http://www.shockabsorber.co.uk/bounceometer/shock.html
Test it out. See how your FF+Gs bounce nude - with a regular bra - and with the shock absorber! Use the bounce-o-meter for animated examples of all breast sizes and activites.
Push your breasts to the limit and see how a sports bra could help you. Either that or wank vigorously if you're a desperate schoolboy.