Longitudinal Changes and Seasonal Variation in Body Composition in Professional Australian Football Players

Purpose: To compare development and variations in body composition of early-, mid-, and latecareer professional Australian Football (AF) players over 3 successive seasons. Methods: Regional and totalbody composition (body mass [BM], fat mass [FM], fatfree softtissue mass [141-STM], and bone mineral content [BMCD were assessed 4 times, at the same time of each season start preseason (SP), end preseason (EP), midseason (MS), and end season (ES) from 22 professional AF players using pencilbeam dualenergy X-ray absorptiometry. Nutritional intake for each player was evaluated concomitantly using 3-d food diaries. Players were classified according to their age at the beginning of the observational period as either early- (<21 y, n = 8), mid- (21 to 25 y, n = 9), or late- (>25 y, n = 5) career athletes. Results: Earlycareer players had lower FFSTM, BMC, and BM than mid- and latecareer throughout. FM and %FM had greatest variability, particularly in the earlycareer players. FM reduced and FFSTM increased from SP to EP, while FM and.FFSTM decreased from EP to MS. FM increased and FFSTM decreased from MS to ES, while FM and FFSTM increased during the off-season. Conclusions: Earlycareer players may benefit from greater emphasis on specific nutrition and resistancetraining strategies aimed at increasing FI-STM, while all players should balance training and diet toward the end of season to minimize increases in FM.