Data are presented as %, unless otherwise stated. EP: extreme pre-term; BDP: bronchopulmonary dysplasia; SOB: shortness of breath. Exact test for comparison between the three subgroups: *: p<0.05; **: p<0.01. ^#: objective assessments of physical activity showed that all children undertook considerably less physical activity than current recommendations of at least 60 min of moderate-vigorous physical activity per day which may explain why 21% of controls experience SOB with exercise.