Author(s): TINGELSTAD, L., RAASTAD, T., LUTEBERGET, L.S., Institution: NORWEGIAN SCHOOL OF SPORT SCIENCE, Country: NORWAY, Abstract-ID: 2238

INTRODUCTION:
Adolescence brings significant physiological changes, with boys and girls experiencing divergent physical performance trajectories due to unique maturation differences, leading to increasing performance differences between sexes (1). In this study we investigated the sex- and age-specific physical performance development in adolescent football players.
METHODS:
In this longitudinal study we followed 132 adolescent football players from Norway, categorized into girls and boys U14 and U16 groups. Using a repeated measures design, data were collected twice with one year apart. Assessments included anthropometrics and physical abilities (sprint, change of direction, countermovement jump (CMJ), leg force and power, eccentric hamstring strength, isometric hip and shoulder strength, and intermittent endurance performance), conducted over two days. Statistical analysis was performed using a mixed model approach and multiple regression.
RESULTS:
Significant time and sex effects were found, with boys outperforming girls at most tests at baseline and showing greater improvements in 30 m sprint (-3.6% vs. -2.3%), CMJ (12% vs. 3%), total power (24% vs. 13%), and abduction strength (21% vs 11%). Group comparisons showed that there was no significant difference in 1-year physical performance development between girls U14 and U16. On the other hand, U14 boys had a significantly greater 1-year improvement in both total (30% vs. 14%) and relative force (12% vs. 4%) than the U16s, and in 30 m sprint (-3.8% vs. -2.7%), CMJ (11% vs 5%), total force (30% vs 16%) and power (26% vs. 18%) compared to U14girls. U16 boys had greater 1-year improvement in CMJ (13% vs 0.1%), hip adduction (11% vs 2%) and hip abduction (14% vs 6%) than the U16 girls. Increases in height and body mass was significant for all group comparisons, with greater changes seen in boys and for the younger age group. Multiple regression analysis sheds light on the determinants of physical development, pinpointing baseline performance levels and sex as key factors for improvement.
CONCLUSION:
In contrast to previous research indicating a greater gap in performance between boys and girls with increasing age, our results highlights that this is not the case for all physical characteristics. Although differences in maturation processes will differentiate performance development between the sexes, this might be mitigated by increased volume of targeted physical training in girls. These results underscore the importance of considering various variables to understand the intricacies of physical development within this athlete population. Tailored training programs could potentially enhance the physical development and injury resilience of adolescent football players. By adopting this approach, it is possible to provide a more tailored path towards peak performance and injury prevention, accounting for the unique trajectories and adaptive responses of each athlete.

1) Malina et al., Human Kinetics, 2004