A system for providing to a plurality of users in a group of users, participating in a community running race along a predetermined path, with an indication of respective positions of the users relative to one or more of the other users. System includes a database for containing location data for the users; a processing station for accessing the database and being responsive selectively to data for generating first signals that are transmitted from a plurality of base stations physically spaced apart along the path; a plurality of wearable devices worn by respective users, the devices including a receiver for receiving first signals, a processor for processing first signals to generate a second signal, and an interface that is responsive to the second signal for visually displaying to the respective user the indication of the position relative to one or more of the other users in the group.