Systolic blood pressure response to exercise has been shown to predict development of hypertension in men, but this association has not been examined in population-based samples of men, or in women or non-whites. This relationship was explored in 3741 normotensive black and white young adults undergoing treadmill testing in the CARDIA study and examined 5 years later for development of hypertension. Exaggerated response to exercise (systolic pressure > or = 210 mm Hg in men and > or = 190 mm Hg in women) was detected in 687 subjects (18%) at baseline, and incident hypertension (blood pressure > or = 140/90 mm Hg or on medication) was detected in 184 subjects (4.9%) at followup. Persons with exaggerated response to exercise at baseline had 5 mm Hg higher systolic and 1 mm Hg higher diastolic pressures at follow-up (P < .005) and were 1.70 times more likely to have developed hypertension than were persons with normal response (P < .001). After adjustment for age, race, sex, clinic, resting systolic pressure, body mass index, heavy activity score, exercise duration, and preexercise systolic pressure, exaggerated response was associated with a 2.14 mm Hg increase in year 5 systolic pressure (P < .0001). These associations did not differ by race or sex. Although the increment in systolic pressure associated with exaggerated exercise response was small (1 to 3 mm Hg), this small increment sustained over time could lead to a substantially increased incidence of hypertension and hypertension-related target organ damage. Determination of factors associated with exaggerated response may provide further insights into the development of hypertension in young adults.(ABSTRACT TRUNCATED AT 250 WORDS)