Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Lie on your back, arms extended, holding a stability ball between your hands and knees. Engage your core, then simultaneously lower your right arm and left leg while stabilizing the ball. Return to start and repeat on the opposite side, alternating sides.
Keep your lower back pressed to the floor. Move slowly and with control, exhaling as you extend limbs. Maintain ball stability. Reduce range of motion or perform without the ball if needed.
MuscleTrain is actively being built. If something looks broken, or you have a suggestion, let us know — it really helps shape the app.