RESUMO
This study aimed to evaluate the effect of discrete passages of play on locomotor demands of international men's and women's rugby sevens matches and their relationship with winning or losing. Thirteen men's and thirteen women's international rugby sevens players wore 10 Hz Global Positioning Systems during twelve Tokyo Olympic games matches (966 observations; 507 for men, 459 for women). Discrete ball-in-play periods were categorised as: 'Single-phase defence', 'single-phase attack', 'multi-phase defence', 'multi-phase attack', 'multi-phase defence to attack', or 'multi-phase attack to defence'. Relative total distance, alongside high-speed (>5.0 mâs-1), acceleration (>3 mâs-2), and deceleration (>3 mâs-2) distances were recorded for each passage. Separately for men and women, linear mixed models examined the effect of passage type and match outcome (win or loss) on locomotor demands, whilst controlling for opposition ranking. In men, relative total distance ranged from 137 mâmin-1 to 174 mâmin-1 for 'multi-phase defence to attack' and 'multi-phase attack', respectively. In women, 'multi-phase attack' elicited the lowest relative total distance (118 mâmin-1), whereas the greatest values (186 mâmin-1) were recorded for 'single-phase defence'. For men, there were significant interactions between match outcome and passage type for relative total (p<0.001) and high-speed (p = 0.006) distance. During 'multi-phase attack', relative total distance was greater for wins versus losses (174 vs 138 m.min-1, p = 0.024). However, for 'single-phase defence', relative total distance was lower for wins (128 vs 164 m.min-1, p<0.001). For women, there were significant interactions between match outcome and passage type for relative total (p = 0.036), high-speed (p = 0.003), and deceleration (p = 0.015) distances. Locomotor responses were influenced by passage type and match result for men and women. Knowing the demands of each passage type may inform training drills targeted at developing match-play-specific physical, technical, and tactical adaptations. Understanding how passages differ between matches won and lost could also inform team technical/tactical preparation including selection.
Assuntos
Desempenho Atlético , Humanos , Masculino , Feminino , Adulto , Desempenho Atlético/fisiologia , Futebol Americano/fisiologia , Locomoção/fisiologia , Sistemas de Informação Geográfica , Adulto Jovem , Rugby/fisiologia , Corrida/fisiologia , AtletasRESUMO
Cold water immersion (CWI) evokes the life-threatening reflex cold shock response (CSR), inducing hyperventilation, increasing cardiac arrhythmias, and increasing drowning risk by impairing safety behaviour. Repeated CWI induces CSR habituation (i.e., diminishing response with same stimulus magnitude) after â¼4 immersions, with variation between studies. We quantified the magnitude and coefficient of variation (CoV) in the CSR in a systematic review and meta-analysis with search terms entered to Medline, SportDiscus, PsychINFO, Pubmed, and Cochrane Central Register. Random effects meta-analyses, including effect sizes (Cohen's d) from 17 eligible groups (k), were conducted for heart rate (HR, n = 145, k = 17), respiratory frequency (fR, n = 73, k = 12), minute ventilation (Ve, n = 106, k = 10) and tidal volume (Vt, n = 46, k=6). All CSR variables habituated (p < 0.001) with large or moderate pooled effect sizes: ΔHR -14 (10) bt. min-1 (d: -1.19); ΔfR -8 (7) br. min-1 (d: -0.78); ΔVe, -21.3 (9.8) L. min-1 (d: -1.64); ΔVt -0.4 (0.3) L -1. Variation was greatest in Ve (control vs comparator immersion: 32.5&24.7%) compared to Vt (11.8&12.1%). Repeated CWI induces CSR habituation potentially reducing drowning risk. We consider the neurophysiological and behavioural consequences.
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Resposta ao Choque Frio , Habituação Psicofisiológica , Humanos , Frequência Cardíaca , Imersão , Temperatura BaixaRESUMO
OBJECTIVE: Drowning is a leading cause of death. The World Health Organization (WHO) and United Nations (UN) emphasise the need for population-level data-driven approaches to examine risk factors to improve water safety policies. Weather conditions, have the potential to influence drowning risk behaviours as people are more likely to spend time around water and/or undertake risky activities in aquatic spaces as a behavioural thermoregulatory response (e.g., seeking coolth). METHODS: A case-crossover approach assessed associations between changes in daily maximum air temperature (data from the nearest weather station to each drowning event) and unintentional drowning risk using anonymous data from the validated UK Water Incident Database 2012-2019 (1945 unintentional deaths, 82% male). Control days were selected using a unidirectional time-stratified approach, whereby seven and 14 days before the hazard day were used as the controls. RESULTS: Mean maximum air temperature on case and control days was 15.36 °C and 14.80 °C, respectively. A 1 °C increase in air temperature was associated with a 7.2% increase in unintentional drowning risk. This relationship existed for males only. Drowning risk was elevated on days where air temperature reached 15-19.9 °C (Odds Ratio; OR: 1.75), 20-24.9 °C (OR: 1.87), and ≥ 25 °C (OR: 4.67), compared with days <10 °C. The greatest elevations in risk appeared to be amongst males and when alcohol intoxication was suspected. Precipitation showed no significant association with unintentional drowning risk. CONCLUSIONS: Identifying such relationships highlights the value of considering weather conditions when evaluating environmental risk factors for drowning, and may inform water safety policy and allocating resources to prevention and rescue.
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Afogamento , Humanos , Masculino , Feminino , Estudos Cross-Over , Temperatura , Fatores de Risco , ÁguaRESUMO
ABSTRACT: McFadden, BA, Bozzini, BN, Cintineo, HP, Hills, SP, Walker, AJ, Chandler, AJ, Sanders, DJ, Russell, M, and Arent, SM. Power, endurance, and body composition changes over a collegiate career in National Collegiate Athletic Association Division I women soccer athletes. J Strength Cond Res 37(7): 1428-1433, 2023-The purpose of this study was to determine longitudinal changes in fitness and body composition throughout athletes' 4-year collegiate soccer careers. Performance testing occurred before preseason during freshman, sophomore, junior, and senior year in 17 female Division I soccer players. Body composition was assessed through air-displacement plethysmography to determine percent body fat (%BF), fat-free mass (FFM), and body mass (BM). Maximal countermovement vertical jump height was assessed through contact mat using arm swing (CMJ AS ) and hands-on-hips (CMJ HOH ) methods to calculate power (CMJ watts / HOHwatts ). Aerobic capacity (VÌ o2 max) and ventilatory threshold (VT) were assessed by indirect calorimetry during a maximal graded exercise test on a treadmill. Linear mixed models were used to assess changes across academic years ( p < 0.05). No changes occurred in %BF, BM, VÌ o2 max, VT, CMJ AS , or CMJ watts . A time main effect was seen for FFM ( p = 0.01) with increases from freshman to senior ( p = 0.02). Time main effects were observed for CMJ HOH ( p < 0.001) and CMJ HOHwatts ( p < 0.001) with increases from freshman to junior (CMJ HOH,p = 0.001; CMJ HOHwatts , p = 0.02) and senior (CMJ HOH , p < 0.001; CMJ HOHwatts , p = 0.003) as well as sophomore to senior (CMJ HOH , p < 0.001; CMJ HOHwatts , p = 0.02). Countermovement vertical jump with hands on hips also increased from sophomore to junior ( p = 0.005). The lower FFM and power capabilities as freshmen compared with upperclassman indicate a potential limited readiness. Coaches and training staff should account for these developmental differences when entering the preseason. Adequate conditioning programs before starting a collegiate program may help build a fitness foundation and prepare freshmen athletes to compete at the same level as their upperclassmen counterparts.
Assuntos
Desempenho Atlético , Futebol , Esportes , Feminino , Humanos , Exercício Físico , Composição Corporal , AtletasRESUMO
ABSTRACT: Aben, HGJ, Hills, SP, Higgins, D, Cooke, CB, Davis, D, Jones, B, and Russell, M. The efficacy of a multimodal recovery strategy implemented after a high-intensity rugby league training session. J Strength Cond Res 37(8): 1634-1642, 2023-The efficacy of a multimodal recovery strategy implemented within 4 hours of rugby league (RL) training was investigated using repeated-measures, randomized, crossover methods in 10 professional academy RL players (age: 17 ± 1 years). Following standardized training (5,383 m covered, 350-m high-speed running, 28 repeated high-intensity efforts, 24 collisions), players completed a multimodal recovery (REC) strategy (i.e., â¼640 kcal meal + â¼1,285 kcal snacks or drinks, cold-water immersion, sleep hygiene recommendations) or control (i.e., â¼640 kcal meal: CONT) practices. Isometric mid-thigh pulls (IMTP), countermovement jumps (CMJ), and wellness questionnaires were completed before (-3 hours) and after (+24, +48 hours) training. The recovery strategy influenced IMTP peak force ( p = 0.026), but between-trial differences were undetectable. No other between-trial effects (all p > 0.05) were seen for IMTP, CMJ, or wellness variables. Training-induced reductions in CMJ peak power (-4 ± 6% vs baseline: 4,878 ± 642 W) at +24 hours ( p = 0.016) dissipated by +48 hours. Fatigue and lower-body soreness reduced by 16 ± 19% ( p = 0.01) and 32 ± 44% ( p = 0.024) at +48 hours versus +24 hours, respectively. Relative to CONT (i.e., posttraining nutrition), the effects of a single bout of recovery practices appeared limited when implemented after RL-specific training. Therefore, when training included limited collisions, balanced postexercise meals appeared equally effective relative to a multimodal recovery strategy. Transient changes in performance and wellness variables after training may have implications for practitioners. Consecutive training sessions, including a high frequency and intensity of eccentric muscle actions, should be carefully planned, especially near match-play.
Assuntos
Desempenho Atlético , Futebol Americano , Corrida , Adolescente , Humanos , Desempenho Atlético/fisiologia , Fadiga , Futebol Americano/fisiologia , RugbyRESUMO
This study assessed the influence of environmental factors, air travel, and epoch estimation method on locomotor demands of international men's rugby sevens match-play. Eighteen men's rugby sevens players wore 10â Hz Global Positioning Systems (STATsport) during 52 international matches over nine global tournaments (418 observations). Whole-match average speed was recorded, whilst average speed and relative high-speed distance (>5.0â m·s-1) were quantified using FIXED and ROLL methods over 60-420 s epochs (60 s increments) to establish worst-case scenario demands. Linear mixed models compared FIXED versus ROLL estimation methods and assessed whether temperature, humidity, travel duration, number of time-zones crossed, and travel direction were associated with locomotor responses. Temperature and humidity were positively associated with overall and worst-case scenario average speed (effect estimates; b: 0.18-0.54), whilst worst-case scenario high-speed distance at 300 s was also related to temperature (b: 0.19). Easterly air travel compromised overall and 180 and 300 s worst-case scenario average speed (b: -8.31 to-7.39), alongside high-speed distance over 300 s (b: -4.54). For worst-case scenario average speed and high-speed distance, FIXED underestimated ROLL at all epoch lengths (â¼9.9-18.4%, p≤0.001). This study indicated that international rugby sevens match-play locomotor responses were greater as air temperature increased but reduced following eastward air travel. Underestimation of demands in FIXED vs ROLL over 60-420 s epochs was confirmed. Such climatic and travel influences warrant the adoption of strategies targeted at maximising performance and safety according to the tournament conditions. Knowing the most demanding periods of match-play facilitates training specificity.HighlightsSelected locomotor responses were reduced following eastward air travel, potentially suggesting interventions to mitigate these effects are warranted.Match-play running responses were greater as air temperature increased. Strategies targeted at optimising body temperature in both warm and cool conditions warrant consideration to promote performance and maintain player safety.Fixed epochs underestimated worst-case scenario average speed (9.9-11.7%) and high-speed distance (11.4-18.4%). Rolling averages may thus be more appropriate for detecting the most intense periods, while duration-specific data provide training targets.
Assuntos
Desempenho Atlético , Futebol Americano , Corrida , Masculino , Humanos , Futebol Americano/fisiologia , Rugby , Desempenho Atlético/fisiologia , Viagem , Corrida/fisiologia , Sistemas de Informação GeográficaRESUMO
ABSTRACT: Dann, E, Quinn, S, Russell, M, Kilduff, LP, Turner, AN, and Hills, SP. Alternate leg bounding acutely improves change-of-direction performance in women's team sports players irrespective of ground type. J Strength Cond Res 37(6): 1199-1203, 2023-This study aimed to assess whether body mass only alternate leg bounding performed post-warm-up on grass or a hard surface acutely improves preplanned change-of-direction performance in women's team sports players relative to a control condition and, if so, profile the time course of such changes. On 3 occasions, 14 amateur women's team sports players performed 20 m preplanned change-of-direction ("Pro-Agility") tests at 4, 8, and 12 minutes after interventions. Interventions were implemented immediately after a standardized warm-up and consisted of 3 sets of 10 repetitions of alternate leg bounding (5 ground contacts per limb) on a hard indoor surface (HARD) or natural grass (GRASS), or a control condition involving approximately 75 seconds of continuous walking with no bounding (CON). Performance was similar between conditions at 4-minutes postintervention. Performance at 8 minutes was greater in HARD (2.9%, p = 0.015) and GRASS (3.8%, p = 0.029) relative to CON, whereas GRASS also exceeded CON at 12 minute post-bounding (5.2%, p = 0.004). All effects were large. No differences existed between HARD and GRASS at any time. Irrespective of the ground surface, alternate leg bounding performed with body mass only can acutely improve indices of change-of-direction performance in women's team sports players when an appropriate post-stimulus recovery period is provided. Bounding on grass or a hard surface represents a feasible match-day practice that enhances subsequent change-of-direction performance and could therefore be used as part of practically applicable pre-match, half-time, and pitch-side (re)warm-up activities.
Assuntos
Desempenho Atlético , Exercício de Aquecimento , Humanos , Feminino , Esportes de Equipe , Perna (Membro) , AtletasRESUMO
ABSTRACT: Aben, HGJ, Hills, SP, Cooke, CB, Davis, D, Jones, B, and Russell, M. Profiling the post-match recovery response in male rugby: A systematic review. J Strength Cond Res 36(7): 2050-2067, 2022-To minimize underperformance, injury, and illness, and to enhance readiness for training and match-play, post-match responses are commonly monitored within professional rugby. As no clear consensus exists regarding the magnitude and duration of post-match recovery, this review summarized the literature (17 studies yielded from literature searching/screening) reporting neuromuscular (countermovement jump [CMJ], peak power output [PP], and flight time [FT]), biochemical (creatine kinase [CK]) or endocrine (cortisol [C] and testosterone [T] concentrations), and subjective (wellness questionnaire and muscle soreness) indices after rugby match-play. For neuromuscular responses (11 studies), reductions in PP <31.5% occurred <30 minutes after match, returning to baseline within 48-72 hours. Post-match reductions in FT of <4% recovered after 48 hours. For biochemical and endocrine responses (14 studies), increases in CK, ranging from 120 to 451%, peaked between 12 and 24 hours, returning to baseline within 72 hours of match-play. Initial increases of <298% in C and reductions in T concentrations (<44%) returned to pre-match values within 48-72 hours. Mood disturbances (6 studies) required 48-72 hours to normalize after peak decrements of <65% at 24 hours. This review highlights that 72 hours were needed to restore perturbations in neuromuscular, biochemical and endocrine, and subjective/perceptual responses after competitive rugby match-play. Notably, only 4 studies reported responses in more ecologically valid scenarios (i.e., those in which regular training and recovery strategies were used) while also reporting detailed match demands. A lack of research focusing on youth players was also evident, as only 3 studies profiled post-match responses in younger athletes. Deeper insight regarding post-match responses in ecologically valid scenarios is therefore required.
Assuntos
Rugby , Atletas , Creatina Quinase , Humanos , Hidrocortisona/fisiologia , Masculino , Rugby/fisiologiaRESUMO
Purpose: To quantify the peak post-pitch-entry physical responses of soccer substitutes while assessing contextual influences. Peak responses may be important performance indicators for substitutes introduced to provide a physical impact. Method: Thirty-three professional substitutes wore Microelectromechanical Systems during 44 matches (4 ± 3 observations·player-1). Post-pitch-entry relative peak values for total and high-speed (> 5.5 m·s-1) distances, average acceleration, and PlayerLoad™ were calculated using rolling averages over 60-s to 600-s. Linear mixed models assessed contextual influences (position, substitution timing, scoreline, and location). Results: Substitutes introduced during the final ~15 min of match-play covered less high-speed distance than first-half substitutes (~2.8-3.1 m·min-1) over 480-s to 600-s epochs, and less than 60:00-74:59 min substitutes (~1.7-1.8 m·min-1) during 540-s and 600-s epochs. Average acceleration during all except 180-s epochs was lower for 75:00+ min substitutes compared with first-half replacements (~0.27-0.43 m·s-2), and lower than 60:00-74:59 min substitutes during 60-s (~0.13 m·s-2). Substitutes introduced when their team was winning recorded greater distances over 120-s to 600-s (~6.2-7.7 m·min-1), and higher PlayerLoad™ values during 120-s, 180-s, 300-s, and 480-s epochs (~2.7-3.6 arbitrary units·min-1), compared with when scores were level at pitch-entry. Irrespective of substitution timing, substitute midfielders exceeded the total distance of substitute attackers (~5.9-16.2 m·min-1) for all except 360-s and 600-s epochs, and defenders (~13.3-26.7 m·min-1) during epochs < 300-s. Conclusions: This study provides benchmark data for practitioners tailoring training and recovery protocols, particularly "top-up" conditioning, to the competitive demands of soccer substitutes. Knowing how contextual factors influence substitutes' peak match-play responses may help managers/coaches assess the efficacy of substitution strategies.
Assuntos
Desempenho Atlético , Corrida , Futebol , Aceleração , Desempenho Atlético/fisiologia , Sistemas de Informação Geográfica , Humanos , Modelos Lineares , Corrida/fisiologia , Futebol/fisiologiaRESUMO
OBJECTIVES: To compare two modes (general and cricket-specific) of morning priming exercise on afternoon physical and cognitive performance, and subjective readiness to perform in professional male cricketers. DESIGN: Randomised, crossover, counterbalanced. METHODS: On three occasions, 16 professional men's cricketers completed afternoon tests of countermovement jump height, cricket-specific sprint performance (running between the wickets, two runs), cognitive function (Stroop test, time taken), and subjective readiness to perform. Control (CON; passive rest), lower-body resistance exercise priming (LIFT; trap bar deadlifts, 6â¯×â¯4 repetitions up to 85% of one repetition maximum), or cricket-specific running priming (RUN; 6â¯×â¯35.36â¯m sprints including a 180° change of direction) interventions were implemented 5.5â¯h before testing. RESULTS: Afternoon sprint times were faster in RUN (-0.04â¯s, pâ¯=â¯0.013) and LIFT (-0.07â¯s, pâ¯<â¯0.001) versus CON, and faster in LIFT than RUN (-0.03â¯s, pâ¯=â¯0.032). Jump height (+1.1â¯cm, pâ¯=â¯0.021) and cognitive function (-3.83â¯s, pâ¯=â¯0.003) were greater in LIFT than CON, whilst RUN outperformed CON for cognition (-2.52â¯s, pâ¯=â¯0.023). Although perceived readiness was not influenced by trial (pâ¯>â¯0.05), players reported favourable responses on the "aggression" subscale in LIFT relative to CON (+1 arbitrary unit, pâ¯=â¯0.022). CONCLUSIONS: Both general (lower-body resistance exercise) and cricket-specific (simulated running between wickets) morning priming are effective match-day strategies to improve afternoon markers of physical and cognitive performance in professional men's cricketers. Practitioners may thus be afforded flexibility in situations where resistance exercise is not feasible on the morning of a match.
Assuntos
Desempenho Atlético , Críquete , Treinamento Resistido , Corrida , Humanos , Masculino , CogniçãoRESUMO
BACKGROUND: Death by drowning is a leading cause of accidental death in the United Kingdom (UK) and worldwide. The World Health Organization (WHO) states that effective documentation of drowning is required to describe drowning frequency and to underpin effective drowning prevention intervention, thus improving the quality of data describing drowning frequency represents a key initiative. The water incident database (WAID) has been used to document UK fatal and non-fatal water-based incidents since 2009. WAID has not undergone a systematic evaluation of its data or data collection procedures to establish if the database meets the WHO requirements. The present study investigated the characteristics of UK fatal drowning incidents and audited current WAID data capture procedures. METHODS: Data for the fatal drowning cases recorded between 2012 and 2019 were reviewed. Descriptive data were generated 1) to describe fatal drownings in the UK's WAID in this period; 2) a sub-set of drownings were audited i) for completeness of data entry and, based on source documents, ii) for quality of data entry; 3) these processes were used to make recommendations for onward revisions to WAID. RESULTS: A total of 5051 fatalities were recorded between 2012 and 2019. Drowning was most frequent amongst males aged 35 to 60 years (n = 1346), whilst suspected accidents and suicides accounted for 44 and 35% of fatalities. Suicide by drowning was at a peak in the most recent year of data analysed (i.e., 2019; 279 cases) highlighting an urgent need for targeted intervention. Audit part 2i) indicated that 16% of all fields were incomplete, thus indicating potential redundancy, duplication, or the need for onward review. Audit part 2ii) indicated high levels of agreement (80 ± 12%) between audited cases and the 'true' WAID entries. CONCLUSIONS: This study confirms WAID as a rigorous, transparent and effective means of documenting UK drownings thereby meeting WHO requirements for data quality; yet future improvements are recommended. Such findings allow researchers and policy makers to use WAID to further investigate UK drowning with a view to improving public safety measures and drowning prevention interventions. Observations alongside several expert recommendations have informed a revised version of WAID.
Assuntos
Afogamento , Suicídio , Acidentes , Afogamento/epidemiologia , Afogamento/prevenção & controle , Humanos , Masculino , Reino Unido/epidemiologia , ÁguaRESUMO
OBJECTIVES: To profile performance and physiological responses to typical patterns of match-day activity for second-half soccer substitutes. DESIGN: Descriptive. METHODS: Following a warm-up, 13 male team sports players underwent â¼85min of rest, punctuated with five min rewarm-ups at â¼25, â¼50, and â¼70min, before â¼30min of simulated soccer match-play. Countermovement jump performance (jump height, peak power output), alongside 15m sprints, were assessed post-warm-up, and pre- and post-simulated match-play. Core temperature, heart rate, ratings of perceived exertion, and blood glucose and lactate concentrations were measured throughout. RESULTS: Warm-up-induced core temperature elevations (â¼2.3%, +0.85°C; p<0.001) were maintained until after the first rewarm-up. Thereafter, core temperature was reduced from post-warm-up values until pre-simulated match-play (â¼1.6%, -0.60°C; p<0.001), where values were similar to pre-warm-up (37.07±0.24°C, p=0.981). Simulated match-play increased core temperature progressively (p≤0.05) but values remained lower than post-warm-up (â¼5min; p=0.002) until â¼10min into exercise. From post-warm-up to pre-simulated match-play, sprint times (â¼3.9%, +0.10s, p=0.003), jump height (â¼9.4%, -3.1cm; p=0.017), and peak power output (â¼7.2%, -296W; p<0.001) worsened. Despite increased ratings of perceived exertion and elevated blood lactate concentrations (p≤0.05), sprint times were maintained throughout exercise, whereas peak power increased (â¼7.8%, +294W; p=0.006) pre- to post-exercise. CONCLUSIONS: At the point of simulated pitch-entry, body temperature and physical performance responses were not maintained from warm-up cessation despite typical substitute-specific match-day practices being employed in thermoneutral conditions. Evidence of performance-limiting fatigue was absent during â¼30min of simulated match-play. These data question the efficacy of practices typically implemented by substitutes before pitch-entry.
Assuntos
Desempenho Atlético/fisiologia , Temperatura Corporal/fisiologia , Futebol/fisiologia , Exercício de Aquecimento/fisiologia , Adolescente , Adulto , Biomarcadores/sangue , Glicemia/metabolismo , Frequência Cardíaca/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Fatores de Tempo , Adulto JovemRESUMO
Hills, SP, Barrett, S, Busby, M, Kilduff, LP, Barwood, MJ, Radcliffe, JN, Cooke, CB, and Russell, M. Profiling the post-match top-up conditioning practices of professional soccer substitutes: An analysis of contextual influences. J Strength Cond Res 34(10): 2805-2814, 2020-Soccer practitioners implement "top-up" conditioning sessions to compensate for substitutes' limited match-play exposure. Although perceived to be valuable for reducing injury risk and augmenting positive physical adaptations, little research has considered the demands of post-match top-up training. To quantify post-match top-up responses, 31 professional soccer players wore 10 Hz microelectromechanical systems after 37 matches whereby they were selected in the match-day squad as substitutes (184 observations; 6 ± 5 observations·player). Linear mixed models and effect sizes (ES) assessed the influence of contextual factors on 23 physical performance variables. Top-ups lasted 17.13 ± 7.44 minutes, eliciting total and high-speed distances of 1.7 ± 6.2 km and 0.4 ± 1.7 km, respectively. Each contextual factor (i.e., position, substitution timing, match location, result, time of day, stage of the season, and fixture density) influenced at least 4 of the dependent variables profiled (p ≤ 0.05). Top-up duration; total, moderate-speed, and low-speed distance; and the number of repeated high-intensity efforts were greater for unused vs. used substitutes (ES: 0.38-0.73, small to moderate). Relative to away matches, home top-ups elicited heightened total, low-speed, and high-speed distances, alongside more moderate-speed accelerations and decelerations, and repeated high-intensity efforts (ES: 0.25-0.89, small to moderate). Although absolute and relative running distances were generally the highest when the fixture density was low, the greatest acceleration and deceleration demands were observed during the most congested fixture periods. Late-season top-ups typically elicited lower absolute physical responses than early and mid-season sessions. These data provide important information for practitioners when considering the aims and design of substitute top-up conditioning sessions, particularly with reference to contextual influences.
Assuntos
Atletas , Desempenho Atlético/fisiologia , Futebol/fisiologia , Aceleração , Adaptação Fisiológica , Humanos , Modelos Lineares , Sistemas Microeletromecânicos , Corrida/fisiologiaRESUMO
Modifying a soccer substitute's pre-pitch-entry activities may represent an opportunity to maximise physical performance and minimise injury-risk following match-introduction. Using a professional team that has previously participated in substitute profiling research, this follow-up case study investigated the effects of a modified match-day protocol that included substitutes; 1) performing a new pre-match warm-up alongside members of the starting team (as opposed to a separate substitute-only warm-up), 2) participating in a staff-led half-time rewarm-up (as opposed to player-led half-time activities), and 3) receiving ongoing education focusing on the efficacy of (re)warm-up activities. English Championship substitutes (n = 15) were monitored using Micro-electromechanical Systems during 13 matches incorporating the modified practices (35 observations). On an individual player basis, data were organised into bouts of warm-up activity (pre-pitch-entry) and five min epochs of match-play (post-pitch-entry). Linear mixed modelling assessed the influence of 'bout' and 'epoch', position, and scoreline. Substitutes performed 3±1 rewarm-up boutsâplayer-1âmatch-1 between kick-off and pitch-entry, which were shorter (-17.2 to -27.1 min) and elicited less distance (-696 to -1257 m) than the pre-match warm-up (p≤0.001). Compared with previous data, heightened absolute movement responses were observed during the pre-match and staff-led half-time (re)warm-ups, alongside greater relative distances covered during player-led activities performed between kick-off and pitch-entry. Whilst less distance (-10%) was covered during the second versus first five min period following match-introduction, values remained higher than previously reported. Between pitch-entry and the end of the match, the scoreline improved and worsened following 26% and 11% of substitutions, respectively; a favourable record compared with existing observations. Acknowledging the likely contribution from external factors, this case study reports heightened movement profiles and improved match scorelines when pre-pitch-entry practices were modified. Practitioners should note the potential influence of match-day activities on the physical responses of soccer substitutes and, if deemed necessary, consider adapting their pre-pitch-entry routines accordingly.
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Desempenho Atlético/estatística & dados numéricos , Futebol , Exercício de Aquecimento , Adulto , Humanos , Movimento/fisiologia , Adulto JovemRESUMO
In professional academy rugby league (RL) players, this two-part study examined; A) the within- and between-day reliability of isometric mid-thigh pulls (IMTP), countermovement jumps (CMJ), and a wellness questionnaire (n = 11), and B) profiled the responses with acceptable reliability (no between-trial differences and between-day coefficient of variation (CV) ≤10% and intraclass correlation coefficient (ICC) ≥0.8) for 120 h (baseline: -3, +24, +48, +72, +96, +120 h) following RL match-play (n = 10). In part A, force at 200, and 250 ms, and peak force (PF) demonstrated acceptable within- (CV%: 3.67-8.41%, ICC: 0.89-0.93) and between-day (CV%: 4.34-8.62%, ICC: 0.87-0.92) reliability for IMTP. Most CMJ variables demonstrated acceptable within-day reliability (CV%: 3.03-7.34%, ICC: 0.82-0.98), but only six (i.e., flight-time, PF, peak power (PP), relative PP, velocity at take-off (VTO), jump-height (JH)) showed acceptable between-day reliability (CV%: 2.56-6.79%, ICC: 0.83-0.91). Only total wellness demonstrated acceptable between-day reliability (CV%: 7.05%, ICC: 0.90) from the questionnaire. In part B, reductions of 4.75% and 9.23% (vs. baseline; 2.54 mâs-1; 0.33 m) occurred at +24 h for CMJ VTO, and JH, respectively. Acceptable reliability was observed in some, but not all, variables and the magnitude and time-course of post-match responses were test and variable specific. Practitioners should therefore be mindful of the influence that the choice of recovery monitoring tool may have upon the practical interpretation of the data.
RESUMO
The physical demands of English Premier League soccer goalkeepers were quantified during training and match-play in a two-part study. Goalkeeper-specific micromechanical electrical systems (MEMS) devices, profiled training and match-day activities throughout one competitive week (n=8; part A). Changes in MEMS-derived outputs were also profiled throughout match-play (100 matches; n=8, 18±14 observations per goalkeeper; part B). In part A, goalkeeping-training elicited the most dives (51±11) versus all activities (all p≤0.030) except shooting-training (p=0.069). Small-sided games elicited the fewest (5±3) dives (all p≤0.012). High-speed distance covered in match (103±72 m) was similar to goalkeeping-training (p=0.484), while exceeding shooting-training, small-sided games, pre-match shooting, and pre-match warm-up (all p=0.012). Most changes of direction (34±12) and explosive efforts (70±18) occurred during goalkeeping-training, with values exceeding match (both p=0.012). In part B, between-half reductions in total distance, but increased high-speed changes of direction and explosive efforts, occurred (both p≤0.05). Excluding the number of high jumps, all variables differed from 0-15-min during at least one match epoch, with more dives (1.3±1.4 vs 1.0±1.1) and explosive efforts (2.5±2.4 vs 2.0±1.8) performed between 75-90-min versus 0-15-min (all p<0.05). These data highlight the differing physical demands of various activities performed by professional soccer goalkeepers throughout a competitive week.
Assuntos
Desempenho Atlético/fisiologia , Comportamento Competitivo/fisiologia , Condicionamento Físico Humano/fisiologia , Futebol/fisiologia , Adulto , Fadiga/fisiopatologia , Monitores de Aptidão Física , Humanos , Masculino , Movimento , Adulto JovemRESUMO
Despite empirical observations suggesting that practitioners value the use of substitutions during soccer match-play, limited research has sought to substantiate such claims. This study used online surveys to assess the perceptions of practitioners within professional soccer about the use and practices of substitutes. Thirty-three practitioners completed one of two surveys (each requiring both open and closed questions to be answered), depending upon whether their primary role related mostly to tactical ('tactical practitioners'; n = 7) or physical ('physical practitioners'; n = 26) aspects of player/team management. Thematic content analysis of responses identified four higher-order themes: 'impact of substitutions', 'planning and communication', 'player preparation and recovery' and 'regulations'. Eighty-five percent of practitioners believed that substitutes are important in determining success during soccer match-play, with the primary justification being the perceived ability of such players to provide a physical and/or tactical impact. However, contextual factors such as the match situation, timing of introduction, and players undergoing adequate pre-pitch-entry preparation, may be important for realising such aims. Although many practitioners believed that there was a need for substitutes to engage in bespoke non-match-day preparations and recovery strategies that differ from starting players, logistical considerations, such as scarcity of resources, often limit their scope. Notwithstanding, 96% of respondents indicated that substitutes frequently perform extra conditioning sessions to account for deficits in high-speed running loads compared with players exposed to a longer period of match-play. Substitutes' pre-match warm-ups are typically led by team staff, however practitioners reported providing varying levels of input with regards to the practices adopted between kick-off and pitch-entry. Uncertainty exists as to the efficacy of current pre-pitch-entry practices, and 100% of practitioners highlighted 'preparatory strategies' as at least a 'moderately important' direction for future research. This study presents novel insights and highlights areas that are considered future research priorities amongst those working in the field.
Assuntos
Atletas/psicologia , Exercício de Aquecimento , Traumatismos em Atletas/prevenção & controle , Desempenho Atlético , Humanos , Futebol , Inquéritos e QuestionáriosRESUMO
OBJECTIVES: To compare fixed epochs (FIXED) and rolling averages (ROLL) for quantifying worst-case scenario ('peak') running demands during professional soccer match-play, whilst assessing contextual influences. DESIGN: Descriptive, observational. METHODS: Twenty-five outfield players from an English Championship soccer club wore 10-Hz microelectromechanical systems during 28 matches. Relative total and high-speed (>5.5ms-1) distances were averaged over fixed and rolling 60-s to 600-s epochs. Linear mixed models compared FIXED versus ROLL and assessed the influence of epoch length, playing position, starting status, match result, location, formation, and time-of-day. RESULTS: Irrespective of playing position or epoch duration, FIXED underestimated ROLL for total (â¼7-10%) and high-speed (â¼12-25%) distance. In ROLL, worst-case scenario relative total and high-speed distances reduced from 190.1±20.4mmin-1 and 59.5±23.0mmin-1 in the 60-s epoch, to 120.9±13.1mmin-1 and 14.2±6.5mmin-1 in the 600-s epoch, respectively. Worst-case scenario total distance was higher for midfielders (â¼9-16mmin-1) and defenders (â¼3-10mmin-1) compared with attackers. In general, starters experienced higher worst-case scenario total distance than substitutes (â¼3.6-8.5mmin-1), but lower worst-case scenario high-speed running over 300-s (â¼3mmin-1). Greater worst-case scenario total and high-speed distances were elicited during wins (â¼7.3-11.2mmin-1 and â¼2.7-7.9mmin-1, respectively) and losses (â¼2.7-5.7mmin-1 and â¼1.4-2.2mmin-1, respectively) versus draws, whilst time-of-day and playing formation influenced worst-case scenario high-speed distances only. CONCLUSIONS: These data indicate an underestimation of worst-case scenario running demands in FIXED versus ROLL over 60-s to 600-s epochs while highlighting situational influences. Such information facilitates training specificity by enabling sessions to be targeted at the most demanding periods of competition.
Assuntos
Desempenho Atlético , Corrida , Futebol , Adulto , Sistemas de Informação Geográfica , Humanos , Modelos Lineares , Fatores de Tempo , Estudos de Tempo e Movimento , Adulto JovemRESUMO
OBJECTIVES: To profile the distances covered during international women's rugby union match-play and assess the duration-specific worst-case scenario locomotor demands over 60-s to 600-s epochs, whilst comparing the values determined by fixed epoch (FIXED) versus rolling average (ROLL) methods of worst-case scenario estimation and assessing positional influences. DESIGN: Descriptive, observational. METHODS: Twenty-nine international women's rugby union players wore 10Hz microelectromechanical systems during eight international matches (110 observations). Total, and per-half, distances were recorded, whilst relative total and high-speed (>4.4ms-1) distances were averaged using FIXED and ROLL methods over 60-600-s. Linear mixed models compared distances covered between match halves, assessed FIXED versus ROLL, and examined the influence of playing position. RESULTS: Players covered â¼5.8kmmatch-1, with reduced distances in the second- versus first-half (p<0.001). For worst-case scenario total (â¼8-25%) and high-speed (â¼10-26%) distance, FIXED underestimated ROLL. In ROLL, worst-case scenario relative total and high-speed distances reduced from â¼144-161mmin-1 and â¼30-69mmin-1 over 60-s, to â¼8089mmin-1 and â¼516mmin-1 in the 600-s epoch, respectively. Forwards performed less high-speed running over all epochs and covered less total distance during epochs of 60-s, 180-s, 420-s and 480-s, compared with backs. Front row players typically returned the lowest locomotor demands. CONCLUSIONS: This is the first study reporting the positional and worst-case scenario demands of international women's rugby union, and indicates an underestimation in FIXED versus ROLL over 60-s to 600-s epochs. Knowledge of the most demanding periods of women's rugby union match-play facilitates training specificity by enabling sessions to be tailored to such demands.
Assuntos
Desempenho Atlético , Futebol Americano , Corrida , Adulto , Feminino , Sistemas de Informação Geográfica , Humanos , Adulto JovemRESUMO
Honey is a natural substance formed primarily of carbohydrates (~80%) which also contains a number of other compounds purported to confer health benefits when consumed. Due to its carbohydrate composition (low glycaemic index, mostly fructose and glucose), honey may theoretically exert positive effects when consumed before, during or after exercise. This review therefore appraised research examining the effects of honey consumption in combination with exercise in humans. Online database (PubMed, MEDLINE, SPORTDiscus) searches were performed, yielding 273 results. Following duplicate removal and application of exclusion criteria, nine articles were reviewed. Large methodological differences existed in terms of exercise stimulus, population, and the nutritional interventions examined. All nine studies reported biochemical variables, with four examining the effects of honey on exercise performance, whilst five described perceptual responses. Acute supplementation around a single exercise session appeared to elicit similar performance, perceptual, and immunological responses compared with other carbohydrate sources, although some performance benefit has been observed relative to carbohydrate-free comparators. When consumed over a number of weeks, honey may dampen immunological perturbations arising from exercise and possibly improve markers of bone formation. More well-controlled research is required to better understand the role for honey in a food-first approach to exercise nutrition.