Speed, power, and frequency sensor for Bluetooth Smart and ANT+, which is directly attached to the Elite Trainer to monitor indoor training on smartphones, tablets, and bike computers. By using ANT+ and Bluetooth Smart communication protocols, maximum compatibility with various hardware types is achieved. Together with the My E-Training app, a standard roller trainer can be transformed into an innovative digital device that provides all the essential information for training. The data sent by the sensor to the display hardware varies depending on the type of home trainer or roller trainer it is used with.