CHAMPAIGN, Ill. — Older adults who practiced hatha yoga three times a week for eight weeks were better able to manage stress and performed better on cognitive tests than their peers who engaged in a stretching and weight-training program for the same amount of time, researchers report in the journal Biological Psychology.
U. of I. kinesiology and community health professor Edward McAuley directs the Exercise Psychology Laboratory, where a new study testing the cognitive effects of yoga was conducted.
Study participants were 55 to 79 years of age, had no mental or physical disabilities and reported being sedentary for at least six months prior to the study. Roughly half of the 118 participants were assigned to a hatha yoga class; the others engaged in a stretching and toning class.
The team also measured levels of cortisol (a chemical marker of stress) in the saliva to gauge participants’ stress before and during cognitive tests, which were conducted at the beginning and end of the eight-week program. The tests challenged their ability to hold information in memory and to multitask.
Hatha yoga is an ancient spiritual practice that involves meditation and focused breathing while moving through a series of stylized postures, said Neha Gothe, who performed the work while a graduate student at the University of Illinois with U. of I. kinesiology and community health professor Edward McAuley.
A new study from U. of I. postdoctoral researcher Neha Gothe and her colleagues found a link between hatha yoga practice, lower cortisol levels and better performance on cognitive tests. Gothe is now a professor at Wayne State University in Detroit.
“Hatha yoga requires focused effort in moving through the poses, controlling the body and breathing at a steady rate,” Gothe said. “It is possible that this focus on one’s body, mind and breath generalizes to situations outside of the yoga classes, resulting in an improved ability to sustain attention.”
The study is a follow-up to a previous analysis of the same experiments, said Gothe, now a professor at Wayne State University.
“In the previous study, we only looked at how the two groups performed on the cognitive tests, and we saw that the yoga group performed better than the control group,” she said. “In this study, we tried to find out what led the yoga group to perform better. We thought maybe stress could be explaining the effects.”
Other studies have found that hatha yoga practice can lower cortisol levels in practitioners, Gothe said.
Previous studies have shown that yoga can have immediate positive psychological effects by decreasing anxiety, depression and stress.
“We were expecting to see something similar in our group,” she said. “But we didn’t see a significant drop in cortisol in the yoga group at the end of the intervention. They pretty much stayed the same.”
The stretching group, however, had significantly higher cortisol levels while performing the cognitive tasks at the end of the intervention.
“The changes that we saw in the salivary cortisol in the groups also predicted performance on the cognitive tests,” Gothe said. “The higher the cortisol, the poorer the performance.”
The differences between the groups were not the result of differences in age, gender, social status or other demographic factors, the researchers found.
Participants in the yoga group took the same amount of time to perform the cognitive tasks as those in the stretching group, but their answers were 4 to 15 percent more accurate, Gothe said.
“We don’t know yet why the yoga participants’ stress responses were lower,” she said. “It’s possible that – consciously or unconsciously – they were doing some deep breathing, relaxation or mindfulness practices that they learned in the yoga sessions, and these helped them better focus on the task and perform better. The control group, on the other hand, showed an increased stress response that appears to have compromised their cognitive performance.”
“Findings from this trial provide preliminary evidence that nontraditional physical activity interventions, such as yoga, may serve to balance neuroendocrine levels in older adults, thereby preventing or slowing cognitive decline,” McAuley said.
The National Institute on Aging at the National Institutes of Health supported this research.
Editor’s notes:
To reach Neha Gothe, call 313-577-6222; email nehagothe@wayne.edu.
To reach Edward McAuley, call 217-333-6487; email emcauley@illinois.edu.
The paper “Yoga practice improves executive function by attenuating stress levels” is available online and from the U. of I. News Bureau.
