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  7. Medicine Ball Russian Twist Legs-Up

Exercise guide

Medicine Ball Russian Twist Legs-Up

  • Intermediate
  • Compound
  • Rep-based
  • Waist

This exercise builds rotational power and core stability by forcing the obliques to rotate the torso while the rectus abdominis maintains a static V-sit position. It is highly effective for developing midsection definition and functional trunk strength.

Reviewed by the Crucible team · Updated June 2026

Watch the Medicine Ball Russian Twist Legs-Up demonstrationGuided video and your full workout live in the Crucible app.

Muscles worked

Primary

  • Abs
  • Obliques

Secondary

  • Serratus anterior

Equipment

  • Medicine ball

Setup

  1. Sit on the floor with your knees bent and feet flat, holding a medicine ball with both hands at chest height.
  2. Lean your torso back to a 45-degree angle, keeping your spine neutral and your chest lifted.
  3. Lift your feet 3-5 inches off the floor, balancing on your sit bones with your knees slightly bent.

How to do it

  1. Exhale as you rotate your torso to one side, bringing the medicine ball toward the floor near your hip.
  2. Inhale as you return to the center position, maintaining a tall posture and keeping your legs as still as possible.
  3. Exhale and rotate to the opposite side, ensuring the movement comes from your ribs and not just your arms.
  4. Continue alternating sides in a controlled, rhythmic tempo, focusing on the squeeze in your obliques.

Form checklist

  • Keep your chest up and avoid rounding your shoulders or lower back.
  • Minimize 'bicycling' or swaying of the legs; keep them locked in space.
  • Follow the medicine ball with your eyes to ensure your entire upper torso is rotating.
  • Maintain the 45-degree lean throughout the entire set to keep the abs under tension.

Pro tips

  • Think about 'wringing out' your midsection like a wet towel at the end of each rotation to maximize oblique fiber recruitment.
  • Squeeze your knees and ankles together to create a stable lower-body anchor, which forces the core to do all the work.

Make it harder

  • Straighten your legs completely into a full V-position to increase the lever length and tension on the lower abs.
  • Slow down the tempo to a 3-second count per rotation to eliminate momentum and increase time under tension.

Frequently asked

What muscles does the medicine ball russian twist legs-up work?
The medicine ball russian twist legs-up primarily targets the abs and obliques, and also works the serratus anterior as secondary muscles.
What equipment do you need for the medicine ball russian twist legs-up?
The medicine ball russian twist legs-up uses medicine ball.
Is the medicine ball russian twist legs-up good for beginners?
The medicine ball russian twist legs-up 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

Train this with a plan, not guesswork

Crucible builds the medicine ball russian twist legs-up into a precise program around your body, equipment, location, and time.

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