A portable device for training and exercising constituted of: a shakable member； a rotational member in communication with the shakable member, the rotational member exhibiting an axis of rotation； a mass exhibiting a center of gravity in communication with the rotational member, the center of gravity of the mass offset from the axis of rotation of the respective rotational member； a motor in communication with the rotational member and arranged to rotate the rotational member about the respective axis of rotation thereof responsive to the at least one motor； and a control circuitry in communication with the motor, the control circuitry arranged to operate the motor so as to irregularly rotate the rotational member to thereby shake the shakable member.
