The recent trend in healthcare support systems is the development of patient-centric pervasive environments in addition to the hospital-centric one. Pervasive health care takes steps to design, develop, and evaluate computer technologies that help citizens participate more closely in their own healthcare, on one hand, and on the other to provide flexibility in patients' active everyday life with work, family and friends. This paper presents the mathematical model of a novel algorithm that generates recommendations and suggestions for preventive intervention instead of emergency care and hospital admissions. The main purpose of this algorithm is to find the dependence between users' health condition and performed physical activities. In this way, the proposed algorithm generates recommendations that will help the user to adapt his physical activities in order to improve his own health. These recommendations also encourage users to lead an active life filled with physical activities and thus become direct participants in maintaining their own health care. The proposed algorithm has been validated using generic data. The results of this validation are presented and conclusions are derived.