Body Position and its Effect on Heart Rate, Blood Pressure, and Respiration Rate After Induced Acute Mental Stress

Abstract

A dominating presence in modern life is stress, manifesting from physical, mental, or emotional triggers. Stress induced hormonal variations can lead to physiological change such as increased heart rate, increased rate of respiration, and vasoconstriction. While everyone experiences stress to some degree, chronic stress may lead to compromised health. One strategy that has been shown to effectively combat elevated stress levels is yoga. The purpose of this study is to analyze how physiological symptoms resulting from acute mental stress are affected by body positions, specifically yoga positions. The 28 participants (14 male; 14 female) were randomly assigned to perform one of four body positions: standing up, laying down, sitting cross-legged, and Child’s pose. To induce acute mental stress, participants were instructed to take a Wonderlic IQ test and informed that their performances would be compared to their peers. Following the stressor, participants assumed the assigned body position. It was hypothesized that the participants’ physiological indicators of stress would measure closer to resting state by performing Child’s pose as compared to sitting cross-legged. Body position was found to significantly affect heart rate and blood pressure. However, results did not support significant changes in respiration rate. Child’s pose failed to reduce heart rate and on average increased heart rate by 6.1 bpm. Child’s pose increased systolic and diastolic blood pressure by 20 mmHg and 14 mmHg, respectively. Sitting cross-legged decreased heart rate by 8.7 bpm, and increased the systolic and diastolic blood pressures by 1 mmHg and 3 mmHg, respectively. Respiration rate was unaffected. We found no other studies that investigated how body position may influence physiological stress symptoms after acute mental stress. Chronic stress is known to manifest adverse health effects. This study provides physiological insight to how stress may be efficiently managed in short time periods while exploring this relatively untouched corner of stress physiology research.