US Patent 10525301 Expandable exercise system

An expandable exercise system is used for mounting a part of an ancillary exercise device. The expandable exercise system includes a main exercise device and another part of the ancillary exercise device. The main exercise device includes a coupling seat. The other part of the ancillary exercise device is pre-mounted to the coupling seat and detachably connected with the part of the ancillary exercise device to form the ancillary exercise device, thereby easily increasing or decreasing the number of training modules to enhance the convenience of product use.