In robotics, activity recognition systems can be used to label large robot-generated activity datasets. It also enables activity-aware human-robot interactions, and opens ways to selflearning autonomous robots. The recognition of human activities from body-worn sensors is also a key paradigm in wearable computing. In that field, the variability in human activities, sensor deployment characteristics, and application domains, have led to the development of best practices and methods to enhance the robustness of activity recognition systems.We argue that these methods can benefit many robotics use cases. We review the activity-recognition principles followed in the wearable computing community and the methods recently proposed to improve their robustness. These approaches aim at the seamless sharing of activity recognition systems across platforms and application domains. Finally, we outline current challenges in wearable activity recognition.