Alternate Oblique Crunch
- Target muscle
- Obliques
- Synergist muscles
- Rectus Abdominis
- Equipment
- Body weight
- Body part
- Waist
- Type
- Strength
The alternate oblique crunch is a bodyweight core exercise that primarily targets the obliques along the sides of your waist, with the rectus abdominis assisting throughout. Performed lying on the floor, it builds rotational core strength and trunk control without any equipment, making it an easy addition to any home or gym ab routine.
How to do the Alternate Oblique Crunch
- 1Lie on your back with your knees bent and feet flat on the floor, hip-width apart.
- 2Place your hands lightly behind your head or by your temples, keeping your elbows wide and your neck relaxed.
- 3Brace your core and lift your shoulder blades slightly off the floor to set your starting position.
- 4Curl your torso up and across, bringing one shoulder toward the opposite knee until you feel your oblique contract.
- 5Pause briefly at the top of the movement and keep the contraction tight without yanking on your neck.
- 6Lower back down under control until your shoulder blades return toward the floor.
- 7Repeat to the same side for your target reps, then switch and crunch toward the other knee.
- 8Alternate sides evenly until you complete the set, keeping your lower back gently anchored throughout.
Form tips
- Drive the movement from your waist by rotating the rib cage toward the opposite hip, not by pulling with your arms.
- Exhale as you crunch up and inhale as you lower to help maintain a strong core brace.
- Move slowly and deliberately, prioritizing a full oblique squeeze over speed or rep count.
- Keep your lower back lightly pressed toward the floor to protect your spine and keep tension on the abs.
Common mistakes
- Pulling on your head and neck with your hands, which strains the cervical spine and takes work off the obliques.
- Rushing through reps with momentum, which removes tension from the muscles and reduces the training effect.
- Lifting only with the neck instead of rotating the torso, so the obliques never fully engage.
- Letting the lower back arch up off the floor, which shifts strain to the spine and weakens the core brace.
Frequently asked questions
What muscles does the alternate oblique crunch work?
It primarily works the obliques along the sides of your waist, with the rectus abdominis (the front abs) assisting as a synergist throughout the movement.
Is the alternate oblique crunch good for beginners?
Yes. It uses only your body weight and a controlled range of motion, so beginners can learn the rotation safely and add reps as their core strength improves.
How many sets and reps should I do?
A sensible starting point is 2–3 sets of 10–15 reps per side. Focus on a slow, controlled squeeze rather than chasing high numbers.
Where should I feel this exercise?
You should feel it along the sides of your waist as the obliques contract, with some support from your front abs. If you mainly feel your neck, you are pulling with your arms instead of rotating your torso.
