Dead Bug
On your back, lower the opposite arm and leg toward the floor while the lower back stays glued down.

How to do it
Setup
On your back, arms to the ceiling, hips and knees at 90°, lower back pressed down.
Steps
- Lower the opposite arm and leg toward the floor.
- The lower back NEVER leaves the floor.
- Return and switch the diagonal.
Common mistakes
Back arching as the leg lowers: shorten the range; the press-down is the whole exercise. Both limbs on one side: opposite pairs only. Rushing: this is a control drill; slow is strong.
Breathing
Exhale lowering the limbs, inhale returning.
