Impact of a Park-Based Afterschool Program Replicated Over Five Years on Modifiable Cardiovascular Disease Risk Factors

Benefits studied:
Uses studied: ,
Place: Miami-Dade County


A daily afterschool program in Miami-Dade County, Florida observes significant decreases in body mass index (BMI) and blood pressure between the beginning and end of the school year. Findings from this research suggest consistent, long-term afterschool programs can effectively reduce childhood obesity and cardiovascular disease risk.


This study is relevant for those interested in developing afterschool parks-based programs to improve children’s health. The results from this study can be used to provide compelling evidence to health care providers, parks and recreation departments, and schools for the effectiveness of this kind of program. The study can also be used to identify how to build an effective program.

This robust study enrolled a large sample of children, gathered data before and after program participation, and replicated the study during five consecutive years. This program structure, plus using professional technicians to collect data, helps ensure the results are reliable and can be replicated.


This study is based in Miami-Dade County, Florida.

Trail Type

This study occurred in 34 urban public parks around Miami-Dade County.


The purpose of this study is to measure the effectiveness of a year-long afterschool physical fitness program to help develop affordable, accessible public programming that reduces childhood obesity and cardiovascular disease risk factors.

This study was funded by the Health Foundation of South Florida and the Aetna Foundation.


  • Mean body mass index (BMI) decreased significantly for the cohort that started the study as obese, from the 98th to 95th For the cohort that began the study as overweight, mean BMI decreased significantly from the 91st to the 89th percentile. The cohort that started at a normal weight did not have any significant change in weight during the program.
  • Mean blood pressure decreased significantly across all groups.
  • Fitness scores increased significantly across all groups.


This study enrolled 1,546 children ages six to 14 who were participating in Miami-Dade County Parks, Recreation and Open Spaces Fit-2-Play afterschool program. The authors asked parents of children already participating in the Fit-2-Play program to participate in the research component of the program. The research program required children to complete baseline and post-program assessments. The assessments collected information regarding height, weight, waist and hip circumference (strong predictors of cardiovascular disease and type 2 diabetes), blood pressure, and physical fitness. Physical fitness was measured using the Presidential Youth Fitness Program protocol. The authors analyzed data separately for participants who were normal weight, overweight, and obese at baseline.

The Fit-2-Play program is a daily program, Monday-Friday, during the school year. The program includes one hour of vigorous physical activity daily and 30-minute classes on nutrition and other wellness topics once per week.

The authors conducted identical rounds—gathering baseline and post-program data—for five consecutive school years.


Messiah, S.E., Vidot, D., Hansen, E., Kardys, J., Matthew, M.S., Nardi, M. and Arheart, K.L., 2017. Impact of a park-based afterschool program replicated over five years on modifiable cardiovascular disease risk factors. Preventive Medicine 95: 66-73.