The impact of different loading sports and a jumping intervention on bone health in adolescent males

Abstract

Adolescence is a crucial period for bone development and exercise can enhance bone acquisition during this period of life. However, there is a lack of scientific evidence on how different loading sports practiced during adolescence can affect bone development in males. The present thesis is part of the PRO-BONE study and aimed to investigate the cross-sectional and longitudinal effects of participation in football (osteogenic sport), swimming and cycling (non-osteogenic sports) on bone mass, bone geometry, texture and bone metabolism in adolescent males. An active control group has been included too. Additionally, the thesis examined the effect of a 9-month jumping intervention programme on bone outcomes in adolescent males involved these sports. Cross-sectional findings from Chapter 4 show that footballers have better bone status than swimmers, cyclists and controls (7 to 21 %), and that there are no differences between participants of non-osteogenic sports and controls. Chapter 5 identifies that lean mass is the strongest determinant of bone outcomes, followed by football participation and height in adolescent male athletes, whereas the contribution of the other predictors, such as nutrition, physical activity and fitness, is site specific. Longitudinal evidence in Chapters 6 and 7 show that bone mass (5 to 8 %) and geometry (4 to 10 %) is higher in adolescent male footballers compared to swimmers and cyclists after one year of sport specific training, and that there are no differences in bone development between non-osteogenic sports groups and controls. Chapters 8 and 9 indicate that a 9-month jumping intervention programme can improve bone outcomes only in male adolescents participating in swimming and cycling (4 to 13 %), but not in those engaged in football, while it can improve fitness outcomes in all 4 groups (4 to 8 %). Collectively, the present thesis contributes to the literature by providing novel evidence in adolescent male athletes on the effects of popular sports such as football, swimming and cycling on bone status and development, and that a jumping intervention programme can improve bone development in those involved in non-osteogenic sports.