542 research outputs found

    Why José Mourinho’s protégés failed when they became managers

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    Martin Kilduff, Craig Crossland, Wenpin Tsai and Matthew T. Bowers discuss the acolyte effec

    The effects of a single whole-body cryotherapy exposure on physiological, performance and perceptual responses of professional academy soccer players following repeated sprint exercise

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    In professional youth soccer players, the physiological, performance and perceptual effects of a single whole body cryotherapy (WBC) session performed shortly after repeated sprint exercise were investigated. In a randomized, counter-balanced and crossover design, 14 habituated English Premier League academy soccer players performed 15 x 30 m sprints (each followed by a 10 m forced deceleration) on two occasions. Within 20 min of exercise cessation, players entered a WBC chamber (Cryo: 30 s at -60°C, 120 s at -135°C) or remained seated (Con) indoors in temperate conditions (~25°C). Blood and saliva samples, peak power output (countermovement jump) and perceptual indices of recovery and soreness were assessed pre-exercise and immediately, 2 h and 24 h post exercise. When compared to Con, a greater testosterone response was observed at 2 h (+32.5 ± 32.3 pg·ml-1, +21%) and 24 h (+50.4 ± 48.9 pg·ml-1, +28%) post-exercise (both P=0.002) in Cryo (trial x treatment interaction: P=0.001). No between trial differences were observed for other salivary (cortisol and testosterone/cortisol ratio), blood (lactate and Creatine Kinase), performance (peak power output) or perceptual (recovery or soreness) markers (all trial x treatment interactions: P>0.05); all of which were influenced by exercise (time effects: all P<0.05). A single session of WBC performed within 20 min of repeated sprint exercise elevated testosterone concentrations for 24 h but did not affect any other performance, physiological or perceptual measurements taken. While unclear, WBC may be efficacious for professional soccer players during congested fixture periods

    Is salivary cortisol moderating the relationship between salivary testosterone and hand-grip strength in healthy men?

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    This study examined the moderating effect of cortisol (C) on the relationship between testosterone (T) and hand-grip strength (HGS) in healthy young men. Sixty-five males were monitored for salivary T, C and HGS before and 15 min after a short bout (5 × 6-s trials) of sprint cycling exercise. Sprint exercise promoted (p < .05) positive changes in T (6.1 ± 24.9%) and HGS (3.4 ± 7.5%), but a negative C response (−14.4 ± 33.1%). The T and C measures did not independently predict HGS, but a significant T × C interaction was found in relation to these outcomes. Further testing revealed that pre-test T and HGS were negatively associated (p < .05), but only in men with high C levels. The exercise changes in T and HGS were also negatively related in men with low C levels (p < .05), but no relationship was seen in men with high C levels. In summary, complex relationships between T and HGS emerged when considering C as a moderating variable. The pre-test combination of high C and low T levels favoured absolute HGS, whereas low pre-test C levels and a smaller T change were linked to larger HGS changes. These associations suggest that, in the current format, T is not necessarily anabolic to muscle strength in healthy young men. Such complexities could also explain some of the inconsistent T relationships with physical performance in lesser trained male populations

    Dose-response and time-lagged effect of daily training load on athlete well-being during an international rugby series

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    Rugby training and competition both impose a stress or training load (TL) affecting athlete well-being. Current understanding of the TL dose-response and time-lagged changes (i.e., delayed effects) in well-being is limited. We addressed these gaps using data from a 3-week international series. Twenty-two elite male rugby players were assessed 4–5 days a week for daily TL and well-being (i.e., mood, stress, soreness, fatigue, sleep quality). A distributed lag non-linear model was used to estimate the TL effect, at the within-person mean (358 A.U), +1SD (576 A.U) and +2SD (794 A.U), on well-being at 0–5 lag days. Average daily TL declined by -38% and -45% in weeks two and three (vs. week 1), respectively, with weekly fluctuations of +27% to -58%(vs. Monday training). The well-being subscales oscillated around a stable baseline. Compared to mean-centered scores, a significant decline in mood and sleep quality (-0.6 to -2.0 units; -9 to -30%) emerged at all TLs, with a delayed shift at higher loads. Elevated stress, soreness, and fatigue responses (up to 3.7 units; 76%) emerged with increasing daily TLs, including a biphasic rise in stress and fatigue at higher loads. In conclusion, we gained detailed insight into physical stress and the temporal sequence of well-being during an international rugby series. Different daily TLs predicted adverse well-being responses (i.e., declining mood and sleep quality, rise in stress, soreness, fatigue) that varied in lag timing, duration, and magnitude. Explicating these associations can assist weekly planning and strategies to optimize recovery, performance, and team success

    Using the split squat to potentiate bilateral and unilateral jump performance

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    The purpose of this study was to examine if a split squat conditioning exercise with no or light loads could potentiate unilateral and bilateral jump performance. Twelve semi-professional rugby players (age: 22.3 +/- 1.4 years; height: 1.84 +/- 0.05 m, mass: 92.4 +/- 9.6 kg) from the English National League 1 performed a series of unilateral and bilateral countermovement jumps (CMJ) and broad jumps (BJ) over the course of two testing days. Both testing days involved performing baseline jumps before completing two sets of ten repetitions of a split squat, this completed with either bodyweight (testing session 1) or a 30kg weighted vest (testing session 2). A five-minute recovery period was permitted both following the warm up and following the completion of the split squat exercise. Significantly larger bilateral jump scores were reported following completion of the bodyweight split squat: CMJ (p = 0.001, ES = 0.44, [mean difference 2.517]), BJ (p = 0.001, ES = 0.37, [mean difference 3.817]), and the weighted vest split squat; CMJ (p = 0.001, ES = 0.8, [mean difference 4.383]), BJ (p = 0.001, ES = 0.68, [mean difference 6.817]). The findings of this study demonstrate that no or light loads of a split squat conditioning exercise are able to potentiate bilateral jump performance in semi-professional rugby players without the need for expensive weight room equipment. As such, this may provide coaches with a viable option of enhancing bilateral jump performance as part of a warm up or on-field conditioning practice

    Can salivary testosterone and cortisol reactivity to a mid-week stress test discriminate a match outcome during international rugby union competition?

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    ObjectivesEvidence suggests that stress-induced changes in testosterone and cortisol are related to future competitive behaviours and team-sport outcomes. Therefore, we examined whether salivary testosterone and cortisol reactivity to a mid-week stress test can discriminate a match outcome in international rugby union competition.DesignSingle group, quasi-experimental design with repeated measures.MethodThirty-three male rugby players completed a standardised stress test three or four days before seven international matches. Stress testing involved seven minutes of shuttle runs (2 × 20 m), dispersed across one-minute stages with increasing speeds. Salivary testosterone and cortisol were measured in the morning, along with delta changes from morning to pre-test (Morn-PreΔ) and pre-test to post-test (Pre-PostΔ). Data were compared across wins (n = 3) and losses (n = 4).ResultsThe Morn-PreΔ in cortisol increased before winning and decreased prior to losing (p < 0.001), with a large effect size difference (d = 1.6, 90% CI 1.3-1.9). Testosterone decreased significantly across the same period, irrespective of the match outcome. The Morn-PreΔ in testosterone and cortisol, plus the Pre-PostΔ in testosterone, all predicted a match outcome (p ≤ 0.01). The final model showed good diagnostic accuracy (72%) with cortisol as the main contributor.ConclusionsThe salivary testosterone and cortisol responses to mid-week testing showed an ability to discriminate a rugby match outcome over a limited number of games. The Morn-PreΔ in cortisol was the strongest diagnostic biomarker. This model may provide a unique format to assess team readiness or recovery between competitions, especially with the emergence of rapid hormonal testing

    Planning and Leveraging Event Portfolios: Towards a Holistic Theory

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    This conceptual paper seeks to advance the discourse on the leveraging and legacies of events by examining the planning, management, and leveraging of event portfolios. This examination shifts the common focus from analyzing single events towards multiple events and purposes that can enable cross-leveraging among different events in pursuit of attainment and magnification of specific ends. The following frameworks are proposed: (1) event portfolio planning and leveraging, and (2) analyzing events networks and inter-organizational linkages. These frameworks are intended to provide, at this infancy stage of event portfolios research, a solid ground for building theory on the management of different types and scales of events within the context of a portfolio aimed to obtain, optimize and sustain tourism, as well as broader community benefits

    The ball in play demands of international rugby union

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    Objectives: Rugby union is a high intensity intermittent sport, typically analysed via set time periods or rolling average methods. This study reports the demands of international rugby union via global positioning system (GPS) metrics expressed as mean ball in play (BiP), maximum BiP (max BiP), and whole match outputs. Design: Single cohort cross sectional study involving 22 international players, categorised as forwards and backs. Methods: A total of 88 GPS files from eight international test matches were collected during 2016. An Opta sportscode timeline was integrated into the GPS software to split the data into BiP periods. Metres per min (m.min-1), high metabolic load per min (HML), accelerations per min (Acc), high speed running per min (HSR), and collisions per min (Coll) were expressed relative to BiP periods and over the whole match (>60min). Results: Whole match metrics were significantly lower than all BiP metrics (p < 0.001). Mean and max BiP HML, (p < 0.01) and HSR (p < 0.05) were significantly higher for backs versus forwards, whereas Coll were significantly higher for forwards (p < 0.001). In plays lasting 61s or greater, max BiP m.min-1 were higher for backs. Max BiP m.min-1, HML, HSR and Coll were all time dependant (p < 0.05) showing that both movement metrics and collision demands differ as length of play continues. Conclusions: This study uses a novel method of accurately assessing the BiP demands of rugby union. It also reports typical and maximal demands of international rugby union that can be used by practitioners and scientists to target training of worst-case scenario's equivalent to international intensity. Backs covered greater distances at higher speeds and demonstrated higher HML, in general play as well as 'worst case scenarios'; conversely forwards perform a higher number of collisions
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