Background: Few Norwegian data are available on the importance of physical activity with regard to mortality. Our objective was to study mortality in light of leisure time physical activity and smoking.
Material and method: Men born in the period 1923-1932 were included in the Oslo Study in 1972-1973 and then investigated again in 2000. A total of 5738 men were included in the analyses. Physical activity was registered as self-reported number of hours at low and high intensity, as well by the Gothenburg question on the degree of leisure activity (sedentary, low, moderate, high). Cox regression analysis was used for statistical computation.
Results: After 12 years, men who reported a moderate amount of activity (approximately 30 minutes per day six times per week of low or high activity) in the year 2000 had a 40% lower mortality rate than the physically inactive (the reference group). A change in activity level in older age was independently associated with a risk of death. The Gothenburg question on amount of activity gave the same predictive information value as smoking.
Interpretation: Our data indicate that there is a dose-response relationship between the degree of physical activity and early death. An increase in activity was just as strongly associated with reduced mortality as quitting smoking. Based on these data, physical activity should be recommended as a daily habit.