Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Stand on a step, feet hip-width apart, holding dumbbells at your sides. Engage your core, step one foot back into a lunge, lowering until your front thigh is parallel to the ground. Keep your front knee over your ankle and back knee just above the floor. Push through your front heel to return to the starting position. Alternate legs.
Maintain an upright chest and shoulders. Lower slowly and with control. Prevent front knee extension beyond toes. Use a mirror or feedback to check form. Start with lighter weights.
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