Thomas Briscoe

Briscoe, T, Darrall-Jones, J, Heyward, O, Sawczuk, T, Jones, B, Brindle, T, Barrow, S, Owen, C, Heavey, K, Mackay, L, Cuthbert, K, Pinckney, M, and Scantlebury, S. Ready or not? The anthropometric and physical qualities of youth female rugby league players in England. J Strength Cond Res XX(X): 000–000, 2026—This study aimed to quantify the physical and anthropometric characteristics of U13 to U17 youth female rugby league players, compare between age categories, and assess relationships between characteristics. Eighty amateur youth female players completed a testing battery including anthropometric (body mass and height) and physical (strength [isometric mid-thigh pull], peak power [counter movement jump], linear speed [40 m sprint], momentum, and high-intensity intermittent running [HIIR] ability [30-15 Intermittent Fitness Test]) qualities. Progressive increases were found in body mass, peak power, strength, speed, momentum, and HIIR ability with age, between age group differences were nonsignificant. Large significant ( p < 0.01) relationships were found between strength and 10 m ( r = 0.54), 20 m ( r = 0.59), 30 m ( r = 0.59), and 40 m ( r = 0.61) momentum. Body mass showed large significant relationships with all momentum distances (10 m: r = 0.54; 20 m: r = 0.59; 30 m: r = 0.59; 40 m: r = 0.61). A large significant ( p = <0.01) relationship was found between strength and peak propulsive power ( r = 0.59). A moderate negative significant ( p < 0.01) relationship was found between body mass and HIIR ( r = 0.49). This study provides novel age-specific reference values for practitioners to assess strengths and areas of development in youth female rugby league players. Findings highlight the need for tailored strength and conditioning programs to ensure players are physically prepared to transition through the development pathway, with practitioners focusing on improving physical readiness for the demands of senior competition.

This study aims to establish the validity and reliability of the prone Yo-YoIRL1 in elite female rugby league players (part one) and determine the anthropometric and physical characteristics contributing to 15m prone Yo-YoIRL1 performance (part two). Part one, 21 subjects completed one Yo-YoIRL1, one 20m and two 15m prone Yo-YoIRL1 tests over four sessions, with 7–14 days in-between. Part two, ten subjects completed a testing battery, including body mass, height, dual-energy x-ray absorptiometry, isometric mid-thigh pull, isometric bench-press, 10m and 20m sprints and an incremental treadmill test (V˙O2max). The 15m prone YoYoIRL1 demonstrated poor reliability with a typical error of 68m (21%) and a smallest worthwhile change of 54m (9%). Validity analysis found the prone versions of the YoYoIRL1 were not sensitive measures of intermittent running performance. Both prone YoYoIRL1 test distances demonstrated large mean bias (76% and -37% respectively) and typical error of the estimate (19% and 21%, respectively) in comparison to the YoYoIRL1. Body mass (r = -0.89), lean mass (r = -0.64), body fat % (r = -0.68), V˙O2max (l∙min-1) (r = -0.64), IMTP (r = -0.69), IBP (r = -0.15), 10m (r = -0.77) and 20m (r = -0.72) momentum displayed large negative relationships with 15m prone Yo-YoIRL1 performance. Due to the poor validity of the 20m prone YoYoIRL1, the poor validity and reliability of the 15m prone YoYoIRL1, and the anthropometric and physical characteristics which negatively impact performance, practitioners should reconsider the use of the prone YoYoIRL1 test to monitor high intensity intermittent running performance.