Anatomical and physiological differences in structural heart lesions may affect peak aerobic capacity ( \(\dot{V}\) O2peak) and influence sports participation in children with congenital heart disease (CHD). We hypothesized that a higher frequency of sports participation would be associated with higher \(\dot{V}{O}_{2peak}\) in these patients. A two-year, single-center, retrospective review (May 2016–November 2018) was conducted in CHD patients who had a maximal cardiopulmonary exercise test (CPET) and documented sport participation. Sports participation was categorized into 3 groups: 0–1 days/week; 2–3 days/week; and ≥ 4 days/week. \(\dot{V}\) O2peak z-scores, % \(\dot{V}\) O2 at gas exchange threshold ( \(\dot{V}{O}_{2GET}\) ), and O2 pulse were calculated. Z-scores were calculated based on a reference population. Means and standard deviation (SD) are reported. p < 0.05 was considered statistically significant. In our study cohort (n = 56), \(\dot{V}\) O2peak z-score was − 1.01 ± 0.95; 83% had a z-score within ± 2 SD, while 59% were within one SD. The overall regression for sport participation with \(\dot{V}{O}_{2peak}\) and \(\dot{V}{O}_{2GET}\) was statistically significant (R2 = 0.40, F(4, 54) = 11.44, p = < .0001) and (R2 = 0.17, F(4, 54) = 3.46, p = 0.0227), respectively. There was a significant main effect for O2 pulse (R2 = 0.41, F(4, 52) = 11.91, p < 0.0001) but not for HRpeak (p = 0.86), SBPpeak (p = 0.74) or DBPpeak (p = 0.94). \(\dot{V}\) O2peak is higher in those who participate in sports compared to those who do not. It is unclear whether those with a higher \(\dot{V}\) O2peak are more inclined to participate in sports or whether sports participation leads to a higher \(\dot{V}\) O2peak.