at an angle between about 30 u00b0 and about 60 u00b0 and most preferably at an angle of about 45 u00b0 to maximize centrifugal forces while avoiding contact between the rotating arm unit and the user by the careful selection of material s for the arm unit as well as that of the main body the overall weight of the device can be limited while concentrating weight in the arm units the arm unit may have weights added to it and or can be at least partially filled with a high density material 18 to thereby weight the end of the arm unit or at least a portion of the length of the arm unit 14 as described in greater detail below in an exemplary embodiment each arm unit or arm unit shaft is inclined at a fixed angle with respect to the main body it is to be understood however that the inclination angle of the arm unit shaft need not be fixed for example by providing a suitable ball joint to interconnect the arm shaft and the main body the arm shaft may be variably inclined with respect to the main body depending on the orientation of the main body and the motion imparted to the main body in such an embodiment when small circulatory.