There's nothing like a big-time biceps flex—and to achieve a muscle peak ... you would use for a standard hammer curl with dumbbells. Engage your glutes and core to create a solid base, then ...

That’s because the biceps function not only to flex the elbow, but also to supinate the forearm (i.e. get you in that palms-up position). The hammer curl puts the onus on the brachialis muscle ...