Scientists have pinpointed the age when our physical activity declines.
It’s 49, researchers at Boston’s Northeastern University said. But, why?
Well, the shift occurs due to changes in key regions of the brain that help us with impulse control.
“We found that the brain can kind of predict some variance in people’s physical activity behaviors,” Timothy Morris, an assistant professor of physical therapy, human movement and rehabilitation sciences, said in a statement.
Morris is a co-author of the study, which was published recently in the Journal of Gerontology.
To reach these conclusions, they analyzed data previously collected by the Cambridge Center for Aging and Neuroscience. They zeroed in on a study that involved adult participants between the ages of 18 and 81. The study included self-reported exercise data and MRIs of participants’ brains, using a statistical technique to reach the drop off age.
Next, they hoped to understand why this was the case. It’s already well-known that we tend to be less active as we age and lose muscle mass and mobility. But understanding how a person’s ability to focus on, plan and carry out goals — including processes such as working memory and self-control — changes is a key focus for researchers.
“We’re now starting to see a convergence across different research groups that looks at precisely what in the brain is predicting physical activity engagement,” said Morris.
Their theory is that aging leads to changes in the salience network — which is made up of structures in that brain that help us orientate ourselves to certain environments — that result in changes in physical activity.
“What we found in this study is that this network is not only associated with physical activity across the lifespan, but it mediates this negative association,” Morris said. “So as age and physical activity becomes negative — it’s the salience network that’s mediating that relationship,.”
However, more research needs to be done to determine the cause.
“We should be ensuring that people are maintaining physical activity through midlife long before they start to see declines in physical activity that are due, in part, to mechanisms in the brain, with the goal of shoring up those cognitive resources that are helping them engage in physical activity,” he said.
