How many sets and reps of the oblique crunch should a beginner do?

Twelve to fifteen slow reps per side for 2 sets is enough for a beginner, pausing briefly at the top of each rep. Once you can keep the hips still and the reps strict through both sets, add a third set or hold a light weight against your chest instead of chasing more reps.

How do I make the oblique crunch easier or harder?

To make it easier, keep the feet on the floor instead of fully dropping the knees, which shortens the range and takes some load off the waist. To make it harder, hold a light dumbbell or plate against your chest, or slow the lowering phase to three seconds.

What is the oblique crunch good for, and when is it not the best pick?

It is a simple, no-equipment way for beginners to feel the side abs work before moving to loaded rotational training. It is not the best pick once you need real overload for the obliques, since bodyweight alone plateaus quickly and a cable or band variation will keep progress going.

Beginner

Oblique Crunch

By letting your bent knees fall to one side, you shorten the obliques and let them do the crunching directly. It is a low-skill, no-equipment way to train the side abs that most people neglect. Use it as a finisher or as a starting point before moving on to loaded rotational work.

Equipment: Body Weight
Body part: Abs
Type: Strength
Browse by muscle: Abdominal External Oblique
Browse by movement: Spinal Flexion

How to do it

1
Lie on your back and bend your knees, then let both knees drop to one side.
2
Place the hand nearest the floor on the mat and your other hand behind your head.
3
Keep your shoulders roughly flat to start.
4
Crunch your top shoulder up toward your hip, contracting the oblique.
5
Lower under control back to the floor without fully relaxing.
6
Complete your reps, then drop the knees to the other side and repeat.

Tips

Curl up and slightly across rather than pulling on your neck.
Exhale hard at the top and feel the side of your waist shorten.
Move slowly; small, strict reps beat big sloppy swings here.

Variations

Common mistakes

The hips lift off the floor as the knees drop to the side, turning a spinal crunch into a hip roll that misses the obliques entirely.
The lower shoulder presses hard into the mat to help push the torso up, borrowing leverage the oblique should be providing alone.
Letting the ribs fully relax at the bottom of each rep drops all tension, so every rep restarts from zero instead of building a burn.
The range shortens on one side once that side starts to fatigue, so reps quietly get smaller and less effective as the set goes on.
Both knees splay open instead of staying together as they drop, turning a clean side crunch into a wider, less controlled sprawl.

Frequently asked

How many sets and reps of the oblique crunch should a beginner do?: Twelve to fifteen slow reps per side for 2 sets is enough for a beginner, pausing briefly at the top of each rep. Once you can keep the hips still and the reps strict through both sets, add a third set or hold a light weight against your chest instead of chasing more reps.
How do I make the oblique crunch easier or harder?: To make it easier, keep the feet on the floor instead of fully dropping the knees, which shortens the range and takes some load off the waist. To make it harder, hold a light dumbbell or plate against your chest, or slow the lowering phase to three seconds.
What is the oblique crunch good for, and when is it not the best pick?: It is a simple, no-equipment way for beginners to feel the side abs work before moving to loaded rotational training. It is not the best pick once you need real overload for the obliques, since bodyweight alone plateaus quickly and a cable or band variation will keep progress going.

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