In this thesis, research questions regarding youth athletic development specific to girls’ association football players are investigated. Part 1: Movement screening and training for young athletes. In Study I, the reliability of the Fundamental Movement Screen™ (FMS) and the effects of a four-week fundamental movement training intervention on FMS™ and physiological performance were quantified. Inter- and intra-rata reliability of the FMS™ was dependent on the task component. Agreement ranged from slight to moderate for the stability tasks (Trunk Stability Press-up; kappa range, 0.36 – 0.43 and Rotatory Stability; kappa range, 0.11 – 0.34) yet, almost perfect for the Active Straight-leg Raise (kappa range, 0.82 – 0.87). The remaining four tasks ranged from moderate to substantial (kappa, 0.43 – 0.77). Post intervention changes in FMS™ total and flexibility were trivial and the intervention was possibly detrimental for side plank (-22 ±90 % confidence limit, 63 s) but very likely beneficial for prone plank (87 ±55 s). A negative standard deviation of change scores for FMS™ total (-1.5 ±1.6%) indicated greater within-subject variation in the control than intervention group. Study II is a case study detailing the effect of neuromuscular training during return-to-play in a girl football player. We observed qualitative improvements in dynamic knee control, and an almost certain improvement in FMS™ total score (7.0 ±2.4 arbitrary units) with large improvement in repeated sprint ability (likely, -3.8 ±4.7 s) and drop-jump height (possibly, 5.7 ±3.0 cm). In Study III, the role of match fatigue on markers of knee control in a single-leg drop jump screen in girls’ soccer players was analysed. Moderate to large improvements in counter movement jump were observed from baseline, while changes in kinematic markers of ACL risk were typically trivial or unclear. However, subjective ratings of perceived exertion and player readiness appeared to be sensitive indicators of accumulated match fatigue within this cohort. For example, we most likely observed, very large increases in overall exertion and large decreases in readiness by the end of the simulated match. Part 2: Training responses in girls’ football players. In study IV, the physical performance characteristics of girls’ football players and their typical variation, both short-term (one week, test-retest) and throughout a full season were quantified. Compared to pre-season substantial decrements were observed in acceleration (u13s; 8.0 ±3.2%, u15s; 3.6 ±3.9%), speed (u13s; 3.1 ±2.5%), change-of-direction speed (u13s; 6.9 ±3.0%, u15s; 10.1 ±5.0%) and repeated-sprint ability (u15s; 1.3 ±1.0%) at mid-season testing and in acceleration (u13s; 5.0 ±3.2%, u15s; 2.0 ±3.2%) and change-of-direction speed (u13s; 4.1 ±2.5%, u15s; 4.2 ±4.3%) at post-season testing. As such, research investigating strategies, e.g. physical training interventions, to counter potential decrements within a football season is justified. In study V, the impact of an eight-week high-intensity-interval-training programme on physiological performance was quantified over a pre-season period in players of differing biological maturation. In players categorised as after peak height velocity (PHV), very likely moderate improvements occurred in the yo-yo intermittent recovery test, level 1 (YYIR) and change-of-direction speed. In contrast, changes in YYIR were unclear in players’ before-PHV with a most likely very large decrement in repeated-sprint ability and a very likely moderate decrement in change-of-direction speed occurred in players’ at-PHV. In study VI, the effects of exposure to structured training were quantified over a 3-year period in girls’ football players demonstrating almost certainly, large to very large improvements. Large to near-perfect within player correlations were observed between maturation and sprint measures indicating systematic exposure to training improves sprint related physical qualities in girls’. Part 3: Practical recommendations. The final paper in this thesis provides a synopsis of current evidence and practical recommendations for strength training and metabolic conditioning for those supporting female youth and adolescent football players.
|Date of Award||25 Oct 2018|
|Supervisor||Greg Atkinson (Supervisor)|