OBJECTIVE: The aim of this study was to investigate the effects of using the Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) as a high intensity training tool for sedentary university female students. METHODS: Baseline measures were recorded for body fat percentage, Wingate Anaerobic Test (WAnT) peak power and mean power, and Yo-Yo IR1 performance. Subjects were matched in pairs for body fat percentage and then randomly allocated to the intervention group (INT) (n=12) or control group (CON) (n=13). The INT undertook a 6-week training programme twice a week using the Yo-Yo IR1. The CON undertook no training. RESULTS: The INT increased their Yo-Yo IR1 performance (230±38m baseline vs 403±152m post-training), WAnT peak power (970±176 Watts baseline vs 1148±159 Watts post-training), and WAnT mean power (399±55 Watts baseline vs 439±53 Watts post-training) (p<0.05). No changes were observed in the CON (p>0.05). CONCLUSION: The results of this study show that a 6-week high intensity intermittent training programme using the Yo-Yo IR1 as a training intervention increases both aerobic and anaerobic capacity in a sedentary female population.