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1.
Nutrients ; 13(4)2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33923663

RESUMO

The main objective of this research was to carry out an experimental study, triple-blind, on the possible immunophysiological effects of a nutritional supplement (synbiotic, Gasteel Plus®, Heel España S.A.U.), containing a mixture of probiotic strains, such as Bifidobacterium lactis CBP-001010, Lactobacillus rhamnosus CNCM I-4036, and Bifidobacterium longum ES1, as well as the prebiotic fructooligosaccharides, on both professional athletes and sedentary people. The effects on some inflammatory/immune (IL-1ß, IL-10, and immunoglobulin A) and stress (epinephrine, norepinephrine, dopamine, serotonin, corticotropin-releasing hormone (CRH), Adrenocorticotropic hormone (ACTH), and cortisol) biomarkers were evaluated, determined by flow cytometer and ELISA. The effects on metabolic profile and physical activity, as well as on various parameters that could affect physical and mental health, were also evaluated via the use of accelerometry and validated questionnaires. The participants were professional soccer players in the Second Division B of the Spanish League and sedentary students of the same sex and age range. Both study groups were randomly divided into two groups: a control group-administered with placebo, and an experimental group-administered with the synbiotic. Each participant was evaluated at baseline, as well as after the intervention, which lasted one month. Only in the athlete group did the synbiotic intervention clearly improve objective physical activity and sleep quality, as well as perceived general health, stress, and anxiety levels. Furthermore, the synbiotic induced an immunophysiological bioregulatory effect, depending on the basal situation of each experimental group, particularly in the systemic levels of IL-1ß (increased significantly only in the sedentary group), CRH (decreased significantly only in the sedentary group), and dopamine (increased significantly only in the athlete group). There were no significant differences between groups in the levels of immunoglobulin A or in the metabolic profile as a result of the intervention. It is concluded that synbiotic nutritional supplements can improve anxiety, stress, and sleep quality, particularly in sportspeople, which appears to be linked to an improved immuno-neuroendocrine response in which IL-1ß, CRH, and dopamine are clearly involved.


Assuntos
Sistema Imunitário/microbiologia , Sistemas Neurossecretores/microbiologia , Futebol/fisiologia , Estresse Psicológico/microbiologia , Simbióticos/administração & dosagem , Acelerometria , Adulto , Ansiedade/sangue , Ansiedade/microbiologia , Ansiedade/terapia , Atletas/psicologia , Bifidobacterium animalis , Bifidobacterium longum , Biomarcadores/sangue , Hormônio Liberador da Corticotropina/sangue , Dopamina/sangue , Exercício Físico , Feminino , Humanos , Interleucina-1beta/sangue , Lactobacillus rhamnosus , Masculino , Oligossacarídeos/administração & dosagem , Projetos Piloto , Probióticos/administração & dosagem , Projetos de Pesquisa , Comportamento Sedentário , Sono , Estresse Psicológico/sangue , Estresse Psicológico/terapia , Estudantes/psicologia , Inquéritos e Questionários , Adulto Jovem
2.
Scand J Med Sci Sports ; 31 Suppl 1: 73-84, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33871087

RESUMO

To optimize use of available resources, professional academies develop strategies to assess, monitor, and evaluate players as they progress through adolescence toward adulthood. However, few published reports exist using longitudinal study designs to examine performance throughout adolescence and the transition from youth to professional soccer. We examined differences in the age of player recruitment alongside longitudinal performance differences on field-based fitness tests of successful vs. unsuccessful graduates across the entire age spectrum recruited by a professional soccer academy. Altogether, 537 youth soccer players volunteered to participate. We recorded the age of recruitment, biannual fitness test performance, and subsequent success in attaining a senior professional contract at the club across a period of 12 years. Only 53 (10%) of players were successful in obtaining a professional contract, with 68% of players who became professional being recruited at 12 years of age or older. Individuals recruited at an earlier age did not display a higher probability of success in attaining a professional contract. Bayesian regression models reported a consistent interaction between age and group for data on all performance measures. Moreover, "successful" academy graduates only physically outperformed their "unsuccessful" counterparts from age ~13-14 years onward, with either no differences in performance, or performance on physical fitness tests favoring "unsuccessful" players prior to this age. Findings suggest that high achievers during childhood and early adolescence may not develop into successful senior professionals, raising concerns about the predictive utility of talent identification models.


Assuntos
Aptidão , Desempenho Atlético/fisiologia , Adolescente , Fatores Etários , Teorema de Bayes , Estatura , Índice de Massa Corporal , Teste de Esforço , Humanos , Estudos Longitudinais , Destreza Motora/fisiologia , Futebol/fisiologia , Adulto Jovem
3.
J Sports Med Phys Fitness ; 61(3): 365-371, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33648333

RESUMO

BACKGROUND: The aims of this study were: 1) to investigate the impacts that an eccentric overload training (EOT) and a small-side game training (SSGT) have on the characteristics of the accelerations (ACC) and decelerations (DCC) of the players in a soccer match; and 2) to determine if EOT and SSGT could affect the ACC and DCC reduction over time in a soccer match. METHODS: Twenty-three female soccer players from a Spanish professional club were split into three groups: a small-sided game training group (SGG), an eccentric overload training group (EOG) and a control group (CG). RESULTS: The SSG improved the high intensity distance performed (ES [CI]=0.72 [0.22; 1.22]), the number of high intensity actions (ES [CI]=0.65 [0.01; 1.29]), the percentage of repeated high intensity actions (ES [CI]=0.54 [-0.17; 1.25]), the initial velocity of the ACC (ES [CI]=0.55 [-0.08; 1.17]) and the percentage of repeated accelerations (ES [CI]=0.87 [-0.18; 1.91]) with respect to the control group. The EOG obtained better results in distance travelling accelerating (ES [CI]=0.84 [0.09; 1.60]) and decelerating (ES [CI]=0.87 [0.23; 1.51]) above 3 m/s2, maximum ACC (ES [CI]=1.92 [0.90; 2.94]) and DCC (ES [CI]=1.29 [0.44; 2.14]) and the average of maximum ACC (ES [CI]=0.89 [0.23; 1.54]) and DCC (ES [CI]=1.08 [0.62; 1.55]) with respect to the CG. A decrement in the ACC and DCC performance was observed between the first and last 15 minutes of the competition, except for the EOG. CONCLUSIONS: The SSG obtained mainly improvements in variables related with efforts repetitions and the capacity of maintaining the ACC and the DCC over time, while improvements in the EOG were related to intensity in the ACC and DCC.


Assuntos
Corrida/fisiologia , Futebol/fisiologia , Aceleração , Desempenho Atlético , Grupos Controle , Desaceleração , Feminino , Humanos , Masculino , Adulto Jovem
4.
Nutrients ; 13(2)2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33670822

RESUMO

Creatine is a popular ergogenic aid among athletic populations with consistent evidence indicating that creatine supplementation also continues to be commonly used among adolescent populations. In addition, the evidence base supporting the therapeutic benefits of creatine supplementation for a plethora of clinical applications in both adults and children continues to grow. Among pediatric populations, a strong rationale exists for creatine to afford therapeutic benefits pertaining to multiple neuromuscular and metabolic disorders, with preliminary evidence for other subsets of clinical populations as well. Despite the strong evidence supporting the efficacy and safety of creatine supplementation among adult populations, less is known as to whether similar physiological benefits extend to children and adolescent populations, and in particular those adolescent populations who are regularly participating in high-intensity exercise training. While limited in scope, studies involving creatine supplementation and exercise performance in adolescent athletes generally report improvements in several ergogenic outcomes with limited evidence of ergolytic properties and consistent reports indicating no adverse events associated with supplementation. The purpose of this article is to summarize the rationale, prevalence of use, performance benefits, clinical applications, and safety of creatine use in children and adolescents.


Assuntos
Desempenho Atlético/fisiologia , Creatina/administração & dosagem , Suplementos Nutricionais , Substâncias para Melhoria do Desempenho/administração & dosagem , Esportes/fisiologia , Adolescente , Fenômenos Fisiológicos da Nutrição do Adolescente , Criança , Feminino , Humanos , Masculino , Futebol/fisiologia , Natação/fisiologia
5.
Scand J Med Sci Sports ; 31(6): 1324-1334, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33560529

RESUMO

A better insight into injuries in elite-youth football may inform prevention strategies. The purpose of this prospective cohort study was to investigate the frequency, incidence, and pattern of time-loss injuries in an elite male football academy, exploring injuries in relation to age and maturation status. Across four consecutive playing seasons, playing exposure and injuries to all academy players (U'9 to U'21) were recorded by club medical staff. Maturation status at the time of injury was also calculated for players competing in U'13 to U'16 aged squads. Time-loss injury occurrence and maturation status at time of injury were the main outcome measures. A total of 603 time-loss injuries were recorded, from 190 different players. Playing exposure was 229 317 hours resulting in an overall injury rate of 2.4 p/1000 h, ranging from 0.7 p/1000 h (U'11) to 4.8 p/1000 h (U'21). Most injuries were traumatic in mechanism (73%). The most common injury location was the thigh (23%), and the most common injury type was muscle injury (29%) combining to provide the most common injury diagnosis; thigh muscle injury (17%). In U'13-U'16 players, a higher number of injuries to early-maturing players were observed in U'13-U'14 players, while more injuries to U'15-U'16 players occurred when classed as "on-time" in maturity status. Maturation status did not statistically relate to injury pattern; however, knee bone (not-fracture) injuries peaked in U'13 players while hip/groin muscle injuries peaked in U'15 players.


Assuntos
Absenteísmo , Futebol/lesões , Esportes Juvenis/lesões , Adolescente , Fatores Etários , Traumatismos do Tornozelo/epidemiologia , Atletas , Inglaterra/epidemiologia , Virilha/lesões , Crescimento/fisiologia , Lesões do Quadril/epidemiologia , Humanos , Incidência , Escala de Gravidade do Ferimento , Traumatismos do Joelho/epidemiologia , Masculino , Músculo Esquelético/lesões , Avaliação de Resultados em Cuidados de Saúde , Estudos Prospectivos , Ruptura/epidemiologia , Estações do Ano , Futebol/fisiologia , Futebol/estatística & dados numéricos , Entorses e Distensões/epidemiologia , Estatísticas não Paramétricas , Coxa da Perna/lesões , Fatores de Tempo , Esportes Juvenis/fisiologia , Esportes Juvenis/estatística & dados numéricos
6.
J Int Soc Sports Nutr ; 18(1): 14, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33568169

RESUMO

BACKGROUND: Chocolate milk has gained recent scientific support as a recovery drink. However, it is known that high exercise-demand triggers gastrointestinal discomfort which continues post-exercise, thereby hindering this nutritional strategy. In addition, those who are lactose intolerant cannot benefit from a milk-based beverage. Thus, the aim of this preliminary study was to develop a low-fat, lactose-free, and leucine-enriched chocolate cow milk prototype (CML) representing nutrition-related recommendations for football players, as well as assess athletes' individual subjective outcomes for gastrointestinal complaints and sensorial acceptability in a field-based setting following strenuous team-sport physical demands. METHODS: This study followed a single group and repeated-measured design with 10 football players (23 ± 2 yrs., 74 ± 14 kg, 174 ± 5 cm) who consumed CML following a 90-min football match simulation protocol (FMP). The total CML intake to achieve 0.150 g leucine·kg [BW]·h- 1 occurred in aliquots of 50, 30 and 20% at 0-, 45- and 75-min post-FMP, respectively. Athletes were evaluated by the prevalence, the type and severity (bloating, nausea, flatulence, and gastric reflux) of gastrointestinal complaints and sensorial acceptability (overall perception, appearance, consistency, and flavour) after drinking each aliquot in a 4-h recovery period. RESULTS: The CML showed higher scores for "Product Acceptability Index" (88%) and sensorial acceptability (~ 8 in 9-point hedonic scale). Kendall's W with bootstrapped resample (95%CI) revealed agreement among respondents as "moderate" (overall perception, flavour) to "strong" (appearance, consistency) and with no significant agreement differences between rater response in the timeline analysis (0.57 up to 0.87; p > 0.05). Agresti-Caffo add-4 analysis (95% confidence interval, [95%CI]) revealed no differences in each time-point analysis versus baseline for athletes classified as having severe gastrointestinal symptoms, but confirmed concern with bloating (three athletes showed a transient response at 2-h and only one continued until 3-h; p = 0.051). CONCLUSIONS: These preliminary findings suggest that CML presents good taste and high acceptability by the sampled athletes. Thus, CML may be an alternative sport drink for immediate post-workout supplementation to overcome the energy deficit, offer co-ingested leucine, maintain palatability and adherence including lactose intolerance following a team sport-specific fatigue. TRIAL REGISTRATION: RBR-2vmpz9 , 10/12/2019, retrospectively registered.


Assuntos
Chocolate , Alimentos Fortificados , Leucina , Leite/química , Futebol/fisiologia , Paladar , Animais , Bovinos , Ingestão de Energia , Flatulência/etiologia , Alimentos Fortificados/efeitos adversos , Refluxo Gastroesofágico/etiologia , Gastroenteropatias/etiologia , Humanos , Lactose , Intolerância à Lactose/complicações , Leucina/administração & dosagem , Masculino , Leite/efeitos adversos , Náusea/etiologia , Fenômenos Fisiológicos da Nutrição Esportiva , Adulto Jovem
7.
PLoS One ; 16(1): e0244970, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33444373

RESUMO

High accuracy in estimating energy expenditure is essential for enhancing sports performance. The resting metabolic rate (RMR), as a primary component of total energy expenditure (TEE), is commonly estimated using predictive equations. However, these references may not be applicable to adolescent athletes. The purpose of this cross-sectional study was to analyse the differences between predicted RMR in relation to energy expenditure measured by indirect calorimetry (IC) among 45 Brazilian male adolescent football athletes. Indirect calorimetry (IC) and anthropometric (bioimpedance) measurements were recorded at a single visit to the laboratory after fasting overnight. The mean age was 15.6 ± 1.14 years, body mass was 63.05 ± 7.8 kg, and height was 172 ± 7.5 cm. The RMR values predicted by equations proposed by the Food and Agriculture Organization (FAO) (United Nations), Henry and Rees (HR), Harris Benedict (HB), and Cunningham (CUN) were compared with IC RMR values, by correlation analysis. The FAO and HR predictive equations yielded different values from IC (IC: 1716.26 ± 202.58, HR: 1864.87 ± 147.78, FAO: 1854.28 ± 130.19, p = 0.001). A moderate correlation of 0.504 was found between the results of HB and IC. In the survival-agreement model, the CUN equation showed low disagreement with the IC RMR, with error values between 200 and 300 kcal/day. The results showed that HB and CUN yielded similar values as IC, with the CUN equation showing low disagreement with IC; hence, adolescent athletes should undergo evaluation with precise laboratory methods to ensure that accurate information about RMR is recorded.


Assuntos
Atletas , Metabolismo Basal , Futebol/fisiologia , Adolescente , Atletas/estatística & dados numéricos , Metabolismo Basal/fisiologia , Calorimetria Indireta/métodos , Calorimetria Indireta/normas , Estudos Transversais , Impedância Elétrica , Metabolismo Energético/fisiologia , Humanos , Masculino , Reprodutibilidade dos Testes
8.
J Sports Sci ; 39(11): 1202-1222, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33423603

RESUMO

This systematic review with meta-analysis (SRMA) was conducted to assess the effects of high-intensity interval training (HIIT) programmes on men soccer players' aerobic fitness (maximal oxygen uptake and aerobic performance), repeated sprint ability (RSA), vertical jump height (VJH), and linear sprinting time (ST). An electronic search yielded 1,714 articles, 33 of which were included in the present study. Meta-analyses revealed significant benefits of HIIT compared to controls in maximal oxygen uptake (p = 0.018), AP (p = 0.041), and RSA (p = 0.049). No significant effects were found in terms of ST (p = 0.080). The meta-analyses of non-controlled studies revealed significant improvements after HIIT in maximal oxygen uptake (p = 0.001), AP (p = 0.007), RSA (p = 0.001), and ST (p < 0.001). However, no significant improvements in VHJ were found (p = 0.063). Furthermore, no significant differences were found in sub-group analysis (comparisons between HIIT types). In conclusion, HIIT is effective for improving maximal oxygen uptake, AP, and RSA regardless of the HIIT type. For VHJ and ST outcomes, it seems reasonable to complement the HIIT since it might not be enough to achieve significant changes.


Assuntos
Desempenho Atlético/fisiologia , Treinamento Intervalado de Alta Intensidade , Consumo de Oxigênio , Aptidão Física/fisiologia , Futebol/fisiologia , Adolescente , Adulto , Viés , Humanos , Masculino , Ensaios Clínicos Controlados não Aleatórios como Assunto , Resistência Física/fisiologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Corrida/fisiologia , Adulto Jovem
9.
PLoS One ; 16(1): e0245277, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33411844

RESUMO

This study was performed aimed at comparing multidirectional bilateral and unilateral jump performance and passive range of motion (ROM) of lower limbs between soccer and basketball young players and evaluating associations between inter-limb ROM asymmetry and bilateral jump performance. A total of 67 young male athletes participated in this study, who were classified as soccer (n = 40; 15.55 ± 1.5 y; 1.76 ± 0.12 m; 58.15 ± 10.82 kg; 19.84 ± 2.98 kg·m2) and basketball (n = 27; 15.7 ± 1.66 y; 1.76 ± 0.12 m; 62.33 ± 16.57 kg; 19.84 ± 2.98 kg·m2) players. Participants were asked to perform bilateral and unilateral multidirectional jumps, and passive ROM of hip (flexion, extension and abduction), knee (flexion) and ankle (dorsiflexion) joints was also assessed. Significant between-group differences were observed for hip extension with flexed knee ROM in dominant (soccer: 142.43 ± 7.74°; basketball: 148.63 ± 8.10°) and non-dominant (soccer: 144.38 ± 8.36°; basketball: 148.63 ± 6.45°) legs; hip flexion with flexed knee ROM in dominant (soccer: 13.26 ± 4.71°; basketball: 9.96 ± 3.42°) and non-dominant (soccer: 12.86 ± 4.55°; basketball: 9.70 ± 3.62°) legs; and for the ratio of hip abduction (soccer: 1.02 ± 0.08; basketball: 0.97 ± 0.11). However, no significant between-group differences were observed for bilateral and unilateral jump capacity, or for inter-limb asymmetries (dominant vs. non-dominant leg). Finally, no associations were observed between ROM ratio (dominant vs. non-dominant leg) and bilateral jump performance. These findings lead to the suggestion that differences on passive ROM values in young male athletes may be sport-specific. Additionally, there seems to be need for the implementation of training strategies specifically aimed at improving bilateral or unilateral jump ability, or at diminishing inter limb passive ROM differences in order to improve multidirectional jump performance for neither soccer nor basketball youth male players.


Assuntos
Basquetebol/fisiologia , Extremidade Inferior/fisiologia , Amplitude de Movimento Articular , Futebol/fisiologia , Adolescente , Desempenho Atlético , Humanos , Articulações/fisiologia , Masculino , Movimento
10.
Nutrients ; 13(2)2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33513989

RESUMO

Hypohydration increases physiological strain and reduces physical and technical soccer performance, but there are limited data on how fluid balance responses change between different types of sessions in professional players. This study investigated sweat and fluid/carbohydrate intake responses in elite male professional soccer players training at low and high intensities in cool and hot environments. Fluid/sodium (Na+) losses and ad-libitum carbohydrate/fluid intake of fourteen elite male soccer players were measured on four occasions: cool (wet bulb globe temperature (WBGT): 15 ± 7 °C, 66 ± 6% relative humidity (RH)) low intensity (rating of perceived exertion (RPE) 2-4, m·min-1 40-46) (CL); cool high intensity (RPE 6-8, m·min-1 82-86) (CH); hot (29 ± 1 °C, 52 ± 7% RH) low intensity (HL); hot high intensity (HH). Exercise involved 65 ± 5 min of soccer-specific training. Before and after exercise, players were weighed in minimal clothing. During training, players had ad libitum access to carbohydrate beverages and water. Sweat [Na+] (mmol·L-1), which was measured by absorbent patches positioned on the thigh, was no different between conditions, CL: 35 ± 9, CH: 38 ± 8, HL: 34 ± 70.17, HH: 38 ± 8 (p = 0.475). Exercise intensity and environmental condition significantly influenced sweat rates (L·h-1), CL: 0.55 ± 0.20, CH: 0.98 ± 0.21, HL: 0.81 ± 0.17, HH: 1.43 ± 0.23 (p =0.001), and percentage dehydration (p < 0.001). Fluid intake was significantly associated with sweat rate (p = 0.019), with no players experiencing hypohydration > 2% of pre-exercise body mass. Carbohydrate intake varied between players (range 0-38 g·h-1), with no difference between conditions. These descriptive data gathered on elite professional players highlight the variation in the hydration status, sweat rate, sweat Na+ losses, and carbohydrate intake in response to training in cool and hot environments and at low and high exercise intensities.


Assuntos
Futebol/fisiologia , Sódio/metabolismo , Suor/metabolismo , Equilíbrio Hidroeletrolítico/fisiologia , Adulto , Carboidratos , Temperatura Baixa , Desidratação , Ingestão de Alimentos , Temperatura Alta , Humanos , Masculino , Temperatura , Adulto Jovem
11.
Artigo em Inglês | MEDLINE | ID: mdl-33401532

RESUMO

Hamstring muscle injury is common in female soccer players. Changes affecting eccentric strength, flexibility, and the quadriceps-hamstring contraction cycle are risk factors associated with this type of injury. Methods: Seventeen soccer players were randomized to two groups: experimental (plyometric and eccentric exercises without external loads) and control (eccentric exercises without external loads). Eighteen sessions were scheduled over 6 weeks. The exercise program included three plyometric exercises (single-leg squat and lunge, 180 jump, and broad jump stick landing) and three eccentric exercises (Nordic hamstring exercise, diver, and glider). Dependent variables were jumping height (My Jump 2.0 App) and anterior, posteromedial, and posterolateral lower limb stability (Y-Balance test). Results: Following intervention, improvements were found in anterior and posteromedial stability (p = 0.04) in the experimental group. Posterolateral stability improved in athletes included in the control group (p = 0.02). There were differences in the repeated measures analysis for all variables, with no changes in group interaction (p > 0.05). Conclusions: Eccentric exercises, either combined with plyometric exercises or alone, can improve lower limb stability. No changes in jump height were noted in either group. There were no differences between the two groups in the variables studied. Future studies should analyze the effect of external loads on jumping stability and height in the performance of plyometric exercises.


Assuntos
Exercício Físico , Locomoção , Exercício Pliométrico , Futebol , Adulto , Exercício Físico/fisiologia , Feminino , Humanos , Locomoção/fisiologia , Projetos Piloto , Método Simples-Cego , Futebol/fisiologia , Adulto Jovem
13.
J Sports Sci ; 39(7): 783-791, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33320053

RESUMO

We examined the interaction between explicit contextual priors and kinematic information during anticipation in soccer. We employed a video-based anticipation task where skilled soccer players had to predict the direction of the imminent actions of an attacking opponent in possession of the ball. The players performed the task both with and without explicit contextual priors pertaining to the opponent's action tendencies. The strength of the opponent's action tendencies was altered in order to manipulate the reliability of contextual priors (low vs. high). Moreover, the reliability of kinematic information (low vs. high) was manipulated using the temporal occlusion paradigm. The explicit provision of contextual priors biased anticipation towards the most likely direction, given the opponent's action tendencies, and resulted in enhanced performance. This effect was greater under conditions where the reliability of kinematic information was low rather than high. When the reliability of kinematic information was high, the players used explicit contextual priors of high, but not low, reliability to inform their judgements. Findings suggest that athletes employ reliability-based strategies when integrating contextual priors with kinematic information during anticipation. The impact of explicit contextual priors is dependent on the reliability both of the priors and the evolving kinematic information.


Assuntos
Atletas , Fenômenos Biomecânicos/fisiologia , Tempo de Reação/fisiologia , Futebol/fisiologia , Adulto , Sinais (Psicologia) , Retroalimentação Sensorial/fisiologia , Feminino , Humanos , Julgamento , Masculino , Reprodutibilidade dos Testes , Gravação em Vídeo
14.
J Sci Med Sport ; 24(4): 391-396, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33317981

RESUMO

OBJECTIVES: Maximal aerobic speed (MAS) may be predicted from 2.0km time trial (TT) running speed in male Australian Rules football (AF) players. Given the between-sex differences in physiological variables precursory to endurance performance, and the impact of this on MAS distance limit, this study determined running speed across various TT distances best approximating MAS in female AF players. METHOD: 33 female AF players completed assessments of MAS and TT performance separated by at least 48h. In a randomised order, half of the athletes completed TT distances of 1.2, 1.6 and 2.0km, and the other half completed distances of 1.4, 1.8 and 2.2km. Bias, limits of agreement (LOA) and linear mixed modelling determined agreement between TT-derived running speed and MAS. RESULTS: Average speed for all TT distances were different to MAS (bias≥0.59±0.45km·h-1; p≤0.015) with the exception of the 1.4km TT (bias=-0.12±0.26km·h-1; p=0.34). LOA was narrowest for the 1.4km TT (±0.76km·h-1; ±6.1%) compared to other TT distances (±0.82-1.67km·h-1; ±6.7-12.9%). A significant linear association between bias and TT distance (r=-0.73; p<0.001) indicated TT speed would be equal to MAS when a 1.4-1.5km TT was completed, and that MAS may be predicted from any distance between 1.2 and 2.2km. CONCLUSIONS: MAS was best approximated by a 1.4-1.5km TT in female AF players, but may be predicted from TT speed for any distance between 1.2 and 2.2km. TT-derived MAS provides a time and resource efficient method for the quantification of aerobic fitness and prescription of future training intensities.


Assuntos
Desempenho Atlético/fisiologia , Teste de Esforço , Consumo de Oxigênio/fisiologia , Corrida/fisiologia , Futebol/fisiologia , Austrália , Feminino , Humanos , Valor Preditivo dos Testes , Adulto Jovem
15.
J Sports Sci ; 39(4): 395-405, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33377421

RESUMO

The aim of the study was to compare ground reaction force (GRF) characteristics between the antepenultimate foot contact (APFC), penultimate foot contact (PFC), and final foot contact (FFC), and to examine the relationships between APFC, PFC, and FFC GRF characteristics with 505 change of direction (COD) speed performance. Twenty university male soccer players performed three COD trials, whereby GRFs were collected over the aforementioned foot contacts. Greater peak braking forces in shorter ground contact times were demonstrated over the APFC compared to the PFC and FFC (p ≤ 0.011, d = 0.96-7.82), while APFC mean GRFs were greater than the PFC (p ≤ 0.001, d = 1.86-7.57). Faster 505 performance was associated with greater APFC peak and mean vertical, horizontal, and resultant braking GRFs (r2 = 21.6-54.5%), greater FFC mean HGRFs (r2 = 38.8%), more horizontally orientated peak resultant APFC and PFC GRFs (r2 = 22.8-55.4%), and greater APFC, PFC, and FFC mean horizontal to vertical GRF ratios (r2 = 32.0-61.9%). Overall, the APFC plays a more pivotal role in facilitating deceleration compared to the PFC for effective 505 performance. Practitioners should develop their athletes' technical ability to express force horizontally across all foot contacts and coach braking strategies that emphasise greater magnitudes of posteriorly directed APFC GRFs to facilitate faster 505 performance.


Assuntos
Fenômenos Biomecânicos/fisiologia , Desaceleração , Movimento/fisiologia , Futebol/fisiologia , Análise e Desempenho de Tarefas , Aceleração , Desempenho Atlético/fisiologia , Estudos Transversais , Pé/fisiologia , Humanos , Cinética , Masculino , Estudantes , Fatores de Tempo , Universidades
16.
J Sci Med Sport ; 24(5): 511-516, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33317982

RESUMO

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 ∼85min of rest, punctuated with five min rewarm-ups at ∼25, ∼50, and ∼70min, before ∼30min 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 (∼2.3%, +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 (∼1.6%, -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 (∼5min; p=0.002) until ∼10min into exercise. From post-warm-up to pre-simulated match-play, sprint times (∼3.9%, +0.10s, p=0.003), jump height (∼9.4%, -3.1cm; p=0.017), and peak power output (∼7.2%, -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 (∼7.8%, +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 ∼30min 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 Jovem
17.
J Sport Health Sci ; 9(6): 614-619, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33308811

RESUMO

BACKGROUND: Most papers examining the lateral abdominal muscles (LAMs) and low back pain (LBP) are cross-sectional, with groups of participants being divided into a control and an LBP group. We hypothesized that morphological measurements of the LAMs in adolescent soccer players may predict future LBP incidence. The aim of this study was to examine the associations between the morphology of LAMs and LBP incidence rate among adolescent soccer players. METHODS: Ninety-seven adolescent male soccer players with no LBP at baseline were recruited into the prospective cohort study. The thickness of the LAMs was measured at baseline by ultrasound imaging in a supine rest position. Nine cases of LBP occurred during the follow-up 6-month observation. RESULTS: An obliquus internus (OI) asymmetry was related to increasing LBP risk (odds ratio = 19.99; 95%CI: 2.4-167.9). Spearman correlation also showed a linear relationship between OI asymmetry value and duration of LBP (R = 0.75, p = 0.02). An OI side-to-side difference greater than 1.25 mm suggests possible LBP incidence in the 6-month observation among adolescent soccer players. CONCLUSION: The morphological changes of the OI may be related to LBP's incidence in adolescent soccer players. The presence of OI asymmetry increases the odds of LBP by at least 2.4 times. Hypertrophy of the OI on one side of the body may contribute to trunk muscle imbalance.


Assuntos
Músculos Abdominais/anatomia & histologia , Dor Lombar/etiologia , Futebol/fisiologia , Músculos Abdominais/diagnóstico por imagem , Músculos Abdominais Oblíquos/anatomia & histologia , Músculos Abdominais Oblíquos/diagnóstico por imagem , Adolescente , Criança , Humanos , Estudos Longitudinais , Dor Lombar/diagnóstico por imagem , Masculino , Estudos Prospectivos , Aumento do Músculo Esquelético , Ultrassonografia
18.
J Sport Health Sci ; 9(6): 620-627, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33308812

RESUMO

PURPOSE: This study aimed to assess the effectiveness and time course for improvements in explosive actions through resistance training (RT) vs. plyometric training (PT) in prepubertal soccer players. METHODS: Thirty-four male subjects were assigned to: a control group (n = 11); an RT group (5 regular soccer training sessions per week, n = 12); a PT group (3 soccer training sessions and 2 RT sessions per week, n = 11). The outcome measures included tests for the assessment of muscle strength (e.g., 1 repetition maximum half-squat test), jump ability (e.g., countermovement jump, squat jump, standing long jump, and multiple 5 bounds test), linear speed (e.g., 20 m sprint test), and change of direction (e.g., Illinois change of direction test). RESULTS: The RTG showed an improvement in the half-squat (Δ = 13.2%; d = 1.3, p< 0.001) and countermovement jump (Δ = 9.4%; d = 2.4, p< 0.001) at Week 4, whereas improvements in the 20-m sprint (Δ = 4.2%; d = 1.1, p < 0.01); change of direction (CoD) (Δ = 3.8%; d = 2.1, p < 0.01); multiple 5 bounds (Δ = 5.1%; d = 1.5, p < 0.05); standing long jump (Δ = 7.2%; d = 1.2, p < 0.01); squat jump (Δ = 19.6%; d = 1.5, p < 0.01); were evident at Week 8. The PTG showed improvements in CoD (Δ = 2.1%; d = 1.3, p< 0.05); standing long jump (Δ = 9.3%; d = 1.1, p< 0.01); countermovement jump (Δ = 16.1%; d = 1.2, p< 0.01); and squat jump (Δ = 16.7%; d = 1.4, p< 0.01); at Week 8 whereas improvements in the 20-m sprint (Δ = 4.1%; d = 1.3, p < 0.01); and multiple 5 bounds (Δ = 7.4%; d = 2.4, p< 0.001); were evident only after Week. The RT and PT groups showed improvements in all sprint, CoD, and jump tests (p< 0.05) and in half-squat performance, for which improvement was only shown within the RTG (p< 0.001). CONCLUSION: RT and PT conducted in combination with regular soccer training are safe and feasible interventions for prepubertal soccer players. In addition, these interventions were shown to be effective training tools to improve explosive actions with different time courses of improvements, which manifested earlier in the RTG than in the PTG. These outcomes may help coaches and fitness trainers set out clear and concise goals of training according to the specific time course of improvement difference between RT and PT on proxies of athletic performance of prepubertal soccer players.


Assuntos
Desempenho Atlético/fisiologia , Exercício Pliométrico , Treinamento de Força , Futebol/fisiologia , Adaptação Fisiológica , Criança , Humanos , Masculino , Força Muscular , Puberdade , Fatores de Tempo
19.
Rev. andal. med. deporte ; 13(4): 195-198, dic. 2020. ilus, tab, graf
Artigo em Espanhol | IBECS | ID: ibc-201286

RESUMO

OBJETIVO: La hormona cortisol participa en situaciones de respuestas fisiológicas y conductuales, preparando al organismo para actuar en un momento de estrés de naturaleza física, insegura, o como lo es la competición deportiva, de ésta manera, se pretende como objetivo principal analizar las respuestas del cortisol de 20 futbolistas (titulares y no titulares) de nivel internacional durante un día de partido de competición. MÉTODO: Durante la Copa Mundial de la Fédération Internationale de Football Association 2018 en Rusia, fueron seleccionados 20 jugadores de un equipo nacional para obtener un perfil individualizado de los jugadores, analizándose durante el día de partido, mediante análisis salival en los primeros 30 minutos tras despertar (8.00 am). Para el análisis estadístico de diferencias entre grupos, se utilizó t-student (Grupo: titulares / no titulares) × 1 (Tiempo: basal). RESULTADOS: Con los resultados obtenidos, observamos un aumento en la Respuesta al Despertar del Cortisol en función de si los jugadores jugaban de inicio como titulares o iniciaban como no titulares, existiendo diferencia significativa (p = 0.005; P= 0.105) entre ambos grupos. CONCLUSIONES: Se observó un perfil diferenciado, con una diferencia en aumento de cortisol de los jugadores titulares, pudiendo deberse a un incremento de la tensión precompetitiva propia, en muchos casos necesaria para encarar la competición


OBJECTIVE: The hormone cortisol participates in situations of physiological and behavioral responses, preparing the body to act in a time of stress of a physical, insecure nature, or as is the sports competition, in this way, it is intended as the main objective to analyze the responses of cortisol of 20 players (starters and no starters) of international level during a match day. METHOD: During the 2018 Fédération Internationale de Football Association World Cup in Russia, 20 players from a national team were selected to obtain an individualized profile of the players, analyzed during the match day, by salivary analysis in the first 30 minutes after waking up (8.00 am). For the statistical analysis of differences between groups, t-student (Group: headlines / non-headlines) × 1 (Time: baseline) was used. RESULTS: With the results obtained, we observed an increase in the Awakening Response of Cortisol depending on whether the players played as starters or started as no starters, there being a significant difference (p = 0.005; P = 0.105) between both groups. CONCLUSIONS: A differentiated profile was observed, with a difference in cortisol increase in the starting players, and may be due to an increase in the pre-competitive tension of their own, in many cases necessary to face the competition


OBJETIVO: O hormônio cortisol participa de situações de respostas fisiológicas e comportamentais, preparando o corpo para agir em um momento de estresse de natureza física, insegura ou, como é a competição esportiva, dessa forma, pretende-se como principal objetivo analisar as respostas do cortisol de 20 jogadores (titulares e não titulares) de nível internacional durante uma jornada. MÉTODO: Durante a Copa do Mundo da Fédération Internationale de Football Association 2018 na Rússia, 20 jogadores de uma equipe nacional foram selecionados para obter um perfil individualizado dos jogadores, analisados durante a jornada, por análise salivar nos primeiros 30 minutos após acordar (8h). Para a análise estatística das diferenças entre os grupos, foi utilizado t-student (Grupo: manchetes / não manchetes) × 1 (Tempo: linha de base). RESULTADOS: Com os resultados obtidos, observamos um aumento no Awakening Response of Cortisol, dependendo se os jogadores jogaram como iniciantes ou começaram como não iniciantes, havendo uma diferença significativa (p = 0.005; P = 0.105) entre os dois grupos. CONCLUSÕES: Um perfil diferenciado foi observado, com uma diferença no aumento de cortisol dos jogadores iniciantes, e pode ser devido a um aumento da tensão pré-competitiva própria, em muitos casos necessários para enfrentar a competição


Assuntos
Humanos , Masculino , Adulto , Hidrocortisona/análise , Futebol/fisiologia , Ansiedade de Desempenho/fisiopatologia , Comportamento Competitivo/fisiologia , Desempenho Atlético/fisiologia , Saliva/química , Estresse Psicológico/fisiopatologia , Fadiga/fisiopatologia , Recuperação de Função Fisiológica/fisiologia
20.
Rev. andal. med. deporte ; 13(4): 205-209, dic. 2020. tab
Artigo em Espanhol | IBECS | ID: ibc-201288

RESUMO

OBJETIVO: Calcular el consumo máximo de oxígeno a través de un test de campo submáximo (Yo-Yo de recuperación intermitente I) y valorar la percepción subjetiva del esfuerzo y la percepción del grado de recuperación entre jugadores y sus diferentes posiciones en el campo. MÉTODO: 32 jugadores de fútbol masculino de 1ª División Andaluza Sub 15, realizaron el test de campo Yo-Yo de recuperación intermitente I para calcular el consumo máximo de oxígeno, posteriormente se registró la percepción de los esfuerzos y la frecuencia cardíaca. RESULTADOS: Diferentes pruebas t comparando los datos obtenidos mostraron tan sólo diferencias significativas en la frecuencia cardíaca tras recuperación de 1' entre centrocampistas vs delanteros, t(10)= 3.04, p < 0.03, d= 1.18. Además, se encontró una correlación entre los datos promediados de la frecuencia cardíaca a velocidad aeróbica máxima y los datos promediados de la percepción del grado de recuperación. CONCLUSIÓN: Estos datos indican un mejor comportamiento cardiovascular en los centrocampistas, coincidiendo con lo datos existentes en la literatura


OBJECTIVE: Calculate the maximum oxygen consumption during physical effort in a submaximal field test (Intermittent Recovery Yo-Yo I) and obtain subjective perception of effort and perception of degree of recovery between the different positions occupied by youth soccer's on the field. METHOD: 32 male soccer players from the 1st Andalusian Division U15. The maximum oxygen consumption was calculated using the Intermittent Recovery Yo-Yo I field test, consequently efforts perception and heart rate was recorded. RESULTS: Different t-test comparing the data obtained, only reflected significant differences between midfielders vs. forwards in heart rate after of 1' recovery, t (10) = 3.04, p < 0.03, d=1.18. In addition, we found a positive correlation in heart rate at maximum aerobic velocity and perception of degree of recovery data. CONCLUSIONS: The data show a better cardiovascular performance in midfielders coincided with literature


OBJETIVO: Calcular o consumo máximo de oxigênio através de um teste de campo submáximo (Recuperação intermitente Yo-Yo I) e avaliar a percepção subjetiva do esforço e a percepção do grau de recuperação entre jogadores e suas diferentes posições em campo. MÉTODOS: 32 jogadores de futebol do sexo masculino da 1ª Divisão da Andaluzia Sub 15 realizaram o teste de campo Recuperação intermitente Yo-Yo I para calcular o consumo máximo de oxigênio, posteriormente foram registradas a percepção de esforços e a frequência cardíaca. RESULTADOS: Diferentes testes t comparando os dados obtidos mostraram apenas diferenças significativas na frequência cardíaca após a recuperação de 1' entre os médios e os avançados, t (10) = 3.04, p <0.03, d = 1.18. Além disso, foi encontrada uma correlação entre os dados médios do frequência cardíaca para o velocidade aeróbica máxima e os dados médios do percepção do grau de recuperação. CONCLUSÃO: Esses dados indicam melhor comportamento cardiovascular em médios, coincidindo com o que existe na literatura


Assuntos
Humanos , Masculino , Adolescente , Futebol/fisiologia , Treinamento de Força/métodos , Aptidão Física/fisiologia , Desempenho Atlético/estatística & dados numéricos , Resistência Física/fisiologia , Antropometria/métodos , Pesos e Medidas Corporais/estatística & dados numéricos
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