Physical inactivity and sedentary behaviour are significant risk factors for diseases such as cardiovascular disease, cancer, and mental health disorders. Kundalini Yoga (KY) is recognised for its potential to improve physical and mental health. Objective: To evaluate the effects of a 6-week KY program on cardiorespiratory fitness (CRF) and health-related quality of life (HRQoL) in physically inactive university students. Methodology: A randomised controlled trial with a parallel-group, double-blind design included 26 university students divided into a Yoga group (YG, n=13) and a control group (CG, n=13). The YG completed twelve KY sessions over six weeks (two per week). Assessments included peak oxygen consumption (VO₂peak) and the SF-36 HRQoL questionnaire. A repeated measures analysis assessed the time×group interaction effect with post-hoc analysis (alpha= .05). Results: Significant improvements were observed in YG for relative (∆=3.21; d=0.66) and absolute (∆=173.07; d=0.40) VO₂peak, and maximal effort test performance (∆=12.31; d=0.34). YG showed significant enhancements in the general health dimension of HRQoL (∆=20.0), physical function (∆=5.0), and overall behaviour (∆=12.9), while CG improved only in physical function (∆=5.0). Discussion The findings suggest that KY provides greater improvements in CRF and comparable enhancements in HRQoL compared to other yoga styles, even within a shorter intervention period. KY appears effective as a health-promoting intervention. Conclusions: Twelve sessions of KY over 6 weeks significantly improved CRF and HRQoL in physically inactive university students. A KY program is recommended for physically inactive individuals who wish to adopt an active lifestyle and improve their CRF and HRQoL.