CHANGES IN PHYSICAL-FITNESS AND CHANGES IN MORTALITY

Background Point estimates of physical fitness give important informat ion on the risk of death in healthy people, but there is little inform ation available on effects of sequential changes in physical fitness o n mortality. We studied this latter aspect in healthy middle-aged men over a total follow-up period of 22 years. Methods 2014 healthy men ag ed 40-60 years had a bicycle exercise test and clinical examination, a nd completed a questionnaire in 1972-75 (survey 1). This was repeated for 1756 (91%) of 1932 men still alive by Dec 31, 1982 (survey 2). The exercise scores were adjusted for age, The change in exercise scores between surveys was divided into quartiles (Q1=least fit, Q4=fittest). An adjusted Cox's proportional hazards model was used to study the as sociation between changes in physical fitness and mortality, with the Q1 men used as controls. Findings By Dec 31, 1994, 238 (17%) of the 14 28 men had died, 120 from cardiovascular causes. There were 37 deaths in the Q4 group (19 cardiovascular); their relative risks of death wer e 0.45 (95% Cl 0.29-0.69) for any cause and 0.47 (0.26-0.86) for cardi ovascular causes. There was a graded, inverse relation between changes in physical fitness and mortality irrespective of physical fitness st atus at survey 1. Interpretation Change in physical fitness in healthy middle-aged men is a strong predictor of mortality. Even smalt improv ements in physical fitness are associated with a significantly lowered risk of death. If confirmed, these findings should be used to influen ce public health policy.