Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Sit with knees bent, feet flat. Lean back slightly, engage core, keep back straight. Lift feet, balancing on sit bones. Hold a medicine ball close to your chest. Twist torso right, bringing ball to hip. Return to center, then twist left. Alternate sides with control.
Engage your core for balance. Rotate your torso, not just your arms. Exhale during the twist, inhale as you return. Feet on the ground is an option for stability. Move slowly and with control. Start with a lighter ball.
MuscleTrain is actively being built. If something looks broken, or you have a suggestion, let us know — it really helps shape the app.