Abstract: A hydro-inflatable, band-form weight device for aiding in the exercise of a limb, including a flexible, elongated, water-tight envelope adapted to contain a substantial weight of water and constructed to wrap circumferentially around a portion of the limb; a longitudinally-extending fastening strap joined to the elongated envelope, adapted to wrap circumferentially about the limb to overlap a portion of the band device, and fasteners associated with the overlapping portions, the strap and fasteners being adapted to secure the inflated band on the limb in a manner that preserves the wrapped condition and prevent migration of the band device along the limb during exercise.