[Alternating Curls] Mainly trains the biceps and isolates the biceps.

[Alternating Curls] Mainly trains the biceps and isolates the biceps. Action: Sitting (or standing), hold dumbbells hanging by your sides with both hands, palms facing each other, and elbows on both sides of the body. Use the elbow joint as the fulcrum, curl upwards, and at the same time externally rotate the forearm with the palm facing upward. Raise it to the highest point and tighten the biceps, pause for a moment, and then control the return. Do it in rotation.