Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Push-up position: hands wider than shoulders, toes down. Lower: lift right foot, drive right knee to right elbow (nearly touch bottom). Press up, straighten/extend right leg to ground. Alternate: left knee to left elbow. Continue.
Bottom: arms arrow (not T). Rigid spine—moving plank. Glutes squeezed, abs braced (neutral ribs). Chin down (no forward look/head jut). Push thumbs together (pec activation). Chest/nose touch together. Explode from floor; full protraction top. Full reps—no shortcuts.
MuscleTrain is actively being built. If something looks broken, or you have a suggestion, let us know — it really helps shape the app.