Changes in exercise tolerance, blood lipids, and blood pressure from youth to middle age was studied in 106 subjects followed 32 years. In addition, the responses to cold pressor and CO2 stress were studied as correlates of future lipids and blood pressure. Treadmill exercise test, cold pressor test, response to breathing a mixture of 6% CO2, and 21% O2, for 5 minutes, blood pressure, and lipid measurements were performed in 1947 when subjects were 20 ± 2 years old. Exercise, blood pressure and lipid tests were repeated in 1979. Tracking of blood pressure and pulse response to exercise over the period was demonstrated. Baseline exercise response correlated with future blood pressure, cholesterol, triglycerides, and high density lipoproteins. Change in exercise pulse rate over the period correlated with change in cholesterol. Cold pressor systolic blood pressure response correlated with future systolic blood pressure and triglycerides. Pulse and blood pressure response to CO2 breathing correlated with cholesterol, triglyceride and high density lipoprotein 32 years later. These correlations were independent of baseline values of the variables and body mass index. Individuals who were judged 'fit' (exercise pulse rise < median) at both baseline and follow-up had the best cardiovascular risk profile (blood pressure and lipids). Blood pressure and pulse response to exercise tracked between ages 20 and 50. Exercise, cold pressor, and CO2 responses in youth correlated with blood lipid levels in middle age.