Smith BH, Lyons MD, Esat G.
Yoga Kernels: A Public Health Model for Developing and Disseminating Evidence-Based Yoga Practices. Int J Yoga Therap. 2019; 29(1):119–26. doi:10.17761/2019-00024
Few scientific articles discuss models for the integration of yoga into the health care system. Despite the growing body of evidence on the physical and mental benefits of yoga, the available literature suffers from heterogeneity of methods and poor studies’ descriptions (i.e. type of yoga practice, attendance rate, elements included in the practice). As Smith et al. contend: “Defining and measuring is one of the main challenges in yoga research”. For these reasons, the findings on the effects of yoga are often contradictory and, for many health conditions, not yet conclusive.This limits the possibility for yoga to be embraced as a public health intervention in the health system.
In a public health approach, yoga interventions should be standardized, to allow for rigorous investigation and communication about the outcome of the practice. Smith et al. proposes to operationalize yoga studies with the use of “kernels”, building blocks that have sufficient evidence of reliable benefit (at least two well-controlled studies that found both benefit and no harm), such has belly breathing, child’s pose, power poses (Tadasana, etc.). Though the whole of the components of yoga have greater value than the sum of the parts, each kernel has its own discrete value as a single component, and can be studied and measured as a stand alone practice.
Yoga researchers and practitioners should collaborate in the selection of yoga kernels and their implementation should be supported by instructions and training procedures. Furthermore, to improve the widespread use of yoga, the authors suggest the use of the RE-AIM public health model (Reach Effectiveness Adoption Implementation Maintenance). To implement effective and generalizable interventions, this model requires firstly to establish the needs of the target population and the effect of the intervention on the desired outcome (RE-), and then to focus on systematic promotion to sustain the adoption-implementation and maintenance (-AIM) of the intervention.