Exercise system. In one example embodiment, an exercise system may include a sensing device, a portable control device, and a remote server. The sensing device may include a first sensor configured to detect exercise data of exercise performed by a user, a first data storage configured to store the exercise data, a first radio frequency (RF) wireless interface, and a first processor. The portable control device may include a second RF wireless interface, a second data storage, and a second processor. The remote server may include a third interface, a third data storage, and a third processor.