Effect of six months pranayama training on stress-induced salivary cortisol response among adolescents-Randomized controlled study.

Abstract Background A combination of yoga practices has been documented to reduce stress and stress-induced cortisol levels. The objective of the current study is to examine the effects of six months of a single pranayama practice (Bhramari [Bhr. P]) on reducing salivary cortisol response to the cold pressor test (CPT) among adolescents. Methods Twenty-six healthy adolescents between the ages of 11 and 19 were randomly assigned to either yoga group (n-13) or control group (n-13). Yoga group participants were trained to do Bhr. P for 45 min, thrice a week for six months. All participants underwent CPT at baseline and at end of six months. Saliva samples were collected at baseline (t0), at 20 min (t1), 40 min (t2), and 60 min after the CPT (t3). Results Contradictory to our hypothesis, participants in the yoga group exhibited a higher salivary cortisol response to the CPT at t1 (p = 0.04) when compared to the control group. However, the t3 salivary cortisol levels showed a statistically significant reduction (p = 0.03) in yoga group when compared to the control group. A significant interaction with time (F (1, 88) = 316.5, p = .001, ηp2:0.91) and between the group × time (F (3, 88) = 2.83, p = 0.04, ηp2:0.8) was found after the intervention. Conclusions An increase in the cortisol responsiveness observed in the study is an indication of the adaptive capability achieved through regular yoga training, evidenced by an initial rise in cortisol followed by a rapid fall below baseline after 60 min. Further research is required to conclusively determine the changes in cortisol levels over time in response to stress in long-term yoga practitioners.