The Acute Effects of Yoga on Physiological and Psychological Measures of Stress in College Students

Abstract

College students commonly report high levels of stress due to academic pressures and social challenges. Subsequently, the use of yoga as a form of stress-relief has become increasingly popular among college students. PURPOSE: to determine the acute effects of yoga on physiological and psychological measures of stress in college students. METHODS: Participants (n=20, 16 female) were initially assessed for baseline proxy measures of psychological and physiological stress. Psychological stress was assessed via the Positive and Negative Affect Schedule (PANAS) Questionnaire. Physiological stress was assessed by outfitting each subject with a five-lead EKG Holter monitor to measure heart rate variability (HRV). HRV was determined as the time interval between R-R waves (ms). Once baseline levels of stress were recorded, participants then completed a 20 min video of a Vinyasa Flow Sun Salutation yoga practice, while supervised by a certified yoga instructor. After the conclusion of the yoga session, participants’ post-baseline stress levels were re-assessed via PANAS and HRV. RESULTS: There was a statistically significant increase in positive affect scores from pre (26.7 ± 8.79) to post (31.0 ± 8.47), p = 0.004. The mean increase in positive affect scores (4.30 ± 5.9) indicated a moderate effect size, d = 0.73. There was a statistically significant decrease in negative affect scores from pre (15.95 ± 4.74) to post (11.35 ± 4.21), p < 0.001. The mean decrease in negative affect scores (4.6 ± 3.76) indicated a large effect size, d = 1.22. —There was a statistically significant increase in HRV scores from pre (665.5 ± 104.36 ms) to post (924.3 ± 122.98 ms), p < 0.001. The mean increase in HRV score (258.8 ± 102.32 ms) indicated a large effect size, d = 2.52. CONCLUSIONS: The results of this study indicated that a 20 min yoga practice resulted in a significant improvement in positive affect scores (16%), a significant decrease in negative affect scores (29%), and a significant improvement in HRV (39%), all indicative of a reduction in psychological and physiological measures of stress levels.