How Does Exercise Benefit Your Brain?
Moderate but regular exercise can boost the size of the parts of the brain that shrink with age, according to scientists who believe that light physical activity is one of the best ways of preventing senile dementia. A study involving 120 people aged between 60 and 80 found that walking briskly for 30 to 40 minutes a day three times a week was all that it takes to “re-grow” the structures of the brain linked with cognitive decline in later life. The effect was equivalent to stopping the aging clock of the brain by between 1-2 years and is one of the first scientific studies demonstrating the power of physical exercise in delaying the onset of mental decline and boosting brain regeneration, scientists said. Brain scans taken before and after the year-long study showed that two regions of the brain in particular, the prefrontal cortex and the hippocampus, grew in volume among the group undertaking light aerobic exercise, while they continued to shrink in those who were given only stretching tasks. The exercise group also did better at cognitive tasks which tested things like memory, language ability and attention, which are known to decline with age, than the second group that did not exercise.
“The results suggest that brain and cognitive function of the older adults remain plastic and highly malleable. There is not this inevitable decline that we used to think there was. We can improve brain function by relatively modest amounts of physical activity,” said Kirk Erickson of the University of Pittsburgh in Pennsylvania. Dr. Erickson continued, “Between six months and one year of regular physical activity can actually increase the size of the prefrontal cortex regions and another region of the brain called the hippocampus. With modest amounts of exercise we are able to increase the size of these structures… the hippocampus increased by about 2% over a one year period. That may sound like a modest amount but that’s actually like reversing the age clock by about one to two years.”
Erickson, K. et al, “Exercise training increases size of hippocampus and improves memory” Proceedings of the National Academy of Sciences, vol. 108 no. 7, 3017–3022.