Yoga, aerobic and stretching exercise effects on neurocognition: Randomized controlled trial protocol.

As the global population ages, the prevalence of cognitive decline and dementia is expected to rise, creating a significant health and economic burden. The purpose of this trial is to rigorously test, for the first time, the efficacy of yoga training as a physical activity intervention to mitigate age-related cognitive decline and impairment. We are conducting a 6-month randomized controlled trial (RCT) of exercise among 168 middle aged and older adults to compare the efficacy of yoga vs. aerobic exercise on cognitive function, brain structure and function, cardiorespiratory fitness, and circulating inflammatory and molecular markers. Using a single-blind, three arm RCT, 168 older adults ages 55-79 will be assigned to either: a Hatha yoga group, an aerobic exercise group or a stretching-toning active control group. Participants will engage in hour long group exercise 3x/week for 6-months. A comprehensive neurocognitive test battery, brain imaging, cardiovascular fitness test, and a blood draw will take place at baseline; end of the 6-month intervention, and at 12-month follow-up. Our primary outcomes of interest are brain regions, such as hippocampal volume and prefrontal cortex, and cognitive functions, such as episodic memory, working memory and executive functions, that are typically affected by aging and Alzheimer's disease. Not only will this RCT test whether yoga is a means to mitigate age-related cognitive decline, but it may also offer an alternative to aerobic exercise, which could be particularly appealing to older adults with compromised physical functioning. ClinicalTrials.gov Identifier: NCT04323163.