In the zorb ball,you don't mind being strapped in and tumbled around.you are actually quite secure inside the inner capsule because all the actual rollingbouncing is absorbed by the larger, air-cushioned outer capsule. As you tumble head over heels, the build up of centrifugal force keeps you pressed hard against the inner plastic wall, so it's easy to feel a sense of weightless ness as you enjoy the revolving view outside.