The Validity and Contributing Physiological Factors to 30-15 Intermittent Fitness Test Performance in Rugby League.
Scott, TJ, Duthie, GM, Delaney, JA, Sanctuary, CE, Ballard, DA, Hickmans, JA, and Dascombe, BJ. The validity and contributing physiological factors to 30-15 intermittent fitness test performance in rugby league. J Strength Cond Res 31(9): 2409-2416, 2017-This study examined the validity of the 30-15 Intermittent Fitness Test (30-15IFT) 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 30-15IFT), 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 30-15IFT was established using Pearson's coefficient correlations. Forward stepwise regression model identified the fewest variables that could predict individual final velocity (VIFT) and change within 30-15IFT performance. Significant correlations between VIFT and Σ7 skinfolds, repeated sprint decrement, V[Combining Dot Above]O2maxMSFT, and average aerobic speed were observed. A total of 71.8% of the adjusted variance in 30-15IFT performance was explained using a 4-step best fit model (V[Combining Dot Above]O2maxMSFT, 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 ΔV[Combining Dot Above]O2maxMSFT (R = 0.25). These relationships suggest that the 30-15IFT 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 30-15IFT is a valid measure of PHIR, it also simultaneously examines various physiological capacities that differ between sporting cohorts.
1Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Footscray, Victoria, Australia; 2Performance Sciences Department, Brisbane Broncos Rugby League Club, Red Hill, Queensland, Australia; 3Applied Sport Science and Exercise Testing Laboratory, Faculty of Science and Information Technology, University of Newcastle, Ourimbah, New South Wales, Australia; 4Queensland Reds Rugby Union, Herston, Queensland, Australia; and 5Department of Rehabilitation, Nutrition and Sport, School of Allied Health, LaTrobe University, Bundoora, Victoria, Australia.
Tannath J
TJ
Scott
Grant M
GM
Duthie
Jace A
JA
Delaney
Colin E
CE
Sanctuary
David A
DA
Ballard
Jeremy A
JA
Hickmans
Ben J
BJ
Dascombe
D000054:Acceleration; D000328:Adult; D056352:Athletes; D054874:Athletic Performance / Q000502:physiology*; D001315:Australia; D015992:Body Mass Index; D001837:Body Weights and Measures; D015444:Exercise; D005080:Exercise Test / Q000379:methods* / Q000592:standards*; D005538:Football / Q000502:physiology*; D006801:Humans; D008297:Male; D010809:Physical Fitness / Q000502:physiology*; D015203:Reproducibility of Results; D012420:Running / Q000502:physiology; D055815:Young Adult