Latest research in football - week 50 - 2022

As previous literature updates, I have performed a PubCrawler search looking for football articles in NCBI Medline (PubMed) and GenBank databases. 


Following studies were retrieved for this week:

#1 Aerobic and Anaerobic Fitness according to High-Intensity Interval Training Frequency in Youth Soccer Players in the Last Stage of Rehabilitation

Reference: Int J Environ Res Public Health. 2022 Nov 23;19(23):15573. doi: 10.3390/ijerph192315573.

Authors: Shuren Yan, Yonghwan Kim, Yongchul Choi

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Summary: In the last stage of rehabilitation, high-intensity interval training (HIIT) for improving physical fitness is appropriate for return-to-play; however, some youth athletes visit the rehabilitation center less frequently due to conflict with their distance to center, and academic schedule. We tested the effects of short-term low-frequency HIIT in 54 youth male soccer players, after dividing them into a low-frequency group (LFG, n = 27 players) and a high-frequency group (HFG, n = 27 players). Muscle mass and body fat were measured using a body composition test, and VO2peak and exercise duration were measured using a treadmill. Five sets of anaerobic peak power and fatigue were measured repeatedly using the Wingate test. To evaluate knee joint muscle function, 60°/s, 180°/s, and 240°/s were measured using the isokinetic muscle function equipment. HIIT sessions were conducted twice a week for LFG and five times a week for HFG for 4 weeks. In this study, Wilcoxon signed-rank test and Mann-Whitney U test were mainly used for analysis. Significant improvements in VO2peak, anaerobic peak power, and knee strength were observed after intervention in both groups (p < 0.05). In the post test, there were significant differences between groups in VO2peak (LFG, 56.4 vs. HFG, 57.1 mL/kg/min; p = 0.035), exercise duration (LFG, 972.3 vs. HFG, 990.4 s; p = 0.041), Wingate anaerobic peak power 5 sets (LFG, 606.3 vs. HFG, 629.3 Watt; p = 0.039), and muscle function test 240°/s (LFG, 68.5 vs. HFG, 70.2 Jouls; p = 0.010). However, neither group showed significant changes in body composition, such as muscle mass or body fat (p > 0.05). In conclusion, although it is a short-term training, the effect of HIIT was shown in the HFG as well as LFG. Although HFG improved physical fitness, significant improvement was also achieved in LFG. Therefore, in the last stage of rehabilitation, low frequency as well as high frequency HIIT would be an appropriate training method to improve physical fitness for youth soccer players.



#2 Using the Conceptual Framework for Examining Sport Teams to Understand Group Dynamics in Professional Soccer

Reference: Int J Environ Res Public Health. 2022 Nov 27;19(23):15782. doi: 10.3390/ijerph192315782.

Authors: Inmaculada González-Ponce, Jesús Díaz-García, José C Ponce-Bordón, Ruth Jiménez-Castuera, Miguel A López-Gajardo

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Summary: The aim of this study is to propose a model of the interactions of group dynamics using the conceptual framework to examine sports teams; The hypothesized model includes measures of group structure (authentic leadership, perceived justice, coaching competency, role clarity/ambiguity, and role conflict), group cohesion (cohesion and team conflict), and group processes (collective efficacy and transactive memory systems). Participants were 581 professional soccer players (M = 24.51, SD = 3.73; 356 males and 225 females) who completed a multisection questionnaire assessing group dynamics variables; The results show that coach leadership predicts coaching competency and perceived justice, and both competency and justice predict role ambiguity and role conflict. Furthermore, role ambiguity and role conflict predict group cohesion and team conflict, whereas group cohesion and team conflict both predict the transactive memory system. Finally, collective efficacy is predicted by the transactive memory system; The results suggest the importance of coach behavior (leadership, justice, and competency) and group processes to improving team functioning in a professional sports context.



#3 The Influence of a Single Instrument-Assisted Manual Therapy (IAMT) for the Lower Back on the Structural and Functional Properties of the Dorsal Myofascial Chain in Female Soccer Players: A Randomised, Placebo-Controlled Trial

Reference: J Clin Med. 2022 Nov 30;11(23):7110. doi: 10.3390/jcm11237110.

Authors: Patrick Weber, Werner Klingler, Robert Schleip, Nadine Weber, Christine Joisten

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Summary: Instrument-assisted manual therapy (IAMT) is indicated to improve flexibility, reduce pain, and induce hyperaemia locally and along myofascial chains. The underlying effects are largely unclear. This randomised, placebo-controlled pilot study aimed to gain first insights into these effects, primarily on the structural level, through ultrasonography. 67 healthy female soccer players aged 20.9 (±3.9) years were examined after right lumbar intervention (IAMT: intervention group (IG), heat application: comparison group (CG), pressure-less placebo: placebo group (PG)). Ultrasonography (absolute movement and shear motion), flexibility tests (passive straight leg raise test (PSLR), lumbar and thoracic double inclinometry), and superficial skin temperature were recorded before (t0), immediately (t1) and 45 min after the intervention (t2). IAMT decreased the absolute mobility of the superficial lamina and its shear motion to the superficial fascia compared with the PG (t1; p < 0.05). PSLR improved in the IG compared with the CG (t2) and PG (t1, t2; p < 0.05). The temperature increased in the IG and CG compared with the PG (t1, t2) and in the CG compared with the IG (t1; p < 0.05). IAMT of the lumbar back briefly reduces absolute mobility of the superficial lamina and its shear motion to the superficial fascia, improves flexibility, and increases the temperature.



#4 Muscle Architecture, Morphology, and Mechanical and Functional Properties of Biceps Femoris Long Head in Professional Soccer Players with a Prior Healed Injured Hamstring

Reference: J Clin Med. 2022 Dec 5;11(23):7222. doi: 10.3390/jcm11237222.

Authors: Francisco Javier Nuñez, Ramona Ritzmann, Fernando Hernandez-Abad, Juan Carlos Martinez, Luis Suarez-Arrones

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Summary: The aim of the present study was to compare the fascicle length, pennation angle, muscle thickness and stiffness of the biceps femoris long head, and eccentric hamstring strength between injured dominant limbs, injured non-dominant limbs, uninjured dominant limbs and uninjured non-dominant legs in previously injured players, and between dominant and non-dominant legs in uninjured elite soccer players. Twenty elite soccer players participated in this study. Ultrasound imaging and MyotonPRO were used to determine the morphological and mechanical properties of the biceps femoris long head. Isokinetic and Nordic hamstring exercises were used to assess eccentric hamstring strength. Previously injured players showed substantially lower fascicle length and muscle thickness, and significantly higher biceps femoris long head stiffness than uninjured players, without differences between limbs. The morphological and mechanical properties of elite soccer players with hamstring injury history were different from those in uninjured players. The lack of differences between limbs showed that these values are characteristics of individual players that must be considered in the design of programs to prevent BFlh injury.



#5 The Effect of a Single Dose of Citrulline on the Physical Performance of Soccer-Specific Exercise in Adult Elite Soccer Players (A Pilot Randomized Double-Blind Trial)

Reference: Nutrients. 2022 Nov 26;14(23):5036. doi: 10.3390/nu14235036.

Authors: Eduard Bezuglov, Ryland Morgans, Artemii Lazarev, Evgeny Kalinin, Mikhail Butovsky, Evgeny Savin, Eduard Tzgoev, Bekzhan Pirmakhanov, Anton Emanov, Andrey Zholinsky, Oleg Talibov

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Summary: The purpose of this study was to evaluate the effect of a single intake of citrulline at 3 g and 6 g doses in adult elite soccer players performing sport-specific exercise. This randomized double-blind placebo-controlled study analyzed 18 soccer players from the top divisions of three European countries. Participants were randomized into three groups of six each and performed a field-based soccer-specific test for 18 min. Comparative analysis of heart rate, fatigue and post-exercise recovery was conducted. There were no statistically significant differences in most of the analyzed parameters, nor at any of the time points for lactate concentration. Players' RPE exercise test score did not reveal any differences. Neither a single intake of 3 g nor of 6 g of citrulline malate affected physical performance, subjective feelings of fatigue or post-exercise recovery in adult elite soccer players who performed a soccer-specific test.



#6 Risks of the Athletic Field Revisited: Report of Unusual Occurrences of Cardiac Arrest and Sudden Death in Professional Soccer Players

Reference: Am J Med. 2022 Dec 7;S0002-9343(22)00884-1. doi: 10.1016/j.amjmed.2022.11.014.

Authors: Jiri Bonaventura, Ethan J Rowin, Martin S Maron, Barry J Maron

Summary: Sudden deaths in competitive athletes are highly visible but potentially preventable events that generate great interest amongst the cardiovascular community and general public. Internet searches was performed using a combination of keywords and operators to produce search results for sudden death or cardiac arrest on the field in professional soccer players. We identified 35 male professional soccer players (mean age 26 ± 5 years) who experienced collapse and cardiac arrest on the field (most during matches) in Europe from December 2002 to February 2022 with 63 % in the last 6 years. Twenty-five have died on the field or later in a hospital despite cardiopulmonary resuscitation. Of the 10 survivors, eight were implanted with cardioverter-defibrillators for secondary (n=6) or primary (n=2) prevention and returned to full competition; five of the 8 required successful device therapy during matches or training. Cardiac arrest and sudden death can occur not uncommonly in professional athletes highly trained over decades and participating at an elite sports level. Our observations also underscore the importance of targeted preparticipation cardiovascular screening, and availability of external defibrillators on the playing field.



#7 The keys of pressing to gain the ball - Characteristics of defensive pressure in elite soccer using tracking data

Reference: Sci Med Footb. 2022 Dec 19;1-9. doi: 10.1080/24733938.2022.2158213. Online ahead of print.

Authors: Leander Forcher, Leon Forcher, Stefan Altmann, Darko Jekauc, Matthias Kempe

Summary: Recently, the availability of big amounts of data enables analysts to dive deeper into the constraints of performance in various team sports. While offensive analyses in football have been extensively conducted, the evaluation of defensive performance is underrepresented in this sport. Hence, the aim of this study was to analyze successful defensive playing phases by investigating the space and time characteristics of defensive pressure.Therefore, tracking and event data of 153 games of the German Bundesliga (second half of 2020/21 season) were assessed. Defensive pressure was measured in the last 10 seconds of a defensive playing sequence (time characteristic) and it was distinguished between pressure on the ball-carrier, pressure on the group (5 attackers closest to the ball), and pressure on the whole team (space characteristic). A linear mixed model was applied to evaluate the effect of success of a defensive play (ball gain), space characteristic, and time characteristic on defensive pressure.Defensive pressure is higher in successful defensive plays (14.47 ± 16.82[%]) compared to unsuccessful defensive plays (12.87 ± 15.31[%]). The characteristics show that defensive pressure is higher in areas closer to the ball (space characteristic) and the closer the measurement is to the end of a defensive play (time characteristic), which is especially true for successful defensive plays. Defensive pressure is a valuable key performance indicator for defensive play. Further, this study shows that there is an association between the pressing of the ball-carrier and areas close to the ball with the success of defensive play.



#8 Ugly side of the beautiful game: the football world cup and domestic violence

Reference: BMJ. 2022 Dec 16;379:o3021. doi: 10.1136/bmj.o3021.

Authors: Kirsty Forsdike, Leesa Hooker, Anne-Marie Laslett

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#9 Changes in body composition during the macrocycle of professional football players in relation to sports nutrition knowledge

Reference: Front Nutr. 2022 Nov 29;9:981894. doi: 10.3389/fnut.2022.981894. eCollection 2022.

Authors: Wiktoria Staśkiewicz, Elzbieta Grochowska-Niedworok, Grzegorz Zydek, Agnieszka Białek-Dratwa, Mateusz Grajek, Sylwia Jaruga-Sȩkowska, Oskar Kowalski, Marek Kardas

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Summary: Professional football players are obligated to meet the physical demands and maintain the best possible performance throughout the whole macrocycle. It is important to assess the players' nutrition knowledge, identify areas that require increased nutrition awareness and identify the impact of knowledge on changes in body composition as this can affect the players' health and performance. This study aimed to assess changes in the body composition of professional football players during the macrocycle of the spring round of the football championship and to identify the correlation between nutrition knowledge and maintaining body composition. The study included 38 football players. The players' body compositions were analyzed 6 times during the macrocycle consisting of preparatory, competitive, and transition periods using the Direct Segmental Multi-Frequency Bioelectrical Impedance Analysis method. Athletes completed the Nutrition for Sport Knowledge Questionnaire to assess their nutrition knowledge. During the preparatory period, a statistically significant negative correlation was demonstrated between the players' knowledge about the subsections of micronutrients in the diet and the dispersion of the adipose percentage tissue content (r = -0.36, p = 0.03). In the competitive period, there was a statistically significant negative correlation between the players' knowledge of sports nutrition and the dispersion of lean body mass (r = -0.46, p = 0.004), and skeletal muscle mass (r = -0.36, p = 0.03). During the transition period, a statistically significant negative correlation between the players' knowledge of weight control and the dispersion of body mass (r = -0.47, p = 0.00) and BMI values (r = -0.48, p = 0.00) was identified. The player's knowledge about the subsection of macronutrients significantly negatively correlated with the dispersion of skeletal muscle mass content (r = -0.33, p = 0.05). Nutrition knowledge has an impact on the stability of body composition during all analyzed periods: preparatory, competitive, and transition periods.




#10 Lifestyle characteristics in adolescent female football players: data from the Karolinska football Injury Cohort

Reference: BMC Sports Sci Med Rehabil. 2022 Dec 14;14(1):212. doi: 10.1186/s13102-022-00603-1.

Authors: Anne Fältström, Eva Skillgate, Nathan Weiss, Henrik Källberg, Victor Lyberg, Markus Waldén, Martin Hägglund, Martin Asker, Ulrika Tranaeus

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Summary: Normative values of lifestyle characteristics in adolescent female football players may be used by clinicians and coaches to take actions because the potential important for well-being, performance on the pitch, and risk of injury. The aim was to report descriptive characteristics of lifestyle factors in adolescent female football players and potential changes over 1 year. We included 419 adolescent competitive female football players from 12 clubs and 27 teams (age 14 ± 1 years, range 12-17 years) and 286 were followed over 1 year. The players completed an extensive questionnaire regarding demographics, football-related factors, and lifestyle factors including tobacco consumption, alcohol use, medicine intake, eating and sleeping habits, well-being, stress, coping, and passion. Baseline data are presented for the total cohort and separately for 4 age groups (12, 13, 14, and 15-17 years). 12% skipped breakfast, 8% skipped lunch and 11% used protein supplements several days per week. 16% slept less than 8 h/night, 8% had impaired sleep with daytime consequences, and 22% stated that they were tired in daily activities several days per week. 32% experienced stress some or most days/week and 24% were classified as having psychological distress. Medicine intake (23% vs. 34%), skipping breakfast or lunch several days per week (10% vs. 47% and 20 vs. 33%), tiredness (20% vs. 27%), stress (26% vs. 40%), and psychological distress (27% vs. 37%) increased significantly (P = 0.031 to < 0.001) at the 1-year follow-up. Many adolescent female football players skip breakfast and lunch, have insufficient sleep, experience stress and are classified as having psychological distress. These factors increased over 1 year.



#11 Bio-secure bubble during the COVID-19 pandemic to host the Asian Football Confederation (AFC) Champions League: A retrospective observational study

Reference: Health Sci Rep. 2022 Dec 9;6(1):e985. doi: 10.1002/hsr2.985. eCollection 2023 Jan.

Authors: AbdulWahab Abubaker Al Musleh, Mohammad Asim, Sameer Abdurahiman, Ayman El-Menyar, Naushad Ahmad Khan, Hassan Al-Thani

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Summary: The purpose was to describe the COVID-19 positivity rate among football players, team staff, and local organizing committee members participated in the Asian Football Confederation (AFC) Champions League (West) tournament organized with the Bio-secure bubble protocol in place. A retrospective observational study was carried out to include a total of 2184 participants during the AFC-West tournament in Qatar, which was a 3-week event (September 14-October 3, 2020). This event was undertaken under the Bio-secure bubble protocol, which was developed and implemented for sports events in Qatar during the pandemic. Within 72 h of departure and upon arrival in Qatar, all participants underwent reverse-transcriptase polymerase chain reaction testing (RT-PCR) to diagnose COVID-19. The test was considered positive based on the cycle threshold (cT) value which was <30, whereas, reactive if cT value was ≥30 and <40, and negative (cT > 40). Of the 2184 participants (528 players, 388 team staff, and 1268 local staff), 916 international participants were tested for COVID-19 PCR upon arrival at the Hamad International Airport, whereas the local staff (n = 1268) were tested 2 days before entering the bubble. The mean age of the players was 27.5 ± 9.8. Fifteen teams participated and as many as 60 matches were played over 3 weeks. Most participants tested negative (95.3%) and 3.9% tests were inconclusive. During the entire tournament, the positivity rate was 2.7% among all participants. Of the total positive cases, 0.8% were positive before entering the bubble system. The remaining (1.9%) tested positive during the tournament phase (19 players, 16 team officials, and 8 organizing committee staff). Bio-secure bubble protocol operated in a controlled environment presents a minimal risk of COVID-19 infection for hosting international football events. This framework could be benchmarked to resume professional football competitions under unprecedented pandemic situations.



#12 Insight into the Molecular Signature of Skeletal Muscle Characterizing Lifelong Football Players

Reference: Int J Environ Res Public Health. 2022 Nov 28;19(23):15835. doi: 10.3390/ijerph192315835.

Authors: Stefania Orrù, Esther Imperlini, Daniela Vitucci, Marianna Caterino, Annalisa Mandola, Morten Bredsgaard Randers, Jakob Friis Schmidt, Marie Hagman, Thomas Rostgaard Andersen, Peter Krustrup, Margherita Ruoppolo, Pasqualina Buono, Annamaria Mancini

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Summary: Aging and sedentary behavior are independent risk factors for non-communicable diseases. An active lifestyle and structured physical activity are positively associated with a healthier quality of life in the elderly. Here, we explored the proteomic/metabolomic muscular signature induced by lifelong football training associated with successful aging. The study was performed on nine lifelong football players (67.3 ± 2.8 yrs) and nine aged-matched untrained subjects. We performed a proteomic/metabolomic approach on V. lateralis muscle biopsies; the obtained data were analyzed by means of different bioinformatic tools. Our results indicated that lifelong football training is able to enhance the muscles' oxidative capacity in the elderly by promoting fatty acids as preferential energetic substrates and hence determining a healthier body composition and metabolic profile; furthermore, we showed that the total polyamine content is higher in lifelong football players' muscle, enforcing the involvement of polyamines in muscle growth and hypertrophy. Lifelong football training, as a structured physical activity, significantly influences the expression of the proteins and metabolites involved in oxidative metabolism and muscle hypertrophy associated with successful aging.



#13 Comparison of the External Load in Training Sessions and Official Matches in Female Football: A Case Report

Reference: Int J Environ Res Public Health. 2022 Nov 28;19(23):15820. doi: 10.3390/ijerph192315820.

Authors: Aratz Olaizola, Ibai Errekagorri, Karmele Lopez-de-Ipina, Pilar María Calvo, Julen Castellano

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Summary: The objective of this study was to compare the external load of training sessions using as a reference an official competition match in women's football in order to find if the training sessions replicate the competition demands. Twenty-two semi-professional football players were analyzed during 17 weeks in the first phase of the competitive period of the 2020-2021 season of Spanish women's football. In addition to the competition (Official Matches, OM), four types of sessions were distinguished: strength or intensity (INT), endurance or extensity (EXT), velocity (VEL), and activation or pre-competitive (PREOM). The external load variables recorded were total distance (TD), high-speed running (HSR), sprint (Sprint), accelerations (ACC2), decelerations (DEC2), player load (PL), distance covered per minute (TDmin), high metabolic load distance (HMLD), and total impacts. The main results were that the external load demanded was different according to the type of session, being, in all cases, much lower than OM. The variables referring to the neuromuscular demands (ACC2 and DEC2) were higher in the INT sessions, the TD variable in the EXT sessions and the velocity variables (HSR and Sprint) in the VEL sessions. We can conclude that there was an alternating horizontal distribution of training loads within the competitive micro-cycle in women's football, although the order was not the usual one for tactical periodization.



#14 The influence of removing home advantage on the Chinese Football Super League

Reference: BMC Sports Sci Med Rehabil. 2022 Dec 9;14(1):208. doi: 10.1186/s13102-022-00604-0.

Authors: Bo Han, Lang Yang, Pengyu Pan, Antonio García-de-Alcaraz, Can Yang, Tianbiao Liu

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Summary: Due to the COVID-19 pandemic, the 2020 season Chinese Super League (CSL) was held in neutral venues, this study aims to analyse the impact of removing home advantage (HA) in CSL. 240 games of the CSL 2019 season (home and away double round-robin system) and 160 games of the 2020 season (in neutral venues) were analysed. 27 technical and tactical performance indicators were involved as dependent variables. A multiple linear regression model was established to analyse the influence of removing HA on the performance indicators. After moving from home stadium to neutral venue in 2020 season, goal, shot, shot on target, shot from outside box, shot from inside box, shot on target from inside box, corner kick, key pass, cross, breakthrough, tackle decreased significantly (p < 0.05), while yellow card and foul increased steeply (p < 0.05). Comparing with playing away match, in neutral venue, free kicks and pass accuracy enhanced radically (p < 0.05), while tackle, clearance and block shot dropped noticeably (p < 0.05). When removing HA and playing in the neutral venue, teams' performance dropped significantly. This study confirmed the positive impact of HA on the teams' performance and may help elite football teams make proper playing strategies regarding different match locations.



#15 An Exploratory Study in Non-Professional Football on the Perception of Stakeholders about the New Working Professional Profile of Sports Kinesiologist

Reference: Int J Environ Res Public Health. 2022 Nov 28;19(23):15839. doi: 10.3390/ijerph192315839.

Authors: Gaetano Raiola, Tiziana D'Isanto, Francesca D'Elia, Gaetano Altavilla

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Summary: In Italy, recent amendments to Legislative Decree n. 36 of 28 February 2021, on sports work, may have made the application of the reform by stakeholders unclear, with the risk of generating further confusion among them. One of the most critical points concerns the possible equivalencies to the professional profile of the kinesiologist, which would be illegitimately recognized even for a different level of education, contrary to the requirements of the European qualification framework. The aim of the study was to understand the perceptions of stakeholders in the world of non-professional football regarding recent legislative provisions. A survey, divided into two sections, was administered to 112 presidents and 112 trainers of non-professional football associations of the province of Salerno. The first section presents five items common for both presidents and trainers, which seek to probe stakeholders' perceptions of the enjoyment, appropriateness, usefulness, and scientificity of kinesiologists. The second section presents five differentiated items. Validity and reliability were calculated. A chi-square analysis (χ2) was performed to test the independence within and between-subjects (trainers and presidents) on their perceptions about the new working professional profile of sports kinesiologist. From the results, it was possible to appreciate a discordance of opinion among stakeholders. Although the majority of presidents and trainers are in favour of introducing such a professional profile (p &lt; 0.05), contradictions emerge concerning the contribution the new professional profile can make in practice (p &gt; 0.05). The perceptual contradictions found among stakeholders' responses demonstrate how the complexity of recent regulatory provisions regarding possible equivalencies to the title of kinesiologist have inevitably generated further confusion among stakeholders.



#16 A survey of organizational structure and operational practices of elite youth football academies and national federations from around the world: A performance and medical perspective

Reference: Front Sports Act Living. 2022 Nov 23;4:1031721. doi: 10.3389/fspor.2022.1031721. eCollection 2022.

Authors: Warren Gregson, Christopher Carling, Antonio Gualtieri, James O'Brien, Patrick Reilly, Francisco Tavares, Daniele Bonanno, Emmanuel Lopez, Joao Marques, Lorenzo Lolli, Valter Di Salvo

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Summary: Medical and performance units are integral components of player development programmes in elite football academies. Nevertheless, the nature of the operational processes implemented by practitioners within clubs and national federations remains unexplored. The aim of the present study, therefore, was to survey elite youth professional football academies from around the world regarding the operational processes adopted by their medical and performance units. Of the 50 organizations invited, 10 national federations and 25 clubs took part in the survey resulting in a response rate of 70% (95% confidence interval, 56%-81%). The respondents represented three groups: senior club and academy management, performance, and medical staff. The majority (60%-90%) of clubs and national federations reported strategic alignment between senior and academy medical and performance units as well as between academy medical and performance units. Survey responses indicated substantial heterogeneity in the composition and number of medical and performance professionals employed in academies. The majority of respondents agreed their medical and performance departments were effective in utilizing staff knowledge and external sources of knowledge to inform their practice (56%-80%). Performance staff (40%-50%) and physiotherapists (30%-32%) were deemed most influential in injury prevention programmes. During the return-to-play process, the influence of specific practitioners in the medical and performance units was dependent upon the phase of return-to-play. Shared decision-making was common practice amongst performance and medical staff in injury prevention and return-to-play processes. Medical and performance data were generally centralized across the first team and academy in majority (50%-72%) of clubs and national federations. Data were integrated within the same data management system to a higher degree in clubs (68%) vs. national federations (40%). Research and development activity were reported for most academies (50%-72%), and generally led by the head of performance (37%) or team doctor (21%). Research activities were largely undertaken via internal staff (~100%), academic collaborations (50%-88%) and/or external consultants and industry partnerships (77%-83%) in the national federation and clubs. Collectively, these findings provide a detailed overview regarding key operational processes delivered by medical and performance practitioners working in elite football academies.


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