Atlas record

Dead Bug

The Dead Bug is a core exercise performed lying on your back, slowly extending the opposite arm and leg and bringing them back. Because the lower back stays in contact with the floor, it teaches trunk control in safe conditions.

Primary muscles
  • Abdominal muscles (rectus abdominis and transversus abdominis)
Secondary muscles
  • Hip flexors
  • Core stabilising muscles
Movement patterncore
LevelBeginner
EquipmentNo equipment (a mat is recommended)
How to perform
  1. Lie on your back; reach your arms towards the ceiling and lift your legs with the knees bent to 90 degrees.
  2. Press your lower back gently into the floor and keep that contact throughout the movement.
  3. Slowly extend one arm overhead and the opposite leg towards the floor.
  4. Pause briefly at the furthest point you can reach without the lower back lifting.
  5. Return to the start under control and continue with the other diagonal.
BreathingBreathe out slowly as you extend and in as you return; letting the abdomen tighten gently on the out-breath supports the movement.
Common mistakes
  • Allowing the lower back to lift off the floor
  • Rushing the movement and losing control
  • Tensing the shoulders up towards the ears
  • Holding the breath
Easier variationOpening only from the knee without touching the floor, or working one limb at a time
Harder variationHolding the far position of arm and leg for 3-5 seconds, or adding a light weight at the ankle
AlternativeBird Dog
CautionLying on the back for long periods may not be suitable in later pregnancy; in that case, and with ongoing low-back pain, it is sensible to consult a specialist about exercise selection.

An odd name, sound logic

Lying on your back with the arms and legs in the air resembles an upturned insect, which is where the name comes from. The real work here is invisible: not letting the lower back lift off the floor as the arm and leg extend. That trains the abdominal muscles in their job of holding the spine steady, and it lays the ground for the trunk to recover in everyday moments of sudden reaching or pushing.

How do you keep the lower back down?

Before you start, press your lower back gently into the floor and feel your ribs stay down. Extend the arm and leg only as far as that contact can be maintained. If the lower back begins to lift, the range is still too much for you, and lowering the leg less far is the first step towards a fix. Keeping a thin towel placed in the gap under your lower back from moving is a practical way to check.

Pairing it with the Bird Dog

The Dead Bug trains cross-body coordination face up; the Bird Dog does the same face down. Using the two back to back in one session makes a balanced core block that loads the trunk muscles from different directions.

Related terms: Bird Dog, Core Stabilising Muscles, Glute Bridge

From the same atlas

First published: 2026-08-12Last reviewed: 2026-08-12Editorial status: working editionReport an error