Additive Manufacturing (AM), commonly called 3D printing, is the process of making objects layer upon layer from 3D model data in order to test design prototypes (called Rapid Prototyping), to obtain production tools (Rapid Tooling) or to build and then use that prototype as a final part in the final product (Direct Manufacturing). This paper aims to show new applications of the Direct Digital Manufacturing philosophy for sports and medical sciences. Particularly, the aim of the study is to present three case-studies that take advantage of AM so as to enable practitioners and professional players to manufacture customised 1) face masks to protect the face during sports or everyday activities, 2) foot insoles to treat foot problems and 3) shin pads to be worn by football players and shield them from shin injuries. In every case study, prior to fabrication, anthropometric features of volunteer patients were captured by a low-cost 3D scanner and a user-friendly semi-automatic modelling procedure was developed with Rhinoceros and Grasshopper in order to model and customise several features of the three products. The resulting virtual designs of the three products were manufactured with the help of four different AM devices while design workflow and the suitability of the physical prototypes were evaluated against volunteers and practitioners. Feedback results from practitioners and volunteers were satisfactory enough in order to consider the design tools provided as a good starting point for future developments. Further work is still necessary in terms of improvement to the design algorithm, inclusion of new materials and test procedures to verify the physical prototypes to the final user requirements. Nevertheless, this work confirmed that the combination of existing tools of three-dimensional digitisation, user-friendly semi-automatic algorithm within a Computer Aided Design (CAD) and Additive Manufacturing can lead to a technologically feasible and cost-effective solution to improve the traditional design and manufacturing process of customised orthotic and protective devices for sports and medical sciences.