Physical activity and adolescent girls: Insight, description, and intervention

"Some girls will, some girls won't...some say they will and some girls lie" (Racey, 1979). The lyrics of this 70s hit song provide an apt description of the physical activity behaviour of adolescent girls. Although some girls are sufficiently active for health benefits, many are not. Research demonstrating the importance of physical activity in the present and future lives of young women reinforces the urgency of understanding this complex human behaviour. The literature surrounding physical activity, pedometry, and youth was systematically reviewed. Three original studies were conducted with adolescent girls aged 15-18 years using both qualitative and quantitative procedures. These included a formative evaluation (N = 47), a descriptive study (N = 415), and an intervention (N = 85).

Qualitative findings indicate that the key factors that motivate adolescent girls to be physically active are orientated around the themes of fun, fatness (body image concerns), and friends (peer acceptance and interaction). Further empirical investigation into the concept of friendship reinforced the importance of friends in influencing habitual physical activity, specifically mutual friends. The methodological implications of this finding are significant. Using pedometry, the mean daily step count of girls was 9617 ± 3108. The least active participants had lower cardiovascular fitness (OR = 2.2, 95% CI = 1.1, 4.5), and were less likely to actively commute to or from school (OR = 0.5, 95% CI = 0.2, 0.9) than their more active counterparts. These studies culminated in the development of a controlled intervention trial with low-active adolescent girls, The Girls Stepping Out Program. Compared with traditional time-based prescription, the use of pedometers and daily step count targets resulted in increased physical activity.