The purpose of the study was to find out the effects of interval training and continuous running on bio motor abilities such as speed, muscular endurance and cardio respiratory endurance. To achieve this purpose of the study, forty five men students in the Department of Physical Education and Sports Sciences, Annamalai University, Annamalai Nagar, Tamil Nadu, India were selected as subjects at random. The selected subjects were divided into three equal groups of fifteen subjects each, such as interval training and continuous training, and control group. The group I underwent interval training programme, Group-II underwent to continuous training for three days per week for twelve weeks. And Group III acted as control group who did not participate any special training programmes apart from their regular physical education activities as per their curriculum. The following variable namely speed, muscular endurance and cardio respiratory endurance were selected as criterion variables and it was measured by using standard tests. All the subjects of three groups were tested on selected criterion variable at prior to and immediately after the training programme. The analysis of covariance was used to analyse the significant difference, if any between the groups. The level of significance to test the ‘F’ ratio obtained by the analysis of covariance was tested at. 05 level of confidence, which was considered as an appropriate. The results of the study revealed that there was a significant difference between interval training and continuous training group and control group on speed, muscular endurance and cardio respiratory endurance. And also it was found that there was a significant improvement on selected variables speed, muscular endurance and cardio respiratory endurance due to interval and continuous.