The purpose of this investigation was to determine the impact of the Indian Knowledge System (IKS)-based Lagori game on the cardio respiratory endurance of school girls. To conduct the present study, thirty (N = 30) school girls from the Alagappa Physical Fitness Academy (APFA) Programme, Karaikudi, Tamil Nadu, India, were selected randomly as subjects. Their ages ranged from 12 to 14 years. The selected subjects were divided into two groups of fifteen each (n = 15). Group I served as the Indian Knowledge System-based Lagori game training group, while Group II served as the control group and did not receive any training. The Indian Knowledge System-based Lagori game training was considered the independent (manipulative) variable, while cardio respiratory endurance was considered the dependent variable. Cardio respiratory endurance was assessed using the cardio respiratory endurance tested by 9 minutes run or walk test and performance was recorded in meters. The training programme was conducted for six weeks, with training sessions held five days per week. Data were collected before the commencement of the training programme (pre-test) and after the completion of the six-week training period (post-test). The collected pre-test and post-test data were analysed using the paired sample t-test to determine the significance of improvement resulting from the training programme. The findings revealed that six weeks of Indian Knowledge System-based Lagori game training significantly improved the cardio respiratory endurance of school girls compared to the control group that did not undergo training.