The middle school years is the time when time kids spend begin to spend less time in physical activity, a growing concern as youth obesity rates rise. A new study of middle school girls shows that after-school programs, in addition to school physical education classes, may be one answer to reducing obesity in teens. The just-released results of the Trial of Activity for Adolescent Girls (TAAG) showed that moderate to vigorous after-school physical activity, in programs that can range from hip hop dancing to surfing, can modestly increase the amount of physical activity for young teenage girls, to the point that it could prevent excess weight gain of about two pounds per year. If sustained, that extra activity could prevent a girl from becoming overweight as a teenager or adult. Results are published in the article, "Promoting Physical Activity in Middle School Girls," in the March issue of the American Journal of Preventive Medicine.

Deborah Young, professor and interim chair of the department of epidemiology and biostatistics in the University of Maryland, College Park, School of Public Health, was a researcher on the TAAG study. Below she answers questions about the study and increasing physical activity in adolescent girls.

BACKGROUND: The TAAG study found that programs which linked schools in six geographic regions of the U.S. with community partners (such as the YMCA or YWCA, local health clubs, and community recreation centers) increased time spent in moderate-to-vigorous physical activity among the middle-school female students by about two minutes per day, or 80 calories a week. This finding occurred after three years of the intervention, but not after two years.

TAAG showed a reduction of 8.2 minutes of sedentary behavior in girls in the intervention schools. Furthermore, the best results were seen in programs offered between 2 p.m. and 5 p.m. on weekdays, which suggest that after-school programs are more effective than programs offered at other times, such as morning weekdays and weekends. The study results, say the authors, support the need for schools and community programs to work together to provide opportunities for physical activity programs in after-school settings. The study was supported by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health.

Q: Why did you study only girls?

Young: While physical activity declines in both boys and girls across adolescence, it declines at a greater rate in girls. Also, previous studies indicate that boys and girls at this age tend to prefer different types of activities and have different reasons for being active. So we would have had to design distinct programs for boys if we included them.

Q: What was the purpose of studying after-school activities and not just school phys ed programs?

Young: We wanted to take a comprehensive approach to altering the environment in which girls are likely to be physically active. Physical education is often only conducted two to three times per week in the schools. A high quality PE class may only get 50 percent of the time in physical activity -- which may be less than 20 minutes or so. So while a major focus of TAAG was on improving physical activity in PE class, we also wanted to provide more opportunities for girls to be active. From early studies we did preparing for TAAG, we found that there weren't many after-school physical activity opportunities for girls at this age -- especially for girls who are "athletes" or play on highly skilled travel teams. So providing after-school programs filled a gap.

Q: What did you find out about motivating girls at this age to stick with physical activity?

Young: To get and keep girls active, we took a comprehensive approach. We developed lessons for the teachers to teach on motivation and goal setting, and gave students an opportunity to practice those skills. We worked with the PE teachers to promote choice in PE class, which from early work the girls said they would like. It might have been a choice of skill level or a choice of activities during class. Many of the programs were short -- sometimes only four weeks in length -- so girls wouldn't get bored. The promotional campaigns were designed to be motivational. For example, in some schools, classes competed against each other in the pedometer challenge.

Q: What kinds of activities did they do?

Young: After school programs included Hip-Hop dance, walking clubs, lacrosse clinics, swimming programs, training for a 5K road race. One site had surfing lessons! Schools and community agencies worked to provide a number of different activities that would appeal to different girls -- athletes and non-athletes.

Q: The prevention of weight gain of two pounds a year seems small. What does this mean in the big picture?

Young: Prevention of weight gain wasn't a goal of the study, so if we were aiming to influence weight gain we might have seen even greater results. However, given the rise of the obesity epidemic, any weight gain prevention on a population level is important. Also, two pounds per year add up to 20 lbs in 10 years -- an amount that could significantly impact an adult's health status.

Q: The paper points to difficulty of funding programs like this. What are some ways communities might address that challenge?

Young: Committed volunteers can be a valuable resource. If a responsible adult can lead a physical activity class even for as few as four weeks, that's a start. The more volunteers that can do this, more programs can be provided. Transportation to and from off-site programs, like the YMCA, is always a problem -- so again, working with volunteers to schedule carpools can help. At the broader level, the comprehensive approach needs to be taken at the school level. If schools can find funds to pay a stipend to teachers to coordinate programs like TAAG and ensure that teachers are trained to implement programs, the programs are more likely to be sustained.

Q: Were you surprised by any of the results of the study?

Young: We were surprised that the control group at the end of the second year of the intervention was as active as it was. We didn't see changes after two intervention years, but did after three years, which we believe was because of an especially active control group. We were also somewhat surprised that at the third year of intervention, after which the program champion directed the intervention, physical activity levels in the intervention schools were identical to the second year, in which there was a more full implementation of the program.

Q: Where can students and families find more information about the value of moderate-to-vigorous physical activity?

Young: There are a number of excellent web sites -- including this by NHLBI: http://www.nhlbi.nih.gov/health/public/heart/obesity/wecan

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