Background Few prospective studies have examined predictors of change in specific physical activity (PA) behaviours in different ethnic groups.

Purpose To assess predictors of change in sports participation in Latino and non-Latino 5–8 year-old children in San Diego, California.

Methods Average sports participation frequency (days/week) was assessed by validated parent-report at baseline (Nov 2006–May 2008) and 1 year later in 541 children (45.0% male, 41.1% Latino; mean±SD age: 6.6±0.7 years) taking part in an obesity prevention study (Project MOVE). Biological (sex, age, Body Mass Index z-score), socio-cultural (ethnicity, income, care giver education), parental (PA rules, PA encouragement) and environmental factors (home PA equipment, PA location) were assessed at baseline. Associations between change in sports participation and potential predictors were studied using multilevel linear regression stratified by Latino ethnicity, adjusted for sex, baseline sport participation, study condition and recruitment area.

Results Sports participation increased over 1 year (mean change: +0.5 days; p<0.001) and change was similar for boys and girls (p=0.95), but Latino children showed a greater increase (p=0.03). The number of locations used for PA (p=0.024) and the total frequency of PA location use (p=0.018) were positively associated with increased sports participation among Latinos. No predictors were identified for non-Latino children.

Conclusions Only factors relating to PA location were identified as predictors of change in sports participation for Latino children. Interventions targeting specific PA behaviours such as sports participation may need to consider PA locations for Latino children and be tailored for specific ethnic groups.