Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Hang from a pull-up bar with an overhand grip, shoulder-width apart. Engage your core, stabilize your body, and lift your knees towards your elbows by flexing at the hips. Lower slowly, maintaining core tension. Repeat.
Maintain a firm grip. Control movements to engage core muscles. Avoid momentum; use muscle contraction. Keep shoulders down and away from your ears. Exhale on the lift, inhale on the lower. Beginners: start with a smaller range of motion.
MuscleTrain is actively being built. If something looks broken, or you have a suggestion, let us know — it really helps shape the app.