The bicycle sharing system in Medellin has become one of the alternatives in the city to achieve more sustainable transportation. To know how people use it on a daily basis is a fundamental resource to plan future expansions and to make the most out of the public investments. Therefore, we present an analysis of the bicycle sharing system and the emerging patterns according to its usage, based on exploratory data analysis and network theory approaches, we characterize users (single-trip vs. multi-trip users, female vs. male, and young vs. adult users). The results show that the main challenges for the future planning of the bicycle sharing system in Medellin are the inclusion of female users, which represents half of the potential users but are less prone to use the system. We also consider the foresight of the placement of new stations and infrastructure according to the purpose of the trip, the topographical configuration of the city, and the articulation with the integrated transportation system in the city.