A GPS watch is a device with integrated GPS receiver that is worn as a single unit strapped onto a wrist, in the manner of a watch. The watch can have other features and capabilities depending on its intended purpose and be an smart watch. GPS watches are most often used for sports and fitness purposes. Many can connect to external sensors by the wireless ANT+ protocol, and/or to a computer by USB to transfer data and configuration. Common sensors used are heart rate monitors and footpods (running cadence and speed sensor). A footpod can be used to supplement or replace GPS data, such as providing treadmill speed and distance for the watch to log and share. Recharging by USB is commonplace.