Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Adjust machine: ankle pad at Achilles, knees on front pad (hips supported); balls of feet on platform. Upright torso, knees firm, ankles secure; arms crossed, shoulders back, deep breath. Lower: extend knees, neutral back/rigid hips (to lockout if possible), exhale. Engage posterior chain, curl torso up (from hamstrings). Breathe, repeat.
Curl body via hamstrings (mind-muscle connection). Emphasize slow lower (safer knees, better eccentric growth). Use partner first time (test hamstring strength). Full-body tension: straight shoulders/hips/knees line.
Muscle Train is actively being built. If something looks broken, or you have a suggestion, let us know — it really helps shape the app.