RationalePremature birth is an independent predictor of long-term cardiovascular risk. Individuals affected are reported to have a lower rate of oxygen consumption at peak exercise intensity and at ventilatory anaerobic threshold, but little is known about their response to exercise training.ObjectivesTo explore if peak exercise oxygen consumption and ventilatory anaerobic threshold responses to exercise training differ between preterm-born and term-born individuals.MethodsFifty-two preterm-born and 151 term-born participants were randomly assigned (1:1) to 16-weeks of aerobic exercise training (n=102) or a control group (n=101). Cardiopulmonary exercise tests were conducted before and after the intervention to measure oxygen consumption at peak exercise intensity and the ventilatory anaerobic threshold. A prespecified subgroup analysis was conducted by fitting an interaction term for preterm and term birth history and exercise group allocation.Measurements and main resultsWithin term-born participants, peak exercise oxygen consumption increased by 3.1 (95% confidence interval: 1.7 to 4.4)ml/kg/min and ventilatory anaerobic threshold increased by 2.3 (95% confidence interval: 0.7 to 3.8)ml/kg/min in the intervention group versus controls. Within preterm-born participants, peak exercise oxygen consumption increased by 1.8 (95% confidence interval: -0.4 to 3.9)ml/kg/min and ventilatory anaerobic threshold increased by 4.6 (95% confidence interval: 2.1 to 7.0)ml/kg/min in the intervention group versus controls. No significant interaction was observed for peak exercise oxygen consumption (p=0.32) or ventilatory anaerobic threshold (p=0.12).ConclusionThe training intervention led to significant improvements in peak exercise oxygen consumption and ventilatory anaerobic threshold, with no evidence of a statistically different response based on birth history. Clinical trial registration available at www.Clinicaltrialsgov, ID: NCT02723552.