This paper is mainly concerned with the integration of wireless body sensor network and walking route navigation system in order to provide the most suitable walking path to the wearer following the wearer's health condition. A novel system called Footpaths is proposed. Footpaths is designed to facilitate the measurement of the user's cardio-respiratory fitness level (CRF), through the use of a wearable wireless sensor network, in which the result is used as a key factor in determining the most suitable walking route. The CRF is assessed based on the maximal oxygen uptake or VO2max through field performance tests (i.e. Rockport 1-mile test). The prototype of Footpaths and showcase of its effective uses are exhibited in the paper.