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Side Plank Reach Through

The side plank reach-through adds rotation to the side plank: the top arm reaches to the ceiling, then threads under the waist as the torso turns, before unwinding back to open. It trains the obliques to control rotation through movement, not just resist it — a demand sport constantly makes. Coached by Maddy (NASM-CPT) — these are the exact form cues he gives on every client's first week.

Muscles worked

Obliques Deep lower back · quadratus lumborum Outer glutes · gluteus medius Deep core · transverse abdominis

Sets & reps by goal

Goal	Sets × Reps	Rest
Strength	4 × 4–6 reaches per side, slow	90 s–2 min
Muscle	3 × 8–12 reaches per side	60–90 s
Endurance	3 × 14–18 reaches per side	45–60 s

Rep ranges per Helms 2014 · Schoenfeld 2016.

Level — Intermediate

Intermediate — master the static side plank first, because this version attacks it with movement.

Proper form — 5 cues

Establish a strong side plank, elbow under shoulder, body in one line
Reach the top arm straight up to the ceiling
Rotate the chest down and thread the arm through the gap under your waist
Follow the moving hand with your eyes
Unwind with control until the chest and arm face open again

Breathing: Exhale as the arm threads under the body, inhale as the chest opens back up.

The 3 mistakes Maddy corrects most

Hips dropping as the arm threads through. Losing hip height during rotation means the plank has failed exactly when the obliques should be working hardest. Fix: Shrink the reach until hip height survives the whole rotation, then expand the range gradually.

Swinging the arm fast to generate momentum. Speed lets the arm's swing rotate the torso for free, removing the controlled oblique work that is the entire point. Fix: Move on a strict two-count each direction, as if the hand were dragging through water.

Pivoting on the forearm so the elbow slides. A migrating elbow destabilises the base and grinds the shoulder as the body turns above it. Fix: Screw the forearm into the floor and rotate the ribcage around a fixed base.

Common questions

What does the reach-through add over a normal side plank?

A static side plank trains the trunk to resist side-bending; the reach-through keeps that job and layers controlled rotation on top, so the obliques must manage two forces at once through a moving range. It is a bridge between holding positions and using lateral core strength athletically.

Should the reach-through be done from the feet or knees?

Both are valid. From the knees, the rotation can be learned with far less at stake, which is where most people should start. Once the knee version stays smooth with level hips for eight or more reps per side, the feet-stacked version provides the next challenge.

How do I stop wobbling during side plank rotations?

Wobble usually comes from a soft base or an oversized range. Stagger the feet heel-to-toe for a wider platform, press the forearm down hard, and rotate only as far as you can reverse smoothly. As control improves, narrow the stance and deepen the thread-through in small steps.

Related exercises

Side Plank HoldObliques · Deep lower back Boat Hold Side TwistObliques Forearm Side Plank (Modified)Obliques · Deep lower back High Side Plank HoldObliques · Deep lower back Side Body StretchLats · Obliques

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