摘要：<b> </b>Despite the well-established benefits of physical activity for both physical and psychological health, current inactivity prevalence continues to be particularly alarming among adolescents and youth. Equally of great concern is the existence of striking gender differences that represent a serious threat to reverse this problem. We aimed to analyze gender-related differences in self-reported physical activity and motivational regulations in a population-based sample of Spaniard adolescents and young adults (<i>n</i> = 9949). To this aim, we used an explanatory mixed-methods design by integrating quantitative and qualitative data using self-determination theory (SDT) as an analytic framework. Our results reported a gender imbalance in physical activity levels and autonomous forms of motivation to the detriment of adolescent girls and young women. An earlier and steeper age-related decline both in activity and volitional types of motivation was observed in girls. Qualitative outcomes depicted a range of key cognitive and contextual mechanisms undermining the degree to which physically active behaviors are volitionally undertaken among women. These findings highlight the importance of implementing gender-sensitive policy approaches and may have a useful application in suggesting how contextual factors and exercise settings can be addressed to foster volitional types of physical activity engagement in adolescent girls and young women.
