An exercise bar assembly includes a pair of rotating grip assemblies, each including a generally planar frame and a hand grip mounted within the frame for rotation within in the plane of the frame. The rotating grip assemblies are attachable to opposite ends of a center bar assembly along the longitudinal axis of the bar assembly. A plate bar assembly is attachable to each of the rotating grip assemblies opposite the center rod, with the plate bar assembly aligned with the longitudinal axis to form a weight lifting bar. A user-selectable elastic band is engageable between the pair of rotating grip assemblies along the longitudinal axis so that the elastic band resists rotation of each hand grip in each of the rotating grip assemblies. The rotating grip assemblies of the exercise bar assembly allow for the full range of motion of the bicep, and the elastic band creates a resistance exercise through the bicep's full range of motion.