Skip to content
Crucible Fit
  • The Crucible
  • The Week
  • Programs
  • Train Your Way
  • Pricing
Get Crucible
  • The Crucible
  • The Week
  • Programs
  • Train Your Way
  • Apple Watch
  • Pricing
  • FAQ
  • Training Guides
Get Crucible
Crucible Fit

A daily functional fitness test for iPhone, Apple Watch and Android. Stations, reps and the Crux, sized to your readiness and your kit.

Download on the App StoreGet it on Google Play

Crucible Fit

  • The Crucible
  • The Week
  • Programs
  • Train Your Way
  • Apple Watch
  • Pricing

Explore

  • Training Guides
  • Exercise Library
  • FAQ
  • Press
  • Support

Legal

  • Terms and Conditions
  • Privacy Policy
  • Consumer Health Data Notice

CRUCIBLE FIT™ and Crux by Crucible Fit are trademarks of Crucible Fit, LLC.

© 2026 Crucible Fit, LLC. All rights reserved. Apple, the Apple logo, iPhone and Apple Watch are trademarks of Apple Inc., registered in the U.S. and other countries. App Store is a service mark of Apple Inc. Google Play and the Google Play logo are trademarks of Google LLC.

  1. Home
  2. /
  3. Exercises
  4. /
  5. Shoulders
  6. /
  7. Side Plank Elbow To Knee Raise

Exercise guide

Side Plank Elbow To Knee Raise

  • Intermediate
  • Compound
  • Timed hold
  • Shoulders
  • Waist

This dynamic side plank variation targets the obliques and lateral chain while integrating hip flexion to engage the lower abs and glutes. It builds exceptional core stability and functional strength by combining an isometric hold with an active crunching motion.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the Side Plank Elbow To Knee Raise demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Abs
  • Obliques

Secondary

  • Erector spinae
  • Serratus anterior

Equipment

  • Body weight

Setup

  1. Lie on your side with your forearm on the ground, ensuring your elbow is positioned directly under your shoulder.
  2. Stack your feet on top of each other or stagger them for additional stability.
  3. Lift your hips off the floor to create a straight line from your head to your heels.
  4. Place your top hand behind your head with your elbow flared out toward the ceiling.

How to do it

  1. Exhale as you simultaneously bring your top knee toward your chest and your top elbow down to meet it in a crunching motion.
  2. Inhale as you return your leg and arm to the starting position with slow, deliberate control.
  3. Maintain a high hip position throughout the movement, resisting the urge to let the bottom hip sag.
  4. Complete the desired number of repetitions on one side before switching to the other.

Form checklist

  • Keep the supporting elbow directly under the shoulder to prevent joint strain.
  • Ensure the bottom hip stays elevated and aligned with the rest of the body.
  • Avoid rounding your lower back; keep your spine neutral during the crunch.
  • Keep your neck in a neutral position, looking straight ahead rather than at your feet.

Pro tips

  • Focus on the 'pinch' in your top obliques as the elbow and knee meet to maximize muscle recruitment.
  • Actively push the floor away with your bottom forearm to engage the serratus anterior and stabilize the shoulder girdle.

Make it harder

  • Perform the exercise from a high side plank (on your hand) to increase the stability demand on the shoulder.
  • Add a 2-second pause at the point of maximum contraction (elbow to knee) to eliminate momentum.

Frequently asked

What muscles does the side plank elbow to knee raise work?
The side plank elbow to knee raise primarily targets the abs and obliques, and also works the erector spinae and serratus anterior as secondary muscles.
What equipment do you need for the side plank elbow to knee raise?
The side plank elbow to knee raise requires no equipment — just your body weight.
Is the side plank elbow to knee raise good for beginners?
The side plank elbow to knee raise is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.

Related exercises

  • 45 Degrees Arms PlankIntermediate · abs, deltoids, obliques, and pectorals
  • Air BikeIntermediate · abs and obliques
  • Alternate Knee Raise Side ReachBeginner · abs, deltoids, and obliques
  • Alternate Leg Lift Tap Arms CircleIntermediate · abs, deltoids, obliques, and pectorals

Train it with Crucible Fit.

Every movement in this library is in the app with video and instructions, ready for your own sessions on the days between Crucibles. Your first Crucible is on us.

Download on the App StoreGet it on Google Play

See how a Crucible works