The purpose of the study was to find out the influence of different altitude training on VO2max and stress. Forty-five male middle distance runners studying in various colleges around Kodaikanal Town, Dindigul District, were selected and divided into three equal groups (n = 15), in which group - I underwent low altitude (sea level) training, five days per week for twelve weeks and group II underwent moderate level altitude training and group – III acted as control which did not participate any special training apart from their regular activities. The subjects were tested on selected criterion variables such as VO2max and stress at prior to and immediately after the training. For testing the VO2max, Cooper’s 12 minutes run/walk test result was taken and a formula recommended by Cooper was applied, and for stress, Girdano and Everly Stress Scale was used. The Analysis of Covariance (ANCOVA) was used as statistical tool to find the training effect difference between three groups. Since there were three groups involved in this study the ScheffẻS test was used as pos-hoc test. The result of the study shows that the VO2max was improved and stress level was decreased significantly for the training groups when compared with the control group. The result of the study also shown that there was no significant difference occurred between the experimental groups, such as, low altitude and moderate altitude training groups.