The development of sports activities in the over forties has increased the number of middle-aged patients performing heavy-load exercise. The normal response of ankle systolic blood pressure (ASBP) and ankle to brachial index (ABI) to intense exercise is known in young athletes, but little is known for other age groups. Three groups of 21 athletes: <20 (G1), 20-40 (G2), and >40 (G3) years old, respectively, were studied. ASBP and brachial systolic blood pressure (BSBP) were measured simultaneously before and after an incremental maximal cycle ergometer test. Rest ABI was higher in G3 compared to G1 (P<0.001: ANOVA, Bonferroni). Compared to respective resting values, BSBP, at 1 min of recovery, was increased for the three groups of age (P<0.001) whereas ASBP was unchanged for G1 and G2, and significantly increased for G3 (P<0.001). ASBP was significantly higher in G3 than in G1 and G2, ABI was lower in G1 and G2 compared to G3: 0.70+/-0.11, 0.76+/-0.09 and 0.91+/-0.14, respectively. This age-related ABI increase is consistent with the impaired vasodilator capacity observed in aging normal subjects but not with the decrease observed in ABI resting values in epidemiological studies. ABI is higher in older than in younger athletes at rest and after exercise. In aging athletes, aiming to detect mild to moderate arterial lesions, it is likely that normal limits defined in young athletes are not valid.