Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
All-fours position, hands wider than shoulders, hips over knees. Grip ground, engage lats, lift to high plank with legs hip-width. Pre-tension shoulders/hips/core, squeeze quads/glutes, tuck chin. Retract shoulder blades together, arms straight, pause. Protract shoulder blades apart, arms straight, pause. Repeat retractions/protractions for reps.
Controlled form, core tight, back straight. Gentle scapular motion, no jerking. Breathe: inhale retraction, exhale protraction. Straight elbows, isolate scapulae only. Core engaged, stable plank always. Move from shoulder blades, not arms.
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