Objective: Motivating clients to change the health behaviour, and maintaining an interest in exercise programmes, is an ongoing challenge for health educators. With new developments in technology, simulation and gaming are increasingly being considered as ways to motivate users, support learning and promote positive health behaviours. The purpose of the present study was to develop an exercise simulation called "BringItOn", which is targeted towards individuals who need to increase their physical activity for health, recovery or rehabilitation. "BringItOn" is a video-based simulation in which individuals use a Kinect system to capture their movements as they exercise. Design: A usability study was conducted to examine software ease of use and perceived usefulness. An expert heuristic evaluation was completed by a software engineer, and user testing was conducted using the think-aloud method, observation, survey and interviews. Results: The majority of participants were very enthusiastic about the exercise simulation's potential to encourage exercise and activity. Three major benefits of the simulation were identified: (1) it promotes proper exercise technique; (2) individualised feedback similar to that received from a personal trainer was viewed as very motivating; (3) the software was "game like", and made exercising fun. Conclusion: The simulation system has considerable potential as a component in an integrated rehabilitation programme for patients or as a health promotion activity for individuals. The results shed light on key components that health educators should look for in simulations if they hope to maximise user motivation and encourage a positive changes in health behaviour.