Sitting Alternate Knee To Elbow Twist

Muscles worked

Setup

1. Sit on the long edge of a flat bench with your feet together and flat on the floor.
2. Place your hands lightly behind your head with elbows flared out, avoiding any pulling on the neck.
3. Lean your torso back to a 45-degree angle while keeping your spine neutral and core braced.
4. Lift your feet slightly off the floor, balancing on your sit bones to create initial tension in the lower abs.

How to do it

1. Exhale as you pull your right knee toward your chest while rotating your torso to bring your left elbow to meet it.
2. Inhale and slowly return to the starting position, keeping your feet hovering off the floor to maintain constant tension.
3. Repeat the movement on the opposite side, bringing your left knee toward your right elbow.
4. Maintain a controlled 2-1-2 tempo (2 seconds to crunch, 1-second squeeze, 2 seconds to return).

Form checklist

• Rotate from the mid-back and waist, not just the shoulders.
• Keep your chest open and avoid tucking your chin into your chest.
• Ensure the movement is driven by the core rather than pulling with the hip flexors.
• Keep your lower back slightly rounded (posterior pelvic tilt) to protect the spine and maximize abdominal contraction.

Pro tips

• Focus on bringing your shoulder toward the opposite hip rather than just touching elbow to knee for maximum oblique engagement.
• Pause for a split second at the peak of the contraction to 'wring out' the abdominal muscles.

Make it harder

• Straighten your legs out fully in front of you between each rep to increase the lever length and difficulty.
• Hold a light medicine ball or weight plate against your chest to add external resistance to the rotation.

Frequently asked

What muscles does the sitting alternate knee to elbow twist work?

The sitting alternate knee to elbow twist primarily targets the abs and obliques, and also works the erector spinae, hip flexors, and quadriceps as secondary muscles.

What equipment do you need for the sitting alternate knee to elbow twist?

The sitting alternate knee to elbow twist requires no equipment — just your body weight.

Is the sitting alternate knee to elbow twist good for beginners?

The sitting alternate knee to elbow twist is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.

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