Eligible participants were randomized in a 1:1 ratio to one of two instructor-led intervention groups: a hatha yoga practice group assigned to 90-minute hatha yoga practice sessions twice weekly for 8 weeks, versus an attention control education group assigned to 90-minute yoga history seminars twice weekly for 8 weeks. Participants in the hatha yoga group learned and practiced a specific sequence of classical yoga breathing techniques, mindful body postures, and a final deep relaxation pose. The attention control education group explored the history and philosophy of the main branches of yoga through seminars featuring lectures, documentary films, and interactive dialogue between instructor and participants; the seminars were designed to control for non-specific mood benefits of the hatha yoga intervention, such as attention from study personnel, peer interaction, time spent away from routine activities, and anticipation/interest related to mastering novel yoga-related information.