Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Lie on your side, head supported, with a dumbbell held in your top hand. Keeping your upper arm stable and elbow aligned, raise the weight vertically, pausing at the top. Lower the weight back down under control, avoiding contact with the floor, and repeat on the opposite side.
Keep your core engaged to stabilize your body during the exercise. Prevent the dumbbell from resting on the floor between repetitions. Focus on contracting your rear deltoids by positioning your upper arm close to perpendicular. A bench can enhance comfort and stability. Maintain a level torso throughout the entire movement.
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