Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Step into a lunge, bending your front knee to 90 degrees, stacked over the ankle. Back knee hovers just above the ground. Maintain an upright torso, engaged core, and centered weight. Avoid knee extension past the toes. Plant your inside hand and sink your hips, placing the opposite hand flat on the floor near the front foot (use a block if needed). Actively push through the ball of the back foot. Rotate your torso toward the front knee, extending your arm overhead, following your gaze. Rotate from the mid-back, keeping hips square. Feel the stretch across your chest and torso. Hold briefly, breathe, and repeat on the opposite side.
Maintain hip squareness throughout the rotation; avoid twisting through the lower back. Reach actively through your fingertips to lengthen the lateral chain. Engage the back leg quad and push through the ball of the foot to straighten the leg. Exhale slowly to release tension and deepen the stretch.
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