The present invention relates to a hidden roller of a treadmill. A hidden roller set is pivotably connected at the bottom end of both hollow support arms by means of a pivot, respectively. As a result, the hidden roller sets can be received inside the hollow support arms when the treadmill base is placed in operational state, thereby avoiding an unexpected sliding shift. To the contrary, the hidden roller sets can be taken out when the treadmill base is folded up in storage position. Thus, the rollers are in contact with the ground and work with the fixed type roller set at the rear end of the base frame. Accordingly, the treadmill can be smoothly moved.
A treadmill that includes a frame supported against the floor at its front and back sections, a belt section arranged on the frame, first device for turning the belt at a desired speed, and second device for adjusting the tilt of the belt section with respect to the horizontal, and a hand support structure extending upward from the plane of the frame in the operating position of the treadmill and comprising a support part on both sides of the frame. Extending from both support parts, there are low supports forming a low frame that are arranged to extend substantially parallel to the frame in the operating position of the treadmill and to rest against the floor at least in the area of the ends. The entity formed by the support parts and the low frame is turnably pivoted to the frame by means of a transverse shaft of the frame so that when the frame is lifted upright on one end, the entity formed by the support parts and low frame turns around the shaft, which is transverse to the frame, so that the ends of the low supports rest against the floor and form points of support to keep the frame upright.
