Physiological characteristics of elite female soccer players: influence of age, position and playing status
Soccer is a highly dynamic and popular sport played by men, women and children of varying levels of expertise throughout the world. At the elite level it is imperative for strength and conditioning coaches to conduct a detailed analysis of the demands of the sport, in order to provide an evidence based evaluation of performance and further to inform specific goals and targets for athlete development. This thesis has sought to gain knowledge for the demands of female soccer at the elite and international level and to provide normative data regarding the physical characteristics associated with competition based on age, position and status as a starter or non-starter. On the basis of the literature review of the physiological demands and characteristics of elite female soccer it was established that performance outcomes are potentially linked to the physical capacity of the individual and could directly influence on-field technical performance and tactical choices. Elite female soccer players should strive to achieve the highest possible level of physical conditioning (aerobic and anaerobic) in conjunction with increased strength and power. There were no studies that focused on a link between physical characteristics and impactful performance outcomes (starters or non starters). The discrepancy in the literature between male and female demands of the game and the physical characteristics of elite female players made it difficult to distinguish what, if any physical characteristics are an asset for elite level competition. Age group data indicated that differences in physiological capacities are evident for the Under 17 players as compared to the Under 20 and Senior capped international players, suggesting a plateau in the development of physical qualities as players mature. Overall, starters tended to be faster (ES = 0.55-1.0, p<0.05) and have a higher maximal aerobic velocity (ES = 0.78-2.45, p<0.05), along with greater eccentric leg strength (ES = 0.33-1.67, p<0.05) as compared to non-starters. When evaluating positional characteristics, isokinetic strength and maximal velocity were the only physiological measures of significant difference between playing position, mainly between strikers and central mid-fielders. In regards to sprint determinants, maximum sprint velocity was significantly correlated with isokinetic strength, sprint kinetics and kinematics, and leg power (r = 0.36 to 0.87, p < 0.05), whereas acceleration was significantly correlated with isokinetic knee strength and horizontal jumping power (r = 0.36 and r = 0.36 respectively, p < 0.05). Practical implications for future research as a result of this thesis include the need for coaches to emphasize the development of speed, maximal aerobic velocity and leg strength in developing female soccer players. It is suggested that improving unilateral leg strength and power may also be effective in enhancing maximal speed for elite players.