Seated Side-to-Side Leg Raise Crunch on Floor
- Target muscle
- Iliopsoas, Obliques, Rectus Abdominis
- Synergist muscles
- Gluteus Medius, Quadriceps, Sartorius, Tensor Fasciae Latae
- Equipment
- Body weight
- Body part
- Waist
- Type
- Strength
Seated Side-to-Side Leg Raise Crunch on Floor is a bodyweight core exercise that targets the iliopsoas, obliques, and rectus abdominis while engaging the gluteus medius, quadriceps, sartorius, and tensor fasciae latae as synergists. Performed seated on the floor, it combines a lateral crunching motion with alternating knee drives to challenge rotational core stability and hip flexor endurance.
How to do the Seated Side-to-Side Leg Raise Crunch on Floor
- 1Sit on the floor with your knees bent and feet flat. Place your hands lightly behind your head or cross them over your chest.
- 2Lean your torso back slightly until your core engages, keeping your spine neutral rather than rounded.
- 3Lift both feet a few inches off the floor to establish the starting position, maintaining the slight trunk lean.
- 4Crunch your torso toward the right while simultaneously drawing your right knee toward your chest.
- 5Return your torso to center and lower your right foot back to the hover position without letting it touch the floor.
- 6Crunch your torso toward the left while simultaneously drawing your left knee toward your chest.
- 7Return to center and lower your left foot to complete one full repetition.
- 8Continue alternating sides for the desired number of reps, keeping your lower back from touching the floor between reps.
Form tips
- Keep your lower back off the floor between reps to maintain constant tension on the rectus abdominis and iliopsoas throughout the set.
- Control the speed of each crunch and knee drive — avoid using momentum to swing the leg up rather than lifting it with deliberate hip flexion.
- Exhale as you crunch toward each side to maximize oblique contraction and brace the core more effectively.
- If your hands are behind your head, keep your elbows wide and your chin neutral — do not pull on the back of your neck.
Common mistakes
- Rounding the lower back and collapsing the spine, which reduces core activation and places excess stress on the lumbar vertebrae.
- Using momentum to swing the legs up instead of lifting them with controlled hip flexion, removing tension from the iliopsoas and rectus abdominis.
- Letting the torso rest fully on the floor between reps, which eliminates the time-under-tension needed to drive core adaptation.
- Pulling forcefully on the neck with the hands, which can strain the cervical spine and shifts the effort away from the obliques.
- Rushing through reps without fully rotating the torso to each side, reducing oblique recruitment and turning the movement into a simple hip flexor exercise.
Frequently asked questions
What muscles does the seated side-to-side leg raise crunch work?
The primary muscles are the iliopsoas, obliques, and rectus abdominis. The gluteus medius, quadriceps, sartorius, and tensor fasciae latae assist as synergists during the leg raise portion.
How is this different from a standard crunch?
A standard crunch moves straight forward and mainly targets the rectus abdominis. This variation adds a lateral rotation toward each side and a simultaneous knee drive, which increases oblique and iliopsoas involvement.
How many reps and sets should I do?
Two to four sets of 10 to 20 alternating reps is a common starting range. Adjust volume based on your core endurance, treating each left-right cycle as one rep.
Can beginners do this exercise?
Yes, beginners can perform it by placing their feet on the floor between reps for a brief rest rather than holding the hover position throughout. Build up to the full floating-foot version as core endurance improves.
What equipment do I need?
No equipment is required — this is a bodyweight exercise performed on the floor. A yoga mat or exercise mat is helpful for comfort.
