Lit Review: Restorative Yoga

Pubmed results for searching “restorative yoga” gathers 15 articles total, suggesting there is opportunities for further research when it comes to applying this type of intervention to a wide array of populations. As is true in most research utilizing yoga, methodologies are widely variable, often not explicit and likely unrepeatable due to the wide variety in teaching styles. Thus we must extrapolate what we can from the research available not only on restorative yoga, but also on how relaxation effect the various systems of the body. 

Restorative yoga and Menopause (Cohen, 2007) looked at feasibility and acceptability of Lasater’s restorative yoga for treatment of hot flushes. Conclusion: it is feasible to teach restorative yoga to women who noted high rates of satisfaction. While the study did not have sufficient power (N=13), there was an over all reduction of hot flush frequency (31%), reduction in hot flush score (34%), reduction in menopause related quality of life scores (16%) and insomnia severity (20%). 

For metabolic syndrome, restorative yoga was compared to stretching (Kanaya 2014). The stretching group had significant reductions in weight at 6 months, reduction in waist circumference at 12 months, improved triglyceride levels, improved mental health scores and improved physical activity and caloric intake. The yoga group had significant reduction in waist circumference and weight at 6 and 12 months, improved fasting insulin, fasting glucose, HbA1c, increased HDL, and improved physical activity and caloric intake. Thus, if patients are unable to perform restorative yoga, for a variety of reasons, a stretching program may be a good alternative. 

Corey (2014) also looked stretching vs restorative yoga and found that there was higher HEP compliance in the restorative yoga group. Stretching showed greater improvement in cortisol and psychosocial scores, which the authors attributed to the social interactions during the stretching group. The authors stressed that social support is a stress buffer itself, and reduces threat reactivity, and reduces the inflammatory pathway. However social support is not a controllable factor and therefore something to encourage. The authors suggested for supine and inverted restorative yoga postures the following physiological mechanism: there is a stimulation of baroreceptor activity, inducing reflexes that produce a wide range of relaxing effects, including shifting the sympathetic/parasympthatic balance towards predominant parasympathetic nervous system activity. Thus there is a reduction in blood pressure, lowering plasma epinephrine and norepinephrine levels (Gharib 1998, Vybiral 1989, Shiraishi 2002), and calming the brain activity via ascending inhibitory pathways (Dell and Marillaud 1966, Cole 1989). Furthermore, supine and inverted postures lower heart rate, VO2max, and brachial arterial blood pressure (Blake 2006), as well as an increase in cardiac vagal tone (Khattab 2007). 

Corey (2014) also looked stretching vs restorative yoga and found that there was higher HEP compliance in the restorative yoga group. Stretching showed greater improvement in cortisol and psychosocial scores, which the authors attributed to the social interactions during the stretching group. The authors stressed that social support is a stress buffer itself, and reduces threat reactivity, and reduces the inflammatory pathway. However social support is not a controllable factor and therefore something to encourage. The authors suggested for supine and inverted restorative yoga postures the following physiological mechanism: there is a stimulation of baroreceptor activity, inducing reflexes that produce a wide range of relaxing effects, including shifting the sympathetic/parasympthatic balance towards predominant parasympathetic nervous system activity. Thus there is a reduction in blood pressure, lowering plasma epinephrine and norepinephrine levels (Gharib 1998, Vybiral 1989, Shiraishi 2002), and calming the brain activity via ascending inhibitory pathways (Dell and Marillaud 1966, Cole 1989). Furthermore, supine and inverted postures lower heart rate, VO2max, and brachial arterial blood pressure (Blake 2006), as well as an increase in cardiac vagal tone (Khattab 2007). 

Cancer studies (8) had methods that either didn’t describe their postures or used gentle yoga rather than the style of restorative this course teaches. Gentle restorative yoga is often slow moving postures that may entail lots of supine postures and small mindful movements, but does not allow the body to stay in stillness for prolonged periods. However this style of yoga may be moving towards relaxation which is the end goal is restorative yoga, and therefore we might be able extrapolate their findings that included  benefits for fatigue, quality of life, body aches, feasibility, decreased depression and anxiety,  and sleep.