Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Stand with feet shoulder-width apart, holding dumbbells (palms down). Keep elbows close to your torso. Curl weights up, bending elbows until forearms are vertical. Lower slowly to the start. Repeat.
Control the movement to engage biceps. Keep wrists straight. Engage your core for stability. Start with lighter weights, focus on full 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.