Describes the UbiFit project and how it relates to the general idea of activity-based computing. UbiFit was a join collaboration between Intel Labs Seattle and the University of Washington. The project attempts to use low-cost sensing, inference, and feedback to allow people to stay physically active. This project is an example of the larger thrust of activity-based ubiquitous computing. This was presented at the 3rd U.S.-China Computer Science Leadership Summit at Peking University, Beijing China on June 14, 2010.