shoulders alone instead of through the thoracic spine, which limits oblique recruitment and reduces the benefit of the twist.
Frequently asked questions
What muscles does the Twist Crunch (leg-up) work?
It primarily targets the rectus abdominis, obliques, and iliopsoas. The quadriceps and tensor fasciae latae assist in holding the legs raised throughout the movement.
What is the difference between a Twist Crunch and a regular crunch?
A regular crunch moves the torso straight up to work the rectus abdominis. The Twist Crunch adds rotation to bring in the obliques, making it a more complete abdominal exercise. The legs-up variation further increases the load by removing the option to brace with the feet.
How many sets and reps should I do?
For core strength and endurance, 3 sets of 12–20 repetitions per side is a practical starting point. Rest 45–60 seconds between sets and prioritize control over speed.
Is the Twist Crunch (leg-up) good for beginners?
It is moderately challenging for beginners because the legs-up position demands continuous core stabilization. New trainees can reduce difficulty by bending the knees and resting feet lightly on the floor while still practicing the rotation.
Where should I feel the Twist Crunch?
You should feel the main effort in your abs and the sides of your core (obliques), with some engagement from the hip flexors holding the legs up. If you feel it primarily in your neck, check that your hands are not pulling your head.
