The California Endowment’s HEAC program aims to support environmental changes to prevent child (and adult) obesity and prevent future cardiovascular morbidity. This investigation focused on youth’s opportunities for physical activity as areas for potential intervention. Given the high prevalence of obesity and low levels of fitness seen in this study, youth in these communities are at great risk of future cardiovascular morbidity and mortality. A major strength of this study is the use of objective measures of weight status and fitness in conjunction with youth’s perceptions of all major opportunities for physical activity in low-income communities. Perceptions, though subject to reporting bias, reflect what youth experience as their reality and can take into account practical issues (e.g., barriers related to access) that objective measures might not. Additionally, perceptions can be more closely linked to youth’s behaviors than external measures.9
Among these at-risk adolescents, physical education stands out as the highest impact area. All facets of PE – exposure, intensity, enjoyability – positively impacted student health. These findings contribute to a growing body of literature identifying the importance of PE in increasing physical activity14, 15
Although there is currently less evidence to link PE and weight status,14
we demonstrate an association between more time spent exercising during PE and better weight status among 9th
grade students. The cross-sectional nature of the present study prevents us from drawing causal inferences; however, 2 recent longitudinal studies among elementary school children support the hypothesis that greater exposure to PE predicts lower BMI.16, 17
Further, we extend findings to date by focusing on youth at greatest risk of future cardiovascular disease and by examining PE within the framework of all youth’s major opportunities for physical activity.
While California legislation mandates that all 7th
grade students take PE, we found significant variation in PE participation in this study and up to 40% of students in some schools reported not taking a full year of PE. Further, while binding PE requirements are associated with greater physical activity during PE,19
nearly half of students reported less than 20 minutes of moderate activity during PE. Although PE is clearly an important area for further intervention, schools must have financial support for it, governing bodies must demonstrate commitment to it, and policies surrounding it must have teeth. An example of such a policy is a proposed (and much-debated) mandate requiring that students pass a physical fitness test in order to graduate from high school in California.
While requiring a certain level of fitness prior to graduation translates readily into a policy with teeth, it does not address making PE enjoyable, yet the present findings suggest that groups of students who report higher enjoyment of PE have higher overall levels of fitness. Greater student enjoyment may reflect higher quality PE instruction that results in students putting forth greater effort. While students who like PE might simply be those who are more athletic to begin with, the present data don’t support this phenomenon, as liking PE tended to be associated with slightly higher BMI z-scores. Thus, it’s unlikely that athletic students drive the relationship between enjoyment and fitness. Similar to these findings, a recent study demonstrated that overweight high school students were just as active during PE as non-overweight students.20
Further investigation identifying factors associated with enjoyment (e.g., instructor’s training and experience, equipment and facility availability) will be necessary to translate this association into action.
While student groups reporting higher rates of active transport to/from school showed a trend toward better mile times, they also had significantly higher
BMI z-scores. Active commuters may live very short distances from school (shorter distance to school has repeatedly been linked to active commuting21–23
) such that the physical activity involved is minimal. Students being driven to school may also come from higher income families. It is also possible that those walking to or from school consume more calories because they purchase foods during their commute. We found that a significantly higher proportion of students using active transport purchased food from a snack cart while in transit than did students commuting by bus or car. Studies in low-income communities would suggest that the foods widely available near schools are not healthy.24, 25
Access to unhealthy foods just outside a school’s doors can readily undermine schools’ efforts to provide healthy environments. While a 15-minute walk may burn off 100 calories, a visit to a fast food establishment may layer on 500 calories in an even shorter time period. Policies, developed in collaboration with local vendors, to provide a “safer” nutrition environment in school zones, could address this, and model community-based interventions to create healthy environments have demonstrated some success.26, 27
Use of school grounds outside of school was significantly associated with greater fitness, particularly for 7th
graders, which may reflect participation in after-school programs. After-school programs are an important health focus and recent studies in the after-school setting have shown promise among elementary school children in low-income areas.28, 29
While use of other recreational facilities was not significantly associated with fitness, based on 95% confidence intervals for these associations, we can’t rule out an effect as large as a 1 minute improvement in mile time for each additional day of participation in these venues.
In the present study, reported utilization of physical activity facilities was linked to better fitness, but greater reported access to indoor facilities was associated with poorer weight status. It’s possible that greater access to recreational facilities also means access to other venues that promote ill-health, such as fast food establishments. While our findings contradict those among adults linking greater access to recreational activities to lower rates of self-reported obesity,30
the gap between providing access to facilities and getting youth to use them was well documented in a study by Rand in a low-income community in Southern California.31
“Build it and they will come” may no longer apply and interventions aimed at increasing access without additional social marketing efforts or use of incentives may not succeed.