Most people know that as we get older, we tend to be less active. It’s often blamed on weaker muscles, joint pain, or simply getting tired more easily. But a new study from Northeastern University suggests that the real reason might be connected to changes in our brain that start happening in middle age.
The research, led by Timothy Morris, an assistant professor of physical therapy and rehabilitation sciences, was published in the Journal of Gerontology.
The team analyzed data collected by the Cambridge Centre for Ageing and Neuroscience, which included information from participants aged 18 to 81. The study combined self-reported exercise habits with brain scans to see if there were any links between brain health and physical activity.
What they found was surprising. Using a statistical method called piecewise regression, they discovered that people’s physical activity levels start to drop significantly around the age of 49. They then looked at brain images to understand why this might happen.
The team focused on a specific part of the brain called the “salience network,” which is a group of brain regions responsible for identifying important things in our environment and deciding how to respond to them. For example, if you walk into a room and see a comfy sofa, your brain quickly processes the option to sit down and relax, even if you originally planned to exercise.
The salience network includes regions like the insula and the dorsal anterior cingulate cortex. These areas help us make decisions, control impulses, and stay focused on goals, like going for a walk instead of sitting down.
As we age, changes in this network might make it harder to overcome the temptation to rest instead of being active. Morris explains that this is part of our natural instinct to save energy. When we see a sofa after a long day, it’s our brain that makes sitting down seem much more appealing than heading to the gym.
The study suggests that as we get older, these brain changes make it harder to stay active, even if our muscles and joints are still in good condition. It becomes more of a mental challenge than a physical one.
In fact, Morris believes that encouraging people to stay active during middle age is crucial. By keeping our brains engaged in regular physical activity, we might be able to slow down these brain changes and stay more active for longer.
Morris and his team plan to take their research further. They want to see if it’s possible to improve people’s activity levels by directly targeting the salience network. Their next study will involve randomly assigning participants to different groups and trying to influence their brain activity in this area to see if it makes a difference in how much they move.
If successful, this could lead to new ways to help people stay active as they age, not just through exercise programs but by directly improving brain health.
The findings of this study are important because they shift the focus from just physical barriers to staying active to include mental and brain-related challenges. It shows that staying fit as we age isn’t just about taking care of our bodies but also keeping our brains healthy.
The brain and body work together in a loop: physical activity boosts brain health, and a healthy brain helps us stay active.
Understanding this connection opens up new possibilities for helping older adults stay active and healthy. If we know the brain is part of the problem, we can start looking for solutions that go beyond just telling people to exercise more. It might mean new therapies or even brain exercises that help people stay motivated and keep moving as they grow older.
This research is a reminder that aging doesn’t just happen to our bodies; it happens to our minds too. If we want to keep moving, we need to take care of both.
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The research findings can be found in The Journals of Gerontology, Series A: Biological Sciences and Medical Sciences.
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