Previous studies have shown the short-term or intermediate-term practice of yoga to be useful for ameliorating several mental disorders and psychosomatic disorders. However, little is known about the long-term influences of yoga on the mental state or stress-related biochemical indices. If yoga training has a stress-reduction effect and also improves an individual's mental states for a long time, long-term yoga practitioners may have a better mental state and lower stress-related biochemical indices in comparison to non-experienced participants. This study simultaneously examined the differences in mental states and urinary stress-related biochemical indices between long-term yoga practitioners and non-experienced participants.
The participants were 38 healthy females with more than 2 years of experience with yoga (long-term yoga group) and 37 age-matched healthy females who had not participated in yoga (control group). Their mental states were assessed using the Profile of Mood States (POMS) questionnaire. The level of cortisol, 8-hydroxydeoxyguanosine (8-OHdG) and biopyrrin in urine were used as stress-related biochemical indices.
The average self-rated mental disturbance, tension-anxiety, anger-hostility, and fatigue scores of the long-term yoga group were lower than those of the control group. There was a trend toward a higher vigor score in the long-term yoga group than that in the control group. There were no significant differences in the scores for depression and confusion in the POMS between the two groups. The urine 8-OHdG concentration showed a trend toward to being lower in the long-term yoga group in comparison to the control group. There were no significant differences in the levels of urine biopyrrin or cortisol.
The present findings suggest that long-term yoga training can reduce the scores related to mental health indicators such as self-rated anxiety, anger, and fatigue.