AbstractsBusiness Management & Administration

NO FULL TEXT AVAILABLE. This thesis contains 3rd party copyright material.  –  – Introduction: Professional Australian Football (AF) is a physically demanding field sport that requires prolonged, high-intensity, intermittent exercise, and is punctuated by many intense accelerations and decelerations (Gray & Jenkins, 2010; Harcourt, Marclay, & Clothier, 2014). In addition to these running demands, AF players are also required to jostle and tackle an opponent and complete very intense skill actions which contribute to the high physical demands of the game. With such high demands, there is a need for a better understanding of the factors that are related to training and match performance. To meet these demands, developing optimal body composition, fat-free soft tissue mass (FFSTM) and fat mass (FM) are considered essential for success for professional AF players. Indeed, physical performance is reliant on muscular activity and therefore it is likely that FFSTM is an important physical characteristic for success in AF. Recent research has suggested FFSTM underpins physical performance in AF (Hrysomallis & Buttifant, 2012). Excess FM however, can be considered detrimental to performance as it is metabolically inactive. Therefore it is important that optimal levels of FFSTM and FM are developed in professional AF players. Despite the perceived importance of FFSTM for AF players, very few studies have investigated the factors related to developing and maintaining optimal body composition in this group. Therefore, the overall goals of this thesis were to: 1) determine the most accurate and precise method to assess anthropometry in AF players, 2) compare the anthropometry, upper body strength and lower body power characteristics in elite junior, sub-elite senior and elite senior AF players, 3) examine the seasonal changes in body composition, dietary intakes, and upper body strength in professional AF players, 4 compare the variations in body composition of early, mid and late career professional AF players over three successive preseasons. The results of five separate studies were reported in five manuscripts. Study 1: Different methods such as skinfolds, bioelectrical impedance (BIA), and dual-energy X-ray absorptiometry (DXA) are used to estimate FFSTM and FM in AF players. However, DXA is commonly reported to be the gold standard measurement device for this purpose. Therefore, a comprehensive evaluation of the precision and accuracy of two different DXA devices for measuring FFSTM, FM and BMC was completed. Additionally, a comparison of the construct validity and reliability of skinfold and BIA measures was also undertaken. DXA showed exceptional precision and accuracy for fat-free soft tissue mass (FFSTM), bone mineral content and fat mass. Body fat percentage derived from a football-specific skinfold equation and the Σ7 skinfolds both showed poor relationships with the criterion measures estimated from DXA. Bioelectrical impedance analysis also showed both poor accuracy and precision for AF players. These results…