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  7. Elbow To Knee

Exercise guide

Elbow To Knee

  • Beginner
  • Compound
  • Rep-based
  • Waist

The Elbow to Knee is a functional standing core exercise that targets the obliques and rectus abdominis while improving balance and hip mobility. It integrates the lower body and core through a cross-body crunching motion that engages the hip flexors and stabilizers.

Reviewed by the Crucible team · Updated June 2026

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

Muscles worked

Primary

  • Abs
  • Obliques

Secondary

  • Erector spinae

Equipment

  • Body weight

Setup

  1. Stand with your feet shoulder-width apart and maintain a tall, upright posture.
  2. Place your fingertips lightly behind your ears with your elbows flared out wide to the sides.
  3. Engage your core and shift your weight slightly onto your left leg to prepare for movement.

How to do it

  1. Exhale as you lift your right knee toward your chest while simultaneously rotating your torso to bring your left elbow toward the rising knee.
  2. Crunch your midsection to bring the elbow and knee together near the midline of your body.
  3. Inhale as you slowly return to the starting standing position with control.
  4. Repeat the movement on the opposite side, alternating legs and elbows for each repetition.

Form checklist

  • Rotate from the torso rather than just pulling your elbow forward.
  • Keep your chest open and avoid pulling on the back of your head or neck.
  • Maintain a slight bend in the standing leg to help with balance and stability.
  • Ensure the knee comes up high enough to meet the elbow at waist level or higher.

Pro tips

  • Focus on the 'mind-muscle connection' by imagining you are wringing out your midsection like a towel during the rotation.
  • Pause for one second at the peak of the contraction when the elbow and knee meet to maximize oblique activation.

Make it harder

  • Perform the movement with a slower 3-second eccentric (lowering) phase to increase time under tension.
  • Add a small hop as you switch sides to increase the heart rate and turn it into a more explosive, plyometric movement.

Frequently asked

What muscles does the elbow to knee work?
The elbow to knee primarily targets the abs and obliques, and also works the erector spinae as secondary muscles.
What equipment do you need for the elbow to knee?
The elbow to knee requires no equipment — just your body weight.
Is the elbow to knee good for beginners?
Yes. The elbow to knee is a beginner-friendly movement and a strong foundation to build on.

Related exercises

  • 3/4 Sit-UpBeginner · abs and obliques
  • 45 Degree Bicycle Twisting CrunchIntermediate · abs and obliques
  • 45 Degree Lean Back Alternate Knee RaiseBeginner · abs and obliques
  • 45 Degrees Arms PlankIntermediate · abs, deltoids, obliques, and pectorals

Train this with a plan, not guesswork

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

Download on the App Store