The aim of our study is to examine the cardiovascular endurance systems of sedentary high school students. The 112 sedentary individual was taken to the 1600 meter walking test run, and the 120 sedentary individual Harward step test. While both individuals were participating in the same test, weight, height, oxygen saturation, and heart rate of participants were measured before starting the test. As soon as the test is finished (recovery period), oxygen saturation and heart rate variability of individuals are measured at 1, 3, 5 minutes. All measured variables were analyzed and compared. Analysis of the data was done according to the SPSS statistical program and the significance level was accepted as p <0.05. In the 1600-meter walking test, it was observed that there was a significant difference in mean heart rate between males and females p<0.05. There was a significant difference between the mean values of the time of completion of the 1600 m running test by males and females (p <0.05). During the 1600-meter walking and Harward step test recovery period, there was no difference in the participants' parameters. There was no significant difference between oxygen saturations at beginning, recovery 1st, 3rd, and 5th minutes in both tests. Significant differences were found between heart rate and oxygen saturation values (beginning, recovery 1st, 3rd, and 5th minutes) in the intra-group comparisons of both groups. Participants' heart rates began to increase with exercise, but remained above the initial heart rate level during recovery. Participants' body mass indexes were observed to be within normal values. We think that can be increased cardio respiratory and cardiovascular fitness levels and can been created lifelong exercise habits by regular exercise programs are given to Sedentary high school students. Thus, we believe that the young population can be prevented from getting sick by providing healthier, social, active individuals.