|dc.description.abstract||The literature pertaining to the development of maximal sprint performance in male youth is sparse. Existing literature suffers from a combination of small sample sizes, a lack of control for the influence of maturity, methodological approaches where maximal speed is not measured or failure to explore the spatiotemporal, kinematic or kinetic characteristics associated with sprint performance in male youth. On this basis, the aim of this thesis was to investigate the influence of growth and maturation upon maximal overground sprint performance in a large cohort of 11-16 year old boys.
Sprint and spatiotemporal variables were found to have acceptable reliability (CV = 3.8-12.6%). Cross-sectional analysis of a large sample of boys showed a maturational effect on sprint performance, with the period of peak height velocity (PHV) eliciting the greatest enhancements in maximal sprint speed. Furthermore, whilst improvements in step length (SL) were observed with increasing maturity, step frequency (SF) was largely stable, with some evidence of small declines during the pre-PHV period. Further cross-sectional analysis revealed that pre-PHV boys were SF-reliant during maximal sprint performance, whilst post-PHV boys were deemed SL-reliant. Analysis of body size revealed that stature had a positive influence upon maximal sprint performance, whilst mass had a negative influence. Cross-sectional analysis of the kinetic characteristics of maximal sprint performance revealed that both relative maximal force and relative vertical stiffness did not increase with advancing age and maturity, but these variables were deemed to be the most important predictors of maximal sprint performance in male youth, independent of age and maturity. Furthermore, longitudinal analysis confirmed that relative force production and relative vertical
stiffness were the most important predictors of maximal sprint performance in boys, and that those who had passed the period of PHV experienced greater gains in maximal speed than those who remained pre-PHV.
Collectively the results of the empirical studies highlight that maximal sprint speed in male youth develops with advancing age and maturation, due to an interaction of changes in SL and SF. These changes are partly related to changes in body size and the period of PHV appears to be a key period during the development of maximal speed. However, there are also key predictors of speed, such as relative force and relative vertical stiffness that do not change between the ages of 11 and 16 years old.||en_US