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 Exploring the relationship among soccer-related knowledge, attitude, practice, and self-health in Chinese campus soccer education

Reference: iScience. 2024 Mar 4;27(4):109409. doi: 10.1016/j.isci.2024.109409. eCollection 2024 Apr 19.
Authors: Honglin Song, Yutao Li, Zhenhang Zhang, Tianbiao Liu
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10992701/pdf/main.pdf
Summary: China has promoted campus soccer for over a decade due to its potential health benefits. The study aimed to explore soccer knowledge (SK), soccer attitude (SA), soccer practice (SP), and health status among Chinese freshmen and sophomore undergraduates who had received campus soccer education. Of the 7419 participants, 1,069 were valid and included in the analysis. Structural equation modeling (SEM) results indicated SK is positively associated with SA (p < 0.001), but negatively with SP (p < 0.01). SA was positively linked to SP (p < 0.001). SK indirectly affected SP through SA (Z = 13.677). Random forest-tree-structured Parzen estimators (RF-TPE) with SHAP indicated SP holds primary importance with a strong negative impact on health. Additionally, differences in rankings for SK, SA, and SP were observed among gender and urban-rural groups. These results reveal current campus soccer education is suboptimal to health promotion.

2 The variability of physical enjoyment, physiological responses, and technical-tactical performance according to the bout duration of small-sided games: a comparative study between female and male soccer players

Reference: BMC Sports Sci Med Rehabil. 2024 Apr 3;16(1):77. doi: 10.1186/s13102-023-00794-1.
Authors: Zouhaier Farhani, Sofiene Amara, Mohamed Ben Aissa, Noomen Guelmami, Anissa Bouassida, Ismail Dergaa
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10988879/pdf/13102_2023_Article_794.pdf
Summary: This study aimed to compare various factors, namely perceived enjoyment (PE), percentage of peak heart rate (%HRpeak), blood lactate (La), rating of perceived exertion (RPE), and technical-tactical performance among soccer players across different bout durations (CB: continuous bout, MIB: medium intermittent bouts, and SIB: short intermittent bouts) and between male and female players during four-a-side (4vs4) small-sided games (SSGs) including goalkeepers. Sixteen female soccer players (age: 20.1 ± 0.5 years old) and sixteen professional male adults (age: 20.7 ± 0.7 years old) participated in the study. SSGs (4vs4) were performed in a CB: (1 × 12 min), and in an interval format: MIB: (2 × 6 min), and SIB: (3 × 4 min) with 2 min of passive recovery. PE was collected after each SSGs. The players‘ heart rate (HR) was continuously measured, whereas ratings of perceived exertion (RPE) and, blood lactate concentration ([La]) were determined at the end of each SSGs. Technical-tactical performance were analyzed during each session of SSGs. Pitch dimensions were (length x width) (25 × 32 m), and relative space per players was 100 m2. For female soccer players, medium intermittent bouts (MIB) elicited significantly higher perceived enjoyment (PE) compared to continuous bouts (CB) (p < 0.001) and short intermittent bouts (SIB) (p < 0.01). Conversely, for male soccer players, CB resulted in higher PE compared to MIB (p < 0.001) and SIB (p < 0.001). During CB and MIB, peak heart rate (PeakHR) and percentage of peak heart rate (%HRpeak) were significantly higher in female players compared to SIB (PeakHR: CB: p < 0.001; PeakHR: MIB: p < 0.01; %HRpeak: CB: p < 0.001; %HRpeak: MIB: p < 0.01). Blood lactate (La) and rating of perceived exertion (RPE) were significantly greater in CB compared to MIB (La: p < 0.001; RPE: p < 0.01) and SIB (La: p < 0.001; RPE: p < 0.001) for female players only. For male players, CB resulted in significantly higher PeakHR, %HRpeak, La, and RPE compared to MIB (peak HR: p < 0.01, dunb = 1.35; %HR: p < 0.01; La: p < 0.01; RPE: p < 0.01) and SIB (peak HR: p < 0,01; %HR: p < 0.01; RPE: md = 0.87, p < 0.05). Regarding technical-tactical performance, in female players, the % of successful passes, successful tackles, and successful duels were higher during SIB compared to CB (p < 0.01; p < 0.001; p < 0.001) and MIB compared to CB (p < 0.01; p < 0.001; p < 0.001), while ball loss was lower during SIB compared to CB (p < 0.001) and MIB compared to CB (p < 0.001). In male players, % of successful passes and tackles were higher during CB compared to MIB (p < 0.001 and p < 0.05) and SIB (p < 0.001 and p < 0.05), while CB had a lower % of ball loss compared to MIB (p < 0.01) and SIB (p < 0.001). There was no significant difference in the % of successful duels between the bouts for either gender. This study showed a difference in physical enjoyment between male and female soccer players depending on the bout duration of SSGs. For that, trainers should consider intermittent bouts for female soccer players and continuous bouts for male soccer players when designing SSGs-based training in order to significantly improve PE, training load, and technical-tactical performance.

3 Eccentric Hamstring Strength Imbalance among Football and Soccer Athletes

Reference: South Med J. 2024 Apr;117(4):214-219. doi: 10.14423/SMJ.0000000000001674.
Authors: Elizabeth M Benson, Joseph W Elphingstone, Kyle D Paul, Samuel Schick, Yazen A Shihab, Dan Barlow, Brent A Ponce, Eugene W Brabston, Amit M Momaya
Summary: Hamstring strain injuries (HSI) are common among football and soccer athletes. Eccentric strength imbalance is considered a contributing factor for HSI. There is, however, a paucity of data on hamstring imbalances of soccer and American football athletes as they age and advance in skill level. High school athletes will display greater interlimb discrepancies compared with collegiate and professional athletes. In addition, soccer athletes will exhibit greater hamstring asymmetry than American football athletes. Hamstring testing was performed on soccer and American football athletes using the NordBord Hamstring Testing System (Vald Performance, Albion, Australia). Age, sex, weight, sport specialization, and sport level were recorded. Maximum hamstring forces (N), torque (N · m), and work (N · s) were measured. Hamstring imbalance (%) was calculated by dividing the absolute value of the difference in leg forces divided by their sum. One-way analysis of variance and independent sample t tests compared measurements between athlete groups. A total of 631 athletes completed measurements, including 88 high school male soccer, 25 college male soccer, 23 professional male soccer, 83 high school female soccer, 28 college female soccer, 288 high school football, and 96 college football athletes. High school soccer players displayed significantly greater imbalances for torque (P = 0.03) and work (P < 0.01) than football athletes. Imbalances for maximum force (P = 0.035), torque (P = 0.018), and work (P = 0.033) were significantly higher for male soccer athletes in high school compared with college- and professional-level athletes. Female high school soccer players had significantly higher imbalance in torque (P = 0.045) and work (P = 0.001) compared with female collegiate soccer players. Football athletes did not experience significant changes in force imbalances between skill levels. High school soccer athletes exhibit greater hamstring imbalances than football athletes. Higher levels of play in soccer, for both male and female athletes, correlate with less hamstring asymmetry.

4 Influence of contextual factors on match running performance of starters and non-starters in elite youth male soccer players

Reference: Sci Prog. 2024 Apr-Jun;107(2):368504241239187. doi: 10.1177/00368504241239187.
Authors: Luiz Guilherme Gonçalves, Hadi Nobari, Alex Ambrosio Rites, Fábio Yuzo Nakamura, Gabriel Rodrigues Garcia, Rodrigo Aquino
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10993682/pdf/10.1177_00368504241239187.pdf
Summary: This study investigated the effects of match location, quality of opposition (classified into: strong [1st to 4th position]; intermediate [5th to 15th position]; weak [16th to 20th position]), and match outcome on the match running performance of starters and non-starters from a top elite Brazilian soccer team. Absolute measures were calculated using total distance, high-speed (19.8-25.2 km·h-1), sprinting (≥ 25.2 km·h-1), total distance high-acceleration (> 2m·s2), and deceleration (< -2m·s2) were recorded by GPS units from a sample of young soccer players (N = 25) in a total of 17 matches. Relative measures were calculated by dividing absolute measures by the total duration of the matches. Non-starters covered greater total distance (p = 0.02), sprinting (p = 0.02), high-acceleration and deceleration (p = 0.04), sprinting distance relative per minute played (p = 0.005), and high-acceleration and deceleration relative per minute played (p < 0.001) when the team plays at home, strong opponents, and wins the matches. Starters covered greater total distance in high-speed running (p = 0.04), high-acceleration and deceleration (p = 0.03), and high-speed running relative per minute played (p = 0.04) when the team plays strong opponents and wins the matches. These findings highlight the impact of contextual factors during matches on the locomotor performance of young soccer players.

5 A survey into the current fitness testing practices of elite male soccer practitioners: from assessment to communicating results

Reference: Front Physiol. 2024 Mar 19:15:1376047. doi: 10.3389/fphys.2024.1376047. eCollection 2024.
Authors: Nikolaos D Asimakidis, Chris J Bishop, Marco Beato, Irvin N Mukandi, Adam L Kelly, Anthony Weldon, Anthony N Turner
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10985349/pdf/fphys-15-1376047.pdf
Summary: This study provides insight into the current fitness testing practices in elite male soccer. One hundred and two practitioners from professional soccer leagues across 24 countries completed an online survey comprising 29 questions, with five sections: a) background information, b) testing selection, c) testing implementation, d) data analysis, and e) data reporting. Frequency analysis was used to evaluate the responses to fixed response questions and thematic analysis was used for open-ended questions to generate clear and distinct themes. Strength (85%) and aerobic capacity (82%) represent the most frequently assessed physical qualities. Scientific literature (80%) is the most influential factor in testing selection and practitioners conduct fitness testing less frequently than their perceived ideal frequency per season (3.6 ± 2 vs. 4.5 ± 2). Time and competitive schedule were the greatest barriers to fitness testing administration. Practitioners mostly used a ‚hybrid‘ approach (45%) to fitness testing, blending ‚traditional‘ (i.e., a day dedicated to testing) and ‚integrated‘ (i.e., testing within regular training sessions) methods. Microsoft Excel is the most used software for data analysis (95%) and visualization (79%). An equal use of the combination of best and mean scores of multiple trials (44%) and the best score (42%) was reported. Comparing a player’s test performance with previous scores (89%) was the most common method for interpreting test results. However, only 38% considered measurement error. Digital displays and verbal feedback are the most common data reporting methods, with different data reporting processes for coaches and players. Practitioners can use data and findings from this study to inform their current testing practices and researchers to further identify areas for investigation, with the overarching aim of developing the field of fitness testing in elite male soccer.

6 Factors associated with the Single Leg Squat test in female soccer players: a cross-sectional study

Reference: BMC Sports Sci Med Rehabil. 2024 Apr 2;16(1):76. doi: 10.1186/s13102-024-00853-1.
Authors: John Ressman, Philip von Rosen, Wilhelmus Johannes Andreas Grooten, Eva Rasmussen-Barr
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10985895/pdf/13102_2024_Article_853.pdf
Summary: The Single Leg Squat (SLS) test is widely used in the clinical setting to examine and evaluate rehabilitation goals. It is simple to perform and is proposed to have biomechanical and neuromuscular similarities to athletic movements. The aim of the present study was to investigate whether demographics, previous injuries, and biomechanical and psychosocial factors are associated with the outcome of the SLS, assessed as a total score for all segments and as a separate knee segment in elite and sub-elite female soccer players. We conducted a cross-sectional study involving 254 female soccer players (22 yrs; SD ± 4, height 1.69 m; SD ± 0.1, weight 64 kg; SD ± 6) from divisions 1-3 of the Swedish Soccer League. During the preseason, we assessed the participants using the SLS and tested their hip strength and ankle mobility. Demographics, previous injury, sleep quality, fear of movement, anxiety, and perceived stress were assessed with questionnaires. Logistic regression models were built to analyse the association between the outcome of the SLS and the independent variables for the dominant and non-dominant leg. Significantly more participants failed the SLS on the dominant leg compared with the non-dominant leg (p < 0.001). The outcome of the SLS associated with various biopsychosocial factors depending on if the dominant or non-dominant leg was tested. The total score associated with hip strength for the dominant (OR 0.99, 95% CI 0.98-0.99, p = 0.04) and the non-dominant leg (OR 0.99, 95% CI 0.97-0.99, p = 0.03). The knee segment associated with division level for the dominant (div 2; OR 2.34, 95% CI 1.01-5.12, p = 0.033. div 3; OR 3.07, 95% CI 1.61-5.85, p = 0.001) and non-dominant leg (div 2; OR 3.30, 95% CI 1.33-8.00, p = 0.01. div 3; OR 3.05, 95% CI 1.44-6.43, p = 0.003). This study identified that leg dominance, division level, hip strength, and psychosocial factors were associated with the outcome of the SLS when assessed as a total score and as a separate knee segment. This indicates that clinicians need to understand that movement control is associated with factors from several domains. Whether these factors and, the results of the SLS are related to injury need to be studied prospectively.

7 The effect of complex contrast training with different training frequency on the physical performance of youth soccer players: a randomized study

Reference: PeerJ. 2024 Mar 29:12:e17103. doi: 10.7717/peerj.17103. eCollection 2024.
Authors: Helder Barra-Moura, João Guilherme Vieira, Francisco Zacaron Werneck, Michal Wilk, Bruno Pascoalini, Victor Queiros, Gilmara Gomes de Assis, Marta Bichowska-Pawęska, Jeferson Vianna, José Vilaça-Alves
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10984173/pdf/peerj-12-17103.pdf
Summary: Complex contrast training (CCT) is potentially an efficient method to improve physical abilities such as muscle strength, power output, speed, agility, are extremely important in developing soccer players of different age categories. This study aimed to analyze the effects of 6 weeks of CCT program applied in different training frequency (sessions per week) on youth soccer players performance. Twenty-one youth soccer players (age: 15.3 ± 1.1 years; body mass 64.9 ± 0.7 kg; height 175.4 ± 0.7 cm) were randomized into three groups: a regular pre-season training control group (G0, n = 8), a group with regular pre-season training plus twice-a-week CCT (G2, n = 6), and a group with regular pre-season training plus thrice-a-week CCT (G3, n = 7). The CCT consisted of soccer skills-based exercises distributed across five stations, to be performed before common regular practice during a 6-week pre-season period. The agility (505 Agility test), sprint (S5 and S15), jump (SJ and CMJ), and free kick speed (11 m from the goal) of the groups were analyzed pre- and post-CCT intervention. During a 6-week pre-season period, the players integrated CCT into their regular training sessions. Furthermore, performance variables were compared between the groups. A statistical difference was identified for the timepoint for the players‘ CMJ (p = 0.023; η2 = 0.343) and the free kick speed (p = 0.013; η2 = 0.383) using ANOVA. The G3 showed a significant improvement in the CMJ (p = 0.001) and the free kick speed (p = 0.003) between pre- to post-CCT test. No other significant changes in performance were observed (p > 0.05). The CCT training program with a weekly frequency of 3 days per week is effective in improving free kick speed and CMJ performance in young male soccer players (U-15 and U-17 categories). CCT training programs have the potential to refine an athlete’s preparation for competition. However, certain performance tests did not demonstrate substantial enhancements. Consequently, additional investigations are required to ascertain the effectiveness of CCT.

8 Sound source localization in blind soccer: differences between sighted and visually impaired players

Reference: J Phys Ther Sci. 2024 Apr;36(4):161-166. doi: 10.1589/jpts.36.161. Epub 2024 Apr 1.
Authors: Masahiro Watanabe
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10981959/pdf/jpts-36-161.pdf
Summary: The sense of vision is omitted in blind soccer, and sound source localization to grasp the position of the ball is extremely important. The purpose of this study was to clarify whether there is a difference in ability in sound source localization in its approaching condition between visually impaired and sighted people, using the source actually used in blind soccer ball competitions. Eighteen participants were divided into two groups; 10 sighted people and eight visually impaired people. The participants were asked to press a switch when a rolling blind soccer ball was sensed in any one of the four directions. We recorded time error as the difference between the time when the ball passed the optical sensor set under the participant’s feet and when the participant pressed the switch. The time error in response increased with the ball speed in all cases; however, its dependence on the ball speed was significantly different between the two groups. The visually impaired participants made less time errors in response to the localization of the ball than the sighted participants, even when the ball speed increased. The results indicate that visually impaired people have better sound source localization ability than sighted people do.

9 Greater Psychophysiological Intensities in Conditioned Games May Impair Technical Performance: An Exploratory Study in Youth Male Soccer Players

Reference: Int J Sports Physiol Perform. 2024 Apr 1:1-9. doi: 10.1123/ijspp.2024-0003. Online ahead of print.
Author: Filipe Manuel Clemente
Summary: The aim of this study was 2-fold: (1) to examine the relationships between psychophysiological responses and locomotor demands with variations in technical performance during 2v2 and 4v4 conditioned games and (2) to compare psychophysiological and locomotor responses among players exhibiting higher and lower technical performance levels during the conditioned games. Twenty-four male youth soccer players (16.3 ± 0.8 y old) participating at the trained/developmental level underwent monitoring for psychophysiological responses (including heart rate, rating of perceived exertion, and visual analog scale), locomotor demands (such as distance covered), and technical performance variables (including successful and unsuccessful passes and shots, as well as lost balls) across 2v2 and 4v4 formats. These formats were applied 4 times within a single session and were replicated twice over 2 weeks. Large correlations between the number of lost balls per minute and mean heart rate were found in both the 2v2 and 4v4 games (r = .586 and r = .665, respectively). Successful shots were inversely and largely correlated with mean heart rate (r = -.518) in 4v4 games. The number of interceptions per minute was inversely and significantly correlated with the visual analog scale in 2v2 and 4v4 games (r = -.455 and r = -.710, respectively). The frequency of lost balls was significantly higher among players who attained a higher mean heart rate (2v2: +42.9%, P = .031, d = -0.965; 4v4: +57.1%, P < .001, d = -2.072). Coaches should be aware that highly psychophysiologically demanding scenarios may significantly impair technical performance. Therefore, prioritizing technical performance by deliberately adjusting the intensity should be considered.

10 Soccer (football) and brain health

Reference: J Neurol. 2024 Apr 1. doi: 10.1007/s00415-024-12320-5. Online ahead of print.
Authors: Umberto Pensato, Pietro Cortelli
Download link: https://link.springer.com/content/pdf/10.1007/s00415-024-12320-5.pdf
Summary: Soccer is one of the most popular sports worldwide, played by over 270 million people and followed by many more. Several brain health benefits are promoted by practising soccer and physical exercise at large, which helps contrast the cognitive decline associated with ageing by enhancing neurogenesis processes. However, sport-related concussions have been increasingly recognised as a pressing public health concern, not only due to their acute impact but also, more importantly, due to mounting evidence indicating an elevated risk for the development of neurological sequelae following recurrent head traumas, especially chronic traumatic encephalopathy (CTE). While soccer players experience less frequent concussions compared with other contact or combat sports, such as American football or boxing, it stands alone in its purposeful use of the head to hit the ball (headings), setting its players apart as the only athletes exposed to intentional, sub-concussive head impacts. Additionally, an association between soccer and amyotrophic lateral sclerosis has been consistently observed, suggesting a potential „soccer-specific“ risk factor. In this review, we discuss the neurological sequelae related to soccer playing, the emerging evidence of a detrimental effect related to recurrent headings, and the need for implementation of comprehensive strategies aimed at preventing and managing the burden of head impact in soccer.

11 Effects of far-infrared radiation lamp therapy on recovery from a simulated soccer-match in elite female soccer players

Reference: Scand J Med Sci Sports. 2024 Apr;34(4):e14615. doi: 10.1111/sms.14615.
Authors: Wei-Chin Tseng, Kazunori Nosaka, Tai-Ying Chou, Glyn Howatson, Trevor C Chen
Download link: https://onlinelibrary.wiley.com/doi/epdf/10.1111/sms.14615
Summary: We investigated the effects of far-infrared radiation (FIR) lamp therapy on changes in muscle damage and performance parameters following six sets of 15-min Loughborough intermittent shuttle test (LIST), a simulated soccer match. Twenty-four elite female soccer players (20-24 y) were assigned into FIR or sham treatment group (n = 12/group). The participants received a 60-min FIR or sham treatment (30 min per muscle) over knee extensors (KE) and flexors (KF) at 2, 25, 49, 73, and 97 h post-LIST. Maximal voluntary isometric contraction (MVC) torque and muscle soreness of the KE and KF, plasma creatine kinase (CK) activity as muscle damage markers, and several performance parameters including countermovement jump (CMJ) and Yo-Yo intermittent recovery test level 1 (YYIR1) were measured before and 1, 24, 48, 72, 96, and 120 h post-LIST. Changes in the measures were compared between groups by a mixed-design two-way ANOVA. The running distance covered during LIST and changes in the measures at 1-h post-LIST (before the treatment) were similar (p = 0.118-0.371) between groups. Changes in muscle damage markers at 24-120 h post-LIST were smaller (p < 0.05, η2 = 0.208-0.467) for the FIR (e.g., MVC-KE torque decrease at 48-h post-LIST: -1 ± 2%, peak KE soreness: 16 ± 10 mm, peak CK: 172 ± 42 IU/L) than sham group (-11 ± 9%, 33 ± 7 mm, 466 ± 220 IU/L, respectively). Performance parameters recovered faster (p < 0.05, η2 = 0.142-0.308) to baseline for the FIR (e.g., decreases at 48-h post-LIST; CMJ: 0 ± 1%, YYIR1: 0 ± 1%) than sham group (-6 ± 2%, -9 ± 6%, respectively). These results suggest that the FIR lamp therapy was effective for enhancing recovery from a soccer match.

12 Effectiveness of motor imagery on sports performance in football players: A randomised control trial

Reference: Hong Kong Physiother J. 2024 Jun;44(1):29-37. doi: 10.1142/S1013702524500021. Epub 2023 Aug 25.
Authors: Jaruwan Prasomsri, Bunthita Thueman, Pichamon Yuenyong, Chayanon Thongnoon, Naruepa Khophongphaibun, Suppakorn Ariyawatcharin
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10988270/pdf/hkpj-44-029.pdf
Summary: Nowadays, the development of training programs for speed, agility and reaction time responses in football players is increasing widely. Motor imagery is a new method that uses collateral with physical training. However, there is still a scarcity of evidence concerning the addition of motor imagery protocol to routine training programs. The main objective was to compare speed, agility and reaction time after motor imagery training in university athletes and amateur athletes who received and did not receive motor imagery training for 2 weeks. Participants were divided into 4 subgroups as follows: university athlete group with motor imagery training and control group, amateur athlete group with motor imagery training and control group. This study collected the training effects of speed, agility and reaction time. The Wilcoxon signed-rank test and the Mann-Whitney U test were selected to analyse the differences within and between groups, respectively. The result presented positive changes in all variables after training sessions for 2 weeks in all groups. Speed at 20 m, agility, and reaction time were found to be significantly different after motor imagery training in both university athletes and amateur athletes. This finding demonstrated that the addition of the motor imagery training along with routine physical training promotes physical performance in athletes at all experience levels. In further studies, the retention effect after practice should be considered.

13 Peak fat oxidation, peak oxygen uptake, and running performance increase during pre-season in sub-elite male football players

Reference: Scand J Med Sci Sports. 2024 Apr;34(4):e14617. doi: 10.1111/sms.14617.
Authors: Tue Rømer, Mikkel Thunestvedt Hansen, Kristine Kjær Lange, Mikkel Lundgren Petersen, Anders Petersen Ibh, Jeppe Panduro, Peter Krustrup, Flemming Dela, Jørn Wulff Helge
Summary: In Football, the high-intensity running bouts during matches are considered decisive. Interestingly, recent studies showed that peak fat oxidation rates (PFO) are higher in football players than other athletes. This study aimed to investigate whether PFO increases following a pre-season. Secondarily, and due to COVID-19, we investigated whether PFO is related to the physical performance in a subgroup of semi-professional male football players. Before and after 8 weeks of pre-season training, 42 sub-elite male football players (18 semi-professionals and 24 non-professionals) had a dual-energy x-ray absorptiometry scan and performed a graded exercise test on a treadmill for the determination of PFO, the exercise intensity eliciting PFO (Fatmax) and peak oxygen uptake (V̇O2peak). Additionally, the semi-professional players performed a Yo-Yo Intermittent Recovery Test level 2 (YYIR2) before and after pre-season training to determine football-specific running performance. PFO increased by 11 ± 10% (mean ± 95% CI), p = 0.031, and V̇O2peak increased by 5 ± 1%, p < 0.001, whereas Fatmax was unchanged (+12 ± 9%, p = 0.057), following pre-season training. PFO increments were not associated with increments in V̇O2peak (Pearson’s r2 = 0.00, p = 0.948) or fat-free mass (FFM) (r2 = 0.00, p = 0.969). Concomitantly, YYIR2 performance increased in the semi-professional players by 39 ± 17%, p < 0.001, which was associated with changes in V̇O2peak (r2 = 0.35, p = 0.034) but not PFO (r2 = 0.13, p = 0.244). PFO, V̇O2peak, and FFM increased following pre-season training in sub-elite football players. However, in a subgroup of semi-professional players, increments in PFO were not associated with improvements in YYIR2 performance nor with increments in V̇O2peak and FFM.

14 Night-to-night variability of objective sleep outcomes in youth Middle Eastern football players

Reference: Sleep Med. 2024 Mar 19:117:193-200. doi: 10.1016/j.sleep.2024.03.023. Online ahead of print.
Authors: Lorenzo Lolli, Daniele Bonanno, Emmanuel Lopez, Valter Di Salvo
Download link: https://www.sciencedirect.com/science/article/pii/S1389945724001278/pdf?crasolve=1&r=871cb7993abc3757&ts=1712688987106&rtype=https&vrr=UKN&redir=UKN&redir_fr=UKN&redir_arc=UKN&vhash=UKN&host=d3d3LnNjaWVuY2VkaXJlY3QuY29t&tsoh=d3d3LnNjaWVuY2VkaXJlY3QuY29t&rh=d3d3LnNjaWVuY2VkaXJlY3QuY29t&re=X2JsYW5rXw%3D%3D&ns_h=d3d3LnNjaWVuY2VkaXJlY3QuY29t&ns_e=X2JsYW5rXw%3D%3D&rh_fd=rrr)n%5Ed%60i%5E%60_dm%60%5Eo)%5Ejh&tsoh_fd=rrr)n%5Ed%60i%5E%60_dm%60%5Eo)%5Ejh&iv=7f40a265f7a5f23e483094b21fcfbd9f&token=33326263653632623666623538353461303937393133383863626337303333353130323264303736333065623234323637363666346436306662353334333633346439343761663231656162656562303333343530613766663438343666326336333036613637373a363230353265643863316264306334386562303237303038&text=fea3e5153dc61426095fd8f353ddb3978c00b325d5cb3b22730a3e2a4836867249f7519c47d1960c279523e484a87c89ba216763d3b3ba327b756752b4c31b85d762b89b30c53a6ea6fb9ee4360049a68256b4401c829984c20da8bad469e0a831b52512853068829b2ed4a4ef070c6ba699af48131c3236e4d590d2d62225fd5dd8ae2af45bb8e39015add9af7668ed30fc39ee04bdd3e539f0ad1e65c88597a6edfcf8e6c34f21e214b79b78a00c62a55737ca086e0ee9889282e14c1fa33abc371c5f47bb87e54a803b7de9eceabfcc844fff09e4fa4d6217a665518c3b46c2715ddf6fa17bfa78316e60c369c76427c9447a614877bf624130680cd237a0a49b90ad1efeab64c10778cba680299fde495093785a11da49047068e292ac6cfa0ed56033bf3d4640ff205ec43f7027&original=3f
Summary: The aim was too describe components of night-to-night variation in objective measures of sleep. We conducted a secondary data analysis of consecutive and chronologically ordered actigraphy-based measurements for time in bed (min), time asleep (min), and wake-after-sleep onset (min). This investigation examined 575 individual night-based measures available for a sub-sample of fifty-two, male youth Middle Eastern football players tracked over a 14-day surveillance period (chronological age range: 12.1 to 16 years). Distinct multivariable-adjusted generalized additive models included each objective sleep outcome measure as dependent variable and disaggregated components of variation for night measurement-by-sleep period interaction, week part (weekday or weekend), and study participant random effects from within-subject night-to-night sleep variation. The within-subject standard deviation (SD) of ±98 min (95% confidence interval [CI], 92 to 104 min) for time in bed, ±87 min (95%CI, 82 to 93 min) for time asleep, and ±23 min (95%CI, 22 to 25 min) for wake-after-sleep-onset overwhelmed other sources of variability and accounted for ∼44% to 53% of the overall night-to-night variation. The night measurement-by-fragmented sleep period interaction SD was ±83 min (95%CI, 44 to 156 min) for time in bed, ±67 min (95%CI, 34 to 131 min) for time asleep, and ±15 min (95%CI, 7 to 32 min) for wake-after-sleep-onset that accounted for ∼22% to 32% of each sleep outcome measure overall variability. Substantial random night-to-night within-subject variability poses additional challenges for strategies aiming to mitigate problems of insufficient and inconsistent sleep that are detrimental to school learning and youth athlete development processes.

15 Strengthening exercise and motor control among football players with ankle sprain: A scoping review

Reference: Med J Malaysia, 2024, Mar; 79(Suppl 1): 197-202.
Authors: A Mohd Tan, Z Zahari, S A Bukry
Download link: https://www.e-mjm.org/2024/v79s1/football-players-with-ankle-sprain.pdf
Summary: The ankles and feet of footballers are the most commonly affected areas by acute and chronic injuries, especially sprains. The durability of changes in motor control for the sprained injury strongly suggests that central motor commands have been reorganized and restructured involving the sensorimotor system. Indirectly, providing strength training improves muscular strength and benefits cardiometabolic health, coordination, sensorimotor, and motor performance. Thus, this study aimed to identify the effects of strengthening exercises on motor control among footballers with sprained ankles. This scoping review selected studies published from January 2002 to November 2022. The articles were searched through PubMed Central, BMJ Journal, Science Direct, and Scopus using „motor control“, „ankle sprain“ and „strengthening exercise“ as the keywords. After finding the articles, the information extracted included author, year of publication, country, objective, type of study, and motor control analysis summary. The literature search strategy used Preferred Reporting Items for Systematic Review and a meta-analysis (PRISMA) where studies that are related to strengthening exercise and motor control were selected. From the initial search, 50 articles were found. After processing, only ten articles were further reviewed. The findings demonstrated strengthening exercises provide changes in neurophysiological parameters with motor performance, improved motor control, strength, balance, pain, and functional movement in footballers with sprained ankles. This review suggests the application of strengthening exercise interventions not only improves motor control, but strength, balance, pain, and functional performance among footballers with sprained ankles.