Abstract: A small, lightweight portable multi-directional or omni-directional rolling abdominal exercise device includes an over-molded roller ball having an outer molded layer; a housing supporting the roller ball for multi-directional movement; bearing members within the housing allowing for the rotational mounting of the roller ball; and handles coupled to the housing allowing for the user to engage the device with at least one of hands, elbows, knees or feet. The over-molded roller ball includes a ball core formed of a first and second hemispherical core member and an outer molded layer which completely encapsulates the ball core forming the ground engaging surface of the roller ball and which is configured to minimize slip, wherein each of the first and second hemispherical core members include grooves configured to engage the outer molded layer and wherein the outer molded layer comprises one of TPE, TPR, TPU, Silicone, rubber and mixtures thereof.

Abstract: Exercise devices for exercising the abdominal muscles and other muscle groups are disclosed. Each of the exercise devices has a housing from which opposing interconnected ends of an axle extend and a support ball that is captured within and partially extends from the housing. The housing has a cavity defining a partial sphere for receiving the support ball. Each of the exercise devices also comprises a plurality of strips which are attached to the surface of the cavity. Each of the strips includes a plurality of bearings each of which is captured within a bearing race. The strips are positioned upon the cavity surface so as to engage the support ball surface and to provide free-rolling support of the housing on the support ball in any direction when the exercise device is in use. Methods of using the exercise devices are also disclosed.