Researchers found that elderly men who decreased the duration or intensity of their physical activity level over a 10-year period experienced a greater decline in cognitive skills, such as attention, memory, and language skills, than men who maintained the intensity of their physical activity.

“Our study suggests that being physically active in old age could keep the brain fit,” says researcher B. M. van Gelder, of the National Institute for Public Health and the Environment in Bilthoven, Netherlands, in a news release.

In the study, which appears in the Dec. 28 issue of the journal Neurology, researchers tracked over a 10-year period the physical activity and mental skills of a group of 295 healthy men from Finland, Italy, and the Netherlands. The men were born between 1900 and 1920.

Starting in 1990, researchers measured the duration and intensity of the men’s physical activities, such as walking, bicycling, gardening, farming, sports, odd jobs, and hobbies. Their mental abilities were assessed using a standardized exam that measures skills such as attention, calculation, recall, language, and orientation to time and place.

The men were divided into four groups according to the level of intensity of physical activity. Men who participated in the lowest intensity activities at the start of the study, such as walking at a slow pace, had the strongest decline in mental skills. These men had up to a 3.5 times greater decline than those who participated in high-intensity activities like swimming.

The researchers also looked at whether the men changed their duration or intensity of physical activity over the 10 years.

Men who decreased the duration of physical activity by more than 60 minutes a day experienced a decline in mental exam scores that was 2.6 times greater than the decline in the men who maintained their duration of physical activity.

Men who decreased their intensity of physical activity experienced a decline in mental exam scores that was 3.6 times greater than the decline in the men who maintained their intensity of physical activity.

There was no decline in mental skills among men who increased the duration or intensity of their physical activity.

“Even in old age, participation in activities with at least a medium-low intensity may postpone cognitive decline,” write the researchers. “Moreover, a decrease in duration or intensity of physical activity results in a stronger cognitive decline than maintaining duration or intensity.”

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