Abstract: The invention relates to a training apparatus, in particular for the muscle system of the hand, arm and upper body, wherein the apparatus has an elongate casing with at least an essentially circular internal cross section, in the interior of which at least one ball (5) is situated in a freely movable manner between shock absorbers (6). There are various forms of such training apparatuses. Their disadvantages include relatively monotonous training and the difficulty or impossibility of using them to train during another activity, for example during running. In order to avoid this, the invention is characterized in that the casing is of flexible design over at least part of its longitudinal extent, in that the ends of the casing are fastened to a handle part, and in that handle part and casing lie at least essentially on one plane.