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1.
Apunts, Med. esport (Internet) ; 55(206): 53-61, abr.-jun. 2020. graf, tab
Artigo em Inglês | IBECS | ID: ibc-ET2-5892

RESUMO

This study examines the effects of two strength training (ST) programs, one based on mean propulsive velocity (MPV) and another under the traditional method, the % one-repetition maximum (1RM), on neuromuscular performance and muscle composition in girls who play soccer. Fifty players with an average age of 13.6 ± 1.2 years participated in the study and were randomly assigned into three groups: a maximal execution velocity training group (VG, n = 15), a maximal strength group (RMG, n = 13), and a control group (CG, n = 18). The study was developed for a period of twelve weeks during regular team training to prepare for the season. The VG and RMG groups performed additional strength or muscle power training three times a week, including movements of full squat and pedaling on a cycle ergometer. The two types of training groups and the control group exhibited significant gains. However, the greatest increases were achieved with VG training, with significant increases (p < 0.000) in maximal strength, (p < 0.000) squat power, (p < 0.000) velocity over 30 m, (p < 0.000) cycle ergometer power, and (p < 0.008) lower limb muscle mass. Statistically significant differences were observed between VG and RMG in countermovement jump (CMJ) (p < 0.008) and squat power (p < 0.01) tests, between VG and CG in CMJ (p < 0.01), squat power (p < 0.000), and maximal squat strength (p < 0.000), and between RMG and CG in maximal squat strength (p < 0.000) only. These findings might indicate that high-velocity ST can be performed simultaneously with regular training to improve the explosive actions of soccer players


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Assuntos
Humanos , Feminino , Criança , Adolescente , Desempenho Atlético/fisiologia , Futebol/fisiologia , Força Muscular/fisiologia , Treinamento Intervalado de Alta Intensidade/métodos , Junção Neuromuscular/fisiologia , Análise de Variância , Treinamento de Resistência/métodos
2.
Int J Sports Med ; 41(8): 552-557, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32289840

RESUMO

This study examined whether professional footballers with previous biceps femoris long head (BFLH) injury in the last 3-years present a smaller proximal aponeurosis (Apo-BFLH) size compared to footballers with no previous injury. We examined the Apo-BFLH and BFLH size using magnetic resonance imaging and tested the knee flexor maximal isometric strength in 80 thighs of 40 footballers. Apo-BFLH size parameters were processed using a semi-automated procedure. Outcomes were compared between thighs with (n=9) vs. without (n=71) previous BFLH injury. No differences were observed between injured and non-injured thighs for the Apo-BFLH and BFLH size parameters (p>0.05) except for Apo-BFLH volume, which was higher in the non-injured thighs of athletes with previous injury (3692.1±2638.4 mm3, p<0.006) compared to the left (2274.1±798.7 mm3) thighs of athletes without previous injury. A higher knee flexor isometric strength was observed in the injured limb of athletes with previous BFLH injury (196.5±31.9 Nm, p<0.003) compared to the left (156.2±31.4 Nm) and right (160.0±31.4 Nm) thighs of non-injured athletes. The present results suggest that BFLH proximal aponeurosis size should not be considered as an independent risk factor for strain injury.


Assuntos
Aponeurose/anatomia & histologia , Músculos Isquiossurais/anatomia & histologia , Músculos Isquiossurais/lesões , Futebol/lesões , Futebol/fisiologia , Entorses e Distensões/epidemiologia , Adulto , Estudos Transversais , Músculos Isquiossurais/fisiologia , Humanos , Contração Isométrica , Masculino , Força Muscular/fisiologia , Fatores de Risco , Adulto Jovem
3.
PLoS One ; 15(4): e0232123, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32324801

RESUMO

The purpose of the present study was to: (a) assess centripetal force (CentF) and changes of direction (COD) in elite soccer players according to playing position (central defender, CD; lateral defender, LD; central midfielder, CM; lateral midfielder, LM; forward, FW), laterality (right-footed vs. left-footed) and field zone (central vs. lateral), and (b) analyze the relationship between anthropometric characteristics (age, weight, height, body mass and fat mass) and non-linear locomotion workload. Thirty professional soccer players (age: 26.57±5.56 years) were tracked during the 2017-2018 season during friendly, national and international matches (38 total games) using inertial measurement devices. CentF and COD were the variables extracted for analysis. A one-way ANOVA was used for playing position comparison, a t-test for laterality and field zone, and Pearson's correlation coefficient to analyze relationships between anthropometric characteristics and dependent variables. There were differences by playing position in COD (556.33-to-412.18), R20COD (484.36-to-354.81) and R60COD (48.38-to-38.61) (p < .01; ωp2 = 0.03-to-0.05; CD>CM>LD>LM = FW); in CODHIA (49.75-to-37.11), R20CODHIA (16.04-to-9.11) and R60CODHIA (10.64-to-9.11) (p < .01; ωp2 = 0.03-to-0.07; CM>FW>LM>CD = LD); in CODSPRINT (14.56-to-8.40) and R20CODSPRINT (3.29-to-1.40) (p < .01; ωp2 = 0.03-to-0.04; FW = LM = CM>CD = LD); and in CentFMAX both in clockwise (992.04-to-902.09N) and counterclockwise (999.24-to-872.61N) directions (p < .02; ωp2 = 0.02-to-0.07; FW = CD>CM = LM = LD). The highest values of counterclockwise CentF were performed by left-footed players in the central zone (p < .001; d = 0.71-to-1.44) and clockwise CentF by right-footed players (p < .001; d = 0.04-to-0.55) in the lateral field zone. Moderate correlations were found between age, body mass and high intensity/sprints COD and repeated COD ability (p < .05; r = 0.235-to-0.383). Therefore, team staff should consider anthropometric characteristics, playing position, laterality and field zone to individualize training workload related to non-linear locomotion in soccer.


Assuntos
Desempenho Atlético/fisiologia , Lateralidade Funcional/fisiologia , Futebol/fisiologia , Acelerometria , Adulto , Antropometria , Europa (Continente) , Humanos , Estudos Longitudinais , Masculino , Adulto Jovem
4.
J Sports Sci ; 38(9): 1053-1061, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32290783

RESUMO

The study aim was to investigate ball movement patterns using network analysis techniques, to compare between successful and unsuccessful outcomes and teams in the Australian Football League (AFL). This analysis focused on possession chains starting from a kick-in (n = 1,720), drawn from all games played in the 2015 AFL Premiership season (18 teams, 206 games). Player interactions were quantified using four network metrics: cluster coefficient, degree centrality, network density, and entropy. Three-way ANOVA with Tukey post hoc and ω2 effect sizes were calculated to assess whether differences existed between kick-in outcomes, ladder brackets, and match outcomes for each network metric. No significant differences were observed between ladder brackets or match outcomes for any network metric. More successful kick-in chains were characterised by lower density (ω2 = 0.26, large effect; F(9, 1678) = 66.6, p < 0.00) and higher entropy (ω2 = 0.17, large effect; F(9, 1678) = 39.6, p < 0.00). This suggests that chains resulting in successful kick-in outcomes exhibited lower interconnectedness, with a high number of players involved, and lower predictability in ball movement patterns. These findings have practical value for coaches and performance analysts and support further applications of network analysis in Australian football.


Assuntos
Desempenho Atlético/fisiologia , Comportamento Competitivo/fisiologia , Futebol/fisiologia , Austrália , Processos Grupais , Humanos , Movimento , Equipamentos Esportivos , Análise e Desempenho de Tarefas
5.
PLoS One ; 15(3): e0230068, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32191716

RESUMO

The aim of this study was to analyse and quantify the acute effects of competition on several performance factors in under-19 male soccer players. To this end, 198 national league players (17.56 ± 0.78 years) performed various tests to measure jump capacity, kicking velocity and sprint times immediately pre-match (T1), at half-time (T2) and post-match (T3). Tests included kicking the ball to measure ball velocity (KICK), sprinting for 40 meters, timing the first 30 meters (30mACCEL), the last 10 meters (10mACCEL) and the total distance (40mACCEL), and performing countermovement jumps (CMJ). For subsequent analysis, the sample was divided into 5 playing positions: goalkeepers (n = 24), defenders (n = 51), midfielders (n = 36), wingers (n = 54) and forwards (n = 33). For all positions, we found a significant decline in performance (p<0.05) for kicking velocity (2.91% - 6.51%) and sprinting (0.44%-5.85%). For the CMJ, all positions except defenders presented a significant decline in performance that ranged from 1.5% to 4.56%. These findings highlight the need to individualise fitness training, taking into account the match needs and demands of the different playing positions in order to minimise the effects of match fatigue and accelerate post-match recovery.


Assuntos
Desempenho Atlético/fisiologia , Comportamento Competitivo/fisiologia , Exercício Físico , Corrida , Futebol/fisiologia , Futebol/psicologia , Análise e Desempenho de Tarefas , Adolescente , Humanos , Masculino
6.
J Sports Med Phys Fitness ; 60(3): 329-337, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32197040

RESUMO

BACKGROUND: An association between training load and changes in aerobic fitness has been established but the effect of training load on changes in strength/power remains controversial. METHODS: Internal (Banister's TRIMP) and external (total distance, high-speed running and sprint distance) training load was collected from sixteen professional soccer players during and aerobic fitness and strength/power variables were measured before and after a 9-week pre-season. RESULTS: Banister's TRIMP had a moderate correlation with changes in maximal oxygen uptake (r=0.46, 90% CI: 0.04; 0.74). Total distance had a large and a moderate correlation with changes in velocity at 2M (r=0.60, 90% CI: 0.23; 0.82) and changes in velocity at 4M (r=0.42, 90% CI: -0.01; 0.72). High-speed running had moderate correlations with changes in maximal oxygen uptake (r=0.45, 90% CI: 0.03; 0.74), velocity at 2M (r=0.45, 90% CI: 0.03; 0.74) and velocity at 4M (r=0.39, 90% CI: -0.00; 0.70). Sprint distance had a large and a moderate correlation with changes in maximal oxygen uptake (r=0.58, 90% CI: 0.20; 0.81) and velocity at 4M (r=0.46, 90% CI: 0.00; 0.74 respectively). High versus low total distance was associated with lower changes in squat jump and countermovement jump (ES=-0.90, 90% CI: -1.57; -0.24 and ES=-1.06, 90% CI: -1.89; -0.24) respectively. High versus low high-speed running was associated with higher changes in maximal oxygen uptake (ES=0.36, 90% CI: 0.02; 0.70) but lower changes in squat jump (ES=-0.58, 90% CI: -1.32; 0.15). CONCLUSIONS: External rather internal training load had more pronounced correlations with changes in aerobic fitness. Higher compared with lower volumes of total distance and high-speed running were associated with lower gains in strength/power indices. Establishing a "dose-response" association between external/internal training load and endurance as well as strength adaptations, may maximize endurance gains with the least possible interference on strength/power gains, thus better informing soccer training practice.


Assuntos
Futebol/fisiologia , Adaptação Fisiológica , Adulto , Desempenho Atlético , Humanos , Masculino , Força Muscular , Corrida , Estações do Ano , Adulto Jovem
7.
J Sports Sci ; 38(7): 827-837, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32149566

RESUMO

Purpose: This study determined the impact of menstrual status on bone tissue in elite post-pubertal female soccer players over an entire season.Methods: Fifty-one elite female soccer players participated. At baseline, forty-one were assigned to the low hormonal androgenic profile (low-HAPL) and 10 to the high hormonal androgenic profile (high-HAPL).Results: An 8-month training program led to increased bone mineral density content (p<0.05). The low-HAPL athletes improved the Narrow neck average cortical thickness (ACT) by 1.4% and reduced the corresponding Buckling ratio (BR) by 2.6%, thus decreasing the fracture risk (p<0.05). The high-HAPL athletes decreased the Narrow neck ACT by 5.4% and increased the BR by 2.6%, increasing fracture risk (p<0.05). Differences were assigned as being "very likely beneficial" for the low-HAPL athletes, supported by very large (d=3.41) and large (d=1.58) effect sizes for the Narrow neck ACT and BR, respectively.Conclusion: A season of soccer training has induced bone geometry improvements in adolescent females. Bone health parameters improved in the two clusters. However, high-HAPL athletes decreased its resistance to loading compare to low-HAPL athletes. Even if female players do not present clinical symptoms related to their hormonal status, sport medicine physicians should pay attention to their structural bone fragility.


Assuntos
Densidade Óssea/fisiologia , Hormônio Foliculoestimulante/sangue , Hormônios Esteroides Gonadais/sangue , Hormônio Luteinizante/sangue , Menstruação/fisiologia , Condicionamento Físico Humano , Futebol/fisiologia , Adolescente , Biomarcadores/sangue , Estudos Transversais , Feminino , Quadril/anatomia & histologia , Humanos , Adulto Jovem
8.
Int J Sports Med ; 41(6): 391-397, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32162295

RESUMO

This study aimed to examine the effects of different sled overloads on maximum sprint velocity achieved by female soccer players with different strength, speed, and power levels. Twenty elite female soccer players from the same club participated. On the same day, athletes performed: linear and resisted-sprint tests with 30 and 60 % of body-mass over 5-, 10-, and 20-m; half-squat maximum bar-power output, and half-squat one-repetition maximum assessment. A median split analysis was used to divide players into two groups according to their velocity, half-squat one-repetition maximum, and half-squat power. Differences in percentage decreases between unresisted- and resisted-sprints comparing higher and lower groups were analyzed using magnitude-based inferences. Overall, the stronger, faster, and more powerful players were less affected by both loads, as demonstrated by their lower decreases in velocity over the different distances. However, half-squat power appeared to be more sensitive for indicating impairments in resisted-sprint performance, due to meaningful differences in percentage decreases observed between higher and lower power groups. Notably, overloads of 30 and 60% of body-mass provoked substantial reductions in resisted-sprint velocity (~22.9% for 30% and ~51.4% for 60% of body-mass, relative to unresisted-sprint velocity). Athletes with superior power levels are less affected by the progressive sled overloading.


Assuntos
Desempenho Atlético/fisiologia , Treinamento de Resistência/métodos , Futebol/fisiologia , Adulto , Índice de Massa Corporal , Estudos Transversais , Feminino , Humanos , Força Muscular/fisiologia , Corrida/fisiologia , Suporte de Carga/fisiologia , Adulto Jovem
9.
J Sports Sci ; 38(8): 848-854, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32122261

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 Jovem
10.
J Sports Sci ; 38(9): 1070-1076, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32174252

RESUMO

The purpose of this study was to quantify possible differences in sprint mechanical outputs in soccer according to soccer playing standard, position, age and sex. Sprint tests of 674 male and female players were analysed. Theoretical maximal velocity (v0), horizontal force (F0), horizontal power (Pmax), force-velocity slope (SFV), ratio of force (RFmax) and index of force application technique (DRF) were calculated from anthropometric and spatiotemporal data using an inverse dynamic approach applied to the centre-of-mass movement. Players of higher standard exhibited superior F0, v0, Pmax, RFmax and DRF scores (small to large effects) than those of lower standard. Forwards displayed clearly superior values for most outputs, ahead of defenders, midfielders and goalkeepers, respectively. Male >28 y players achieved poorer v0, Pmax and RFmax than <20, 20-24 and 24-28 y players (small to moderate), while female <20 y players showed poorer values than 20-24 and >24 y players for the same measures (small). The sex differences in sprint mechanical properties ranged from small to very large. These results provide a holistic picture of the force-velocity-power profile continuum in sprinting soccer players and serve as useful background information for practitioners when diagnosing individual players and prescribing training programmes.


Assuntos
Desempenho Atlético/fisiologia , Corrida/fisiologia , Futebol/fisiologia , Aceleração , Adulto , Fatores Etários , Feminino , Humanos , Masculino , Condicionamento Físico Humano , Caracteres Sexuais , Adulto Jovem
11.
J Sports Sci ; 38(6): 658-668, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32009533

RESUMO

Visual exploratory action, in which football players turn their head to perceive their environment, improves prospective performance with the ball during match-play. This scanning action, however, is relevant for players throughout the entire match, as the information perceived through visual exploration is needed to guide movement around the pitch during both offensive and defensive play. This study aimed to understand how a player's on-pitch position, playing role and phase of play influenced the visual exploratory head movements of players during 11v11 match-play. Twenty-two competitive-elite youth footballers (M = 16.25 years) played a total of 1,623 minutes (M = 73.8). Inertial measurement units, global positioning system units and notational analysis were used to quantify relevant variables. Analyses revealed that players explored more extensively when they were in possession of the ball, and less extensively during transition phases, as compared to team ball-possession and opposition ball-possession phases of play. Players explored most extensively when in the back third of the pitch, and least when they were in the middle third of the pitch. Playing role, pitch position and phase of play should be considered as constraints on visual exploratory actions when developing training situations aimed at improving the scanning actions of players.


Assuntos
Comportamento Competitivo/fisiologia , Futebol/psicologia , Percepção Visual/fisiologia , Adolescente , Criança , Sistemas de Informação Geográfica , Cabeça/fisiologia , Humanos , Masculino , Movimento , Futebol/fisiologia , Análise e Desempenho de Tarefas
12.
J Sports Sci ; 38(6): 676-681, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32028853

RESUMO

The aim of this study was to assess if tactical and technical performance indicators (PIs) could be used in combination to model match outcomes in Australian Football (AF). A database of 101 technical PIs and 14 tactical PIs from every match in the 2009-2016 Australian Football League (AFL) seasons was merged. Two outcome measures Win-loss and Score margin were used as dependent variables. The top 45 ranked technical and tactical PIs from a feature selection process were used to model match outcome using decision tree and Generalised Linear Models (GLMs). Of the top 45 selected features, this included seven tactical PIs. The Win-loss-based Decision tree model achieved a classification accuracy of 89.0% and GLM 93.2%. A Score margin-based GLM achieved a root mean squared error (RMSE) of 6.9 points. A combined approach to the classification of match outcomes provided no improvement in model accuracy compared with previous literature. However, this study has established the relative importance of technical and tactical measures of performance in relation to successful team performance in AF.


Assuntos
Desempenho Atlético/fisiologia , Comportamento Competitivo/fisiologia , Árvores de Decisões , Modelos Lineares , Futebol/fisiologia , Austrália , Humanos , Análise e Desempenho de Tarefas
13.
Int J Sports Med ; 41(8): 528-532, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32059247

RESUMO

The purpose of this study was to examine the effect of a 4-week off-season period (transition period) on the anthropometric and performance parameters in elite female soccer players who participated in the UEFA women's Champions league. Eighteen female players (age 23.6±4.3 years) underwent testing at the end of the competitive period and right after the transition period. An incremental cardiopulmonary testing, body composition assessment and isokinetic testing at 60 °/sec were performed on both occasions. The cardiopulmonary exercise testing revealed that VO2max (p=0.001) and time on the treadmill (p=0.000) were significantly reduced after the transition period that included a 2 times/week exercise regimen. Furthermore, the quadriceps torque production at 60 °/s was significantly reduced for both the right (p=0.013) and left quadriceps (p=0.004) following the transition period. Finally, body weight (p=0.001) and body fat (p=0.000) significantly increased after 4 weeks of significantly reduced training volume. It is concluded that the transition period negatively affected the anthropometric and performance parameters of the female players. These data maybe informative for coaches and trainers as they demonstrate that despite the efforts to keep the players physically active the performance parameters decreased significantly.


Assuntos
Desempenho Atlético/fisiologia , Distribuição da Gordura Corporal , Peso Corporal , Comportamento Competitivo/fisiologia , Força Muscular , Consumo de Oxigênio , Futebol/fisiologia , Adulto , Feminino , Humanos , Extremidade Inferior/fisiologia , Condicionamento Físico Humano , Corrida/fisiologia , Fatores de Tempo , Adulto Jovem
14.
J Sports Med Phys Fitness ; 60(1): 1-10, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32008309

RESUMO

BACKGROUND: The purpose of this study was twofold: 1) to characterize a common microcycle considering both internal and external training loads; and 2) to identify the effects of small-sided games (SSGs) and of power and strength training on the fitness status of football players. METHODS: Fifteen male football players (age: 18.55±0.39 years) participated in this study. Ninety-two consecutive training sessions were monitored and analyzed over a period of nineteen weeks. Rating of perceived exertion (RPE ) was used as an internal load marker, and the distances covered at different speed thresholds and accelerations/decelerations were used as external load markers to characterize the common microcycle. Participants' body composition, vertical jumping ability, maximal strength, speed, and agility were assessed twice before and after the training monitoring process. RESULTS: The results revealed that match day -5 (MD-5) and MD-1 were associated with the lowest RPE scores (4.2 and 3.8 A.U., respectively). MD-4 and MD-3 were associated with the highest RPE values (9.2 and 8.8 A.U., respectively). Meaningful changes in RPE were found between training days. External load monitoring revealed that MD-4 had the highest values of accelerations and decelerations >2 m/s2/min (4.22 and 3.17, respectively) and MD-3 had the highest values of distance covered at high intensity (6.11 m/s2/min). Meaningful moderate improvements in jumping performance (d=0.90) and maximal strength parameters (d=0.83) were also found between assessments. CONCLUSIONS: It was identified that the concurrent approach had meaningful impacts on the fitness development of players and should be considered by coaches for future training interventions.


Assuntos
Esforço Físico/fisiologia , Aptidão Física/fisiologia , Treinamento de Resistência/métodos , Futebol/fisiologia , Aceleração , Adolescente , Desaceleração , Humanos , Masculino , Corrida/fisiologia
15.
J Sports Sci ; 38(5): 568-575, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32019482

RESUMO

This study aimed to assess the effect of playing surface (Natural [NT] and Artificial [AT] Turf) on the fatigue response to a soccer-specific exercise protocol (SSEP). Eighteen male soccer players completed the SSEP on NT and AT with pre-, post-, and 48 h post-assessments of eccentric knee flexor (eccKF) and concentric knee extensor peak torque (PT), peak countermovement (CMJ) and squat jump (SJ) height, and Nordic hamstring break angle. No significant main effects for surface or any surface and time interactions were observed for any of the outcome measures, except for eccKF PT recorded at 3.14 rad·s-1, which was significantly lower 48 h post-trial in the AT condition (AT = 146.3 ± 20.4 Nm; NT = 158.8 ± 24.7 Nm). Main effects for time were observed between pre- and post-trial measures for eccKF PT at all angular velocities, Nordic break angle, CMJ and SJ height. Nordic break angle, and both CMJ and SJ height were significantly impaired 48 h post-trial when compared to pre-trial. The findings of the current study suggest surface dependent changes in eccKF PT which may have implications for recovery and subsequent performance after competition on AT.


Assuntos
Planejamento Ambiental , Exercício Físico/fisiologia , Articulação do Joelho/fisiologia , Fadiga Muscular/fisiologia , Músculo Esquelético/fisiologia , Futebol/fisiologia , Adulto , Desempenho Atlético/fisiologia , Estudos Cross-Over , Músculos Isquiossurais/fisiologia , Humanos , Masculino , Fenômenos Fisiológicos Musculoesqueléticos , Desempenho Físico Funcional , Amplitude de Movimento Articular , Futebol/lesões , Torque , Adulto Jovem
16.
Int J Sports Physiol Perform ; 15(5): 648-653, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31896076

RESUMO

PURPOSE: To determine whether daily perceived recovery is explained from a multifactorial single-session classification of recovery (ie, faster vs slower) or other circumstantial factors (ie, previous training load, self-reported sleep, or phase of the microcycle). METHODS: Nineteen elite male futsal players were initially allocated to a recovery-classification group (faster recovery, slower physiological, or slower perceptual) based on previous research using a multifactorial cluster-analysis technique. During 4 ensuing weeks of preseason, training loads were monitored via player load, training impulse, and session rating of perceived exertion. Before each day's training, players reported their perception of recovery (Total Quality of Recovery scale [TQR]) and the number of hours and perceived quality of sleep the night prior. A hierarchical linear mixed model was used to analyze the effect of the different recovery profiles, training load, sleep, and phase of the microcycle (ie, start, middle, end) on daily TQR. RESULTS: The recovery classification of players (P = .20), training load (training impulse, P = .32; player load, P = .23; session rating of perceived exertion, P = .46), and self-reported hours slept the night before (P = .45) did not significantly influence TQR. However, perceived sleep quality (P < .01) and phase of the microcycle (P < .01) were significantly associated with TQR (r2 = .41). CONCLUSIONS: Neither recovery classification nor prior training load influenced perceived recovery during the preseason. However, higher TQR was evident with better self-reported sleep quality, whereas lower values were associated with phases of the training week.


Assuntos
Percepção/fisiologia , Condicionamento Físico Humano/fisiologia , Esforço Físico/fisiologia , Autorrelato , Sono/fisiologia , Futebol/fisiologia , Humanos , Adulto Jovem
17.
Int J Sports Physiol Perform ; 15(5): 748-758, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32000140

RESUMO

PURPOSE: To analyze and compare the effects of 4 different resisted sprint training (RST) modalities on youth soccer players' performance after 8 weeks of training. METHODS: Forty-eight youth soccer players were first randomly assigned to 4 groups and only then completed 8 weeks of RST: horizontal resisted sprint, vertical resisted sprint (VRS), combined resisted sprint, and unresisted sprint. Performance in horizontal and vertical jumps, sprint, and change of direction (COD) ability were assessed 1 week before and after the training intervention. Magnitude-based inference analysis was performed for calculating within-group pre-post differences. In addition, an analysis of covariance test was performed for between-group comparison, using the pretest values as covariates. After that, the analysis of covariance P values and the effect statistic were transformed to magnitude-based inference. RESULTS: Within-group outcomes showed that all resisted training modalities experienced improvements in sprint (small to moderate) and COD (small to large) performance. Moreover, all groups, except unresisted sprint, enhanced the horizontal jump performance. However, only VRS improved on vertical jump. Between-group comparison outcomes revealed that only VRS improved the sprint time compared with horizontal resisted sprint (moderate) and COD performance compared with all groups (moderate to large). In addition, VRS enhanced the countermovement jump performance (small to large) compared with the other groups. CONCLUSIONS: Independent of the orientation of the resistance applied, RST is an effective training method for improving sprinting and COD performance. Nevertheless, VRS may promote greater improvements on sprint and COD ability and have a positive additional effect on countermovement jump performance and the reduction of COD deficit.


Assuntos
Desempenho Atlético/fisiologia , Treinamento de Resistência/métodos , Futebol/fisiologia , Adolescente , Teste de Esforço , Humanos , Masculino , Destreza Motora/fisiologia
18.
JAMA Neurol ; 77(4): 419-426, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31985774

RESUMO

Importance: Emerging evidence suggests that long-term exposure to ball heading in soccer, the most popular sport in the world, confers risk for adverse cognitive outcomes. However, the extent to which the apolipoprotein E ε4 (APOE ε4) allele, a common risk factor for neurodegeneration, and ball heading are associated with cognition in soccer players remains unknown. Objective: To determine whether the APOE ε4 allele and 12-month ball heading exposure are associated with verbal memory in a cohort of adult amateur soccer players. Design, Settings, and Participants: A total of 379 amateur soccer players were enrolled in the longitudinal Einstein Soccer Study from November 11, 2013, through January 23, 2018. Selection criteria included participation in soccer for more than 5 years and for more than 6 months per year. Of the 379 individuals enrolled in the study, 355 were genotyped. Three players were excluded for reporting extreme levels of heading. Generalized estimating equation linear regression models were employed to combine data across visits for a cross-sectional analysis of the data. Exposures: At each study visit every 3 to 6 months, players completed the HeadCount 12-Month Questionnaire, a validated, computer-based questionnaire to estimate 12-month heading exposure that was categorized as low (quartiles 1 and 2), moderate (quartile 3), and high (quartile 4). Main Outcome and Measures: Verbal memory was assessed at each study visit using the International Shopping List Delayed Recall task from CogState. Results: A total of 352 soccer players (256 men and 96 women; median age, 23 years [interquartile range, 21-28 years]) across a total of 1204 visits were analyzed. High levels of heading were associated with worse verbal memory performance (ß = -0.59; 95% CI, -0.93 to -0.25; P = .001). There was no main association of APOE ε4 with verbal memory (ß = 0.09; 95% CI, -0.24 to 0.42; P = .58). However, there was a significant association of APOE ε4 and heading with performance on the ISRL task (χ2 = 7.22; P = .03 for overall interaction). In APOE ε4-positive players, poorer verbal memory associated with high vs low heading exposure was 4.1-fold greater (APOE ε4 negative, ß = -0.36; 95% CI, -0.75 to 0.03; APOE ε4 positive, ß = -1.49; 95% CI, -2.05 to -0.93), and poorer verbal memory associated with high vs moderate heading exposure was 8.5-fold greater (APOE ε4 negative, ß = -0.13; 95% CI, -0.54 to 0.29; APOE ε4 positive, ß = -1.11, 95% CI, -1.70 to -0.53) compared with that in APOE ε4-negative players. Conclusions and Relevance: This study suggests that the APOE ε4 allele is a risk factor for worse memory performance associated with higher heading exposure in the prior year, which highlights that assessing genetic risks may ultimately play a role in promoting safer soccer play.


Assuntos
Alelos , Apolipoproteína E4/genética , Atletas , Memória/fisiologia , Futebol/fisiologia , Adulto , Estudos Transversais , Feminino , Genótipo , Humanos , Estudos Longitudinais , Masculino , Testes Neuropsicológicos , Adulto Jovem
19.
Artigo em Inglês | MEDLINE | ID: mdl-31936244

RESUMO

This study aimed to identify the effects of continuous and fractionated game formats on internal and external load in small-sided games in soccer. Twenty male professional soccer players participated in the study performing the same exercise (5 vs. 5 players) continuously (1 × 24 min) and in a repeated/fractioned manner (2 × 12 min, 4 × 6 min, and 6 × 4 min). A comparison between playing conditions was assessed by means of standardized mean differences calculated with combined variance and respective confidence intervals of 90%. The limits for the statistics were 0.2, trivial; 0.6, small; 1.2, moderate; 2.0, large; and >2.0, very large. The results indicate that the use of the continuous method seems to present the tendency of less physical impact on the internal and external loads compared to the fractionated method. In addition, the higher number of exercise repetitions in the fractionated method was found to increase the external load compared to the continuous method. This study showed that application of small-sided games by the fractionated method tends to result in higher training loads.


Assuntos
Exercício Físico/fisiologia , Futebol/fisiologia , Futebol/estatística & dados numéricos , Algoritmos , Frequência Cardíaca , Humanos , Estudos Longitudinais , Masculino , Corrida/fisiologia , Adulto Jovem
20.
J Sports Sci ; 38(5): 552-558, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31941416

RESUMO

The objective of this study was to analyse the effect of the use of social networks in smartphones or playing video games on the passing decision-making performance in professional soccer athletes. Participants were 25 male professional soccer athletes (mean ± SD: age 23.4 ± 2.8 years). The participants performed three randomised conditions divided into three groups: control (CON), smartphone (SMA), and video game (VID). Before and after each experimental condition, the Stroop Task assessed the level of induced mental fatigue. Then, the athletes performed a simulated soccer match. A CANON® camera recorded the matches for further analysis on passing decision-making performance. A group effect was identified (p < .01) with impairment on passing decision-making performance for the SMA (p = .01, ES = 0.5) and VID (p = .01, ES = 0.5) conditions. We concluded that the use of social networks on smartphones and/or playing video games right before official soccer matches might impair the passing decision-making performance in professional soccer athletes.


Assuntos
Tomada de Decisões , Smartphone , Futebol/psicologia , Jogos de Vídeo , Adulto , Desempenho Atlético , Estudos Cross-Over , Humanos , Masculino , Redes Sociais Online , Estado de Hidratação do Organismo/fisiologia , Distribuição Aleatória , Futebol/fisiologia , Teste de Stroop , Adulto Jovem
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