BACKGROUND: Resistive breathing practices are known to improve endurance and performance in competitive swimmers. However, the effect of Pranayama or Yogic Breathing Practices (YBP) in improving respiratory endurance and performance of competitive swimmers remains un-investigated.OBJECTIVES: To study effects of yogic breathing practices on lung functions of swimmers. MATERIAL AND METHODS: Twenty seven national and international competitive swimmers of the age range 13-20 years, with 8.29 ± 2.9 years of competitive swimming experience and practicing swimming for 9.58 ± 1.81 km everyday, were assigned randomly to either an experimental (YBP) or to wait list control group (no intervention). Outcome measures were taken on day 1 and day 30 and included (1) spirometry to measure lung function, (2) Sport Anxiety Scale-2 (SAS-2) to measure the antecedents and consequences of cognitive and somatic trait anxiety of sport performance and (3) number of strokes per breath to measure performance. The YBP group practiced a prescribed set of Yogic Breathing Practices - Sectional Breathing (Vibhagiya Pranayama), Yogic Bellows Breathing (Bhastrika Pranayama) and Alternate Nostril Breathing with Voluntary Internal Breath Holding (Nadi Shodhana with Anthar kumbhaka) for half an hour, five days a week for one month. RESULTS: There was a significant improvement in the YBP group as compared to control group in maximal voluntary ventilation (p = 0.038), forced vital capacity (p = 0.026) and number of strokes per breath (p = 0.001). CONCLUSION: The findings suggest that YBP helps to enhance respiratory endurance in competitive swimmers.