The exercise bike is indoor fitness equipment, which is used in cardiopulmonary endurance assessment and self-service fitness exercise. But the existing exercise bike is high cost and poor universality because of the using of serial communication. The mobile client of exercise bike is based on Wireless Local Area Network (WLAN), which communicates with the exercise bike, assists exercise bike to connect the WLAN, and provides real-time sports information display and exercise bike control. Compared with the traditional serial communication, it makes the exercise bike more widely range of using, and easier for popularize. The result shows that the mobile client can communicate with the exercise bike stably, and reduce the cost obviously.