Yoga Lifestyle with Cristina

Yoga is a term used to describe a range of practices, following a number of traditions of schools.¹⁰ The findings of this review mirror those of systematic reviews of yoga for other health conditions, in that the positive outcomes of individual studies must be countered by concerns about their lack of replicability and their heterogeneity.^12,48,49 Yoga practice is growing exponentially,²⁴ particularly in the population most likely to experience menstrual distress: women of childbearing age.

The complex mechanisms by which yoga practice may affect the person cognitively and physiologically, with an assumed impact on the stress response, have been noted earlier.^19–21 The effect of yoga specifically on the underlying mechanisms of menstrual disorder is therefore hard to determine here. The reduction of menstrual disorder symptoms (as reflected in pain or well-being scores) may be due to a generic effect of yoga on pain tolerance and stress reduction, rather than an impact on underlying causes of menstrual disorder, such as hormone imbalance, for example.

While the studies did discuss the possible and previously trialed benefits of yoga, there was no rationale for the specific regimens that were followed: neither the sets of postures used in the interventions nor the duration and frequency of the intervention. In the studies that used a limited and specific practice, for example, Yoga Nidra^35,36–39 or the comparison of two types of Pranayama^,42 there was not a justification for these practices over others in the yoga pantheon. The exception is Rakhshaee and colleagues’ study⁴⁵ using three specific poses. Their use is justified because of the action of the cobra pose on spinal flexibility and muscular strength, the cat pose on movement and breath coordination, and the fish pose on relief of stiffness and improvement of flexibility. The mechanism by which these proposed effects address menstrual disorder requires further inquiry, however.

All included studies reported some change in their outcome measures suggesting reduced symptoms of menstrual distress following a yoga intervention; however, the interventions and outcome measures used varied considerably. Several studies documented the effect of intensive programs of daily yoga that may be difficult to sustain outside of the college or industrial settings of the studies, whereby the same groups of women could be present in the same place for several days in a week. Among the 18 studies there was limited parity of intervention or outcome measure. Most studies measured the effect of yoga on an intervention group with no prior experience of yoga practice, meaning that the influence of yoga on menstruation over the long term or in regular practitioners was not gauged. Frequency of practice is a predictor of good health and high subjective well-being in established practitioners;²² however, the regimens described for yoga novices in some studies in this cohort were particularly intensive.^{33,34,40,43,44} There is scope for future research that both controls for the effect of frequency and duration of practice on menstrual disorders and explores the specific influence of frequency and duration.

Another main methodologic drawback is lack of comprehensive reporting of trial methods and heterogeneity of interventions, as has been identified in reviews of yoga for depression,^54,55 weight management,⁵⁶ and menopausal symptoms.⁵³ A recent comprehensive review of research on yoga 2010 to 2016 concluded that RCTs should compare yoga to other forms of exercise and that physiologic tests to identify underlying mechanisms should be used rather than self-reported measures.¹⁵ Recent systematic review and meta-analyses of yoga intervention studies for physical and mental health conditions have also called for a more sophisticated approach, whereby aspects of the practice and characteristics of different practitioners are explored.