The present disclosure envisages a physiology-sensitive system (100) for managing physical behavior of a user. The system (100) comprises a treadmill (102), a physiological data characterization unit (104), a physical data characterization unit (106), a speed tracker (108), an adaptive speed engine (ASE) module (110), and a speed modulator (109). The physiological data characterization unit (104) and the physical data characterization unit (106) are configured to collect physiological data and physical data of the user and compute physical and physiological indices. The adaptive speed engine (ASE) module (110) is configured to analyze the computed indices and speed with respect to pre-defined age-specific and medication-specific thresholds to generate at least one speed change command for effecting adaptive increase, adaptive decrease, or no change in the speed of the treadmill. The speed modulator (109) is configured to receive the speed change command for changing the speed of the treadmill (102).