Fitness level and obesity have been associated with death in older populations. We investigated the relationship between aerobic fitness in late adolescence and early death, and whether a high fitness level can compensate the risk of being obese.
The cohort comprised 1 317 713 Swedish men (mean age, 18 years) that conscripted between 1969 and 1996. Aerobic fitness was assessed by an electrically braked cycle test. All-cause and specific causes of death were tracked using national registers. Multivariable adjusted associations were tested using Cox regression models.
During a mean follow-up period of 29 years, 44 301 subjects died. Individuals in the highest fifth of aerobic fitness were at lower risk of death from any cause [hazard ratio (HR), 0.49; 95% confidence interval (CI), 0.47-0.51] in comparison with individuals in the lowest fifth, with the strongest association seen for death related to alcohol and narcotics abuse (HR, 0.20; 95% CI, 0.15-0.26). Similar risks were found for weight-adjusted aerobic fitness. Aerobic fitness was associated with a reduced risk of death from any cause in normal-weight and overweight individuals, whereas the benefits were reduced in obese individuals (P