Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Feet shoulder-width on floor. Jump to split stance (left forward/right back), knees to 90° (front knee over ankle, back knee off floor). Jump switch to right forward/left back, knees 90°. Alternate jumps, land controlled.
Warm up thoroughly (core/glutes); progress slowly from mild jumps. Front knee over ankle—no further (knee stress). No knee lockout (reduces shock absorption). Heel down on landing; reset if balance lost.
MuscleTrain is actively being built. If something looks broken, or you have a suggestion, let us know — it really helps shape the app.