A cushioned treadmill is provided for cushioning impact between a runner's feet and the treadmill platform. The cushioned treadmill includes a base and a platform coupled to the base. The platform has a first side and a second side. A belt assembly is coupled to and extends between the first side and the second side of the platform. The belt assembly includes a movable belt forming a running surface designed for supporting a user on the platform. A cushioning material is contained in a flexible bladder positioned in the platform beneath the running surface.