A semiconductor device includes a semiconductor element and a connector. The training device includes a first attachment portion configured to couple the training device to a golf club and a second attachment portion coupled to the first attachment portion. A terminal of a second capacitor is connected, via a second switching device, to a first node at which the first switching device and the first capacitor are connected, the other terminal thereof being connected to the reference potential terminal. The back side of the bib can also be formed by a lower, middle panel partially overlapping the upper back panel.