Even If You Are Otherwise Sedentary Exercise Will Protect Your Brain

Those of us that are stuck at a desk all day are aware that being sedentary all day is not good for us, but research is suggesting some good news that despite being stuck at that desk all day a daily bout of exercise will protect our brain because it helps to keep the brain’s cortex thick and healthy.

The cortex is the outermost layer of the brain, with age it will naturally thin which is associated with age-related cognitive decline, especially when it occurs in the frontal and temporal lobes that are responsible for memory, attention and planning. Research has shown that you can help to prevent this thinning by limiting sedentary behaviour and with regular moderate to vigorous physical activity. But what is less clear is whether exercise can protect against cortical thinning independent of being otherwise sedentary. 

To further investigate a group of scientists from British Columbia enrolled 30 adults with an average age of 61 who were enrolled in another study on increasing exercise and reducing sedentary time among adults with osteoarthritis of the knee. Activity levels, sedentary behaviour, and cortical thickness were measured from each participant. 

Participant exercise and sedentary time were tracked by using fitness trackers for 7 days, and MRI imaging was used to measure their cortical thickness. An average of 70 minutes of daily moderate to vigorous physical activity was reached by the group while spending close to 12 hours a day doing nothing more strenuous than reading or using a computer outside of their daily exercise. 

According to the researchers after analyzing the data and comparing brain scan high levels of physical exercise were found to be associated with greater cortical thickness, especially in the frontal areas regardless of sedentary time, and there was no link between less thickness/thinning with greater amounts of sedentary behaviour outside of exercise. 

“One potential explanation is that higher amounts of MVPA [moderate to vigorous physical activity] provide a strong neuroprotective response, which ameliorates the negative consequences of too much SB [sedentary behaviour],” the study authors wrote in Medicine & Science in Sports & Exercise.

Maintaining a thick cortex with regular exercise can help to fend off dementia and brain disease, and according to this study meeting the current guidelines of at least 150 minutes per week with moderate to vigorous exercise can help to reduce the risk of developing Alzheimer’s disease by up to 38%. 

While this is great news for those of us stuck at a desk all day, sitting for long periods of time and being sedentary is generally bad for your health and should be limited as much as possible. You can take simple steps to help decrease sitting time by standing every so often and perhaps stretching, stand and perhaps move around during phone calls, use a refillable water bottle and walk to the farthest station to fill it, and invest in a desk that can be raised so that you can stand and work for some of the day.