Cognitive decline, characterized by slow speed of information processing and mild memory loss, is common in aging. However, contrary to what was once believed, cognitive decline is not inevitable. Researchers now believe it is possible to prevent, delay, or modify cognitive decline by making certain lifestyle adjustments, such as participating in mentally and physically stimulating activities.

Research investigating the link between physical activity and cognitive decline has been promising. A number of studies have found that increased levels of physical activity are associated with improved cognitive functioning. However, other studies have shown a weak or no relationship, and have had weaknesses in study design.

A new study in the December 2004 issue of Neurology found that elderly men who exercised at higher intensities were less likely to experience cognitive decline over the next 10 years. In addition, the men who maintained or increased the duration or intensity of their physical activity over 10 years had less cognitive decline than men who exercised less.

About the Study

Researchers used data from the Finland, Italy, and the Netherlands Elderly (FINE) study, which included 1,416 Finnish, Dutch, and Italian men born between 1900 and 1920 who were alive in 1990. Examinations of these men were conducted in 1990, 1995, and 2000.

For the current study, researchers looked at the 295 healthy men who were still alive in 2000. The participants were free from heart attack , stroke , diabetes, and cancer, and were not severely cognitively impaired in 1990.

The researchers assessed the men’s physical activity (both duration and intensity, assessed separately) and cognitive function using reliable, well-tested questionnaires. Information on physical activity was not available for the Finnish men in 2000, so they were not included in the change in physical activity results presented below.

Each subject was assigned to one of four groups based on their total daily duration of physical activity: less than 30, 31-60, 61-120, and more than 120 minutes per day.

The researchers calculated average intensity scores for each participant according to the types of activities the participants performed. The participants were classified into quartiles based on these scores:

  • Quartile 1: includes activities such as playing billiards and walking slower than three miles per hour
  • Quartile 2: includes activities such as playing volleyball and walking about three miles per hour
  • Quartile 3: includes activities such as gymnastics and walking about 3.3 miles per hour
  • Quartile 4: includes activities such as swimming and walking faster than 3.5 miles per hour

The Findings

Duration of physical activity in 1990 did not affect the men’s cognitive functioning in 1990, nor did it affect their 10-year cognitive decline. However, men whose duration of physical activity decreased by more than 60 minutes per day had 2.6 times more cognitive decline than the men whose duration remained stable.

The men’s baseline intensity scores did not affect their cognitive functioning in 1990, but they did affect their 10-year cognitive decline. Specifically, the cognitive capability of men in the lowest intensity quartile (Quartile 1) declined 3.5 times more during this time compared to men in the other quartiles. In addition, men whose activity intensity decreased the most from 1990-2000 had 3.6 times more cognitive decline than men whose intensity remained stable.

Interestingly, there was no cognitive decline among the men who increased either duration or intensity of physical activity over the 10 years.

These results are compelling, but it is important to note that the study design is limited because it is possible, though unlikely, that cognitive decline caused the changes in physical activity, not vice versa. The study was also relatively small, but its consistent and significant results make its findings relevant.

How Does This Affect You?

These findings suggest that elderly men who perform medium-intensity activities such as walking at a speed of three miles per hour or more, or increase the duration or intensity of physical activity can prevent or significantly reduce cognitive decline. This study provides even more evidence supporting the importance of being physically active throughout your lifetime.

Instead of slowing down as we age, research is showing that it is even more important to be active. The exercise you are doing now —not what you were doing 20 years ago—has the biggest impact on your health. So, whether you have never exercised or haven’t exercised in years, it is never too late to start. Apparently, it can save not only your body—but also your mind—from age-related decline that is by no means inevitable.