The side plank is the anti-lateral flexion companion to the plank and hollow body hold. Where frontal core work (dead bug, hollow body, plank) trains the ability to resist spinal extension, the side plank trains the ability to resist lateral flexion — side bending. These are different stability demands and both are required for full core function.
Form
Forearm side plank. Lie on your side, forearm perpendicular to your body, feet stacked (or staggered for more stability). Lift your hips until your body forms a straight line from heels to crown — lateral version of the plank straight line. Free arm can be at your hip or extended toward the ceiling.
What to brace. Drive your forearm into the floor. Squeeze your glutes. Push your hips forward slightly to prevent them from dropping back behind the line. Hold everything.
Regression. Knees bent, ankles stacked — reduces the length of the lever. Build to straight legs over weeks.
Hip Abductor Loading
The top hip in a side plank must be supported by hip abductors against gravity. Weakness here shows up as the hip sagging (hip adduction) during the hold. This is the same hip abductor demand present in single-leg squat stability — the side plank builds it as an isometric.
Progression Standards
3 × 45 seconds each side, straight line maintained, consistent → add hip raises (lower hip to floor and back up) as a dynamic progression.
Move. Groove. Repeat. Smooth.
← Hollow Body Rock | Next: Tuck L-Sit →
Move. Groove. Repeat. Smooth.
You're on your way. And we're here with you.