Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Stand with feet shoulder-width apart. Extend one arm to the side, elbow bent 90 degrees, forearm parallel to the ground and braced against a wall. Rotate your torso away from the wall until you feel a chest and shoulder stretch. Hold for 15-30 seconds, breathing steadily. Return to start and repeat on the opposite side.
Relax shoulders, avoid shrugging. Maintain a 90-degree elbow angle. Stretch gently, avoid forcing. Keep your spine neutral.
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