(American Thoracic Society) -- In tests of male subjects over periods of up to 25 years, Finnish investigators found that higher levels of physical activity were associated with a slower rate of decline in pulmonary function with aging, along with lower mortality rates.

The researchers found the decline in a baseline lung function test was about 10 ml per year less among men who were in the highest one-third (tertile) category for physical activity as compared with those in the lowest one-third. Consequently, the authors point out that middle-aged and older people should be encouraged to enjoy exercise.

The Finnish investigators studied a group of men in southwestern rural Finland to understand the influence of physical activity on the longitudinal decline in pulmonary function among middle-age men (55 years average age at study start). They had complete data on physical activity, smoking habits, and decline in pulmonary function for 429 men for 10 years from 1964 to 1974, 275 men for 20 years until 1984, and 186 men for 25 years until 1989. From a questionnaire developed for another study, trained nurses gathered information on the men's habitual walking, cycling, or cross-country skiing.

The scientists said that their results suggest physical activity can delay the decline in pulmonary function occurring in middle and older age. The beneficial results were independent of smoking and similar in all smoking categories. (From 37 to almost 43 percent of the subjects were continuous smokers during the 25 years of the study.) Most of the participants were farmers and were involved in heavy to very heavy occupational activities, but all had retired by 1984.

The study appears in the second issue for August 2003 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.