Abstract: Improvements in an exercise machine where the fan blades alter the resistance created by the blades or vanes by moving a cone that pushes the blades out from a central position. The blades or vanes push against the cone with springs. The cone is then moved into or out of the central axle to alter the effective diameter of the blades or vanes. A twist or contouring of the blades or vanes can be obtained at the same time to alter the resistance. In another embodiment, the fan blades can be individually or collectively adjusted to change the resistance. As the diameter is increased the speed of the blade tips increases as a squared function of the radius without changing the rotational speed of the vane(s). The shape, angle, scoop or tilt of the blade or vanes can also be altered to change the resistance.