Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Lie on your side, head supported, holding a dumbbell with an overhand grip. Rotate your forearm downwards, lifting the weight while keeping your upper arm stable and your elbow bent. Slowly reverse the motion to return to the starting position, then switch sides.
Keep your upper arm pressed firmly against your side and maintain a 90-degree angle at your elbow. Control the movement slowly, avoiding any swinging or momentum. Use a pad under your arm if needed for added comfort and stability. Modify the exercise by sitting with forearm support or changing your side's position. Slightly offset your grip on the dumbbell to increase the challenge.
MuscleTrain is actively being built. If something looks broken, or you have a suggestion, let us know — it really helps shape the app.