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Side Crunches

The side crunch is a floor exercise that shortens the waist laterally, drawing the ribs toward the hip on one side to work the obliques directly. It gives beginners a low-skill way to train the side of the trunk before graduating to planks, holds and rotational drills. Coached by Maddy (NASM-CPT) — these are the exact form cues he gives on every client's first week.

Muscles worked

Obliques Abs · rectus abdominis Deep core · transverse abdominis

Sets & reps by goal

Goal	Sets × Reps	Rest
Strength	4 × 6–10 per side, slow	90 s
Muscle	3–4 × 9–12 per side	60 s
Endurance	3 × 18–27 per side	45–60 s

Rep ranges per Helms 2014 · Schoenfeld 2016.

Level — Beginner

True beginner exercise — the floor supports everything while you learn to feel the obliques shorten.

Proper form — 5 cues

Lie on your back, knees bent, then drop both knees to one side
Keep both shoulder blades starting in contact with the floor
Place the fingertips lightly behind the head — no pulling
Crunch the upper body straight up, drawing the bottom ribs toward the top hip
Lower with a slow two-count and repeat before switching sides

Breathing: Exhale as the ribs crunch toward the hip, inhale on the way down.

The 3 mistakes Maddy corrects most

Yanking the head forward with the hands. Pulling on the skull strains the neck and creates fake range while the obliques barely shorten. Fix: Let the fingertips touch the head like headphones — the lift must come from the waist.

Crunching forward instead of laterally. A straight-ahead crunch from the knees-dropped position works the front abs and misses the oblique bias the setup creates. Fix: Aim the bottom of the ribcage at the top hip, feeling the side of the waist fold like a closing hinge.

Using momentum to bounce reps off the floor. Rebounding removes the controlled lowering phase, which is half the stimulus for the obliques. Fix: Touch down softly, pause for a breath, and start each rep from a dead stop.

Common questions

Do side crunches give you a smaller waist?

They strengthen and can modestly build the obliques, but waist size is dominated by body fat levels, which respond to overall nutrition and activity rather than any single exercise. Train side crunches for trunk strength and control; pair them with a sensible calorie approach if a leaner waist is the goal.

Side crunches vs bicycle crunches — which is better for obliques?

Bicycle crunches add rotation and hit the obliques through a bigger range, but they are also easier to rush and butcher. Side crunches are simpler, slower and easier to feel in exactly the right place. Beginners do well starting with side crunches, then adding bicycles once control is automatic.

How many side crunches per day should I do?

Daily high-rep crunching is not necessary — the obliques grow and strengthen like any muscle, from two to four quality sessions per week. Three sets of nine to twelve controlled reps per side within a session is a productive dose; progress by slowing the tempo or pausing at the top.

Related exercises

Bicycle KicksObliques Bicycle Kicks (Modified)Obliques Cross Knee to Elbow PulseObliques Downward Dog Cross Knee to Elbow TouchObliques Downward Dog Knee to Elbow TouchObliques

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