The objective of this study is to determine the effect of varied intensity interval sprint training and detraining impact on selected speed parameters. To achieve the purpose of the study 45 male students were selected and randomly assigned into three groups of 15 each. Group-I (n=15) underwent high intensity interval sprint training, group-II (n=15) underwent moderate intensity interval sprint training and group-III (n=15) acted as control. The duration of the training programme was 12 weeks with three sessions per week on alternative days. Speed, speed endurance and anaerobic power were assessed prior to and immediately after 12 weeks of training and also during the period of cessation of experimental treatment for 40 days at an interval of every 10 days, from high and moderate intensity interval sprint training groups and control group. The obtained data was analyzed statistically by analysis of covariance and 3 x 5 factorial ANOVA with repeated measures on last factor. Findings of the study revealed significant improvement on selected speed parameters whereas significant decrease during the detraining period.