https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:32862 IFT) within rugby league. Sixty-three Australian elite and junior-elite rugby league players (22.5 ± 4.5 years, 96.1 ± 9.5 kg, Σ7 skinfolds: 71.0 ± 18.7 mm) from a professional club participated in this study. Players were assessed for anthropometry (body mass, Σ7 skinfolds, lean mass index), prolonged high-intensity intermittent running (PHIR; measured by 30-15_IFT), predicted aerobic capacity (MSFT) and power (AAS), speed (40 m sprint), repeated sprint, and change of direction (COD—505 agility test) ability before and after an 11-week preseason training period. Validity of the 30-15_IFT was established using Pearson’s coefficient correlations. Forward stepwise regression model identified the fewest variables that could predict individual final velocity (V_IFT) and change within 30-15_IFT performance. Significant correlations between V_IFT and Σ7 skinfolds, repeated sprint decrement, VO₂max_MSFT, and average aerobic speed were observed. A total of 71.8% of the adjusted variance in 30-15_IFT performance was explained using a 4-step best fit model (VO₂max_MSFT, 61.4%; average aerobic speed, 4.7%; maximal velocity, 4.1%; lean mass index, 1.6%). Across the training period, 25% of the variance was accounted by ΔVO₂max_MSFT (R² = 0.25). These relationships suggest that the 30-15_IFT is a valid test of PHIR within rugby league. Poor correlations were observed with measures of acceleration, speed, and COD. These findings demonstrate that although the 30-15_IFT is a valid measure of PHIR, it also simultaneously examines various physiological capacities that differ between sporting cohorts.]]> Tue 31 Jul 2018 11:55:18 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:50319 Tue 18 Jul 2023 14:29:54 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:28052 Sat 24 Mar 2018 07:41:02 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:28336 0.7), whereas the ICCs for Under 16s and Under 18s were almost perfect (r > 0.9). Coefficients of variation were 1.9% (95% confidence interval, 1.6–2.4) for the combined test-retest of the 30-15IFT and 0.6% (0.5–1.0) for HRpeak. As the typical error of measurement (TE) (0.36 km·h−1) was greater than the smallest worthwhile change (SWC) (0.21 km·h−1) value, the usefulness of the VIFT was rated as “marginal.” The TE for HRpeak was similar to the SWC, rating the usefulness of this variable as “OK.” Despite the usefulness of the 30-15IFT being deemed Marginal, a change as small as 0.5 km·h−1 (1 stage) in VIFT could be considered substantial or “real.” As a consequence, the 30-15IFT presents as both a reliable and useful field test in the assessment of intermittent fitness for rugby league players.]]> Sat 24 Mar 2018 07:25:14 AEDT ]]>