• Carbohydrate and caffeine improves high intensity running of elite rugby league interchange players during simulated match play

      Clarke, Jon; Highton, Jamie M.; Close, Graeme L.; Twist, Craig; University of Chester; Warrington Wolves RLFC; Liverpool John Moores University (Lippincott, Williams & Wilkins, 2016-11-19)
      Carbohydrate and caffeine improves high intensity running of elite rugby league interchange players during simulated match play
    • Changes in anthropometry and performance, and their inter-relationships, across three seasons in elite youth rugby league players

      Waldron, Mark; Worsfold, Paul R.; Twist, Craig; Lamb, Kevin L.; University of New England, Australia ; University of Chester ; University of Chester ; University of Chester (Lippincott, Williams & Wilkins, 2014-11-30)
      This study investigated changes in anthropometry and performance, and their inter-relationships, across three consecutive seasons (under-15 to under-17 age group) in elite youth rugby league players. Each player took part in annual anthropometrical and performance assessments, comprising measurements of stature; body mass; limb lengths and circumference; skinfolds, predicted muscle cross-sectional area (CSA); 20 m speed, counter-movement jump height, vertical power and aerobic power. Lean body mass % changed (P < 0.05) between the under-15 (70.9 ± 5.9 %), under-16 (72.0 ± 5.8 %) and the under-17 age groups (74.1 ± 5.7 %). Likewise, predicted quadriceps muscle cross-sectional area (CSA) also changed (P < 0.05) between each age group (under-15 = 120.9 ± 37.8 cm2; under-16 = 133.2 ± 36.0 cm2; under-17 = 154.8 ± 28.3 cm2). Concomitant changes between the under-15 and under-16 group were found for 20 m speed (3.5 ± 0.1 cf. 3.4 ± 0.2 s; P = 0.008) and predicted jumping power (3611.3 ± 327.3 W cf. 4081.5 ± 453.9 W; P = 0.003). Both lean body mass and quadriceps muscle CSA consistently, related to both 20 m sprint time and jumping power, with r-values ranging between -0.39 to –0.63 (20 m sprint time) and 0.55 to 0.75 (jumping power). Our findings demonstrate the importance of gains in lean body mass across later-adolescence that support the ability to generate horizontal speed and predicted vertical power. This information should inform the expectations and subsequent training programs of elite rugby league practitioners.
    • A comparison of load-velocity and load-power relationships between well-trained young and middle-aged males during three popular resistance exercises.

      Fernandes, John; Lamb, Kevin L.; Twist, Craig (Lippincott, Williams & Wilkins, 2018-05-05)
      This study examined the load-velocity and load-power relationships among 20 young (age 21.0 ± 1.6 y) and 20 middle-aged (age 42.6 ± 6.7 y) resistance trained males. Participants performed three repetitions of bench press, squat and bent-over-row across a range of loads corresponding to 20 to 80% of one repetition maximum (1RM). Analysis revealed effects (P < 0.05) of group and load x group on barbell velocity for all three exercises, and interaction effects on power for squat and bent-over-row (P < 0.05). For bench press and bent-over-row, the young group produced higher barbell velocities, with the magnitude of the differences decreasing as load increased (ES; effect size 0.0 to 1.7 and 1.0 to 2.0, respectively). Squat velocity was higher in the young group than the middle-aged group (ES 1.0 to 1.7) across all loads, as was power for each exercise (ES 1.0 to 2.3). For all three exercises, both velocity and 1RM were correlated with optimal power in the middle-aged group (r = .613 to .825, P < 0.05), but only 1RM was correlated with optimal power (r = .708 to .867, P < 0.05) in the young group. These findings indicate that despite their resistance training, middle-aged males were unable to achieve velocities at low external loads and power outputs as high as the young males across a range of external resistances. Moreover, the strong correlations between 1RM and velocity with optimal power suggest that middle-aged males would benefit from training methods which maximise these adaptations.
    • The concurrent validity of a rugby-specific Yo-Yo Intermittent Recovery Test (Level 1) for assessing match-related running performance

      Dobbin, Nick; Highton, Jamie M.; Moss, Samantha L.; Hunwicks, Richard; Twist, Craig; University of Chester; Rugby Football League, Leeds (Lippincott, Williams & Wilkins, 2018-06-01)
      This study investigated the concurrent validity of a rugby-specific high-intensity intermittent running test (HIIR) against the internal, external and perceptual responses to simulated match-play. Thirty-six rugby league players (age 18.5 ± 1.8 years; stature 181.4 ± 7.6 cm; body mass 83.5 ± 9.8 kg) completed the prone Yo-Yo IR1, of which sixteen also completed the Yo-Yo IR1, and 2 x ~20 min bouts of a simulated match-play (RLMSP-i). Most likely reductions in relative total, low-speed and high-speed distance, mean speed and time above 20 W·kg-1 (HMP) were observed between bouts of the RLMSP-i. Likewise, rating of perceived exertion (RPE) and percentage of peak heart rate (%HRpeak) were very likely and likely higher during the second bout. Pearson’s correlations revealed a large relationship for the change in relative distance (r = 0.57-0.61) between bouts with both Yo-Yo IR1 tests. The prone Yo-Yo IR1 was more strongly related to the RLMSP-i for change in repeated sprint speed (r = 0.78 cf. 0.56), mean speed (r = 0.64 cf. 0.36), HMP (r = 0.48 cf. 0.25), fatigue index (r = 0.71 cf. 0.63), %HRpeak (r = -0.56 cf. -0.35), RPEbout1 (r = -0.44 cf. -0.14), and RPEbout2 (r = -0.68 cf. -0.41) than the Yo-Yo IR1, but not for blood lactate concentration (r = -0.20 to -0.28 cf. -0.35 to -0.49). The relationships between prone Yo-Yo IR1 distance and measure of load during the RLMSP-i suggests it possesses concurrent validity and is more strongly associated with measures of training or match load than the Yo-Yo IR1 using rugby league players.
    • The effects of variable resistance using chains on bench throw performance in trained rugby players

      Godwin, Mark S.; Fernandes, John; Twist, Craig; University College Birmingham; University of Chester (Lippincott, Williams & Wilkins, 2018-04-01)
      This study sought to determine the effects of variable resistance using chain resistance on bench throw performance. Eight male rugby union players (19.4 ± 2.3 y, 88.8 ± 6.0 kg, 1RM 105.6 ± 17.0 kg) were recruited from a national league team. In a randomised cross-over design participant’s performed three bench throws at 45% one repetition maximum (1RM) at a constant load (No Chains) or a variable load (30% 1RM constant load, 15% 1RM variable load; Chains) with seven days between conditions. For each repetition the peak and mean velocity, peak power, peak acceleration and time to peak velocity were recorded. Differences in peak and mean power were very likely trivial and unclear between the Chains and No Chains conditions, respectively. Possibly greater peak and likely greater mean bar velocity were accompanied by likely to most likely greater bar velocity between 50-400 ms from initiation of bench press in the Chains compared to the No Chains condition. Accordingly, bar acceleration was very likely greater in the Chains compared to the No Chains condition. In conclusion, these results show that the inclusion of chain resistance can acutely enhance several variables in the bench press throw and gives support to this type of training.
    • The influence of different work and rest distributions on performance and fatigue during simulated team handball match play

      Moss, Samantha L.; Twist, Craig; University of Chester (Lippincott, Williams & Wilkins, 2015-05-05)
      This study investigated the effect of different interchange strategies on performance and pacing strategy during a simulated team-sports protocol. Eight youth male team handball players completed two conditions (LONG; work: 3 x 13:00 min, rest: 8:00 min, SHORT; work: 5 x 7:48 min, rest: 3:45 min). Participants were tested for 20 m sprint, counter-movement jump, throwing performance and heart rate during conditions. Postcondition measures included repeated shuttle-sprint and jump ability, session rating of perceived exertion, blood lactate and glucose. Faster sprint (3.87 ± 0.27 s cf. 3.97 ± 0.24 s, ES = 0.39, P= 0.03) and throwing performance (70.02 ± 7.40 km*h-1 cf. 69.04 ± 5.57 km*h-1, P> 0.05, ES = -0.15) occurred in SHORT compared to LONG by a 'likely small' difference. Higher summated heart rate (157 ± 21 cf. 150 ± 15 AU) occurred in SHORT compared to LONG by a 'likely small' difference (ES = 0.37, P> 0.05). SHORT resulted in lower session rating of perceived exertion (224 ± 45 AU cf. 282 ± 35 AU, ES = 1.45, P= 0.001) and higher blood glucose (6.06 ± 0.69 mmol*l-1 cf. 4.98 ± 1.10 mmol*l-1, ES = -1.17, P= 0.03) by a 'most likely moderate' difference compared to LONG. Repeated shuttle-sprint was better preserved after SHORT, with 'moderately lower' 10 m and 25 m times (P< 0.05). Interchange strategies using SHORT rather than LONG work and rest periods result in lower physiological load, leading to improved fatigue resistance and better preservation of high-intensity movements during matches.
    • The movement and physiological demands of international and regional men's touch rugby matches

      Beaven, Robert; Highton, Jamie M.; Thorpe, Cari; Knott, Emma; Twist, Craig; University of Chester; Manchester Metropolitan University; Huddersfield University (Lippincott, Williams & Wilkins, 2014-05-14)
      This study compared the internal and external match demands imposed on international and regional standard male touch rugby players. The study adopted a cohort design with independent groups. Twelve international players (mean age 27.8 ± 6.2 y, body mass 72.8 ± 3.7 kg, stature 174.5 ± 5.4 cm) and nine regional players (mean age 25.5 ± 5.5 y, body mass 74.2 ± 7 kg, stature 174.1 ± 7 cm) were analysed during nine competitive matches from the 2013 season. Movement demands were measured using a 5 Hz global positioning system (GPS), alongside heart rate and session rating of perceived exertion (s-RPE) to quantify internal load. Total distance covered by international players was lower than regional players (2265.8 ± 562.3 cf. 2970 ± 558.9 m, p<0.05). However, international players had greater relative distance (137.1 ± 13.6 cf. 126.2 ± 17.2 m·min) due to shorter playing times per match (p<0.05). Absolute high speed running (>14 km·h) was not different between groups (p>0.05), but relative high speed running (39.3 ± 12.0 cf. 26.0 ± 13.6 m·min) was higher for international players. Regional players performed more absolute low speed activity (≤14 km·h) than international players (p<0.05), whereas relative low speed activity was not different between groups (p>0.05). Very high speed running (>20 km·h) distance, bout number and frequency, peak and average speed were all greater in international players (p<0.05). Higher average heart rate, summated heart rate and s-RPE (p<0.05) indicated higher internal loads during matches for regional players. These data indicate that performance in men's touch rugby is characterised by more relative high speed running and better repeated sprint capacities in higher standard players.
    • The number of directional changes alters the physiological, perceptual and neuromuscular responses of netball players during intermittent shuttle running

      Ashton, Ruth; Twist, Craig; University of Chester (Lippincott, Williams & Wilkins, 2015-10-31)
      This study investigated whether an increased number of changes in direction altered the metabolic, cardiovascular, perceptual and neuromuscular responses to intermittent shuttle running. Using a randomized crossover design, ten female netball players completed 30 min of intermittent shuttle running over a 10 m (ISR10) and 20 m (ISR20) linear course. Measures of expired air, heart rate (HR), RPE, blood lactate concentration ([BLa]) and peak torque of knee extensors and flexors were measured. Differences (% ± 90% CL) in VO2 (1.5 ± 5.6%) was unclear between conditions, while HR was possibly higher (1.5 ± 2.5%) and [BLa] very likely lower in ISR20 compared to ISR10 (-32.7 ± 9.9%). RPE was likely lower in the ISR20 compared to the ISR10 condition at 15 (-5.0 ± 5.0%) and mosly likely lower at 30 min (-9.4 ± 2.0%). Sprint times over 20 m were likely slower during ISR20 at mid (3.9 ± 3.2%) but unclear post (2.1 ± 5.4%). Changes in muscle function were not different between ISR10 and ISR20 conditions for knee extension (-0.2 ± 0.9%) but were likely different for knee flexion (-5.7 ± 4.9%). More directional changes during shuttle running increases the physiological and perceptual load on female athletes that also causes a greater reductions in knee extensor torque. These findings have implications for the effective conditioning and injury prevention of female team sport athletes.
    • Passive heat maintenance after an initial warm-up improves high intensity activity during an interchange rugby league match simulation protocol.

      Fairbank, Matthew; Highton, Jamie M.; Twist, Craig; University of Chester (Lippincott, Williams & Wilkins, 2019-01-01)
      This study examined using passive heat maintenance to maintain core temperature after a warm-up and its effect on first half running performance in rugby players. Thirteen male rugby players completed this randomized crossover study. Tympanic temperature was taken before a warm-up and then after a further 15 minutes passive recovery either with (PHM) or without (CON) a passive heat maintenance garment. Participants then completed 23 min of the rugby league match simulation protocol (RLMSP-i). Differences in tympanic temperature were unclear between CON and PHM before (35.7 ± 1.3 cf. 36.0 ± 1.1oC; ES = 0.20) and during exercise (34.5 ± 0.1 cf. 35.2 ± 0.1oC; ES = 0.26-0.35). High-intensity running (ES = 0.27) and peak sprint speed were higher (ES = 0.46-0.56) during the PHM compared to the CON trial. Time spent above 20 W.kg-1 also increased in the first quartile of PHM compared to CON trial (ES = 0.18). All other between trial comparisons of performance were unclear. HRmean (ES = 0.38) was higher in PHM compared to CON, while differences in RPEmean (ES = -0.19) were unclear. There are small to large increases in high intensity work performed during a playing bout when rugby players wear a PHM garment after a warm-up. Rugby players should consider PHM during extended periods of time between a warm-up and starting a match.
    • The Reliability and Validity of A Submaximal Warm-Up Test for Monitoring Training Status in Professional Soccer Players.

      Rabbani, Alireza; Kargarfard, Mehdi; Twist, Craig; University of Isfahan; University of Chester (Lippincott, Williams & Wilkins, 2017-11-27)
      Two studies were conducted to assess the reliability and validity of a submaximal warm-up test (SWT) in professional soccer players. For the reliability study, 12 male players performed SWT over three trials, with one week between trials. For the validity study, 14 players of the same team performed SWT and 30-15 Intermittent Fitness Test (30-15IFT) 7 days apart. Week-to-week reliability in selected heart rate (HR) responses [exercise HR (HRex), HR recovery (HRR) expressed as the number of beats recovered within 1 min (HRR60s) and expressed as the mean HR during 1 min (HRpost1)], were determined using intraclass correlation coefficient (ICC) and typical error of measurement expressed as coefficient of variation (CV). The relationships between HR measures derived from SWT and the maximal speed reached at the 30-15IFT (VIFT) were used to assess validity. The range for ICC and CV values were 0.83 to 0.95 and 1.4 to 7.0% in all HR measures, respectively, with the HRex as the most reliable HR measure of SWT. Inverse large (r = -0.50, 90% confidence limits, CL (-0.78; -0.06)) and very large (r = -0.76, CL, -0.90; -0.45) relationships were observed between HRex and HRpost1 with VIFT in relative (expressed as the % of maximal HR) measures, respectively. SWT is a reliable and valid submaximal test to monitor high-intensity intermittent running fitness in professional soccer players. In addition, the test’s short duration (5-min) and simplicity mean that it can be used regularly to assess training status in high-level soccer players.
    • The reliability of Functional Movement Screening (FMS) and in-season changes in physical function and performance among elite rugby league players

      Waldron, Mark; Gray, Adrian; Worsfold, Paul R.; Twist, Craig; University of New England, Australia ; University of New England, Australia ; University of Chester ; University of Chester (Lippincott, Williams & Wilkins, 2014-03-26)
      Functional Movement Screening (FMS) comprises seven tests that assess fundamental movement characteristics of athletes. However, the reliability of the FMS protocol and its sensitivity to changes in physical performance has not been appropriately investigated. Accordingly, this study aimed to assess the real-time reliability of the FMS protocol and to establish changes in both FMS and tests of physical performance throughout a season. The reliability of the FMS components (12 in total) were assessed via a non-parametric statistical approach, based on two trials, separated by one week. Score on the FMS, strength (3 RM full squat, 1 RM bench press), running speed (10 & 40 m) and jump height of 12 elite male under-19 rugby league players was monitored at pre-, mid- and late-season periods. There was no bias found between trials for the FMS, with the majority of components reaching 100% ‘perfect agreement’. There were no effects of season stage on any of the FMS components; however, an improvement in every performance test was apparent between the pre- and both mid- and late-season periods. Our findings demonstrate that the FMS can be reliably administered to elite rugby league players but question its sensitivity to systematic changes in athletic performance.
    • Reproducibility of the internal load and performance-based responses to simulated amateur boxing

      Thomson, Edward; Lamb, Kevin L.; University of Chester (Lippincott, Williams & Wilkins, 2017-12-01)
      The aim of this study was to examine the reproducibility of the internal load and performance-based responses to repeated bouts of a three-round amateur boxing simulation protocol (BOXFIT). Twenty-eight amateur boxers completed two familiarisation trials before performing two complete trials of the BOXFIT, separated by 4-7 days. To characterise the internal load, mean (HRmean) and peak (HRpeak) heart rate, breath-by-breath oxygen uptake (V ̇O2), aerobic energy expenditure (EEaer), excess carbon dioxide production (CO2excess) and ratings of perceived exertion (RPE) were recorded throughout each round and blood lactate determined post-BOXFIT. Additionally, an indication of the performance-based demands of the BOXFIT was provided by a measure of acceleration of the punches thrown in each round. Analysis revealed there were no significant differences (P > 0.05) between repeated trials in any round for all dependent measures. The typical error (coefficient variation %) for all but one marker of internal load (CO2excess) was 1.2 – 16.5% and reflected a consistency that was sufficient for the detection of moderate changes in variables owing to an intervention. The reproducibility of the punch accelerations was high (CV% range = 2.1 – 2.7%). In general, these findings suggest that the internal load and performance-based efforts recorded during the BOXFIT are reproducible and thereby offers practitioners a method by which meaningful changes impacting on performance could be identified.
    • Selected physiological, perceptual and physical performance changes during two bouts of prolonged high intensity intermittent running separated by 72 hours

      Dobbin, Nicholas; Lamb, Kevin L.; Twist, Craig; University of Chester (Lippincott, Williams & Wilkins, 2017-12-01)
      This study investigated the effects of performing a second 90-minute intermittent running protocol 72 hours after an initial trial on selected physiological, perceptual, and sprint running measures. Eight subelite soccer players provided measures of isokinetic muscle function, countermovement jump (CMJ), 10-m sprinting, and muscle soreness before, and at 0, 24, 48, and 72 hours after a 90-minute intermittent high-intensity running bout (IHIR-1). A second 90-minute IHIR bout (IHIR-2) was performed 72 hours after the first. Heart rates, ratings of perceived exertion (RPE), blood lactate concentration [Bla], and 10-m sprint times were recorded periodically during both IHIR. Analysis of effects revealed that in the 72-hour period after IHIR-1, there were most likely increases in muscle soreness and likely to very likely deteriorations in CMJ, 10-m sprint, and isokinetic muscle function. During IHIR-2, heart rates (possibly to likely) and [Bla] (possibly to very likely) were lower than IHIR-1, whereas RPE remained unchanged. Sprint times during IHIR-2 were also likely to very likely higher than in IHIR-1. It was evident that these team sport players exposed to repeat bouts of prolonged high-intensity running within 72 hours downregulated their sprint performances in the second bout despite no change in perceived effort. These findings have implications for managing training and match loads during periods of intense scheduling.
    • Transient fatigue is not influenced by ball-in-play time during elite rugby league matches

      Waldron, Mark; Highton, Jamie M.; Thomson, Edward; Twist, Craig; University of Chester (Lippincott, Williams & Wilkins, 2017-03-13)
      The capacity to sustain high-speed running is important for rugby league players. Transient fatigue, described as a reduction in high-speed running in the 5-min after a peak 5-min period, is a phenomenon observed during rugby league matches. This concept has recently been questioned based on the proposed confounding influence of ball-in-play time during these periods. Therefore, this study examined the changes in high-speed running (> 14 km∙h-1) of elite rugby league players, as well as ball-in-play time, during the peak, subsequent and mean 5-min periods of five competitive matches using 5 Hz GPS devices. The suitability of ball-in-play time as a covariate was also evaluated. The high-speed running and ball-in-play time was different between peak (26.7 ± 5.5 m∙min-1 and 177 ± 37 s) and subsequent (12.1 ± 6.2 m∙min-1 and 147 ± 37 s) 5-min periods (P < 0.05; most likely ↓). However, there was no relationship (r = 0.01 to -0.13; P > 0.05) between ball-in-play time and high-speed running and ball-in-play time was not independent of the match period. This study has reaffirmed the presence of transient fatigue during elite rugby league matches but questioned the influence of ball-in-play time as a confounding factor. These observations have implications for the design of appropriate training practices and informing tactical strategies employed by coaches. Most importantly, any practitioner wishing to measure transient fatigue could follow a similar statistical approach taken herein and, based on the current findings would not need to account for ball-in-play time as a confounding variable.