BACKGROUND:Preliminary studies investigating yoga and breath work for treating asthma have been promising. Several randomized controlled trials have shown a benefit from yoga postures and breathing vs control, but the control in these cases involved no intervention other than usual care. This study advances the field by providing an active control.

OBJECTIVE:To determine the effectiveness and feasibility of a yoga and breath work intervention for improving clinical indices and quality of life in adults with mild-to-moderate asthma.

METHODS:A randomized, controlled, double-masked clinical trial was conducted between October 1, 2001, and March 31, 2003. Random assignment was made to either a 4-week yoga intervention that included postures and breath work or a stretching control condition. Outcome measures were evaluated at 4, 8, 12, and 16 weeks and included the Mini Asthma Quality of Life Questionnaire, rescue inhaler use, spirometry, symptom diaries, and health care utilization.

RESULTS: Sixty-two participants were randomized to the intervention and control groups, and 45 completed the final follow-up measures. Intention-to-treat analysis was performed. Significant within-group differences in postbronchodilator forced expiratory volume in 1 second and morning symptom scores were apparent in both groups at 4 and 16 weeks; however, no significant differences between groups were observed on any outcome measures.

CONCLUSIONS:Iyengar yoga conferred no appreciable benefit in mild-to-moderate asthma. Circumstances under which yoga is of benefit in asthma management, if any, remain to be determined.