Physical activity and asthma development in childhood: Prospective birth cohort study.

Physical activity at early school age was not associated with reported asthma development later in life. However, lung function results showed that sedentary activity time was associated with lower FEV1/FVC later in childhood. As this is the first longitudinal study with objectively measured physical activity and lung function, and because the subgroup sample size was small, this result needs replication.