• Exercise-induced muscle damage: what is it, what causes it and what are the nutritional solutions?

      Owens, Daniel J; Twist, Craig; Cobley, James; Howatson, Glyn; Close, Graeme; Liverpool John Moores University; University of Chester; Northumbria University (Taylor & Francis, 2018-08-15)
      Exercise-induced muscle damage (EIMD) is characterised by symptoms that present both immediately and for up to 14 days after the initial exercise bout. The main consequence of EIMD for the athlete is the loss of skeletal muscle function and soreness. As such, numerous nutrients and functional foods have been examined for their potential to ameliorate the effects of EIMD and accelerate recovery, which is the purpose of many nutritional strategies for the athlete. However, the trade-off between recovery and adaptation is rarely considered. For example, many nutritional interventions described in this review target oxidative stress and inflammation, both thought to contribute to EIMD but are also crucial for the recovery and adaptation process. This calls into question whether long term administration of supplements and functional foods used to target EIMD is indeed best practice. This rapidly growing area of sports nutrition will benefit from careful consideration of the potential hormetic effect of long term use of nutritional aids that ameliorate muscle damage. This review provides a concise overview of what EIMD is, its causes and consequences and critically evaluates potential nutritional strategies to ameliorate EIMD. We present a pragmatic practical summary that can be adopted by practitioners and direct future research, with the purpose of pushing the field to better consider the fine balance between recovery and adaptation and the potential that nutritional interventions have in modulating this balance.
    • An examination of a modified Yo-Yo test to measure intermittent running performance in rugby players

      Dobbin, Nick; Moss, Samantha; Highton, Jamie M.; Twist, Craig; University of Chester; University of Chester (Taylor & Francis, 2018-06-17)
      This study examined how starting each shuttle in the prone position altered the internal, external and perceptual responses to the Yo-Yo Intermittent Recovery Test Level 1. Using a randomized crossover design, 17 male rugby players completed the Yo-Yo IR1 and prone Yo-Yo IR1 on two separate occasions. External loads (via microtechnology), V ̇O2, heart rate (HR), rating of perceived exertion (RPE) were measured at 160, 280 and 440 m (sub-maximal) and when the test was terminated (peak). The pre-to-post change in blood lactate concentration (∆[La]b) was determined for both tests. All data were analysed using effect sizes and magnitude-based inferences. Between-trial differences (ES  90%CL) indicated total distance was most likely lower (-1.87  0.19), whereas other measures of peak external load were likely to very likely higher during the prone Yo-Yo IR1 (0.62-1.80). Sub-maximal RPE was likely to most likely higher (0.40-0.96) and peak RPE very likely higher (0.63  0.41) in the prone Yo-Yo IR1. The change in [La]b was likely higher after the prone Yo-Yo IRl. Mean HR was possibly lower at 440 m (-0.25  0.29) as was peak HR (-0.26  0.25) in the prone Yo-Yo IR1. "V" ̇E, "V" ̇O2 and "V" ̇CO2 were likely to very likely higher at 280 and 440 m (ES = 0.36-1.22), while peak values were possibly to likely higher (ES = 0.23-0.37) in the prone Yo-Yo IR1. Adopting a prone position during the Yo-Yo IR1 increases the internal, perceptual and external responses, placing greater emphasis on metabolically demanding actions typical of rugby.
    • 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 influence of preseason training phase and training load on body composition and its relationship with physical qualities in professional junior rugby league players

      Dobbin, Nick; Gardner, Adrian; Daniels, Matthew; Twist, Craig; University of Chester (Taylor & Francis, 2018-05-08)
      This study investigated changes in body composition in relation to training load determined using RPE and duration (sRPE), and its relationship with physical qualities over a preseason period. Sixteen professional academy players (age = 17.2 ± 0.7 years; stature = 179.9 ± 4.9 cm; body mass = 88.5 ± 10.1 kg) participated in the study. Body composition was assessed before and after each training phase and physical qualities assessed at the start and end of preseason. Across the whole preseason period, skinfold thickness, body fat percentage and fat mass were most likely lower (ES = -0.73 to -1.00), and fat free mass and lean mass were likely to most likely higher (ES = 0.31 to 0.40). Results indicated that the magnitude of change appeared phase-dependent (ES = -0.05 to -0.85) and demonstrated large individual variability. Changes in physical qualities ranged from unclear to most likely (ES = -0.50 to 0.64). Small to moderate correlations were observed between changes in body composition, and TL with changes in physical qualities. This study suggests training phase and TL can influence a player’s body composition; that large inter-participant variability exists; and that body composition and TL are related to the change in physical qualities.
    • Playing exposure does not affect movement characteristics or physiological responses of elite youth footballers during an intensified period of competition.

      Gibson, Neil; McCunn, Robert; MacNay, Sophie; Mullen, Thomas; Twist, Craig; Heriot-Watt University; University of Chester (Taylor & Francis, 2018-05-08)
      This study investigated the effect of playing time on physiological and perceptual responses to six, 60 min matches played over five days. Thirty youth football players (age = 14.1 ± 0.4 years; body mass = 57.4 ± 12.9 kg; stature 169.3 ± 7.7 cm) were grouped into low (<250 min; LPG, n = 18) and high (≥250 min; HPG, n = 12) match exposure groups and monitored daily for lower body power and perceived wellness. GPS technology was used to assess match running demands in total distance (m•min-1), low (<13 km•h-1) and high (≥13 km•h-1) speed running categories. Hypothesis based testing and effect sizes (ES) were used to analyse data. The HPG performed moderately more total distance (103.7 ± 10.4 cf. 90.2 ± 19.7 m•min-1, P = 0.03; ES=0.74 ± 0.63) and high speed running (26.7 ± 6.6 cf. 20.3 ± 6.5 m•min-1, P = 0.01; ES=0.87 ± 0.6) than the LPG across all six matches. Differences of a small magnitude were observed between groups for lower body power (P = 0.08; ES =0.59 ± 0.8) and perceived wellness (P = 0.09; ES=0.42 ± 0.4) which were both higher in the HPG. Youth football players appear well equipped to deal with intensified period of competition, such as those experienced in tournaments, irrespective of match exposure.
    • The influence of music genre on explosive power, repetitions to failure and mood responses during resistance exercise

      Moss, Samantha L.; Enright, Kevin; Cushman, Simon; University of Chester; Liverpool John Moores University (Elsevier, 2018-05-04)
      Objectives: To investigate the influence of different music genres on the psychological, psychophysical and psychophysiological responses during power-based and strength-based resistance exercises. Design: Repeated-measures counterbalanced design. Method: Sixteen resistance-trained participants completed an explosive power test in the squat and bench exercises at 30% 1RM across no music, electronic dance music, metal and self-selected conditions. Peak and mean values were recorded for power and velocity. A progressive loading protocol assessed the impact of condition on repetitions to failure at 60, 70 and 80% 1RM in the squat and bench exercises. For all tests, recording of heart rate and rating of perceived exertion were completed after every set, blood lactate after protocol completion, and mood states before and after. Results: Using magnitude-based inferences, music either had no effect or a small detrimental effect on power and velocity, depending on the exercise. Repetitions to failure increased by a small to moderate amount for all music conditions compared to no music at low but not high intensities. Self-selected music provided additional small benefits in repetitions than other music conditions. Rating of perceived exertion was similar between self-selected, metal and no music conditions, whereas electronic dance music revealed higher responses. Vigour increased after all music conditions but remained unchanged in no music. Conclusions: Explosive power exercises either remain unchanged or are disadvantaged when completed to music. Various music genres could improve repetition to failure training at low to moderate intensities, although individuals might expect greatest improvements using self-selected music, without concomitant increases in perceived effort.
    • Movement characteristics, physiological and perceptual responses of elite standard youth football players to different high intensity running drills

      Gibson, Neil; Henning, Greig; Twist, Craig; Heriot-Watt University; University of Chester (Taylor & Francis, 2018-04-06)
      Purpose: To examine responses to high intensity running drills in youth football players. Methods: Seventeen players completed the YoYo Intermittent Recovery test level one (YYIR1) and a 15 m maximal sprint to quantify target running speeds. Players performed three conditions on separate occasions comprising: 12 x 15 s high intensity runs at 100% of the final YYIRT1 speed, 12 x ~4 s repeated sprints with ~26 s recovery, and combination running using both modalities. Heart rate was monitored continuously with PlayerLoadTM and movement characteristics using microtechnology. Ratings of perceived exertion and blood lactate responses were measured 2 min after the final repetition. The ratio of Flight:contraction time was calculated from a countermovement jump before and at 2 min and 14 hours after each condition. Data analysis used magnitude based inferences and effect sizes statistics. Results: Peak speed (1.1%; ES 0.23 ± 0.44) and mean speed over the initial 4s (6.3%; ES 0.45 ± 0.46) were possibly faster during combination compared to high intensity running with unclear differences when compared to repeated sprinting. This was despite most likely (21.6%; ES 7.65 ± 1.02) differences in prescribed speeds between conditions. There were likely reductions in F:C at 14 hours ratio after high intensity (-5.6%; ES –0.44 ± 0.32) and combination running (-6.8%; ES -0.53 ± 0.47). Changes in the repeated sprinting condition were unclear. Conclusions: Actual movement characteristics of high intensity running drills may not reflect those used to prescribe them whilst reductions in F:C ratio are still evident 14 hours after their completion.
    • The effects of variable resistance using chains on bench throw performance in trained rugby players

      Godwin, Mark S.; Fernandes, John F. T.; 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.
    • Beetroot supplementation improves the physiological responses to incline walking

      Waldron, Mark; Waldron, Luke; Lawlor, Craig; Gray, Adrian; Highton, Jamie M.; St Mary's University; University of New England; Medical Education Centre Royal Cornwall Hospitals NHS Trust; University of Chester (Springer, 2018-03-15)
      Purpose: We investigated the effects of an acute 24-h nitrate-rich beetroot juice supplement (BR) on the energy cost, exercise efficiency and blood pressure responses to intermittent walking at different gradients. Methods: In a double-blind, cross-over design, eight participants were provided with a total of 350 ml of nitrate-rich (~20.5 mmol nitrate) BR or placebo (PLA) across 24-h before completing intermittent walking at 3 km/h on treadmill at gradients of 1%, 5%, 10%, 15% and 20%. Results: Resting mean arterial pressure (MAP) was ~4.1% lower after BR (93 vs. 89 mmHg; P = 0.001), as well as during exercise (102 vs. 99 mmHg; P = 0.011) and recovery (97 vs. 94 mmHg; P = 0.001). Exercising (1227 vs. 1129 ml/min P < 0.001) and end-stage (1404 vs. 1249 ml/min; P = 0.002) oxygen uptake (𝑉O2) was lower in BR compared to PLA, which was accompanied by an average reduction in phase II 𝑉 ̇O2 amplitude (1067 vs. 940 ml/min; P = 0.025). Similarly, recovery 𝑉O2 (509 vs. 458 ml/min; P = 0.001) was lower in BR. Whole-blood potassium concentration increased from pre-post exercise in PLA (4.1 ± 0.3 vs. 4.5 ± 0.3 mmol/L; P = 0.013) but not BR (4.1 ± 0.31 vs. 4.3 ± 0.2 mmol/L; P = 0.188). Conclusions: Energy cost of exercise, recovery of 𝑉O2, MAP and blood markers were ameliorated after BR. Previously reported mechanisms explain these findings, which are more noticeable during less efficient walking at steep gradients (15-20%). These findings have practical implications for hill-walkers.
    • Criterion and construct validity of an isometric mid-thigh pull dynamometer for assessing whole body strength in professional rugby league players

      Dobbin, Nicholas; Hunwicks, Richard; Jones, Ben; Till, Kevin; Highton, JM; Twist, Craig; University of Chester, Rugby Football League, Leeds Beckett University (Human Kinetics, 2018-02)
      Purpose: The purpose of this study was to examine the criterion and construct validity of an isometric mid-thigh pull dynamometer to assess whole body strength in professional rugby league players. Methods: Fifty-six male rugby league players, (33 senior and 23 youth professional players) performed four isometric mid-thigh pull efforts (i.e. two on the dynamometer and two on the force platform) in a randomised and counterbalanced order. Results: Isometric peak force was underestimated (P<0.05) using the dynamometer compared to the force platform (95% LoA: -213.5 ± 342.6 N). Linear regression showed that peak force derived from the dynamometer explained 85% (adjusted R2 = 0.85, SEE = 173 N) of the variance in the dependent variable, with the following prediction equation derived: predicted peak force = [1.046 * dynamometer peak force] + 117.594. Cross-validation revealed a non-significant bias (P>0.05) between the predicted and peak force from the force platform, and an adjusted R2 (79.6%), that represented shrinkage of 0.4% relative to the cross-validation model (80%). Peak force was greater for the senior compared to youth professionals using the dynamometer (2261.2 ± 222 cf. 1725.1 ± 298.0 N, respectively; P<0.05). Conclusion: The isometric mid-thigh pull assessed using a dynamometer underestimates criterion peak force but is capable of distinguishing muscle function characteristics between professional rugby league players of different standards.
    • Education, Physical Education and Physical Activity Promotion

      Smith, Andy; Green, Ken; Thurston, Miranda; Edge Hill University; University of Chester; Innland Norway University (Routledge, 2018)
      This chapter examines: (i) the policy rationale for viewing education and schools as an appropriate setting for PA promotion; (ii) the apparent role PE is expected to have in fostering lifelong participation in PA and sport; and (iii) the limits of education in promoting PA given the significance of wider social inequalities in families and the wider societies of which they are a part. It is suggested that while engaging in PE may help promote PA among young people in schools, and may strengthen their sporting predispositions and biographies, whether the content, organization and delivery of curricula promotes PA often depends on the predispositions, habits and experiences that are acquired and reproduced outside of education in childhood and family contexts characterized by varying degrees of social inequality.
    • When transport policy becomes health policy: A documentary analysis of active travel policy in England

      Bloyce, Daniel; White, Chris; University of Chester (Elsevier, 2018)
      There has been a succession of policy documents related to active travel published by the British government since the implementation of a National Cycle Network (NCN) in 1995. However, as the latest National Travel Survey (NTS) reveals, the number of journeys made by bike in the UK has remained steadfastly around only 2% (Department for Transport [DfT], 2018a). By using documentary analysis of the available official policy documents and statements, the aim of this paper is to make sense of the policies that have been published concerning active travel (AT) in England. This is done from a figurational sociological perspective. Three key themes emerge from the analysis: (1) the rhetorical, advisory level of the vast majority of the policies; (2) the reliance on a wide network of local authorities to implement AT policy; and (3) the focus placed on individuals to change their behaviour. Furthermore, the analysis reveals that despite a large number of policy publications from a range of government departments claiming to promote AT, little has actually changed in this time period in terms of a national agenda. Despite the successive policies, it seems there is little appetite on behalf of recent governments to make widespread infrastructural changes, where instead the focus has largely been on persuading the individual to seek more active modes of travel, increasingly for their own, individual ‘health’ gains.
    • 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.
    • Estimates of Energy Intake and Expenditure in Elite Female Touch Players During an International Tournament

      Marsh, Nicola; Dobbin, Nick; Twist, Craig; Curtis, Chris; St Mary’s University; University of Chester (Human Kinetics, 2017-12)
      This study assessed energy intake and expenditure of international female Touch players during an international tournament. Energy intake (food diary) and expenditure (accelerometer, global positioning system) were recorded for 16 female Touch players during a four-day tournament, competing in 8.0 ± 1.0 matches; two on days one, two and four, and three on day three. Total daily energy expenditure (43.6 ± 3.1 Kcal.kg-1 body mass (BM)) was not different (P > 0.05) from energy intake (39.9 ± 9.4 Kcal.kg-1 BM). Carbohydrate intakes were below current recommendations (6-10 g.kg-1 BM) on days one (4.4 ± 0.6 g.kg-1 BM) and three (4.7 ± 1.0 g.kg-1 BM) and significantly below (P < 0.05) on day two (4.1 ± 1.0 g.kg-1 BM). Protein and fat intakes were consistent with recommendations (protein; 1.2 - 2.0 g.kg-1 BM, fat; 20 - 35 % total Kcal) across days one to three (protein; 1.9 ± 0.8, 2.2 ± 0.8 & 2.0 ± 0.7 g.kg-1 BM, fat; 35.6 ± 6.8, 38.5 ± 6.4 & 35.9 ± 5.4 % total Kcal). Saturated fat intakes were greater (P < 0.05) than recommendations (10 % total Kcal) on days one to three (12.4 ± 2.9, 14.2 ± 5.1 & 12.7 ± 3.5 % total Kcal). On average, female Touch players maintained energy balance. Carbohydrate intakes appeared insufficient and might have contributed to the reduction (P < 0.05) in high-intensity running on day three. Further research might investigate the applicability of current nutrition recommendations and the role of carbohydrate in multi-match, multi-day tournaments.
    • The Reliability and Validity of A Submaximal Warm-Up Test for Monitoring Training Status in Professional Soccer Players.

      Rabbani, Alizera; 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.
    • Validity of an isometric mid-thigh pull dynamometer in male youth athletes

      Till, Kevin; Morris, R.; Stokes, K.; Trewartha, G.; Twist, Craig; Dobbin, Nick; Hunwicks, Richard; Jones, Ben (2017-11-16)
      The purpose of the present study was to investigate the validity of an isometric mid-thigh pull dynamometer against a criterion measure (i.e., 1,000 Hz force platform) for assessing muscle strength in male youth athletes. Twenty-two male adolescent (age 15.3 ± 0.5 years) rugby league players performed four isometric mid-thigh pull efforts (i.e., two on the dynamometer and two on the force platform) separated by 5 minutes rest in a randomised and counterbalanced order. Mean bias, typical error of estimate (TEE) and Pearson correlation coefficient for peak force (PF) and peak force minus body weight (PFBW) from the force platform were validated against peak force from the dynamometer (DynoPF). When compared to PF and PFBW, mean bias (with 90% Confidence limits) for DynoPF was very large (-32.4 [-34.2 to -30.6] %) and moderate (-10.0 [-12.8 to -7.2] %), respectively. The TEE was moderate for both PF (8.1 [6.3 to 11.2] %) and PFBW (8.9 [7.0 to 12.4]). Correlations between DynoPF and PF (r 0.90 [0.79 to 0.95]) and PFBW (r 0.90 [0.80 to 0.95] were nearly perfect. The isometric mid-thigh pull assessed using a dynamometer underestimated PF and PFBW obtained using a criterion force platform. However, strong correlations between the dynamometer and force platform suggest that a dynamometer provides an appropriate alternative to assess isometric mid-thigh pull strength when a force platform is not available. Therefore, practitioners can use an isometric mid-thigh pull dynamometer to assess strength in the field with youth athletes but should be aware that it underestimates peak force.
    • A reliable testing battery for assessing physical qualities of elite academy rugby league players

      Dobbin, Nicholas; Hunwicks, Richard; Highton, JM; Twist, Craig (2017-11-14)
      This study assessed the inter-day reliability of a testing battery for the assessment of physical qualities of rugby league players. Fifty players (age 17.1 ± 1.1 years; stature 181.3 ± 6.3 cm; body mass 89.0 ± 11.6 kg) from three Super League academies participated in this study. Tests of countermovement jump performance, 10 and 20 m sprint performance, change of direction, medicine ball throw and a modified Yo-Yo Intermittent Recovery Test Level 1 (prone Yo-Yo IR1) were completed on three separate occasions. Between-day intraclass correlation coefficient, typical error (TE), coefficient of variation (CV) and the smallest worthwhile change (SWC) were calculated to determine the reliability and sensitivity of each measure. Individual tests (except medicine ball throw) were not systematically different between trials (P>0.05), with an inter-day variability that was <10%. In all instances, the TE was larger than the calculated SWC change although variability was less than that typically observed after a training intervention or specific training period (i.e. preseason). Using a magnitude-based inference approach, we present the required change for all performance tests to be 75% confident the change is beneficial. This simple and time efficient testing battery is sufficiently reliable to detect previously observed changes in a range of physical qualities of rugby league players.
    • ‘It’s alpha omega for succeeding and thriving’: Parents, children and sporting

      Johansen, Patrick F.; Green, Ken; Innland University Norway; University of Chester (Taylor & Francis, 2017-11-13)
      It has become increasingly apparent, internationally, that childhood is a crucial life-stage in the formation of predispositions towards sports participation and that parents are increasingly investing in the sporting capital of their children via a process of ‘concerted cultivation’. It is surprising, therefore, that parents’ involvement in the development of their children’s sporting interests has received so little attention in Norway, given that sport is a significant pastime for Norwegians and participation has been steadily increasing – among youngsters, in particular – over the past several decades. Through a qualitative case study of a combined primary and secondary school in a small Norwegian city, this study sought to add to recent explorations of the role of parents in children’s sporting involvement in Norway. As expected, it was evident that sport becomes taken for granted and internalized very early on in Norwegian children’s lives. Less expected was the recognition that children’s nascent sporting interests were often generated by sports clubs via early years schooling and, therefore, that parents played only one (albeit very important) part in the formation of their youngsters’ early sporting habits. Thus, parents, sports clubs and early years schooling appeared to form something akin to a ‘sporting trinity’ in youngsters’ nascent sporting careers. These findings may have implications for policy-makers looking towards Norway for the ‘recipe’ for sports participation.
    • A community-based, bionic leg rehabilitation program for patients with chronic stroke: clinical trial protocol

      Wright, Amy; Stone, Keeron; Lambrick, Danielle; Fryer, Simon; Stoner, Lee; Tasker, Edward; Jobson, Simon; Smith, Grace; Batten, John; Batey, Jo; Hudson, Vicky; Hobbs, Helen; Faulkner, James; University of Winchester; University of Gloucestershire; University of Southampton; University of North Carolina; University of Chester; Hobbs Rehabilitation Winchester (Elsevier, 2017-10-30)
      Stroke is a major global health problem whereby many survivors have unmet needs concerning mobility during recovery. As such, the use of robotic assisted devices (i.e., a bionic leg) within a community-setting may be an important adjunct to normal physiotherapy in chronic stroke survivors. This study will be a dual-centre, randomized, parallel group clinical trial to investigate the impact of a community based, training program using a bionic leg on biomechanical, cardiovascular and functional outcomes in stroke survivors. Following a baseline assessment which will assess gait, postural sway, vascular health (blood pressure, arterial stiffness) and functional outcomes (6-minute walk), participants will be randomized to a 10-week program group, incorporating either: i) physiotherapy plus community-based bionic leg training program, ii) physiotherapy only, or iii) usual care control. The training program will involve participants engaging in a minimum of 1 hour per day of bionic leg activities at home. Follow up assessment, identical to baseline, will occur after 10-weeks, 3 and 12 months post intervention. Given the practical implications of the study, the clinical significance of using the bionic leg will be assessed for each outcome variable. The potential improvements in gait, balance, vascular health and functional status may have a meaningful impact on patients’ quality of life. The integration of robotic devices within home-based rehabilitation programs may prove to be a cost effective, practical and beneficial resource for stroke survivors.