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 Does maturity estimation, 2D:4D and training load measures explain physical fitness changes of youth football players?
Reference: BMC Pediatr. 2022 Dec 20;22(1):726. doi: 10.1186/s12887-022-03801-5.
Authors: Rui Miguel Silva, Filipe Manuel Clemente, Francisco González-Fernández, Hadi Nobari, Hamed Haghighi, José Ma Cancela Carral
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9764734/pdf/12887_2022_Article_3801.pdf
Summary: The purpose of the present study was two-fold: (1) To analyse physical fitness changes of youth football players after a full-season; and (2) to examine whether physical fitness changes are explainable by estimated maturity status, 2digit:4digit ratio (2D:4D) from each hand and training load (TL) measures. Twenty-seven youth elite Under-15 football players were daily monitored for training load measures during 38 weeks. At the beginning and at the end of the season, all players were assessed for physical fitness. Also, the maturity status estimation and the length of the second and fourth digits of both hands were collected at the beginning of the season. Significant differences were found for all physical fitness measures after the season. The second and fourth digits of left and right hands had negative moderate correlations with change of direction (COD) changes (r=-.39 to - 0.45 | p = .05 to 0.02). Also, the maturity offset measure had negative moderate correlations with COD changes (r=-.40 | p = .04). From the reported significant correlations, the maturity offset, Left 4D, Right 2D and Right 4D significantly predicted the Mod.505 COD test changes (β = 0.41, p = .04; β = -0.41, p = .04; β = -0.45, p = .02; and β = -0.44, p = .03, respectively). The maturity offset and the 2D:4D measures have the potential to predict COD performance changes over-time in youth football players. Given the lack of associations between the maturity estimation, 2D:4D and training load measures, with the overall physical fitness measures, coaches should rely only at COD changes.
#2 Study on Nutritional Knowledge, Attitude and Behavior of Chinese School Football Players
Reference: Children (Basel). 2022 Dec 6;9(12):1910. doi: 10.3390/children9121910.
Authors: Yao Chen, Yingshuang Sun, Zhiyun Liu, Donglin Hu
Summary: This study aims to validate previous structural models of factors influencing dietary behavior changes and construct the knowledge, attitude, and behavioral models of youth school football players. 279 school football players aged 12-17 years in Grades 7-12 in Hunan Province, China, completed a questionnaire to collect data on sports nutrition knowledge, attitudes, and behavior. A structural equation model (SEM) was built based on the knowledge-attitude-behavior (KAB) model and the theory of planned behavior (TPB) model to introduce nutritional knowledge directly or by altering attitudes into the dietary behavior path of players. Four factors affecting dietary behaviors were involved in the hypothetical structure, which consists of the following hypotheses: (1) nutrition knowledge affects the attitude towards sports nutrition (H1); (2) nutrition knowledge affects dietary behaviors (H2); (3) nutrition knowledge affects subjective norms (H3); (4) nutrition knowledge affects perceived behavioral control (H4); (5) subjective norms affect dietary behaviors (H5); and 6) perceived behavioral control affects dietary behaviors (H6). Confirmatory factor analysis (CFA) revealed that the reliability, convergent validity, and discriminant validity of the built SEM conformed to the measured relationships in each dimension. In the final structural model, it was found that nutrition knowledge had a direct impact on the attitudes of players and affected their dietary behaviors in a direct manner or through their subjective norms and perceived behavioral control. The results are in agreement with the TPB-based KAB chain and support the KAB theory for youth school football players in Hunan Province, China.
#3 Examining the Effects of Mirror Therapy on Psychological Readiness and Perception of Pain in ACL-Injured Female Football Players
Reference: J Funct Morphol Kinesiol. 2022 Dec 14;7(4):113. doi: 10.3390/jfmk7040113.
Authors: Tiziana D'Isanto, Francesca D'Elia, Giovanni Esposito, Gaetano Altavilla, Gaetano Raiola
Summary: Virtual reality-guided imagery (VRGI) and mirror therapy (MT) have been used in isolation to treat patients suffering from different injuries. However, no attempts have been made to understand the effects of combined VRGI and MT added to conventional physical therapy, and no information exists regarding perceptual responses to these rehabilitation strategies in female football players. Thus, this study aimed to examine the effect of MT added to conventional rehabilitation on psychological readiness and perception of pain in ACL-injured female football players. Thirty ACL-injured female football players competing in the 2nd and 3rd Italian tier who underwent an ACL rehabilitation program from the same clinic participated in this study. Players were randomly distributed in an MT group (n = 15) and a CON group (n = 15). All participants reported their perception of pain on a VAS before and after the interventions and their psychological readiness to return to sport after ACL injury and reconstruction surgery on the ACL-RSI scale after the intervention. An independent-sample t-test was performed to assess between-group differences in post-intervention ACL-RSI, and a further independent-sample t-test to assume non-significant differences between VAS values before the intervention. A two-way repeated-measures analysis of variance was used to test the null hypothesis of no different change in VAS over time between groups. After the intervention, the MT group perceived largely greater psychological readiness (p < 0.01). MT and CON groups experienced a large reduction in VAS after the intervention (p < 0.001). However, a small time × group interaction was observed (p = 0.023). MT reported a greater perception of the psychological readiness of the soccer players and a lower perception of pain than those who performed conventional therapy.
#4 On-field rehabilitation in football: Current knowledge, applications and future directions
Reference: Front Sports Act Living. 2022 Dec 5;4:970152. doi: 10.3389/fspor.2022.970152. eCollection 2022.
Authors: Mark Armitage, Stuart A McErlain-Naylor, Gavin Devereux, Marco Beato, Matthew Buckthorpe
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9760760/pdf/fspor-04-970152.pdf
#5 Alcohol related harms and elite men's football
Reference: BMJ. 2022 Dec 21;379:o2906. doi: 10.1136/bmj.o2906.
Author: Robin Ireland
Download link: https://www.bmj.com/content/bmj/379/bmj.o2906.full.pdf
#6 Alcohol related disorders among elite male football players in Sweden: nationwide cohort study
Reference: BMJ. 2022 Dec 21;379:e074093. doi: 10.1136/bmj-2022-074093.
Authors: Peter Ueda, Björn Pasternak, Henrik Svanström, Carl-Emil Lim, Martin Neovius, Magnus Forssblad, Jonas F Ludvigsson, Manzur Kader
Download link: https://www.bmj.com/content/bmj/379/bmj-2022-074093.full.pdf
Summary: The aim was to assess whether male elite football players are at increased risk of alcohol related disorders compared with men from the general population, and whether such an increased risk would vary on the basis of calendar year of the first playing season in the top tier of competition, age, career length, and goal scoring abilities. 6007 male football players who had played in the Swedish top division, Allsvenskan, from 1924 to 2019 and 56 168 men from the general population matched to players based on age and region of residence participated in this study. Primary outcome was alcohol related disorders (diagnoses recorded in death certificates, during hospital admissions and outpatient visits, or use of prescription drugs for alcohol addiction); secondary outcome was disorders related to misuse of other drugs. During follow-up up to 31 December 2020, 257 (4.3%) football players and 3528 (6.3%) men from the general population received diagnoses of alcohol related disorders. In analyses accounting for age, region of residence, and calendar time, risk of alcohol related disorders was lower among football players than among men from the general population (hazard ratio 0.71, 95% confidence interval 0.62 to 0.81). A reduced risk of alcohol related disorders was observed for football players who played their first season in the top tier in the early 1960s and later, while no significant difference versus men from the general population was seen in the risk for football players from earlier eras. The hazard ratio was lowest at around age 35 years, and then increased with age; at around age 75 years, football players had a higher risk of alcohol related disorders than men from the general population. No significant association was seen between goal scoring, number of games, and seasons played in the top tier and the risk of alcohol related disorders. Risk of disorders related to other drug misuse was significantly lower among football players than the general population (hazard ratio 0.22, 95% confidence interval 0.15 to 0.34). In this nationwide cohort study, male football players who had played in the Swedish top tier of competition had a significantly lower risk of alcohol related disorders than men from the general population.
#7 Research on women's football: a scoping review
Reference: Sci Med Footb. 2022 Dec 1;6(5):549-558. doi: 10.1080/24733938.2020.1868560. Epub 2021 Jan 8.
Authors: Katrine Okholm Kryger, Albert Wang, Ritan Mehta, Franco M Impellizzeri, Andrew Massey, Alan McCall
Summary: This study aims to scope available peer-reviewed literature published in a FIFA language to understand the current quantity of research on women's football. Five databases were searched on the 15/12/2019. Studies were included when containing original research published in a peer-reviewed journal around female competitive football of any level, any age and on any subject. Author, journal, title and abstract of all included studies were scoped. Population assessed number of participants, level of play, age level of football and publication theme(s) were extracted. A total of 1,634 articles were scoped. The oldest publication dated back to 1939, whilst a total of 202 studies were gathered from 2019. The publication theme most frequently researched was sports medicine (N = 521) followed by strength and conditioning (N = 331) and sociology (N = 299). The majority of studies has focussed on elite (N = 442), senior (N = 977) players. A continuous growth in research attention has been seen. However, the numbers are not comparable to current research output levels in men's football. This study represents an essential first step in a larger 'research agenda-setting' project to determine research priorities for women's football during the next 10 years.
#8 The menstrual cycle and football: The experiences of African women football players
Reference: Sci Med Footb. 2022 Dec 1;6(5):626-632. doi: 10.1080/24733938.2021.2005252.
Authors: Nonhlanhla S Mkumbuzi, Senanile B Dlamini, Fidelis Chibhabha, Fredrick M Govere, Lucinda Manda-Taylor
Summary: The menstrual cycle is a normal biological process in women and girls. However, it is often the reason why they tend to be excluded from football medicine research. Consequently, our understanding of the menstrual cycle and football performance is still limited, especially in African women football players. The study aimed to explore African women football players' current and historical menstrual cycle status, menstrual symptoms, lived experiences, and perceptions of the menstrual cycle. Women football players at the COSAFA Women's Championship 2020 completed demographic questionnaires and the Moos Menstrual Distress Questionnaire. The main findings were that 90% of the players did not use contraceptives, . Most of the players had access to their preferred choice of sanitary product; however, 36% used alternatives such as old rags during their periods, . The most commonly reported symptoms during menses were abdominal cramps (53%), headache (41%), mood swings (41%) and irritability (47%). Further, players reported irritability (48%), mood swings (52%), and breast tenderness (48%) in the week before their period. The low use of contraceptives is likely due to community level socio-cultural factors. While the use of old rags as impromptu sanitary products is likely because they cannot always afford their preferred choice. Menstrual symptoms can affect training and competition; therefore, team support personnel should be aware of the menstrual cycle's implications for African women football players and their effect on athletic performance and well-being. Additionally, team support personnel ought to be mindful of African women football players' socio-economic and religio-cultural contexts and their interaction with biological processes such as the menstrual cycle and contraceptive use.
#9 Nitric oxide therapy is beneficial to rehabilitation in professional soccer players: clinical and experimental studies
Reference: Med Gas Res. 2023 Jul-Sep;13(3):128-132. doi: 10.4103/2045-9912.344983.
Authors: Victoria A Zaborova, Alexandra V Butenko, Anatoly B Shekhter, Alexey L Fayzullin, Alexander V Pekshev, Natalia B Serejnikova, Ol'ga V Chigirintseva, Kira Yu Kryuchkova, Konstantin G Gurevich
Summary: Nitric oxide can activate neutrophils and macrophages, facilitate the synthesis of collagen, which allows significantly accelerating the regeneration of traumatized tissues. We studied the effects of nitric oxide-containing gas flow generated by plasma-chemical device "Plason" in a rat model of full-thickness wounds. Histological and morphometric analyses revealed that Plason treated wounds expressed significantly fewer signs of inflammation and contained a more mature granulation tissue on day 4 after the operation. Considering the results of the experimental study, we applied the Plason device in sports medicine for the treatment of lower limb bruises of 34 professional soccer players. Athletes were asked to assess the intensity of pain with the Visual Analogue Scale. Girths of their lower limbs were measured over the course of rehabilitation. Nitric oxide therapy of full-thickness wounds inhibited inflammation and accelerated the regeneration of skin and muscle tissues. Compared with the control, we observed a significant reduction in pain syndrome on days 2-7 after injuries, edema, and hematoma, and shortened treatment duration. This pilot study indicates that the use of nitric oxide is a promising treatment method for sports injuries.
#10 Did the quarantine period of covid-19 interfere with the physical demands of central referees and assistants in professional soccer in a high level competition in Brazil?
Reference: Sci Sports. 2022 May;37(3):184-190. doi: 10.1016/j.scispo.2021.04.007. Epub 2021 Sep 28.
Authors: A A B Preissler, P Schons, L F M Kruel
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9758415/pdf/main.pdf
Summary: This study compares the performance demanded from central referees and soccer assistants during professional games before and after the quarantine of COVID-19 during the same competition. Ten central referees and 19 assistants were monitored. Using a watch with Global Positioning System technology and a heart rate monitor, data were obtained of the distance they moved and information on their heart rate. A game before the quarantine period was compared to a game played 128 days after the quarantine period. These participants represented all the referees who played at least one game in the pre- and post-quarantine period of the same high-level competition in Brazil. The results indicated that the total distance, average, and maximum heart rate did not present significant differences between the pre-and post-quarantine time of the central and assistant referees, except for the distance covered by the assistant referees in the second half, which was significantly greater in the post-quarantine period (Δ% = 6.27; P = 0.034). In conclusion, the central referees and assistants' performance was not affected after the 128-day quarantine period compared to the traditional transition period between the 37-day seasons.
#11 Sport specialization in Swedish football players: Investigating a model of antecedents and outcomes
Reference: Eur J Sport Sci. 2022 Dec 28;1-9. doi: 10.1080/17461391.2022.2153084. Online ahead of print.
Authors: Tor Söderström, Alex C Garn
Download link: https://www.tandfonline.com/doi/epdf/10.1080/17461391.2022.2153084?needAccess=true&role=button
Summary: Drawing on data from the present and former football players (N = 1026) selected to a national football talent programme at the age of 15, this study explores a model of sport specialisation. We examined three specific aspects of sport specialisation including early football specialisation, participation in youth elite football training environments (i.e. academies) and enrolment in upper secondary football specialisation schools. Antecedents of these sport specialisation factors included gender (i.e. sociocultural), grit (i.e. personality) and perceptions of family finances (i.e. social). Outcomes focused on adult football participation at the age of 21 including elite skill acquisition (i.e. playing elite football) and personal development (i.e. participation in non-elite football). Findings revealed that females were less likely to gain access to elite football training or school specialisation environments. There was also a positive association between grit and participation in elite training environments. In terms of outcomes, players, who got trained in elite training environments during adolescence, were twice as likely to play elite football at the age of 21, while those who attended football specialisation schools were more likely to participate in non-elite football at the age of 21. Early specialisation was not associated with either adult participation outcome. This is one of the few studies to date addressing diverse antecedents and outcomes of sport specialisation factors. Understanding how sport specialisation practices relate to future skill acquisition and personal development can provide guidance for maximising the benefits of youth sport programming.
#12 The perception of injury risk and prevention among football players: A systematic review
Reference: Front Sports Act Living. 2022 Dec 7;4:1018752. doi: 10.3389/fspor.2022.1018752. eCollection 2022.
Authors: Beatriz Cardoso-Marinho, Ana Barbosa, Caroline Bolling, José Pedro Marques, Pedro Figueiredo, João Brito
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9768495/pdf/fspor-04-1018752.pdf
Summary: Football is associated with a certain risk of injury, leading to short- and long-term health consequences. However, the perception of football players about injury risk and prevention strategies is poorly documented. The present article reviewed the literature about perceptions, beliefs, attitudes and knowledge toward injury risk and prevention strategies in football players. An electronic search was performed in PubMed, Scopus, Web of Science, and APA PsychINFO until July 2022. Studies were eligible if they included the perceptions, beliefs, attitudes, and knowledge about injury risk and prevention in football players from any competitive level. The risk of bias was assessed in included studies using the Joanna Briggs Institute critical appraisal checklist. A total of 14 studies were included. Most football players agreed that their risk of injury is high and prevention strategies are important, however they do not intend to use some of these strategies. The most frequent perceived injury risk factors were low muscle strength, lack of physical fitness, fatigue, excessive training and type and condition of surfaces. The most frequent perceived injury prevention factors were warm-up, workload monitoring and strength and conditioning training. It is essential to acknowledge perceived injury risk factors, as well as a better understanding of how coaching and medical departments' perceptions match with players' perceptions, and a modification in the perceptions of the several stakeholders at different levels of action.
#13 Changes in Performance on Common Return-to-Sport Tests During a Collegiate Women's Soccer Season: Implications for Baseline Testing
Reference: Sports Health. 2022 Dec 27;19417381221146556. doi: 10.1177/19417381221146556.
Authors: Melissa M Montgomery, Steven Carranza
Download link: https://journals.sagepub.com/doi/epub/10.1177/19417381221146556
Summary: Baseline testing of objective lower limb function may help clinicians make more informed return-to-sport (RTS) decisions in the event of an anterior cruciate ligament (ACL) injury. However, as these tests are based on physical performance, it is possible that they improve during the season as athletes get stronger and fitter. Hence, it may be difficult to ascertain the patient's preinjury status and have an accurate reference for comparison when determining readiness for RTS. The purpose of this study was to examine changes in common ACL RTS tests during a college soccer season to determine the most appropriate time to perform baseline testing. We hypothesized that the hop test performance will improve across the season. A total of 31 women's soccer players from 1 NCAA Division I university agreed to participate this study. Participants performed 4 single-leg hop tests and the 505-agility test to measure cutting speed on 3 occasions: preseason (PRE), midseason (MID), and end-of-season (END). Performance on each test was compared across days to determine whether performance increased during the season. As a secondary analysis, limb symmetry index (LSI) was also compared across the season. A total of 23 participants (age, 19.7 ± 1.3 years; height, 1.69 ± 0.07 m; weight 60.9 ± 7.2 kg) completed all 3 testing sessions during the season. Performance during PRE was better than MID and END for all hop tests (all P < 0.01). LSI did not change during the season (P value range, 0.18-0.79). Performance on the hop tests was best during preseason and declined thereafter, which may be reflective of cumulative fatigue. Baseline testing of RTS tests performed during preseason may provide an accurate representation of an athlete's best abilities over the course of a collegiate soccer season. Preseason testing would also enable athletic trainers to acquire baseline data for all athletes before they are injured.
#14 The effect of volume equated 1- versus 2-day formats of Nordic hamstring exercise training on fitness in youth soccer players: A randomized controlled trial
Reference: PLoS One. 2022 Dec 29;17(12):e0277437. doi: 10.1371/journal.pone.0277437. eCollection 2022.
Authors: Jason Moran, Norodin Vali, Ben Drury, Raouf Hammami, Jamie Tallent, Helmi Chaabene, Rodrigo Ramirez-Campillo
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9799302/pdf/pone.0277437.pdf
Summary: This randomised controlled trial examined the effect of an 8-week volume-equated programme of Nordic hamstring exercise (NHE) training, executed at frequencies of 1- or 2-days per week, on fitness (10 m and 40 m sprint, '505' change of direction [COD] and standing long jump [SLJ]) in male youth soccer players (mean age: 16.4 ± 0.81 years). Players were divided into an experimental group (n = 16) which was further subdivided into 1-day (n = 8) and 2-day (n = 8) per week training groups and a control group (n = 8). There were significant group-by-time interactions for 10-m sprint (p<0.001, η2 = 0.120, d = 2.05 [0.57 to 3.53]), 40-m sprint (p = 0.001, η2 = 0.041, d = 1.09 [-0.23 to 2.4]) and COD (p = 0.002, η2 = 0.063, d = 1.25 [-0.09 to 2.59). The experimental group demonstrated a 'very large' effect size (d = 3.02 [1.5 to 4.54]) in 10-m sprint, and 'large' effect sizes in 40-m sprint (d = 1.94 [0.98 to 2.90]) and COD (d = 1.84 [0.85 to 2.83). The control group showed no significant changes. There were no significant differences between the 1-day and 2-day training groups. In three of the four tests (40 m, COD, SLJ) the 2-day group demonstrated larger effect sizes. Ratings of perceived exertion (RPE) were significantly lower in the 2-day group (p<0.001, 3.46 [1.83 to 5.04). The NHE increases fitness in youth soccer players and there may be advantages to spreading training over two days instead of one.
#15 The relative age effect in under-17, under-20, and adult elite female soccer players
Reference: Sci Med Footb. 2023 Jan 6;1-8. doi: 10.1080/24733938.2022.2164608. Online ahead of print.
Authors: Elaine Ribeiro, Júlia Barreira, Dayse Carraco, Larissa Galatti, Martin Götze, Cesar Cavinato Cal Abad
Summary: The aim was to investigate the RAE in elite female soccer players, the absolute and relative birthdate distributions of players who disputed the Women's World Cup were assessed. Differences between observed and expected distributions were analyzed using chi-square and effect sizes. The birthdates of 1224 female soccer players were assessed in Under-17 (N = 336), Under-20 (N = 336) and adult (N = 552) categories. There was no significant RAE in adult category for different playing positions and players in general (including all playing positions per age category). There was significant RAE for midfielders and players in general with mainly small effect sizes for the U-17 and U-20. In both age categories, players born in Q1 were over-represented with the highest quartile ratio for midfielders. In regard of RAE and success defined by final ranking at the World Cup, we found no significant differences between the birthdate distributions of players who participated in either the group stages or finally the knockout phases. Coaches should consider this information to avoid bias in talent programs designed to promote and select female soccer players independently of their birthdates. Young female players should be encouraged to learn to play in different field positions before to reach high-level performance.
#16 Deconstructing stereotypes: Stature, match-playing time, and performance in elite Women's World Cup soccer
Reference: Front Sports Act Living. 2022 Dec 14;4:1067190. doi: 10.3389/fspor.2022.1067190. eCollection 2022.
Authors: Ciara N Manning, Yasuki Sekiguchi, Courteney L Benjamin, McKenna R Spaulding, Erin E Dierickx, Jayson M Spaulding, Dayshia M Davenport, Jillian R Picard-Busky, George T Chiampas, George P Nassis, Douglas J Casa
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9795175/pdf/fspor-04-1067190.pdf
Summary: Recruiting companies recommend elite female soccer players be ≥165 cm (5'5″) in stature. This study investigated if stature limits match-playing time and performance in elite World Cup soccer among players, positions, and countries. We hypothesized stature would not affect match-playing time or performance. Descriptive data were collected on 552 players from 2019 FIFA Women's World Cup. Odds ratios determined likelihood of starting for players <165 cm and ≥165 cm. ANOVAs compared playing time between stature groups, among positions, and between countries. Performance factors including assists, goals, attempts, corners, shots blocked, and defending blocks were reported. Independent t-tests compared differences between players (≥165 cm, < 165 cm). Data are reported, mean difference [95% confidence interval] [MD (95%CI)] and effect sizes (ES). On average, 32.3% of players were <165 cm. Of total players, no differences existed in total minutes (F = 0.98, p = 0.32), matches (F = 0.27 p = 0.59), or average minutes per match (F = 0.48, p = 0.49) between stature groups, regardless of position. No differences existed in playing time between players <165 cm and ≥165 cm among any positions (p > 0.05), or between countries (p > 0.05). Taller mid-fielders exhibited greater performance in goals, assists, attempts, shots blocked, and defending blocks (MD [95%CI] ES; assists, -0.44[-0.76,-0.11]0.59, p = 0.009; goals, -0.35[-0.69,-0.01]0.44, p = 0.047); attempts, 3.14[1.38, 4.90]0.80, p = 0.001; corners, 2.04[0.12, 3.95]0.48, p = 0.037; shots blocked, 0.96[0.40, 1.51]0.75, p = 0.001; defending blocks, 0.43[0.32,0.82]0.48, p = 0.035), however, actual differences were minimal. Our findings indicate stature does not inhibit playing and performing elite women's soccer, as nearly one-third of players were <165 cm.
#17 Sleep duration is associated with overnight changes in perceived fatigue in elite women soccer players
Reference: Sci Med Footb. 2023 Jan 1;1-8. doi: 10.1080/24733938.2022.2163511. Online ahead of print.
Authors: João Barreira, João Brito, Júlio A Costa, Pedro Figueiredo
Summary: The current study aimed to describe sleep habits and analyze the associations between sleep indices, changes in perceived fatigue (Δ Fatigue) and external training load measures in women soccer players during a 7-day training camp. Sixteen elite women soccer players (age: 25.4 ± 3.6 years; mean ± SD) from the Portuguese Women's National Team participated in the study. Sleep indices (sleep duration and efficiency) were measured using a wrist-worn accelerometer. External training loads measures were measured using GPS devices. Players also reported perceived fatigue using a Likert scale (1 - very, very low to 7 - very, very high) before and immediately after sleep. Players' within-subject coefficient of variation for sleep duration was 5.6%, and 4.6% for sleep efficiency. Individually, 8 players (50%) slept less than 7 h per night throughout the training camp, and the same number of athletes had a sleep efficiency lower than 85%. Similar values (p<0.05) were measured for sleep duration and efficiency between training and match days. A moderate negative within-subjects correlation was found between Δ Fatigue and sleep duration (adjusted for pre-sleep fatigue) [r = -0.32; 95% Confidence Interval (-0.51 - -0.08); p = 0.04]. These findings reinforce the importance of sleep in the recovery process of elite women soccer players, showing that more sleep may help to attenuate fatigue.
#18 Mental fatigue changes from regular season to play-offs in semiprofessional soccer: A comparison by training days
Reference: Scand J Med Sci Sports. 2023 Jan 5. doi: 10.1111/sms.14301. Online ahead of print.
Authors: Jesús Díaz-García, Luca Filipas, Antonio La Torre, Jorge Gómez-Rivera, Ana Rubio-Morales, Tomás García-Calvo
Summary: The main purpose was to compare by each training the mental load and fatigue reported by semiprofessional soccer players comparing between regular season phase and the play-offs. Fifty-three players (Mage = 24.59 years) for two teams participated during the 2020/21 season. Mental load was measured with a Likert questionnaire. Mental fatigue was quantified with a Visual Analogue Scale. Four trainings were recorded each week (Monday = MD+1, Wednesday = MD-4, Thursday = MD-3 and Saturday = MD-1), with a competitive match on Sunday across 10 weeks (five dates of regular season - five dates of play-offs). A Linear Mixed Model was performed with R-studio, using the training days and the competitive phase as independent variables. The influence of time played as co-variable was also checked. Results showed MD+1 as the more mentally fatiguing day in both phases, although MD-4 were the training with higher mental load reported (p = 0.001). Comparing phases, mental fatigue was significantly higher during the play-offs (p = 0.037). With regard time played, players that did not usually play showed a decrease in mental load during the play-offs. Then, we recommend coaches to use recovery strategies for mental fatigue, avoid mentally fatiguing tasks close to competition and considerer the time played as a factor which may contribute to individual differences in player mental fatigue.