Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Rings support hold (arms locked, body hovering). Core/quads engaged, lift straight legs forward. To parallel floor ('L' shape). Hold: Arms straight, push rings, legs together/toes pointed. Lower controlled to start.
MuscleTrain is actively being built. If something looks broken, or you have a suggestion, let us know — it really helps shape the app.