Maximal treadmill tests five years apart in asymptomatic men aged 45-72 years

169 asymptomatic male volunteers aged 45-72 years not taking part in any fitness or intervention program performed two maximal treadmill tets (Bruce protocol) five years apart. Treadmill endurance time declined 4 to 8 seconds per year; 72% of subjects had changes in endurance time of less than one minute. Maximal heart rate declined about 1 beat/min-1 per year. Horizontal or downsloping ST segment depressions of 0.1 mv or more or slowly upsloping ST depressions of 0.2 mv or more occurred in 26% of subjects at test 1, 38% of subjects at test 2. 25% of subjects with ST abnormality at test 1 were normal at test 2, and 26% of subjects with a normal ST segment at test 1 were classified as abnormal at test 2. Ventricular ectopic beats during or after exercise occurred in 22% of subjects at test 1 and in 37% of subjects at test 2, and the frequency of complex ventricular ectopic activity increased from 2% at test 1 to 9% at test 2. There is a high frequency of exercise induced ventricular extrasystoles, and ST depression in a normal population of older men and it is not known whether there is any need for intervention.