Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Stand with your arms down and a dumbbell in each hand. As you lift the weights, rotate your forearms so your palms face the ceiling. At the highest point, feel a strong contraction in your biceps, hold briefly, and then reverse the motion to return to the initial position, rotating your wrists back down.
Keep your upper arms stationary and close to your body to avoid using momentum. Anchor your elbows to your sides to ensure your biceps are doing the work. Completely rotate your wrists upwards at the top of the lift, so your palms are facing forward. Contract your biceps intensely at the peak of the movement, pausing for a beat. Lower the weights slowly, fighting against the weight to keep constant tension in your biceps.
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