The objective of this study was to investigate the association between physical activity (PA) and different goal setting and strategies in youth. The study took into consideration different sources of support as well as gender variations. Classmate and Teacher Support scales were used to evaluate support in physical education (PE) classes, and moderate-to-vigorous physical activity (MVPA) was reported. Garmin Vivofit(®) activity trackers were used during an 8 week-long intervention to count daily steps. Data was collected from 65 adolescents (mean age 17.2 ± 0.2), 74 young adolescents (mean age 15.3 ± 0.2) and 57 children (mean age 11.5 ± 0.4). An experimental design was employed, with "goal" and "do your best" groups given different step goal strategies. The results show that both groups achieved a comparable number of steps. Two-way ANOVA showed interactional effects between gender and teacher support. There were no such effects for MVPA and number of steps. Although classmate support in PE was reported to be reasonably high, the findings show that it does not play a significant role in increasing MVPA behaviors in youths. However, the problem of significantly lower support given to adolescent girls by PE teachers should be embedded into the teaching context of PE students and counteracted in school setting realities.
Keywords: activity monitors; classmate support; goal strategy; physical activity; teacher support; youth.