Introduction and objectivesThe MOVI physical activity program has been shown to reduce adiposity and to improve serum lipid profiles in schoolchildren. However, MOVI may have not achieved its maximum potential effectiveness, as increased physical activity on weekdays may have been offset by more sedentary behavior at weekends. We therefore developed the MOVI-2 program, which includes physical activity at weekends as well. This paper reports the rationale and methods of a trial to assess the effectiveness of MOVI-2 in preventing overweight and reducing cardiovascular risk in 1200 4th- and 5th-grade primary schoolchildren in Cuenca, Spain. MethodsTen schools were randomly assigned to MOVI-2 and 10 schools to the control group. MOVI-2 consisted of recreational physical activity in after-school time, including two 90-min sessions on weekdays and one 150-min session on Saturdays, during each week of one academic year. The control group was expected to follow their usual patterns of physical activity. The primary end points, which were assessed at the start and the end of the MOVI-2 program, were weight and height, waist circumference, skinfold thickness, body fat percentage, blood pressure, lipid profile, and insulin resistance. Secondary end points were physical activity, fitness, health-related quality of life, sleep quality, academic performance, enjoyment with physical activity, and physical self-concept. ConclusionsThis study will assess whether MOVI-2 overcomes some potential limitations of physical activity interventions in children (Clinicaltrials.gov number NCT01277224).Full English text available from:www.revespcardiol.org