Mobility in big cities is a growing problem and the use of bicycles has been a solution which, together with new sharing services, helps to motivate users. There are also more and more users practicing sports involving the use of bicycles. It was in this context that the present dissertation was developed, a distributed sensor system for monitoring cyclists. With the support of a wireless sensor network connected to the internet and, using a set of smart sensors as end-nodes, it is possible to obtain data that will help the cyclist to improve his performance. The coach can monitor and evaluate the performance to improve their training sessions. The health status condition during training it is also monitored using cardiac and respiratory assessment sensors. The information from the nodes of the wireless sensor network is uploaded, via the internet connection, to the Firebase platform. An Android mobile application has been developed, this allows trainers to register cyclists, plan routes and observe the results collected by the network. With the inclusion of these technologies, the coach and the athlete may analyze the performance of a session and compare it with the previous training results. New training sessions may be established according to the athlete's needs. The effectiveness of the proposed system was experimentally tested and several results are included in this dissertation.