RESUMO
Wellman, AD, Coad, SC, Flynn, PJ, Siam, TK, and McLellan, CP. A Comparison of preseason and in-season practice and game loads in NCAA Division I football players. J Strength Cond Res 33(4): 1020-1027, 2019-The aim of this study was to quantify the individual practice and game loads throughout the National Collegiate Athletic Association (NCAA) Division I football season to determine whether significant differences exist between the practice loads associated with the preseason training camp and those undertaken during the in-season period. Thirty-one NCAA Division I football players were monitored using the global positioning system and triaxial accelerometer (IA) (MinimaxX S5; Catapult Innovations, Melbourne, Australia) during 22 preseason practices, 36 in-season practices, and 12 competitions. The season was divided into 4 distinct phases for data analysis: preseason week 1 (preseason 1), preseason week 2 (preseason 2), preseason week 3 (preseason 3), and 12 in-season weeks. Individual IA data sets represented players from every offensive and defensive position group Wide Receiver (WR: n = 5), Offensive Line (OL: n = 4), Running Back (RB: n = 4), Quarterback (QB: n = 2), Tight End (TE: n = 3), Defensive Line (DL: n = 4), Linebacker (LB: n = 4), Defensive Back (DB: n = 5). Data were set at the practice level, where an observation for each player's maximum player load (PLMax) or mean player load (PLMean) from each training camp phase was referenced against each player's respective PL from each game, Tuesday, Wednesday, or Thursday practice session. Notable results included significantly (p ≤ 0.05) greater PLMax values attributed to preseason 1 compared with PL resulting from all in-season practices, and significantly (p ≤ 0.05) higher cumulative PL reported for preseason 1, 2, and 3 compared with every in-season week. Data from this study augment our understanding of the practice demands experienced by NCAA Division I college football players, and provide scope for the improvement of preseason practice design and physical conditioning strategies for coaches seeking to optimize performance.
Assuntos
Futebol Americano/fisiologia , Condicionamento Físico Humano/fisiologia , Esforço Físico , Prática Psicológica , Acelerometria , Adolescente , Sistemas de Informação Geográfica , Humanos , Masculino , Adulto JovemRESUMO
Wellman, AD, Coad, SC, Flynn, PJ, Siam, TK, and McLellan, CP. Perceived wellness associated with practice and competition in National Collegiate Athletic Association Division I football players. J Strength Cond Res 33(1): 112-124, 2019-This study assessed the influence of movement demands resulting from weekly practice sessions and games, on perceived wellness measurements taken postgame (Sunday) and 48 hours pregame (Thursday) throughout the in-season period in National Collegiate Athletic Association (NCAA) Division I football players. Thirty players were monitored using global positioning system receivers (OptimEye S5; Catapult Innovations) during 12 games and 24 in-season practices. Movement variables included low-intensity distance, medium-intensity distance, high-intensity distance, sprint distance, total distance, player load, and acceleration and deceleration distance. Perceived wellness, including fatigue, soreness, sleep quality and quantity, stress, and mood, was examined using a questionnaire on a 1-5 Likert scale. Multilevel mixed linear regressions determined the differential effects of movement metrics on perceived wellness. Post hoc tests were conducted to evaluate the pairwise differentials of movement and significance for wellness ratings. Notable findings included significantly (p ≤ 0.05) less player load, low-intensity distance, medium-intensity distance, high-intensity distance, total distance, and acceleration and deceleration distance at all intensities, in those reporting more favorable (4-5) ratings of perceived fatigue and soreness on Sunday. Conversely, individuals reporting more favorable Sunday-perceived stress ratings demonstrated significantly (p ≤ 0.05) higher player load, low-intensity and medium-intensity distance, total distance, low-intensity and medium-intensity deceleration distance, and acceleration distance at all intensities than individuals reporting less favorable (1-2) perceived stress ratings. Data from this study provide a novel investigation of perceived wellness associated with college football practice and competition. Results support the use of wellness questionnaires for monitoring perceived wellness in NCAA Division I college football players.
Assuntos
Futebol Americano , Nível de Saúde , Inquéritos e Questionários , Aceleração , Afeto , Desempenho Atlético , Desaceleração , Fadiga , Sistemas de Informação Geográfica , Humanos , Masculino , Modelos Estatísticos , Movimento , Mialgia , Universidades , Adulto JovemRESUMO
Wellman, AD, Coad, SC, Goulet, GC, and McLellan, CP. Quantification of accelerometer derived impacts associated with competitive games in National Collegiate Athletic Association division I college football players. J Strength Cond Res 31(2): 330-338, 2017-The aims of the present study were to (a) examine positional impact profiles of National Collegiate Athletic Association (NCAA) division I college football players using global positioning system (GPS) and integrated accelerometry (IA) technology and (b) determine if positional differences in impact profiles during competition exist within offensive and defensive teams. Thirty-three NCAA division I Football Bowl Subdivision players were monitored using GPS and IA (GPSports) during 12 regular season games throughout the 2014 season. Individual player data sets (n = 294) were divided into offensive and defensive teams, and positional subgroups. The intensity, number, and distribution of impact forces experienced by players during competition were recorded. Positional differences were found for the distribution of impacts within offensive and defensive teams. Wide receivers sustained more very light and light to moderate (5-6.5 G force) impacts than other position groups, whereas the running backs were involved in more severe (>10 G force) impacts than all offensive position groups, with the exception of the quarterbacks (p ≤ 0.05). The defensive back and linebacker groups were subject to more very light (5.0-6.0 G force) impacts, and the defensive tackle group sustained more heavy and very heavy (7.1-10 G force) impacts than other defensive positions (p ≤ 0.05). Data from the present study provide novel quantification of positional impact profiles related to the physical demands of college football games and highlight the need for position-specific monitoring and training in the preparation for the impact loads experienced during NCAA division I football competition.
Assuntos
Acelerometria/métodos , Futebol Americano/fisiologia , Sistemas de Informação Geográfica , Universidades , Humanos , Masculino , CorridaRESUMO
The aims of this study were to examine the movement demands of preseason practice in National Collegiate Athletic Association Division I college football players using portable global positioning system (GPS) technology and to assess perceived wellness associated with preseason practice to determine whether GPS-derived variables from the preceding day influence perceived wellness the following day. Twenty-nine players were monitored using GPS receivers (Catapult Innovations, Melbourne, Australia) during 20 preseason practices. Individual observations (n = 550) were divided into offensive and defensive position groups. Movement variables including low-, medium-, high-intensity, and sprint distance, player load, and acceleration and deceleration distance were assessed. Perceived wellness ratings (n = 469) were examined using a questionnaire which assessed fatigue, soreness, sleep quality, sleep quantity, stress, and mood. A 1-way analysis of variance for positional movement demands and multilevel regressions for wellness measures were used, followed by post hoc testing to evaluate the relational significance between categorical outcomes of perceived wellness scores and movement variables. Results demonstrated significantly (p ≤ 0.05) greater total, high-intensity, and sprint distance, along with greater acceleration and deceleration distances for the defensive back and wide receiver position groups compared with their respective offensive and defensive counterparts. Significant (p ≤ 0.05) differences in movement variables were demonstrated for individuals who responded more or less favorably on each of the 6 factors of perceived wellness. Data from this study provide novel quantification of the position-specific physical demands and perceived wellness associated with college football preseason practice. Results support the use of position-specific training and individual monitoring of college football players.
Assuntos
Futebol Americano/fisiologia , Futebol Americano/psicologia , Percepção , Corrida/fisiologia , Corrida/psicologia , Aceleração , Adolescente , Afeto , Austrália , Fadiga/epidemiologia , Sistemas de Informação Geográfica , Humanos , Masculino , Sono , Estresse Psicológico/epidemiologia , Universidades , Adulto JovemRESUMO
The aim of the present study was to examine the competitive physiological movement demands of National Collegiate Athletic Association (NCAA) Division I college football players using portable global positioning system (GPS) technology during games and to examine positional groups within offensive and defensive teams, to determine if a player's physiological requirements during games are influenced by playing position. Thirty-three NCAA Division I Football Bowl Subdivision football players were monitored using GPS receivers with integrated accelerometers (GPSports) during 12 regular season games throughout the 2014 season. Individual data sets (n = 295) from players were divided into offensive and defensive teams and subsequent position groups. Movement profile characteristics, including total, low-intensity, moderate-intensity, high-intensity, and sprint running distances (m), sprint counts, and acceleration and deceleration efforts, were assessed during games. A one-way ANOVA and post-hoc Bonferroni statistical analysis were used to determine differences in movement profiles between each position group within offensive and defensive teams. For both offensive and defensive teams, significant (p ≤ 0.05) differences exist between positional groups for game physical performance requirements. The results of the present study identified that wide receivers and defensive backs completed significantly (p ≤ 0.05) greater total distance, high-intensity running, sprint distance, and high-intensity acceleration and deceleration efforts than their respective offensive and defensive positional groups. Data from the present study provide novel quantification of position-specific physical demands of college football games and support the use of position-specific training in the preparation of NCAA Division I college football players for competition.
Assuntos
Futebol Americano/fisiologia , Sistemas de Informação Geográfica , Movimento/fisiologia , Esforço Físico/fisiologia , Corrida/fisiologia , Universidades , Aceleração , Acelerometria , Adolescente , Futebol Americano/classificação , Humanos , Adulto JovemRESUMO
Given the importance of ensuring athletes train and compete in a nonfatigued state, reliable tests are required to regularly monitor fatigue. The purpose of this study was to investigate the reliability of a cycle ergometer to measure peak power during short maximal sprint cycle efforts in running-based team sport athletes. Fourteen professional male Australian rules footballers performed a sprint cycle protocol during 3 separate trials, with each trial separated by 7 days. The protocol consisted of a standardized warm-up, a maximal 6-second sprint cycle effort, a 1-minute active recovery, and a second maximal 6-second sprint cycle effort. Peak power was recorded as the highest power output of the 2 sprint cycle efforts. Absolute peak power (mean ± SD) was 1502 ± 202, 1498 ± 191, and 1495 ± 210 W for trials 1, 2, and 3, respectively. The mean coefficient of variation, intraclass correlation coefficient, and SE of measurement for peak power between trials was 3.0% (90% confidence intervals [CIs] = 2.5-3.8%), 0.96 (90% CIs = 0.91-0.98), and 39 W, respectively. The smallest worthwhile change for relative peak power was 6.0%, which equated to 1.03 W·kg⻹. The cycle ergometer sprint test protocol described in this study is highly reliable in elite Australian rules footballers and can be used to track meaningful changes in performance over time, making it a potentially useful fatigue-monitoring tool.
Assuntos
Desempenho Atlético/fisiologia , Teste de Esforço/métodos , Fadiga Muscular/fisiologia , Corrida/fisiologia , Adolescente , Adulto , Futebol Americano/fisiologia , Humanos , Masculino , Reprodutibilidade dos Testes , Adulto JovemRESUMO
The aim of the present study was to examine the positional differences in physical performance measures of professional, semiprofessional, and junior elite rugby league match-play using portable Global Positioning Systems (GPSs). Twelve professional, 12 semiprofessional, and 18 junior elite male rugby league players were monitored during 5 regular-season competition matches using portable GPS software. The mean total distance traveled during professional (8,371 ± 897 m) and semiprofessional (7,277 ± 734 m) match-play was significantly (p < 0.05) greater than that traveled during elite junior (4,646 ± 978 m) match-play. Position-specific total distance traveled and distance traveled per minute of playing time were significantly (p < 0.05) less for junior elite backs (5,768 ± 765 m; 74 ± 11 m·min) and forwards (4,774 ± 564 m; 82 ± 5 m·min) in comparison to those in professional (backs: 8,158 ± 673 m; 101 ± 8 m·min and forwards: 8,442 ± 812 m; 98 ± 12 m·min) and semiprofessional (backs: 7,505 ± 765 m; 94 ± 8 m·min and forwards: 6,701 ± 678 m; 89 ± 8 m·min) match-play. Maximum running speed, maximum sprints, and total sprint distance traveled by professional players were all significantly (p < 0.05) greater than those traveled by junior elite players but not semiprofessional players during match-play. Professional backs and forwards performed significantly (p < 0.05) more maximum sprints and traveled greater total distance during match-play in comparison to semiprofessional and junior elite players. The present findings demonstrate minimal differences in the physical performance measures of professional and semiprofessional rugby league match-play. The position-specific performance characteristics of junior elite match-play indicate that current junior elite player-development pathways may not provide adequate preparation for players transitioning into professional competition.
Assuntos
Desempenho Atlético/fisiologia , Futebol Americano/fisiologia , Sistemas de Informação Geográfica , Análise e Desempenho de Tarefas , Adulto , Austrália , Humanos , Masculino , Corrida/fisiologia , Adulto JovemRESUMO
The purpose of this study was to investigate the relationship between the prematch and short-term postmatch neuromuscular responses to the intensity, number, and distribution of impacts associated with collisions during elite Rugby League match play. Twenty-two elite male Rugby League players were monitored during 8 regular season competition matches using portable global positioning system (GPS) technology. The intensity, number, and distribution of impact forces experienced by players during match play were recorded using integrated accelerometry. Peak rate of force development (PRFD), peak power (PP), and peak force (PF) were measured during a countermovement jump on a force plate 24 hours prematch, 30 minutes prematch, 30 minutes postmatch and then at 24-hour intervals for a period of 5 days postmatch. The change in the dependent variables at each sample collection time was compared with that at 24 hours prematch and 30-minute prematch measures. There were significant (p < 0.05) decreases in PRFD and PP up to 24 hours postmatch with PF significantly (p < 0.05) being decreased 30 minutes postmatch. Significant (p < 0.05) correlations were found between the total number of impacts and PRFD and PP 30 minutes postmatch. Impact zones 4 (7.1-8.0 G), 5 (>8.1-10.0 G), and 6 (>10.1 G) were significantly (p < 0.05) correlated to PRFD and PP 30 minutes postmatch with the number of zone 5 and 6 impacts significantly (p < 0.05) correlated to PRFD and PP 24 hours postmatch. Elite Rugby League match play resulted in significant neuromuscular fatigue and was highly dependent on the number of heavy collisions >7.1G. Results demonstrate that neuromuscular function is compromised for up to 48 hours postmatch indicating that at least 2 days of modified activity is required to achieve full neuromuscular recovery after elite Rugby League match play. Position-specific demands on energy systems and the influence of repeated blunt force trauma during collisions during elite Rugby League match play should be considered when planning postmatch recovery protocols and training activities to optimize subsequent performance.
Assuntos
Futebol Americano/fisiologia , Fadiga Muscular , Força Muscular , Músculo Esquelético/fisiologia , Ferimentos não Penetrantes/fisiopatologia , Aceleração , Adolescente , Adulto , Futebol Americano/lesões , Sistemas de Informação Geográfica , Humanos , Masculino , Monitorização Ambulatorial , Músculo Esquelético/lesões , Análise e Desempenho de Tarefas , Fatores de Tempo , Adulto JovemRESUMO
The purpose of this study was to investigate the relationship between the prematch and short-term postmatch biochemical and endocrine responses to the intensity, number, and distribution of impacts associated with collisions during elite Rugby League match play. Seventeen elite male Rugby League players each provided blood and saliva samples 24 hours prematch, 30 minutes prematch, 30 minutes postmatch, and then at 24-hour intervals for a period of 5 days postmatch to determine plasma creatine kinase concentration ([CK]) and salivary cortisol concentration ([sCort]). The intensity, number, and distribution of impact forces experienced by players during match play were recorded using portable global positioning systems (GPSs). The change in the dependent variables at each sample collection time was compared to 24 hours prematch and 30-minute prematch measures. The [CK] and [sCort] increased significantly (p < 0.05) during match play. Significant correlations (p < 0.05) were observed between the number of hit-ups and peak [CK] 24 hours postmatch, 48 hours postmatch, and 72 hours postmatch (p < 0.05). The number of impacts recorded in zone 5 (8.1-10.0G) and zone 6 (>10.1G) during match play was significantly correlated (p < 0.05) to [CK] 30 minutes postmatch, 24 hours post, 48 hours post, and 72 hours postmatch. The GPS was able to provide data on the intensity, number, and distribution of impacts resulting from collisions during match play. Elite Rugby League match play resulted in significant skeletal muscle damage and was highly dependent on the number of heavy collisions >8.1G. [CK] remained elevated 120 hours postmatch identifying that at least 5 days modified activity is required to achieve full recovery after elite Rugby League match play.
Assuntos
Futebol Americano/fisiologia , Hidrocortisona/fisiologia , Músculo Esquelético/lesões , Adolescente , Adulto , Atletas , Creatina Quinase Forma MM/sangue , Humanos , Hidrocortisona/análise , Hidrocortisona/sangue , Masculino , Músculo Esquelético/enzimologia , Saliva/química , Ferimentos não Penetrantes/sangue , Adulto JovemRESUMO
The purpose of this study was to examine a) the relationship between rate of force development (RFD) and vertical jump (VJ) performance during a counter movement jump (CMJ), and b) the reliability of RFD recorded during the CMJ and squat jump (SJ) forms of the VJ. Twenty-three physically active men aged 23 ± 3.9 years participated in the study. Subjects completed 3 unloaded CMJ and 3 unloaded SJ in random order on a force plate. The RFD was measured during CMJ and SJ movements with vertical jump displacement (VJD) measured simultaneously during the CMJ only. Subjects incorporated arm swing to their CMJ technique to reach up as high as possible, and VJD was measured. All SJ were executed with both hands on the hips throughout the full range of movement. Peak rate of force development (PRFD), peak force (PF), and time to peak force (TPF) were significantly correlated to VJD during the CMJ (r = 0.68, r = 0.51, and r = -0.48, respectively). The RFD and TPF during the CMJ and SJ were associated with low test-retest reliability (coefficient of variation [CV]: 11.8-7.9%). Peak and average power, PF, and VJD produced high test-retest reliability (CV: 2.8-5.1%) during both the CMJ and SJ movements. Our results indicate that PRFD, a measure of explosive strength, and PF, a measure of maximal strength, are the primary contributors to VJD during the CMJ in physically active men. However, caution must be used when interpreting data using PRFD because of its low retest reliability.
Assuntos
Contração Muscular/fisiologia , Força Muscular/fisiologia , Atletismo/fisiologia , Adulto , Humanos , Cinética , Masculino , Músculo Esquelético/fisiologia , Resistência Física/fisiologia , Valores de Referência , Reprodutibilidade dos Testes , Estresse Mecânico , Análise e Desempenho de Tarefas , Adulto JovemRESUMO
The aim of the present study was to identify neuromuscular, biochemical, and endocrine markers of fatigue after Rugby League match play. Seventeen elite Rugby League players were monitored for a single match. Peak rate of force development (PRFD), peak power (PP), and peak force (PF) were measured during a countermovement jump (CMJ) on a force plate pre and postmatch play. Saliva and blood samples were collected 24 hours prematch, 30 minutes prematch, 30 minutes postmatch, and then at 24-hour intervals for a period of 120 hours to determine plasma creatine kinase concentration ([CK]) and salivary cortisol concentration ([sCort]). There were significant (p < 0.05) decreases in PRFD and PP up to 24 hours postmatch with PF significantly (p < 0.05) decreased immediately postmatch. The [sCort] significantly (p < 0.05) increased from 24 hours prematch to 30 minutes prematch and up to 24 hours postmatch compared with 24 hours prematch. Plasma [CK] significantly (p < 0.05) increased 30 minutes postmatch with a peak occurring 24 hours postmatch and remained elevated above 24 hours prematch for at least 120 hours postmatch. There were significant (p < 0.05) correlations between the increase in [CK] and reduction in PRFD 30 minutes postmatch and 24 hours postmatch. The [sCort] was significantly (p < 0.05) correlated with the reduction in PF 30 minutes postmatch. Results demonstrate that neuromuscular function is compromised for up to 48 hours after match play. Elevated [CK] despite 120-hour recovery indicate that damage to muscle tissue after Rugby League match play may persist for at least 5 days postmatch. Despite the prolonged presence of elevated [CK] postmatch, strength training 48 hours postmatch may have resulted in a compensatory increase in PRFD supporting the inclusion of strength training during the short-term postmatch recovery period.
Assuntos
Futebol Americano/fisiologia , Fadiga Muscular/fisiologia , Adolescente , Biomarcadores/sangue , Creatina Quinase/sangue , Humanos , Hidrocortisona/análise , Masculino , Treinamento Resistido , Saliva/química , Adulto JovemRESUMO
The aim of this study was (a) to examine the physiological demands of competitive Rugby League match play using portable Global Positioning Systems (GPSs) to monitor players' movement patterns and heart rate (HR) and (b) examine positional comparisons to determine if players' physiological requirements are influenced by their playing position during Rugby League match play. Twenty-two elite male Rugby League players were monitored during 5 regular season competition matches using portable GPS software. There was no difference in the total distance traveled between backs (5,573 ± 1,128 m) and forwards (4,982 ± 1,185 m) during match play. Backs and forwards had an average HR of approximately 80% of their maximum (162 ± 11 and 165 ± 12 b · min(-1), respectively) throughout each match. Backs achieved greater maximum running speed (8.6 ± 0.7 m · s(-1)), completed a greater number of sprints (18 ± 6), had less time between sprints (3.2 ± 1.1 minutes), achieved a greater total duration of sprinting (44.7 ± 9.1 seconds), and covered more distance sprinting (321 ± 74 m) than forwards did (6.8 ± 0.7 m · s(-1), 11 ± 5, 5.2 ± 2.2 minutes, 25.8 ± 9.2 seconds, and 153 ± 38 m, respectively). The GPS successfully provided real-time feedback to identify significant positional differences in distances covered, running speed characteristics, and the physiological demands of competitive Rugby League match play.
Assuntos
Desempenho Atlético/fisiologia , Futebol Americano/fisiologia , Sistemas de Informação Geográfica , Análise e Desempenho de Tarefas , Adolescente , Adulto , Atletas , Frequência Cardíaca/fisiologia , Humanos , Masculino , Corrida/fisiologia , Adulto JovemRESUMO
Lovell, DI, Mason, DG, Delphinus, EM, and McLellan, CP. Do compression garments enhance the active recovery process after high-intensity running? J Strength Cond Res 25(12): 3264-3268, 2011-This study examined the effect of wearing waist-to-ankle compression garments (CGs) on active recovery after moderate- and high-intensity submaximal treadmill running. Twenty-five male semiprofessional rugby league players performed two 30-minute treadmill runs comprising of six 5-minute stages at 6 km·h, 10 km·h, approximately 85% VO(2)max, 6 km·h as a recovery stage followed by approximately 85% VO(2)max and 6 km·h wearing either CGs or regular running shorts in a randomized counterbalanced order with each person acting as his own control. All stages were followed by 30 seconds of rest during which a blood sample was collected to determine blood pH and blood lactate concentration [La]. Expired gases and heart rate (HR) were measured during the submaximal treadmill tests to determine metabolic variables with the average of the last 2 minutes used for data analysis. The HR and [La] were lower (p ≤ 0.05) after the first and second 6 km·h recovery bouts when wearing CGs compared with when wearing running shorts. The respiratory exchange ratio (RER) was higher and [La] lower (p ≤ 0.05) after the 10 km·h stage, and only RER was higher after both 85% VO(2)max stages when wearing CGs compared with when wearing running shorts. There was no difference in blood pH at any exercise stage when wearing the CGs and running shorts. The results of this study indicate that the wearing of CGs may augment the active recovery process in reducing [La] and HR after high-intensity exercise but not effect blood pH. The ability to reduce [La] and HR has important consequences for many sports that are intermittent in nature and consist of repeated bouts of high-intensity exercise interspersed with periods of low-intensity exercise or recovery.
Assuntos
Vestuário , Ácido Láctico/sangue , Corrida/fisiologia , Equipamentos Esportivos , Adulto , Teste de Esforço , Frequência Cardíaca , Humanos , Concentração de Íons de Hidrogênio , Masculino , Consumo de Oxigênio , Esforço Físico , Descanso/fisiologia , Adulto JovemRESUMO
The purpose of the present study was to (a) examine player-movement patterns to determine total distance covered during competitive Rugby League match play using global positioning systems (GPSs) and (b) examine pre, during, and postmatch creatine kinase (CK) and endocrine responses to competitive Rugby League match play. Seventeen elite rugby league players were monitored for a single game. Player movement patterns were recorded using portable GPS units (SPI-Pro, GPSports, Canberra, Australia). Saliva and blood samples were collected 24 hours prematch, 30 minutes prematch, 30 minutes postmatch, and then at 24-hour intervals for a period of 5 days postmatch to determine plasma CK and salivary testosterone, cortisol, and testosterone:cortisol ratio (T:C). The change in the dependent variables at each sample collection time was compared to 24-hour prematch measures. Backs and forwards traveled distances 5,747 ± 1,095 and 4,774 ± 1,186 m, respectively, throughout the match. Cortisol and CK increased significantly (p < 0.05) from 30 minutes prematch to 30 minutes postmatch. Creatine kinase increased significantly (p < 0.05) postmatch, with peak CK concentration measured 24 hours postmatch (889.25 ± 238.27 U·L). Cortisol displayed a clear pattern of response with significant (p < 0.05) elevations up to 24 hours postmatch, compared with 24 hours prematch. The GPS was able to successfully provide data on player-movement patterns during competitive rugby league match play. The CK and endocrine profile identified acute muscle damage and a catabolic state associated with Rugby League match play. A return to normal T:C within 48 hours postmatch indicates that a minimum period of 48 hours is required for endocrine homeostasis postcompetition. Creatine kinase remained elevated despite 120 hours of recovery postmatch identifying that a prolonged period of at least 5 days modified activity is required to achieve full recovery after muscle damage during competitive Rugby League match play.
Assuntos
Creatina Quinase/sangue , Futebol Americano/fisiologia , Hidrocortisona/sangue , Testosterona/sangue , Atletas , Creatina Quinase/fisiologia , Sistemas de Informação Geográfica , Humanos , Hidrocortisona/análise , Hidrocortisona/fisiologia , Masculino , Atividade Motora/fisiologia , Esforço Físico/fisiologia , Saliva/química , Testosterona/análise , Testosterona/fisiologia , Fatores de Tempo , Adulto JovemRESUMO
OBJECTIVE: To quantify the effects of acute hypoxic exposure on exercise capacity and performance, which includes continuous and intermittent forms of exercise. DESIGN: A systematic review was conducted with a three-level mixed effects meta-regression. The ratio of means method was used to evaluate main effects and moderators providing practical interpretations with percentage change. DATA SOURCES: A systemic search was performed using three databases (Google scholar, PubMed and SPORTDiscus). Eligibility criteria for selecting studies: Inclusion was restricted to investigations that assessed exercise performance (time trials (TTs), sprint and intermittent exercise tests) and capacity (time to exhaustion test, TTE) with acute hypoxic (<24â h) exposure and a normoxic comparator. RESULTS: Eighty-two outcomes from 53 studies (N = 798) were included in this review. The results show an overall reduction in exercise performance/capacity -17.8 ± 3.9% (95% CI -22.8% to -11.0%), which was significantly moderated by -6.5 ± 0.9% per 1000 m altitude elevation (95% CI -8.2% to -4.8%) and oxygen saturation (-2.0 ± 0.4%; 95% CI -2.9% to -1.2%). TT (-16.2 ± 4.3%; 95% CI -22.9% to -9%) and TTE (-44.5 ± 6.9%; 95% CI -51.3% to -36.7%) elicited a negative effect, whilst indicating a quadratic relationship between hypoxic magnitude and both TTE and TT performance. Furthermore, exercise less than 2 min exhibited no ergolytic effect from acute hypoxia. Summary/Conclusion: This review highlights the ergolytic effect of acute hypoxic exposure, which is curvilinear for TTE and TT performance with increasing hypoxic levels, but short duration intermittent and sprint exercise seem to be unaffected.
Assuntos
Altitude , Desempenho Atlético/fisiologia , Exercício Físico/fisiologia , Hipóxia , Teste de Esforço , Humanos , Oxiemoglobinas/análise , Ensaios Clínicos Controlados Aleatórios como Assunto , Análise de RegressãoRESUMO
BACKGROUND: Rugby union is a collision-based ball sport played at the professional level internationally. Rugby union has one of the highest reported incidences of injury of all team sports. PURPOSE: To identify the characteristics, incidence, and severity of injuries occurring in Australian professional Super Rugby Union. DESIGN: Descriptive epidemiology study. METHODS: The present study was a prospective epidemiology study on a cohort of 180 professional players from 5 Australian Super Rugby teams during the 2014 Super Rugby Union Tournament. Team medical staff collected and submitted daily training and match-play injury data through a secure, web-based electronic platform. The injury data included the main anatomic location of the injury, specific anatomic structure of the injury, injury diagnosis, training or match injury occurrence, main player position, mechanism of injury, and the severity of the injury quantified based on the number of days lost from training and/or competition due to injury. RESULTS: The total combined incidence rate for injury during training and match-play across all Australian Super Rugby Union teams was 6.96 per 1000 hours, with a mean injury severity of 37.45 days lost from training and competition. The match-play injury incidence rate was 66.07 per 1000 hours, with a mean severity of 39.80 days lost from training and competition. No significant differences were observed between forward- and back-playing positions for match or training injury incidence rate or severity. CONCLUSION: The incidence of injury for the present study was lower during match-play than has previously been reported in professional rugby union; however, the overall time loss was higher compared with previous studies in professional rugby union. The high overall time loss was due fundamentally to a high incidence of injuries with greater than 28 days' severity.