A wheelchair-accessible treadmill with a safety system allowing wheelchair users to exercise without the risk off steering off-course, tipping over, or rolling backwards off the treadmill. The wheelchair is secured by straps or similar means to two or more linear bearings that move along the side of the treadmill on rods or in tracks. When securely fastened, these allow the wheelchair to move forward and backward on the treadmill belt. The treadmill belt may be wider than standard, the height may be lower than standard, and a ramp may be used for access. An optical sensor may be used to determine the forward and backward movement of the wheelchair user. Wheelchair specific programs may be available through the control panel.