Global market for physical fitness equipment will exceed 10.5 Billion USD by 2015. Stationary exercise bikes represent the fastest growing product segment in the global physical fitness equipment market. Stationary bikes are a popular indoor gym equipment with the complementary workout monitoring capabilities. The essential output physiological variables are the athleteÍs pedaling speed, traveled distance, heart rate and the subsequently calculated burnt calories. Recent efforts were made to simulate the natural conditions of the road bike for the user by means of the rich virtual reality interface or augmented haptic feedbacks, i.e. adding vibrators to the pedals so as to represent uneven surfaces. æThe design of a compact fitness kit to be added on the road bike is explained. The kit is composed of a battery-powered electronic circuit, to be installed on the bikeÍs pedal or crank arm, the smartphone based application and the complimentary online database. The add-on enables the biker to monitor the physiological variables including pedaling speed, travelled distance and burnt calories during the biking activity in dynamic physical environment. Other physiological transducers such as heart rate monitor can be augmented to the system for further monitoring purposes. The collected data will be displayed to the subject in real-time and will be stored in an online data base for later monitoring. The proposed add-on can be used to enrich the biking experience by providing quantitative assessment of the ongoing activity, and provide directions to improve the quality of exercise.