title: Strength, power, and speed qualities in English junior elite rugby league players.
abstract: The aim of this study was to compare strength, power, and speed characteristics of elite junior English rugby league forwards and backs. A squad of males under 20's (n = 24; age 18.70 ± 0.90 years; body mass 86.4 ± 9.93 kg; height 178.47 ± 6.97 cm) players from a Super League team performed a range of assessments, including 10-, 20-, and 40-m sprints; vertical jump; and 1 repetition maximum (1RM) bench press and 1-RM back squat. Independent t-tests revealed no significance between body mass and height (180.13 ± 7.65 cm, 176.83 ± 6.10 cm; p > 0.05) or body mass (90.08 ± 11.72 kg, 82.75 ± 6.28 kg; p > 0.05) for the forwards and backs, respectively. Backs were significantly quicker over the 10-m sprints (1.99 ± 0.60 seconds, 2.06 ± 0.10 seconds; p = 0.011), 20-m sprints (3.26 ± 0.70 seconds, 3.39 ± 0.17 seconds; p = 0.002), and 40-m sprints (5.55 ± 0.13 seconds, 5.80 ± 0.26 seconds; p = 0.0001) compared with the forwards. No significant difference (p > 0.05) was observed for the vertical jump performances between the forwards (50.58 ± 7.06 cm) and the backs (50.60 ± 5.02 cm). In addition, forwards demonstrated a higher 1RM bench press and 1RM back squat (110.00 ± 15.8 kg and 140.21 ± 26.21 kg) compared with the backs (101.67 ± 9.13 kg and 132.71 ± 9.38 kg), although this was not statistically significant (p > 0.05); when expressed relative to body mass the differences between forwards and backs was reduced further for both bench press (1.22 ± 0.10 kg/kg, 1.23 ± 0.08 kg/kg, respectively; p > 0.05) and back squat (1.61 ± 0.13 kg/kg, 1.56 ± 0.20 kg/kg, respectively; p > 0.05). In addition, relative squat strength demonstrated moderate inverse correlations between relative squat strength sprint times (r = -0.45, -0.46, and -0.44; p < 0.01) across 10, 20, and 40 m, respectively. These findings highlight the importance of maximizing squat strength in academy rugby league athletes and highlight that differences in sprint performance between positions may be attributable to the differences in relative strength levels between positions.
authors.affiliation: St Helens Rugby League Football Club Academy, St Helens, Merseyside, United Kingdom.
authors.forename: John
authors.initials: J
authors.lastname: Kirkpatrick
authors.forename: Paul
authors.initials: P
authors.lastname: Comfort
mesh_terms: D000293:Adolescent; D054874:Athletic Performance / Q000502:physiology* / Q000706:statistics & numerical data; D001827:Body Height / Q000502:physiology; D015992:Body Mass Index; D004739:England; D005538:Football / Q000502:physiology* / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D012420:Running / Q000502:physiology