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  7. Alternating Leg V Up

Exercise guide

Alternating Leg V Up

  • Intermediate
  • Compound
  • Rep-based
  • Waist

The alternating leg V-up is a dynamic core exercise that isolates the rectus abdominis and obliques while improving hip flexor strength and coordination. By lifting one leg at a time, it reduces lower back strain compared to the standard V-up while maintaining high muscular tension.

Reviewed by the Crucible team · Updated June 2026

Watch the Alternating Leg V Up demonstrationGuided video and your full workout live in the Crucible app.

Muscles worked

Primary

  • Abs
  • Obliques

Secondary

  • Hip flexors

Equipment

  • Body weight

Setup

  1. Lie flat on your back on a mat with your legs fully extended and feet together.
  2. Extend your arms straight overhead, resting them on the floor.
  3. Press your lower back into the mat and engage your core to eliminate any arch in your spine.

How to do it

  1. Exhale as you simultaneously lift your right leg and your entire upper body off the floor, reaching both hands toward your right toes.
  2. Pivot on your sit-bones to form a 'V' shape at the top of the movement, keeping your arms and legs straight.
  3. Inhale as you slowly lower your torso and leg back to the starting position with a controlled 2-second tempo.
  4. Repeat the movement using your left leg, alternating sides for each repetition.

Form checklist

  • Keep your legs as straight as possible throughout the movement.
  • Ensure your shoulder blades clear the floor entirely at the peak of the contraction.
  • Avoid using momentum or swinging your arms to pull yourself up.
  • Keep your neck neutral and gaze toward your feet to avoid straining the cervical spine.

Pro tips

  • Focus on 'folding' at the hips rather than just reaching with your arms to ensure the deep core is doing the work.
  • For better oblique engagement, slightly rotate your torso toward the lifting leg at the top of the rep.

Make it harder

  • Keep both heels hovering 2 inches off the floor between reps to maintain constant tension on the lower abs.
  • Hold a light dumbbell or medicine ball with both hands to increase the load on the upper abdominals.

Frequently asked

What muscles does the alternating leg v up work?
The alternating leg v up primarily targets the abs and obliques, and also works the hip flexors as secondary muscles.
What equipment do you need for the alternating leg v up?
The alternating leg v up requires no equipment — just your body weight.
Is the alternating leg v up good for beginners?
The alternating leg v 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 alternating leg v up into a precise program around your body, equipment, location, and time.

Download on the App Store