Context: The vital capacity of the lungs is a critical component of good health. Vital capacity is an important concern for those with asthma, heart conditions, and lung ailments; those who smoke; and those who have no known lung problems.
Objective: To determine the effects of yoga postures and breathing exercises on vital capacity.
Design: Using the Spiropet spirometer, researchers measured vital capacity. Vital capacity determinants were taken near the beginning and end of two 17-week semesters. No control group was used.
Setting: Midwestern university yoga classes taken for college credit.
Participants: A total of 287 college students, 89 men and 198 women.
Intervention: Subjects were taught yoga poses, breathing techniques, and relaxation in two 50-minute class meetings for 15 weeks.
Main outcome measures: Vital capacity over time for smokers, asthmatics, and those with no known lung disease.
Results: The study showed a statistically significant (P < .001) improvement in vital capacity across all categories over time.
Conclusions: It is not known whether these findings were the result of yoga poses, breathing techniques, relaxation, or other aspects of exercise in the subjects' life. The subjects' adherence to attending class was 99.96%. The large number of 287 subjects is considered to be a valid number for a study of this type. These findings are consistent with other research studies reporting the positive effect of yoga on the vital capacity of the lungs.