• child and adolescent health;
  • emotional health;
  • physical fitness and sport

BACKGROUND: Protective factors associated with positive youth development predict health and education outcomes. This study explored trends in these protective factors and in physical activity among low-income students, and determined the impact of a school-based youth development program on these trends.

METHODS: This study used a quasi-experimental time series design including data from 158 low-income schools from 2001 to 2007. Ninety-four schools had exposure to a school-based program promoting physical activity and youth development through structured play; 64 schools served as controls. Primary outcomes were 5th-grade student scores (n = 13,109) on a California statewide survey for physical activity (1–6 scale) and measures of protective factors including problem solving skills, meaningful participation in school, and caring adults (1–4 scales). Predictors were time (year) and school's number of years of exposure to the program.

RESULTS: Overall, significant annual declines were seen in protective factors, including students' report of feeling safe (−0.03, 95% CI [−0.03, −0.01]), caring adults at school (−0.03 [−0.05, −0.02]), and problem solving skills (−0.03 [−0.04, −0.02]). Cumulative declines over 6 years were equivalent to a drop of 1 school-level SD. Each additional year of exposure to the program predicted greater meaningful participation (0.02 [0.001, 0.5]), problem-solving skills (0.03 [0.0001, 0.06]), and increased physical activity (0.06 [0.01, 0.10]); exposure throughout elementary school (6 years) increased scores by 1 school-level SD.

CONCLUSIONS: Low-income students reported a significant decline in protective factors since 2001. School partnerships with youth development programs promoting physical activity may ameliorate declines in emotional well-being and increase physical activity.