RESUMEN
OBJECTIVES: To evaluate the acute and chronic effects of yoga practice. DESIGN: Quantitative study using a one-group pre-posttest design. SETTING: Visão Futuro Institute, Porangaba, São Paulo, Brazil. PARTICIPANTS: 22 volunteers (7 men and 15 women). INTERVENTION: Six weeks of a tantric yoga program (TYP), 50 minutes per session, held twice a week from 8 a.m. to 9 a.m. The local ethics committee approved the protocol. OUTCOME MEASURES: Data were collected in the first week and at the end of the sixth week of TYP. Salivary cortisol concentration (SCC) was used to measure physiology of distress and to analyze the short- and long-term effects of TYP. Psychological distress was evaluated by applying a specific perceived stress questionnaire (PSQ). Results (mean±standard deviation) were analyzed by Wilcoxon test (p<0.05). RESULTS: SCC decreased 24% after the first (0.66±0.20 µg/dL versus 0.50±0.13 µg/dL) and last (1.01±0.37 versus 0.76±0.31 µg/dL) sessions, showing the short-term effect of yoga. Long-term effects were analyzed by daily rhythm of cortisol production. In the beginning, volunteers showed altered SCC during the day, with nighttime values (0.42±0.28) higher than those at noon (0.30±0.06). After the TYP, SCC was higher in the morning (1.01±0.37) and decreased during the day, with lower values before sleep (0.30±0.13). The TYP was also efficient to reduce PSQ scores (0.45±0.13 versus 0.39±0.07). Specifically, the irritability, tension, and fatigue domains on the PSQ decreased (0.60±0.20 versus 0.46±0.13), as did the fear and anxiety domains (0.54±0.30 versus 0.30±0.20). CONCLUSION: Over the short term, TYP led to the decrease of cortisol production. Over the long term, TYP induced higher cortisol production in the morning and lower production in the evening. Those effects contributed to the physical and mental well-being of the participants.