The study was undertaken to find out the effect of simplified Kundalini yoga and pranayama on academic performance and selected psychological variables among schoolboys on aggression. To achieve the purpose of the study, 45 students studying various Higher Secondary Schools at Erode District were selected as subjects. The age of the subjects ranged from 14 to 16 years. The subjects were divided into three groups of fifteen each (n=15) randomly. Experimental Group I underwent simplified Kundalini yoga, Experimental Group II underwent Pranayama, and Group III is Control group were kept under active rest. The training period is for three days per week for eight weeks, in addition to the school curriculum. All the subjects were tested on selected criterion variables prior and immediately after the training period. The result of the study that there is a significant difference in the adjusted post-test means of the simplified Kundalini yoga group and the pranayama practice group and control group. It was identified that the simplified yoga group is better than the pranayama group and control group in improving explosive strength.