Purpose: The insufficient physical activity (PA) of adolescents is a global challenge, and there is a need to find opportunities to engage youth in active lifestyles. The majority of adolescents do not meet the recommended guidelines of physical activity, and especially females have low levels of activity as they approach adolescence. The goal of this study was to obtain insight into Finnish adolescent girls’ objectively measured physical activity by evaluating the effects of an activity-based homework intervention on low, medium, and high-active girls during after-school hours.

Method: A physical activity homework intervention was put into place for female adolescent girls. Physical activity was measured by accelerometers and a self-reported diary from 87 girls aged 13 to 15 years.

Results: Results indicated that high-active girls maintained their activity until the last measurement hour (10 pm), while the moderate- and low-active girls’ activity declined towards the evening hours. The high-active girls participated the most frequently in organized sports activities, and the low-active girls were the most active in participating in household chores. The PE homework intervention increased girls’ activity time an average of 34 minutes per week.

Conclusion: This study offers a picture of the diverse nature of the physical activity that adolescent girls engage in during after-school hours and shows the potential of PE homework assignments to reduce sedentary time and thereby increase physically active time during after-school hours.

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Published in Physical Activity and Health, v. 5, issue 1.

© 2021 The Author(s)

This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC-BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. See https://creativecommons.org/licenses/by/4.0/.

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