Abstract: A bar preferably formed of tubular aluminum is formed to have a yoke and extensions for holding the shoulders of a user in a neutral position for exercising. Trunk twists and bends may be performed using the bar to maintain positions of the arms and torso for maximum effectiveness of the exercises. The bar is configured for adding weight inside or outside and particularly at its ends for increasing the rotational moment of inertia of the bar to give the effect of greater weight. End caps are configured to conveniently secure weights within or around the bar, by friction and threaded engagement. Weight materials include water, shot, cylinders, wheels and annuli configured as dead weights. The weight greatly enhances the moment of inertia when the bar is in motion during exercises, and can also be used with a leverage advantage to increase its effectiveness over conventional dead weights.