A Review of Comparison Studies Alyson Ross, R_N_, and Sue Thomas, FAA,N_, Ph.D.,

Objectives: Exercise is taken into account an acceptable method for improving and maintaining physical and emotional health. A growing body Of evidence supports the belief that yoga benefits physical and mental health via down- regulation of the hypothalamic—pituitary—adrenal (HPA) axis and the sympathetic nervous system (SNS). The purpose Of this text is to supply a scholarly review Of the literature regarding research studies comparing the consequences of yoga and exercise on a spread of health outcomes and health conditions.

Methods: Using PubMed’ and therefore the key word “yoga,” a comprehensive search of the research literature from core scientific and nursing journals yielded 81 studies that met inclusion criteria. These studies subsequently were classified as uncontrolled (n = 30), wait list controlled (0=16), or comparison (n = 35). The most common comparison interventlon (n = 10) involved exercise. These studies were included in this review.

Results: within the studies reviewed, yoga interventions seemed to be equal or superior to exercise in nearly every outcome measured except those involving fitness .

Conclusions: The studies comparing the consequences Of yoga and exercise seem to point that, in both healthy and diseased populations, yoga could also be as effective as or better than exercise at improving a spread of health-related outcome measures. Future clinical trials are needed to look at the distinctions between exercise and yoga, particularly how the 2 modalities may differ in their effects on the SNS/HPA axis. Additional studies using rigorous methodologies are needed to look at the health benefits of the varied sorts of yoga.

Introduction Y OGA IS AN ANCIENT discipline designed to bring balance and health to the physical, mental, emotional, and spiritual dimensions of the individual. Yoga is usually depicted metaphorically as a tree and comprises eight aspects, or “limbs;” yama (universal ethics), (individual ethics), asana (physical postures), pranayama (breath control), pra\yo- harn (control of the senses), dhnronil (concentration), dyano (meditation), and samadhi (bliss).l Long a popular practice in India, yoga has become increasingly more common in Western society.

In a natlonal, popula tion-based telephone survey (n = 2055), 3.8% of respondents reported using yoga within the previous year and cited wellness (64%) and specific health conditions (48%) as the motivation for doing yoga_2 A growing body Of research evidence supports the belief that certain yoga techniques may improve physical and mental health through down-regulation of the hypothalamic— pituitaryadrenal (HPA) axis and the sympathetic nervous system (SNS)_ The HEA axis and SNS are triggered as a response to a physical or psychologic demand (stressor), leading to a cascade Of physiologic, behavioral, and psy School of Nursing, University of Maryland, Baltimore, MI), chologic effects, primarily as a result of the release of cortisol and catecholamines (epinephrine and norepinephrine). response results in the mobilization Of energy needed to combat the Stressor through the classic “fight or flight” syndrome. Over time, the constant state of hypervigilence resulting from repeated firing of the HPA axis and SNS can lead to dysregulation Of the system and ultlmately diseases such as obesity, diabetes, autoimmune disorders, depression, drug abuse , and disorder . As detailed numerous studies have shown yoga to have an immediate downregulating effect on both the SNS/ HPA axis response to stress. Studies show that yoga decreases levels Of salivary cortisol* blood sugar ,7’S also as plasma rennin levels, and 24-hour urine norepineph- rine and epinephrine levels. 9 Yoga significantly decreases heart rate and systolic and diastolic blood pressure. 9-11 Stu- dies Suggest that yoga reverses the negative impact Of Stress on the immune system by increasing levels of immuno ulin A12 as well as natural killer cells.13 Yoga has been found to decrease markers of inflammation such as high sensitivity C-reactlve protein as well as inflammatory cytokines such as interleukin-614 and lymphocyte-I B.