Lone atrial fibrillation in vigorously exercising middle aged men: case-control study

Abstract

We chose top level veteran orienteers to represent subjects doing long term vigorous exercise. A high position in the veteran ranking list is an indicator of years of intense training. We enrolled the 60 top ranked orienteers in 1984 from the race classes age 35-39 years, 40-44 years, 45-49 years, and 55-59 years, a total of 300 runners. The 495 controls comprised all men aged 35-59 enrolled for an earlier study.2 At 20 years old these subjects had been completely healthy (fully fit for military service). Mean (SD) age at baseline was 47.5 (7.0) years in orienteers and 49.6 (5.3) years in controls. Controls had responded in 1985 to a questionnaire which included items on physical activity and occurrence of various diseases.2