Core · Spinal flexion
Oblique Crunches
Oblique crunches are a floor ab exercise where you lie on your side and curl your shoulders up toward your hip. The small, controlled movement targets the obliques at the sides of the waist, with the rectus abdominis helping. It is a simple bodyweight option for side-body core work.
Also known as: Side crunches, Side-lying crunch, Lateral crunch
- Muscle group
- Core
- Movement pattern
- Spinal flexion
- Type
- Isolation
- Equipment
- Bodyweight, Exercise mat
- Difficulty
- Beginner
What muscles does the oblique crunches work?
Primary movers
- Obliques
Assisting muscles
- Rectus abdominis
- Transverse abdominis
- Quadratus lumborum
The obliques are the main target. They sit on the sides of the waist and bend the trunk sideways and rotate it. In this exercise, they pull the ribs toward the top hip as you curl up.
The rectus abdominis and the deep abs help hold the curl. They give you a bit of extra work but are not the focus, since the side-lying position puts the obliques in the best line of pull.
The quadratus lumborum, a deep muscle along the lower back, also helps with side bending. It works more when you try to lift higher, so keep the range small and aim for a squeeze rather than height.
With your knees dropped to the floor and stacked, your lower body stays still. This lets the obliques work against the rotation without needing any equipment, and makes the exercise easy for beginners.
How to do the oblique crunches
Setup
- 1
Lie on your side with your knees bent and stacked.
- 2
Drop your knees to the floor so your hips rotate while your upper back stays flat.
- 3
Place your fingertips lightly behind your head with your elbows wide.
- 4
Keep your knees on the floor for the whole set.
Execution
- 1
Curl your shoulders up off the floor, crunching your ribs toward your top hip.
- 2
Exhale as you crunch up.
- 3
Pause at the top and squeeze your obliques.
- 4
Lower your shoulders slowly back down.
- 5
Keep your hands light and your neck relaxed.
- 6
Complete all reps on one side, then switch sides.
Common oblique crunches mistakes
Pulling the head up with the hands
It strains the neck and takes work away from the obliques.
The fix: Keep your fingertips light and lead with your ribs.
Using momentum
Jerking up cuts the muscle tension.
The fix: Curl up slowly and pause at the top.
Letting the knees lift off the floor
The hips stop rotating and the obliques lose their line of pull.
The fix: Keep your knees stacked and on the floor.
Rushing through short, bouncy reps
The reps lose control and don't build tension.
The fix: Slow down and focus on squeezing the obliques.
How many sets and reps?
| Goal | Sets | Reps | Load | Rest |
|---|---|---|---|---|
| Hypertrophy | 3–4 | 12–20 per side | Bodyweight, slow tempo, 1–2 reps in reserve | 45–60 s |
| Endurance | 2–3 | 20–30 per side | Bodyweight, steady pace | 30–45 s |
| Beginner | 2–3 | 8–12 per side | Bodyweight, short range | 45–60 s |
The movement is small, so focus on squeezing the obliques instead of how high you go. Use it as an add-on to other core work, two or three times a week, and progress by slowing the tempo or moving on to a decline version.
Running the oblique crunches in your next block? Hercules logs every set, shows last session's numbers before you lift, and suggests when to add weight.
Get it on Google PlayOblique Crunches variations and alternatives
Crunches
EasierA simpler front-facing curl to learn the ab squeeze.
Bicycle Crunches
AlternativeAdds rotation and a dynamic leg movement.
Decline Oblique Crunch
HarderA bench makes the range and load greater.
Side Plank
AlternativeTrains the obliques with a hold instead of a curl.
Russian Twist
AlternativeAdds rotation through the trunk from a seated position.
Frequently asked questions
Do oblique crunches reduce love handles?
No exercise removes fat from one area. They train the obliques, while fat loss depends on your overall diet and activity.
How high should I crunch up?
Not high. The movement is small, and a squeeze matters more than range.
Why do I feel it in my neck?
You may be pulling with your hands. Keep your fingertips light and lead with your ribs.
How many oblique crunches should I do?
Two to four sets of 12 to 20 per side works for most people.
Hercules tracks every oblique crunches you log, shows you last session's numbers before you lift, and flags when your progress stalls.
Get it on Google Play