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  7. Dead Bug

Exercise guide

Dead Bug

  • Beginner
  • Compound
  • Rep-based
  • Waist

The Dead Bug is a foundational core stability exercise that teaches you to move your limbs while maintaining a neutral spine and braced core. It effectively targets the deep abdominals and obliques by forcing the core to resist lumbar extension as the limbs extend.

Reviewed by the Crucible team · Updated June 2026

Watch the Dead Bug demonstrationGuided video and your full workout live in the Crucible app.

Muscles worked

Primary

  • Abs
  • Obliques

Secondary

  • Erector spinae

Equipment

  • Body weight

Setup

  1. Lie flat on your back on a mat with your arms extended straight up toward the ceiling, shoulders retracted.
  2. Lift your legs and bend your knees to a 90-degree angle (tabletop position) so your knees are directly over your hips.
  3. Engage your core to press your lower back firmly into the floor, eliminating any gap between your spine and the mat.

How to do it

  1. Slowly lower your right arm behind your head while simultaneously straightening and lowering your left leg toward the floor.
  2. Exhale deeply as you extend, moving only as far as you can without your lower back arching off the floor.
  3. Inhale as you slowly return your arm and leg to the starting tabletop position with a controlled 2-second tempo.
  4. Repeat the movement on the opposite side (left arm and right leg) and continue alternating sides.

Form checklist

  • Keep the lower back glued to the floor throughout the entire movement.
  • Maintain a 90-degree bend in the stationary knee while the other leg extends.
  • Ensure the moving arm and leg move at the same speed.
  • Keep your neck relaxed and your chin slightly tucked to maintain a neutral cervical spine.

Pro tips

  • Focus on the 'ribs to hips' cue to keep the ribcage down and prevent the chest from flaring.
  • Imagine you are crushing a grape under your lower back to ensure constant spinal contact and maximum transverse abdominis engagement.

Make it harder

  • Perform the movement with straight legs throughout the entire range of motion to increase the lever length and tension.
  • Hold a light dumbbell or medicine ball between your hands to increase the stability demand on the upper core.

Frequently asked

What muscles does the dead bug work?
The dead bug primarily targets the abs and obliques, and also works the erector spinae as secondary muscles.
What equipment do you need for the dead bug?
The dead bug requires no equipment — just your body weight.
Is the dead bug good for beginners?
Yes. The dead bug 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 dead bug into a precise program around your body, equipment, location, and time.

Download on the App Store