I like the convenience and effectiveness of this simple work-out . I can pick it up and use it anywhere and feel great . the best feature be that it have improve my posture like nothing else have - after four spinal injure and other back problem , I have work physical therapy and other machine and have strengthe my back , yet this be the best ever for improve posture . I usually use it longer that the 6 minute , although it be good to start out that length of time . thank you Shake Weight !