Effect of swimming initiation period and continuation frequency on motor competence development in children aged up to 3 years: the Japan environment and children’s study

Although involvement of toddlers in swimming activities has increased recently, information regarding the impact of swimming during toddlerhood on subsequent child motor competence development is scarce. This study aimed to determine how swimming experience, particularly the timing of initiation and the continuity of swimming activities up to the age of 3 years, affects motor competence development. This prospective cohort study included data on children aged 1.5 and 3 years (100,286 mother–child pairs) from the Japan Environment and Children’s Study. The outcomes measured were gross and fine motor function, using the Japanese version of the Ages and Stages Questionnaire (Third edition). We assessed how these functions correlated with the continuous pattern of swimming pool use frequency from age 1 up to 3 years. The group that used a swimming pool once a month or more from age 1–1.5 years but stopped from age 2–3 years showed consistently significant negative associations with gross motor development delay (minimum adjusted odds ratio [aOR]: 0.66, 95% confidence interval [CI]: 0.60–0.73) and fine motor development delay (minimum aOR: 0.66, 95% CI: 0.58–0.76). The group that continued swimming once a month or more from age 1–3 years showed consistently significant negative associations with gross motor development delay (minimum aOR: 0.64, 95% CI: 0.54–0.75) and fine motor development delay (minimum aOR: 0.42, 95% CI: 0.31–0.55). These results suggest that swimming experience starting around age 1 year is positively associated with gross and fine motor function development. The beneficial impact on gross motor function persisted from age 1–3 years. In contrast, the effects on fine motor function were not evident until age ≥ 2.5 years after starting swimming at approximately age 1 year. These findings underscore the potential benefits of early swimming experiences in enhancing overall motor skills development during early childhood.