Ageing changes in the cardiovascular, respiratory, central nervous system and musculoskeletal systems etc results in an overall reduction of functional capacity, which may affect daily activities in middle age group individuals. So assessment of functional capacity is an important aspect in this population group. The 6 Minute walk test is extensively being used to assess the functional capacity as it is more reflective of activities of daily living than the other walk tests and it is easy to administer and better tolerated. Treadmills can be an efficient, and space-saving alternative for performing the standard 6 MWT, as it saves the space, and enables constant hemodynamic surveillance that is necessary for the safety test performance, and will also minimize the errors in calculating the various parameters during the 6MWT. The aim of the study: This study is aimed at comparing the physiological responses and the distance walked during the 6MWT on level ground (LG) and on a treadmill (TM) in normal healthy middle age group individuals. The results showed a statistically significant increase in blood pressures, heart rate, respiratory rate and RPE on Borg’s scale (P < 0.001) and, statistically significant decrease in six-minute walk distance (P < 0.001) after the TM 6MWT as compared to the LG 6MWT. The present study was attempted to analyze the comparative effects of TM 6MWT and LG 6MWT on physiological responses and distance walked in healthy middle group individuals. There was a significant increase in physiological responses from the baseline after TM 6MWT as compared to LG 6MWT in healthy middle group individuals. There was a significant decrease in 6-minute walk distance after TM 6MWT as compared to LG 6MWT in healthy middle group individuals.