Cardiovascular disease is the leading cause of morbidity and mortality worldwide, and signs of atherosclerosis are present in all large arteries already in adolescence. We investigated the association between high physical fitness in late adolescence and myocardial infarction (MI) later in life.
The study cohort comprised 743 498 Swedish men examined at the age of 18 years during conscription 1969-84. Aerobic fitness (Wmax) and muscle strength at conscription were measured using standardized methods. Myocardial infarctions occurring in the cohort were tracked through national registers. During a median follow-up period of 34 years, 11 526 MIs were registered in the cohort. After adjusting for age, body mass index (BMI), diseases, education, blood pressure, and socio-economic factors, one standard deviation increase in the level of physical fitness (Wmax) was associated with an 18% decreased risk of later MI [hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.80-0.85]. The beneficial effects of Wmax were significant across all recognized BMI groups, ranging from lean (BMI 30) (P 30) in the highest fourth of Wmax had a higher risk of MI than did lean men (BMI