Exercise movement reviewed by:Marie Braga, PT, DPT, CSCS

How Iridium Programs This

Iridium evaluates anterior deltoid recovery before assigning this variation to ensure shoulder fatigue does not become the limiting factor for your core training. Since this is a time-based isometric, the AI measures progressive overload by comparing your hold duration trends against RPE feedback rather than standard rep schemes.

Form Cues

Press your forearms actively into the ball to separate your shoulder blades
Squeeze your glutes and quads to create full-body tension
Pull your belly button in toward your spine to brace the core
Keep your gaze slightly forward of the ball to maintain a neutral neck
Breathe rhythmically into your diaphragm while maintaining tension

Don't

Don't let your lower back sag or arch toward the floor
Don't hike your hips up into a pike position
Don't allow your shoulders to shrug up toward your ears
Don't clasp your hands together; keep forearms parallel if possible
Don't hold your breath during the hold

Common Mistakes

Hyperextending the lower back
Shrugging shoulders due to fatigue
Holding the hips too high
Resting the chest on the ball
Inconsistent breathing patterns

Muscles Worked

This exercise primarily targets the deep core muscles, specifically the transverse abdominis and rectus abdominis, which must work intensely to prevent spinal extension against gravity and instability. Secondary emphasis is placed on the anterior deltoids and serratus anterior for upper body stability, while the glutes and quadriceps engage isometrically to maintain a rigid, straight line from head to heels.