The effects of an 8-week hatha yoga intervention on executive function in older adults

Background. Few scientific studies have examined movement-based embodied contemplative practices such as yoga and their effects on cognition. The purpose of this randomized controlled trial was to examine the effects of an 8-week Hatha yoga intervention on executive function measures of task switching and working memory capacity. Methods. Community-dwelling older adults (N = 118; mean age = 62.0) were randomized to one of two groups: a Hatha yoga intervention or a stretching-strengthening control. Both groups participated in hour-long exercise classes 3×/week over the 8-week study period. All participants completed established tests of executive function including the task switching paradigm, n-back and running memory span at baseline and follow-up. Results. Analysis of covariances showed significantly shorter reaction times on the mixed and repeat task switching trials (partial η² =. 04, p <. 05) for the Hatha yoga group. Higher accuracy was recorded on the single trials (partial η² =. 05, p <. 05), the 2-back condition of the n-back (partial η² =. 08, p <. 001), and partial recall scores (partial η² =. 06, p <. 01) of running span task. Conclusions. Following 8 weeks of yoga practice, participants in the yoga intervention group showed significantly improved performance on the executive function measures of working memory capacity and efficiency of mental set shifting and flexibility compared with their stretching-strengthening counterparts. Although the underlying mechanisms need to be investigated, these results demand larger systematic trials to thoroughly examine effects of yoga on executive function as well as across other domains of cognition, and its potential to maintain or improve cognitive functioning in the aging process.