Physiological profiles of Hong Kong élite soccer players

Assessment of Strength and Power Capacities in Elite Male Soccer: A Systematic Review of Test Protocols Used in Practice and Research

BACKGROUND

Strength and power represent two crucial physical qualities for the attainment of a high level of performance considering the frequency and the importance of explosive actions occurring during elite soccer match-play. Evaluation of strength and power is a multifaceted concept involving a vast array of tests and outcome variables. Nevertheless, a comprehensive and systematic search of strength and power assessment procedures in elite soccer has yet to be undertaken.

OBJECTIVES

The aims of this systematic review were to: (1) identify the tests and outcome variables used to assess strength and power of elite male soccer players; (2) provide normative values for the most common tests of strength and power across different playing levels; and (3) report the reliability values of these strength and power tests.

METHODS

A systematic review of the academic databases MEDLINE, CINAHL, SPORTDiscus, Web of Science and OVID for studies published until August 2023 was conducted, following the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were eligible for inclusion if they: (1) were original research studies, published in a peer-reviewed journal, and written in English language; (2) had the primary aim to assess strength and/or power; (3) players were male and older than 17 years of age (i.e., mean age of the group); and (4) their playing level was defined as "professional", "international" or "elite".

RESULTS

Regarding strength testing, 115 studies and 29 different tests were identified. The three most frequent strength tests were the knee extensor isokinetic strength test (58 studies), the knee flexor isokinetic strength test (55 studies) and the Nordic hamstring strength test (13 studies). In terms of power testing, 127 studies with 31 different tests were included. The three most frequent power tests were the countermovement jump with hands fixed on hips (99 studies), the squat jump (48 studies) and the vertical jump with arm swing (29 studies).

CONCLUSIONS

The wide range of different tests and outcome variables identified in this systematic review highlights the large diversity in the employed testing procedures. The establishment of a hybrid testing approach, combining standardised and widely accepted tests for establishing normative standards and enabling comparisons across different contexts, with flexible context-specific testing batteries, has the potential to maximise the impact of testing information for practitioners. In addition, the limited reporting of reliability data across studies highlights the need for practitioners to establish their own reliability measure within their specific contexts, informing the selection of certain tests and outcome variables.

Assessing Cardiorespiratory Fitness of Soccer Players: Is Test Specificity the Issue?-A Review

It is important that players and coaches have access to objective information on soccer player’s physical status for team selection and training purposes. Physiological tests can provide this information. Physiological testing in laboratories and field settings are very common, but both methods have been questioned because of their specificity and accuracy respectively. Currently, football players have their direct aerobic fitness assessed in laboratories using treadmills or cycle ergometers, whilst indirect measures (using estimation of aerobic performance) are performed in the field, typically comprising multiple shuttle runs back and forth over a set distance. The purpose of this review is to discuss the applied techniques and technologies used for evaluating soccer players’ health and fitness variables with a specific focus on cardiorespiratory testing. A clear distinction of the functionality and the specificity between the field tests and laboratory tests is well established in the literature. The review findings prioritize field tests over laboratory tests, not only for commodity purpose but also for motivational and specificity reasons. Moreover, the research literature suggests a combination of various tests to provide a comprehensive assessment of the players. Finally, more research needs to be conducted to develop a specific and comprehensive test model through the combination of various exercise modes for soccer players.

Power and endurance in Hong Kong professional football players

Background

The purpose of this study was to investigate the power and endurance characteristics of Hong Kong professional football players. Training recommendations can be deduced based on the comparison between Hong Kong and international football players.

Methods

Eighty-eight Hong Kong professional football players (height, 177.2 ± 6.4 cm; weight, 70.6 ± 7.6 kg; age, 25.6 ± 5.0 years) in the first division league participated in a battery of tests, which included: (1) height, (2) weight, (3) countermovement jump, (4) 30-m sprinting, and (5) Yo-Yo Intermittent Recovery Test Level 2.

Results

Compared with the test results of the first division players in other countries as reported in the literature (Norway, France, and Scandinavian countries), Hong Kong players were shorter in height (0.1–2.1%), lighter in weight (5.5–8.3%), fair in vertical jump height (−4.8–17%), slower in acceleration (4.2–5.1%) and maximum speed (3–14.2%), and had poorer aerobic and anaerobic endurance (22.9%).

Conclusion

The present study suggests that Hong Kong football players (or players with similar physique and ability) need to improve their power and endurance.

Analysis of body mass components in national club football players in republic of macedonia

Aim:

This study aims to analyze body composition in adult male football players and its changes during adulthood.

Methods:

Adult male football players (n=942, mean age 24.11 ±4.69y), all members of national competitive clubs from Macedonia were included in the study. The absolute and the relative body components were calculated: lean body mass (LBMkg), muscle mass (MMkg; MM%), bone mass (BMkg; BM%) and fat components (FMkg; FM%), using the anthropometric protocol by Matiegka.

Results:

Mean values of anthropometric measures for all included participants were as follows: height=178.39±6.11cm; weight=77.02±7.57; LBM=65.65±6.38; MM%=53.23±2.78; BM%=17.05±1.27; FM%=14.58±1.48. Descriptive statistics for these parameters was made for age specific groups.

Conclusions:

The results obtained could be used as reference values for adult football players in Republic of Macedonia. In the examined age span (18-35 years) a slight increase of absolute values of all three body components has been registered with advancing age. The most significant increase in the absolute values was registered for the muscle component, followed by the fat and bone components, respectively. Regarding the relative values (%), the muscle and the fat components showed an equally slight positive correlation with the age increase of 1 year, whilst the bone component decreased with advancing age.

The incidence and nature of injuries sustained on grass and 3rd generation artificial turf: a pilot study in elite Saudi National Team footballers

PURPOSE OF THE STUDY

To compare the incidence, severity and nature of injuries sustained by Saudi National Team footballers during match-play and training on natural grass and 3rd generation (3G) artificial turf.

METHOD

Injury data was collected on all Saudi National Team players competing at the Gulf Cup (Yemen December 2010: 3G) and the Asian Cup (Qatar January 2011; grass). A total of 49 players were studied (mean ± SD; Age 27 ± 4 yr; body mass 71.4 ± 6.7 kg; height 176.8 ± 6.3 cm; professional playing experience 9 ± 3 yr) of which 31 competed at the Gulf Cup, 32 at the Asian Cup (14 at both). A prospective cohort design was used to investigate the incidence, nature and severity of injuries sustained with data collected using a standardised injury questionnaire. All data were collected by the team physiotherapist with the definition of injury set at any injury that required player and clinician contact. Injury and exposure data were collected and reported for games, training and all football activity.

RESULTS

A total of 82 injuries [incidence - 56.1 per 1000 h total game and training exposure] were recorded at the Asian Cup (grass) and 72 injuries [incidence - 37.9 per 1000 h total game and training exposure] were recorded at the Gulf Cup (3G). Incidence data for training, game and all football exposure injury rates were higher when playing on grass. The vast majority of injuries on both surfaces were very minor that, whilst requiring medical attention, did not result in loss of match/training exposure. Injuries that resulted in 1-3 days absence from training or game play had similar incidence rates (Grass: 7.4 vs. 3G: 7.4 injuries per 1000 h exposure). More severe injuries were less frequent but with a higher incidence when playing on grass. Lower limb injuries were the most common in both tournaments with a higher incidence on grass (Grass: 14.2 vs. 3G: 7.9 injuries per 1000 h exposure). Muscle injuries were the most frequent of all injuries with similar incidence rates on both surfaces (Grass: 5.4 vs. 3G: 4.7 injuries per 1000 h exposure). Injuries that involved player contact were also more common on grass (Grass: 11.5 vs. 3G: 3.2 injuries per 1000 h exposure).

CONCLUSION

Whether reporting all injuries or just those that prevented players from taking part in training or match play, injury incidence rates were generally higher when Saudi National Team footballers played on grass than on 3G artificial surface. Although this is a small study, the unique quasi-repeated measures study design with elite Saudi National Team footballers, adds to the current belief that 3G artificial turf does not increase injury risk in football.

Anthropometry and body composition in soccer and volleyball players in West Bengal, India

50 sedentary males and 128 sports persons (volleyball=82, soccer=46) of 20-24 years were selected from West Bengal, India, to evaluate and compare their anthropometry and body composition. Skinfolds, girth measurements, body fat percentage (%fat), and endomorphy were significantly higher among sedentary individuals, but lean body mass (LBM) and mesomorphy were significantly (p<0.001) higher among the sports persons. Soccer and volleyball players were found to be ectomorphic mesomorph, whereas sedentary subjects were endomorphic mesomorph. The soccer and volleyball players had higher %fat with lower body height and body mass than their overseas counterparts. %fat exhibited a significant correlation with body mass index (BMI) and thus prediction equations for %fat from BMI were computed in each group. The present data will serve as a reference standard for the anthropometry and body composition of Indian soccer and volleyball players and the prediction norms for %fat will help to provide a first-hand impression of body composition in the studied population.

Estudo comparativo do consumo de oxigênio e limiar anaeróbio em um teste de esforço progressivo entre atletas profissionais de futebol e futsal

O consumo de oxigênio (VO2) tem sido de grande valia na avaliação funcional de atletas. A ergoespirometria é um procedimento não invasivo, utilizado para avaliar o desempenho físico ou a capacidade funcional de um indivíduo, conciliando a análise de gases espirados e variáveis respiratórias. No esporte, esse método de avaliação é de fundamental importância, pois traz significativa contribuição na verificação de índices de aptidão cardiorrespiratória, como é o caso do consumo máximo de oxigênio (VO2 máx.) e o limiar anaeróbio (LA). O presente estudo teve como objetivo realizar uma comparação do consumo de oxigênio e limiar anaeróbio entre atletas profissionais de futebol e futsal em um teste progressivo. Participaram voluntariamente 31 indivíduos do sexo masculino, sendo: 19 atletas profissionais de futebol e 12 atletas profissionais de futsal. Os atletas foram submetidos a um protocolo de avaliação cardiorrespiratória progressiva pelo método ergoespirométrico e os resultados foram analisados quanto a sua diferença estatística através do teste t de Student (p < 0,05). Os valores de VO2 pico médios entre os dois grupos não apresentaram diferença estatisticamente significante (p > 0,05); entretanto, houve diferença estatística entre os dois grupos em relação ao limiar anaeróbio (LA) (p < 0,05). Com base nos resultados obtidos em nosso estudo pudemos concluir que, mesmo praticando esportes com diferentes características, os atletas de ambos os grupos possuem valores similares de consumo de oxigênio, porém, o limiar anaeróbio entre os dois grupos não apresentou a mesma similaridade, sugerido maior predominância do metabolismo anaeróbio durante o exercício nos atletas de futsal.

Physiology of soccer: an update

Soccer is the most popular sport in the world and is performed by men and women, children and adults with different levels of expertise. Soccer performance depends upon a myriad of factors such as technical/biomechanical, tactical, mental and physiological areas. One of the reasons that soccer is so popular worldwide is that players may not need to have an extraordinary capacity within any of these performance areas, but possess a reasonable level within all areas. However, there are trends towards more systematic training and selection influencing the anthropometric profiles of players who compete at the highest level. As with other activities, soccer is not a science, but science may help improve performance. Efforts to improve soccer performance often focus on technique and tactics at the expense of physical fitness. During a 90-minute game, elite-level players run about 10 km at an average intensity close to the anaerobic threshold (80-90% of maximal heart rate). Within this endurance context, numerous explosive bursts of activity are required, including jumping, kicking, tackling, turning, sprinting, changing pace, and sustaining forceful contractions to maintain balance and control of the ball against defensive pressure. The best teams continue to increase their physical capacities, whilst the less well ranked have similar values as reported 30 years ago. Whether this is a result of fewer assessments and training resources, selling the best players, and/or knowledge of how to perform effective exercise training regimens in less well ranked teams, is not known. As there do exist teams from lower divisions with as high aerobic capacity as professional teams, the latter factor probably plays an important role. This article provides an update on the physiology of soccer players and referees, and relevant physiological tests. It also gives examples of effective strength- and endurance-training programmes to improve on-field performance. The cited literature has been accumulated by computer searching of relevant databases and a review of the authors' extensive files. From a total of 9893 papers covering topics discussed in this article, 843 were selected for closer scrutiny, excluding studies where information was redundant, insufficient or the experimental design was inadequate. In this article, 181 were selected and discussed. The information may have important implications for the safety and success of soccer players and hopefully it should be understood and acted upon by coaches and individual soccer players.

A comparison of the physiological profiles of elite Gaelic footballers, hurlers, and soccer players

BACKGROUND

Gaelic football, soccer, and hurling are prominent field games in Ireland and involve participants undertaking a variety of playing tasks and skills which place various physiological demands on the participants. The aim of this study was to evaluate and compare the mid-season physiological profiles of elite players.

METHODS

Physiological assessment was carried out on 29 inter-county Gaelic footballers, 30 inter-county hurlers, and 21 League of Ireland soccer players.

RESULTS

Significant differences were reported for % body fat (p<0.05), aerobic capacity (p<0.05), flexibility (p<0.05), upper body strength (p<0.05), upper body strength endurance (p<0.05), abdominal endurance (p<0.05), and speed endurance (p<0.05), while there were no differences recorded for height, weight, or speed levels. A relatively heterogeneous body size is evident for all three sports. Soccer players had lower body fat levels, greater aerobic capacity, greater strength endurance, and greater flexibility compared to both Gaelic footballers and hurlers, possibly due to specific training and conditioning programmes or physical adaptation to match play The greater strength of both Gaelic footballers and hurlers and the superior speed endurance levels of Gaelic footballers also reflect the physical nature of the sports. Similar speed levels amongst all three sports reflect the importance of speed for performance.

CONCLUSIONS

The various physiological attributes for Gaelic football, soccer, and hurling reflect the physical requirements for success and participation in each of these field games.

Football injuries at Asian tournaments

PURPOSE

To examine the incidences and patterns of injuries that required medical attention among Asian football players.

METHODS

A total of 411 Asian football players at both senior and youth (U-20) elite levels were observed during 50 international matches. Independent injury observers and team doctors determined the occurrence of injuries and recorded the location, type, time, and circumstances of the injuries using a protocol sheet.

RESULTS

The overall injury frequency rate was 45.8 out of 1000 hours. As the tournaments progressed into the knockout stages, the incidence and severity of the injuries increased. The most common sites of injuries were the knees (18.5%), lower legs (17.3%), and ankles (14.2%). Although most injuries were diagnosed as contusions, the more serious injuries were those diagnosed as sprains (especially concerning the knee and ankle) or strains (thigh and back).

CONCLUSIONS

The incidences of injuries to Asian football players were higher than those to European players, but the patterns of the injuries showed no major differences.

CLINICAL RELEVANCE

To develop an injury-prevention program, more solid and comprehensive data need to be collected to identify the risk factors and variables associated with higher incidences of injuries to Asian football players.

Índices de aptidão funcional em jogadores de futebol da Seleção Nacional da Jamaica

O principal objetivo deste estudo foi mostrar alguns índices de aptidão funcional em 24 jogadores de futebol da Seleção Nacional da Jamaica, com média de idade de 23,9 ± 3,7 anos, equipe pré-classificada para a Copa do Mundo da França. Todos os atletas foram submetidos a uma bateria de testes que constou de: 1) avaliação da potência, resistência muscular e o índice de fadiga no teste de Wingate, realizado numa bicicleta computadorizada da marca Cybex, modelo Bike; 2) teste isocinético computadorizado de membros inferiores no equipamento da marca Cybex, modelo 1200; 3) avaliação da flexibilidade pelo teste de Wells e Dillon; 4) exames laboratoriais; e 5) avaliação odontológica, realizada através de exames clínicos num consultório da marca Funk modelo MLX Plus. Os seguintes parâmetros e os resultados encontrados foram: Wingate: potência pico corrigida pelo peso = 11,8 ± 1,8w.kg-1; potência média = 9,1 ± 1,2w.kg-1; índice de fadiga = 46,2 ± 15,2%; Flexibilidade = 19,8 ± 4,6cm; Exames laboratoriais: urina tipo I; fezes; hemoglobina = 14,3 ± 1,0g%; ferro = 104 ± 29ng/dl; ferritina = 81,8 ± 41,7ng/dl; transferrina = 502,5 ± 113,5ug/dl; hematócrito = 43,5 ± 2,9%; eritrócitos = 4,95 ± 0,40 milhões/m³; glicose = 91,0 ± 8,5mg/dl; Avaliação odontológica: tártaro em 5 (21%); cáries em 24 (100%); gengivites em 10 (42%); endodontia em 3 (12,5%); pulpites em 1 (4%); diastema em 2 (8%); heterotópicos em 13 (54%); extrações realizadas em 14 (58%); extrações não realizadas em 4 (17%); obturações em 4 (17%); próteses em 16 (67%); a profilaxia estava sendo feita em 17 (71%) dos atletas examinados; Desempenho isocinético: torque de MMII direito a 60°S-1 na extensão = 290,4 ± 95,6Nm; na flexão = 216,1 ± 31,4Nm; torque de MMII esquerdo a 60°S-1 na extensão = 291,6 ± 62,5Nm; na flexão = 205,8 ± 35,8Nm. CONCLUSÃO: Apesar da falta de estrutura tecnológica do futebol jamaicano, os resultados demonstraram que os índices de aptidão funcional dos futebolistas avaliados neste estudo foram semelhantes aos de jogadores verificados no Centro de Medicina Integrada da Associação Portuguesa de Desportos.

P, Battistella LR. Efeito do treinamento físico específico nas respostas cardiorrespiratórias e metabólicas em repouso e no exercício máximo em jogadores de futebol profissional

O objetivo deste estudo foi analisar as alterações provocadas pelo treinamento físico específico (TFE) nas respostas cardiorrespiratórias e metabólicas de 16 jogadores de futebol profissional, com média de idade de 24,2 ± 3,6 anos. Todos os atletas foram avaliados antes e depois de quinze semanas de um programa de TFE, durante período competitivo. Os futebolistas foram submetidos a teste máximo em esteira rolante, utilizando-se o protocolo de Ellestad20. A resposta de freqüência cardíaca (FC) foi registrada por meio de um eletrocardiógrafo de 3 derivações simultâneas e a pressão arterial (PA), por meio de método auscultatório. A ventilação pulmonar (V E), o consumo de oxigênio (VO2), a produção de dióxido de carbono (VCO2) e a razão de troca respiratória (RER) foram calculados a partir de valores medidos por um sistema espirométrico computadorizado (Beckman) e a capacidade anaeróbia máxima, por meio da concentração sanguínea de ácido lático, utilizando-se analisador automático. O TFE não modificou significativamente a FC máxima (192 ± 8 vs. 186 ± 6bpm) e a PA sistólica máxima (196 ± 10 vs. 198 ± 8mmHg). A resposta ventilatória máxima foi significativamente aumentada (129 ± 19 vs. 140 ± 16L.min_1 [p< 0.05]), enquanto a capacidade aeróbia máxima não foi significativamente modificada (50,0 ± 6,0 vs. 53,0 ± 5,0ml.kg._1min_1) por esse treinamento. Ao contrário, a capacidade anaeróbia máxima aumentou significativamente (8,3 ± 0,2 vs. 9,8 ± 2,4mmol.L_1 [p< 0,05]). Concluiu-se: 1) o TFE não modificou as respostas de FC e PA no repouso e no exercício máximo; 2) a maior V E no exercício máximo associada a elevada concentração sanguínea de ácido lático demonstraram que o TFE utilizado nesse estudo foi caracterizado por exercícios predominantemente intensos; e 3) o TFE não representou estímulo adequado para aumentar a capacidade aeróbia máxima dos futebolistas.

Physiological profiles and sport specific fitness of Asian elite squash players

There is a scarcity of descriptive data on the physiological characteristics of elite Asian squash players. The purpose of this study was to evaluate the physiological profile and sports specific fitness of Hong Kong elite squash players. It was conducted before the selection of the Hong Kong national squash team for the 1992 Asian Squash Championship. Ten elite squash players were selected as subjects for the study. Maximum oxygen uptake was measured using a continuous treadmill running test. A sports specific field test was performed in a squash court. The following means (s.d.) were observed: height 172.6(4.3) cm; weight 67.7(6.9) kg; body fat 7.4(3.4)%; forced vital capacity (FVC) 5.13(0.26) litres; maximum oxygen uptake (VO2max) 61.7(3.4) ml.kg-1.min-1; anaerobic threshold (AT) 80.2(3.3)% of VO2max; alactic power index 15.5(1.8) W.kg-1; lactic work index 323.5(29.4) J.kg-1, peak isokinetic dominant knee extensor and flexor strengths 3.11(0.29) Nm.kg-1 and 1.87(0.18) Nm.kg-1. The results show that the Hong Kong squash players have relatively high cardiorespiratory sports specific fitness and muscle strength which may be one of the key factors that contributed to the success of the Hong Kong team in the Asian Championship.