Dead bug

What it is

An exercise performed lying on your back, extending an opposite arm and leg while keeping your lower back pressed to the floor. It trains the core to resist the spine arching — the same job it does under a loaded barbell — with essentially no risk.

Muscles worked

Primary: Core (rectus abdominis), Core (rectus abdominis, deep core). Secondary: Obliques, Hip flexors.

How to perform it

1. Lie on your back with your knees and hips bent to right angles and your arms straight up over your shoulders.
2. Press your lower back flat into the floor and hold it there — this is the position you must not lose.
3. Slowly lower one arm overhead and the opposite leg towards the floor, stopping before your back arches.
4. Return to the start under control and repeat on the other side.

Common form faults

• Lower back arching off the floor. Reduce the range — stop the limbs higher — and exhale as you extend. The back staying flat is the exercise.
• Moving too fast. Slow down considerably. Speed hides the loss of position this drill exists to expose.
• Holding the breath. Exhale as the limbs extend; breathing while braced is a large part of the skill.

Programming

A warm-up or accessory in controlled reps per side. Progress by slowing the tempo and increasing range before adding any load. It is a particularly good option for anyone with a cranky lower back.