The main purpose of this study is to find out the effect of step aerobic training on selected physical variables among long-distance runner. For the present study, the researcher takes the male long distance runners from Pudukkottai District taken as sources of data. Thirty male long distance runners, who had participated in intercollegiate tournaments, were preferred as an area under discussion for this study. The age of the subject matter was ranging from 18 years to 25 years. The criterion measures adopted for the study measuring the physical variables are given below. To measure the physical variables 50 m dash for speed, 600 m run for speed endurance, 12 minutes run and walk for cardiorespiratory endurance and sit-ups for muscular strength and endurance the effect of step aerobic training on selected physical variables among long-distance runners the independent “t” test was used at 0.05 level of significance. Result: There was a significant difference in experimental groups in speed, speed endurance, Cardiorespiratory endurance, and muscular strength and endurance.