Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Stand with feet together, core engaged, shoulders relaxed. Step wide to one side, pushing hips back and down as you bend the lunging leg. Keep the opposite leg straight and foot planted. Sink deep, reaching across your body towards the lunging foot's toes (or shin). Drive through the heel of the lunging leg to return to standing, engaging your glutes. Alternate sides with controlled movements.
Maintain a comfortable step width, aligned with your shoulders. Extend the opposite leg fully without locking the knee. Ensure a stable, flat foot placement. Hinge at your hips to reach forward, maintaining a straight back.
MuscleTrain is actively being built. If something looks broken, or you have a suggestion, let us know — it really helps shape the app.