There are contradictory reports whether exercise capacity is reduced in patients on long-term follow-up after coarctation repair. Data from unselected patient groups are missing. In a cross-sectional, long-term follow-up study of a tertiary congenital cardiology referral center, 260 patients (30.2 ± 11.4 years old, 84 women), after surgical repair for isolated aortic coarctation (age at surgery 11.5 ± 11.2 years), underwent a symptom-limited exercise test. Peak workload was 180 ± 52 W, significantly less than the age- and height-related reference values (p <0.0005). A peak workload under 80% of expected was found in 200 patients (77%). Exercise performance of the patients was independent from age at surgery, type of surgery, or the systolic brachial-ankle blood pressure difference. The only exercise-limiting factor found was the chronic administration of diuretics to treat hypertension (p = 0.005). Exercise hypertension, defined as a systolic blood pressure >2 SD above the load-dependent reference value, was found in 73 patients (28%). It was independently related to the systolic brachial-ankle blood pressure difference (p <0.0005) and diuretics administration (p = 0.037). In conclusion, most patients after coarctation repair have a reduced exercise performance. This reduction is not related to the surgical results. Particularly, as these patients are at risk of early atherosclerosis, exercise should be promoted as primary prevention after restenosis, aortic or cerebral aneurysms, and severe exercise hypertension are ruled out.