Abstract: A kettlebell having a housing which is configurable to an as-used configuration by filling a cavity in the housing with fill material. The kettlebell is returnable to a substantially planar stored configuration by emptying the cavity. The fill material can be varied from a group of different fill materials to vary the weight of the kettlebell in the as-used configuration. The housing has straps engaged to minimize twisting of the housing when the handle engaged to the housing is gripped by a user during exercise.