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  7. Elbow To Knee Decline Side Plank

Exercise guide

Elbow To Knee Decline Side Plank

  • Intermediate
  • Compound
  • Timed hold
  • Lower arms
  • Upper legs
  • Waist

This advanced core exercise intensifies the side plank by adding a decline angle and dynamic movement, significantly increasing the demand on the obliques, glutes, and shoulder stabilizers.

Reviewed by the Crucible team · Updated June 2026

Watch the Elbow To Knee Decline Side Plank demonstrationGuided video and your full workout live in the Crucible app.

Muscles worked

Primary

  • Abs
  • Deltoids
  • Obliques

Secondary

  • Erector spinae
  • Hip flexors
  • Quadriceps

Equipment

  • Body weight

Setup

  1. Place your feet on a bench and your supporting forearm on the floor, ensuring the elbow is directly beneath your shoulder.
  2. Stack your feet on the bench or place the top foot slightly in front for added stability.
  3. Lift your hips until your body forms a straight line from your head to your heels.
  4. Extend your top arm straight overhead, creating a long line from your top hand to your feet.

How to do it

  1. Exhale as you simultaneously drive your top knee toward your chest and pull your top elbow down to meet it in a side-crunch motion.
  2. Inhale as you slowly extend the arm and leg back to the starting position with control.
  3. Maintain a steady 2-1-2 tempo, focusing on a one-second squeeze at the point of contact.
  4. Complete the full set on one side before switching to the opposite side.

Form checklist

  • Keep the bottom hip elevated; do not let it sag toward the floor during the crunch.
  • Ensure the supporting shoulder remains packed and stable, not shrugging toward the ear.
  • Maintain a neutral neck position, looking straight ahead rather than at your feet.
  • Keep your chest open and avoid rotating your torso toward the floor.

Pro tips

  • Focus on 'shortening' the space between your lower ribs and your hip bone to maximize oblique recruitment.
  • Actively push the floor away with your forearm to engage the serratus anterior and stabilize the shoulder complex.
  • Keep the glute of the bottom leg squeezed tight to maintain hip extension and lateral stability.

Make it harder

  • Pause for 3 seconds at the point of elbow-to-knee contact to increase time under tension.
  • Hold a small dumbbell in the top hand to increase the resistance on the obliques and deltoids.

Frequently asked

What muscles does the elbow to knee decline side plank work?
The elbow to knee decline side plank primarily targets the abs, deltoids, and obliques, and also works the erector spinae, hip flexors, and quadriceps as secondary muscles.
What equipment do you need for the elbow to knee decline side plank?
The elbow to knee decline side plank requires no equipment — just your body weight.
Is the elbow to knee decline side plank good for beginners?
The elbow to knee decline side plank 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
  • Bosu Ball Plank HoldIntermediate · abs, deltoids, obliques, and pectorals
  • Explosive Dynamic PlankIntermediate · abs, deltoids, obliques, and pectorals
  • Front Plank Against WallIntermediate · abs, deltoids, and obliques

Train this with a plan, not guesswork

Crucible builds the elbow to knee decline side plank into a precise program around your body, equipment, location, and time.

Download on the App Store