Considerable interindividual variation in the response of blood pressure to exercise has been found. In this study the response of systolic blood pressure during a progressive maximal bicycle ergometer test was investigated in 747 physically active male subjects over age of 40 years with normal, borderline elevated, and elevated resting blood pressure. The influence of several subject characteristics on this response was studied: 53% of variation in exercise systolic blood pressure (eSBP) could be explained by work load, pre-eSBP, and maximal working capacity (Wmax). No difference in the slope of eSBP during the exercise test was seen between the three groups. Subjects with higher Wmax had lower systolic blood pressures at the same work load compared with subjects with a lower Wmax. Subjects in the elevated blood pressure group had significantly lower Wmax, although maximal heart rate and lactate were similar. Other variables were not significantly associated with eSBP.