Comparison of anthropometry, upper-body strength, and lower-body power characteristics in different levels of Australian football players.

The aim of this study was to compare the anthropometry, upper-body strength, and lower-body power characteristics in elite junior, sub-elite senior, and elite senior Australian Football (AF) players. Nineteen experienced elite senior (≥4 years Australian Football League [AFL] experience), 27 inexperienced elite senior (<4 years AFL experience), 22 sub-elite senior, and 21 elite junior AF players were assessed for anthropometric profile (fat-free soft tissue mass [FFSTM], fat mass, and bone mineral content) with dual-energy x-ray absorptiometry, upper-body strength (bench press and bench pull), and lower-body power (countermovement jump [CMJ] and squat jump with 20 kg). A 1-way analysis of variance assessed differences between the playing levels in these measures, whereas relationships between anthropometry and performance were assessed with Pearson's correlation. The elite senior and sub-elite senior players were older and heavier than the elite junior players (p ≤ 0.05). Both elite playing groups had greater total FFSTM than both the sub-elite and junior elite players; however, there were only appendicular FFSTM differences between the junior elite and elite senior players (p < 0.001). The elite senior playing groups were stronger and had greater CMJ performance than the lower level players. Both whole-body and regional FFSTM were correlated with bench press (r = 0.43-0.64), bench pull (r = 0.58-0.73), and jump squat performance measures (r = 0.33-0.55). Australian Football players' FFSTM are different between playing levels, which are likely because of training and partly explain the observed differences in performance between playing levels highlighting the importance of optimizing FFSTM in young players.

The reliability of ten-meter sprint time using different starting techniques.

Acceleration is an important factor for success in team-sport athletes. The purpose of this investigation was to compare the reliability of 10-m sprint times when using different starting techniques. Junior male rugby players (n = 15) were tested for speed over 10 m on 2 different testing sessions. Three trials of 3 different starting techniques (standing, foot, and thumb starts) were assessed. Despite large differences in the time taken to perform 10-m sprints from different starts, there was minimal difference in the typical error (approximately 0.02 seconds, or <1%) between the 3 different starts. There was a small, 0.02 +/- 0.02 second, decrease (p = 0.05) in sprint time between sessions for the foot start. For all starting techniques, the magnitude of error (typical error) was greater than the smallest worthwhile change (<0.01 second), indicating that acceleration over 10 m measured by photocells only has a marginal chance of reliably detecting a change of sufficient magnitude to be worthwhile in practical terms. However, by accounting for the smallest worthwhile change and typical error, it is possible to establish the probability an individual has had a worthwhile change in sprint performance. Coaching and sports-science practitioners can use a variety of sprint-start techniques shown to have small typical errors (<1%); however, the results from the different starting technique are not interchangeable.