Governmental interventions and youth physical activity in France

Trajectories of Physical Activity Among Adolescents in the Transition From Primary to Secondary School

Research on physical activity (PA) behavior reveals an overall decrease worldwide from early childhood and throughout adulthood. The ability to illuminate which factors promote activity for whom and in which phase of life, therefore, becomes a key concept in extending our understanding of individuals' physical activity trajectories. Accordingly, this study investigates latent trajectories of objectively measured PA in adolescents (n = 306) over 3 years from ages 13 to 15. Further, it was tested whether eagerness for physical activity, perceived athletic competence, and parental support were associated with the different trajectories of PA. Latent class growth analysis revealed two PA trajectories (trajectory 1: "decrease from very high" and trajectory 2: "steeper decrease from high"). Trajectory 1 had a higher PA level at baseline and less PA decline than trajectory 2. Trajectory 1, "decrease from very high," was associated with higher levels of eagerness for physical activity and perception of competence at all three time points. Furthermore, the effect size of differences between trajectory 1, "decrease from very high," and trajectory 2, "steeper decrease from high," increased from baseline (age 13, seventh grade) to posttest (age 15, ninth grade). This finding indicates a stronger experience of PA as enjoyable, personally relevant, and self-confirming behavior (i.e., "I regard myself as a person who exercises") within the most active adolescents and even stronger as they get older. Consistent with previous research, the PA level declined from seventh to ninth grade. Being more eager for PA and perceiving oneself more as athletically competent is related to higher levels of PA. This highlights the importance of optimizing environmental factors that increase adolescents' experience of eagerness for physical activity and physical athletic competence.

Does biological maturity actually confound gender-related differences in physical activity in preadolescence?

AIM

To examine: (i) if maturity-related gender differences in moderate-to-vigorous physical activity (MVPA) depend on how maturity status is defined and measured; and (ii) the influence of maturity level on compliance with PA recommendations.

METHODS

The study involved 253 children (139 boys) aged 9.9 ± 0.9 years, with mean stature and weight of 1.39 ± 0.08 m and 35.8 ± 8.8 kg respectively. Their PA was evaluated using an Actigraph accelerometer (Model 7164). Maturity was assessed using the estimated age at peak height velocity (APHV) and a standardized APHV by gender (i.e. centred APHV).

RESULTS

Boys engaged in significantly more MVPA than girls (P < 0.0001). There was a significant correlation between the centred APHV and MVPA in boys (r = 0.20; P = 0.016), but not in girls (r = 0.13; P = 0.155). An ancova controlling for the estimated APHV showed no significant interactions between gender and APHV, and the main effect of gender on MVPA was negated. Conversely, there was a significant main effect of APHV on MVPA (F 1,249 = 6.12; P = 0.014; η p (2) = 0.024). Only 9.1% of children met the PA recommendations, including 14.4% of boys and 2.6% of girls (P < 0.01). This observation also applies in both pre-APHV (12.7% of boys vs. 2.4% of girls, P < 0.001) and post-APHV children (23.8% of boys vs. 3.4% of girls, P < 0.0001). No differences in PA guidelines were observed between pre-APHV and post-APHV children.

CONCLUSIONS

Among prepubescent children, the influence of biological maturity on gender differences in PA may be a function of how maturity status is determined. The most physically active prepubescent children were those who were on time according to APHV.