The 4th risk factor of global mortality is lacking of physical activity. There is about 70% population with lacking physical activity in Taiwan. Emerging information technologies are very useful to improve and increase physical activities for people. There are many virtual reality technologies designed for improving fitness or physical activities. Most of them are not based on clinical knowledge and guidelines and cannot be intuitively used. Such systems might not helpful for health promotion. In this paper, we applied augmented reality technologies to design an intelligent fitness platform for health promotion based on clinical knowledge and guidelines. It provides fitness training for health people or some with chronic diseases. Moreover, we design a research model including enjoyment to evaluate the usability and user acceptance of our proposed system. The results show that users have high willing to accept our system.