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 Comparison of external load measures per minute based on match seasonal periods and playing positions of a soccer Turkish super league team
Reference: BMC Musculoskelet Disord. 2023 Aug 17;24(1):656. doi: 10.1186/s12891-023-06787-y.
Authors: Zeki Akyildiz, Yılmaz Yüksel, Yaşar Birgonül, Halil İbrahim Ceylan, Rafael Oliveira, Erhan Çene, Coskun Parim, Filipe Manuel Clemente, Hadi Nobari
Summary: Turkish Super League teams need more information about the external load. Considering the specific country and the coaches' philosophies, the purpose of this study was to compare the external match load of a Turkish Super League team considering the different playing positions and in-season periods. A longitudinal study design was employed by observing 29 official matches of the same team. A total of fifteen players, consisting of five defenders, five midfielders, and five forwards, were analyzed using the Sentio Sports Optical Tracking System. The following outcomes were extracted in each match: total distance (TD), walking [from 0 to 7.2 km/h], jogging [from 7.2 to 14.4 km/h], running [from 14.4 to 20 km/h], high speed running (HSR) [> 20 km/h], metabolic power (MP), maximum deceleration (Decmax) [Dec < -3 m/s2], total deceleration distance (Dectotal), maximum acceleration (Accmax) [Acc > 3 m/s2], and total acceleration distance (Acctotal). Statistical analysis consisted of ANOVA and Bonferroni correction post hoc tests. The main results showed that all variables were similar between periods of the season (p > 0.05) except for walking (p = 0.021 witha large effect size), which revealed lower values in the mid-season period. When analyzing periods of the season considering playing positions, there were several significant results for TD, walking, jogging, running, HSR, Dectotal and Acctotal (p < 0.05, with small to large effects). A tendency for higher values was noted in the mid and end-season. Considering the playing positions comparisons, midfielders showed higher values than defenders for TD, MP, Dectotal and Acctotal (p < 0.05 with large effect for all). Midfielders also showed higher values than forwards for TD, jogging, Dectotal and Acctotal (p < 0.05 with a large effect for all). The present study emphasizes the significance of analyzing data based on minute, playing position, and season period. Findings reveal that defenders consistently displayed the lowest values in all external load measures during matches compared to other positions throughout the season. Furthermore, midfielders demonstrated a higher activity profile during the initial and middle stages of the season compared to other positions, with a slight tendency to decrease load towards the end of the season.
#2 The bone mineral density and isokinetic knee strength in amputee soccer players
Reference: Rev Assoc Med Bras (1992). 2023 Aug 14;69(8):e20230100. doi: 10.1590/1806-9282.20230100. eCollection 2023.
Authors: Izzet Islamoglu, Mehmet Çebi, Fevziye Canbaz Tosun
Summary: The aim of this study was to examine the isokinetic knee strength, H/Q ratio (%), and bone mineral density values between amputees (n=14; amputee soccer players) and healthy football players (n=14; non-amputee soccer players). A total of 28 amputee soccer players and non-amputee soccer players participated in the study. An isokinetic dynamometer was used to determine the knee flexion/extension forces of the dominant legs of the athletes at 60, 180, and 240°/s. Bone mineral density scans were performed using dual-energy X-ray absorptiometry. H/Q ratio and 60º/s flexion and 180 and 240º/s flexion/extension strength (p<0.05) were found to be high (180º/s, p=0.03; 240º/s, p=0.048) in the non-amputee soccer player group. Accordingly, the bone mineral density values of the lumbar vertebra, femoral neck, proximal metaphysis of the femur (p<0.01), tibia/fibula proximal metaphysis, and tibia/fibula distal metaphysis (p<0.05) were found to be high. A correlation was observed between the 60º/s knee extension strength and tibia/fibula diaphyseal bone mineral density (p=0.025; r=0.594) and tibia/fibula distal metaphysis bone mineral density (p=0.017; r=0.623) values in the amputee soccer players group. The Z-scores of the amputee soccer players and non-amputee soccer players were in the expected range according to age (>-2). The bone mineral density, H/Q ratio, and all measured angular velocities of isokinetic strength were high in non-amputee soccer players. This finding made us think that lower extremity amputation may also be associated with losing strength. However, it was observed that the relationship between strength and bone mineral density in amputee athletes might vary according to different angular velocities. It is recommended that isokinetic strength measurement can be evaluated together with bone mineral density in athletes.
#3 Effect of curcumin supplementation on inflammatory status and muscle damage in competitive female soccer players: a placebo-controlled, singleblind, nonrandomized, crossover pilot study
Reference: Phys Act Nutr. 2023 Jun;27(2):34-38. doi: 10.20463/pan.2023.0016. Epub 2023 Jun 30.
Authors: Youngju Choi, Song-Gyu Ra, Takahiko Nishijima, Seiji Maeda
Download link: https://www.e-pan.org/upload/pdf/pan-2023-0016.pdf
Summary: Curcumin, a major component of turmeric, has anti-inflammatory and antioxidative properties, which are associated with protective effects against muscle damage. This study examined the effects of dietary curcumin on inflammation and muscle damage in female competitive soccer players. A single-blinded, placebo-controlled, nonrandomized, crossover pilot study was conducted. Six competitive female soccer players (20.0 ± 2.0 yearsold) who participated in a 2-week preseason training program were assigned to two conditions: placebo and curcumin. The participants ingested a placebo or curcumin dosage (270 mg/day) during 2 weeks of preseason training, with 1 week of washout. Fasting blood samples were collected under resting conditions before (day 0) and after (day 15) the training period to examine changes in the concentration of interleukin 6 (IL-6), an inflammatory marker, and indices reflective of muscle damage. Curcumin decreased the concentration of IL-6 released (mean decrease, -30.2 ± 28.1%), whereas no decrease was observed in the placebo condition (13.4 ± 17.4%). Changes in plasma IL-6 concentrations were significantly greater in the curcumin condition than in the placebo condition (p < 0.05). However, curcumin supplementation had no significant effects on muscle damage indices. The present study shows that curcumin supplementation could attenuate inflammation, as indicated by IL-6 concentrations, in competitive female soccer players during the training period.
#4 Republication of "High-Speed Video Analysis of Syndesmosis Injuries in Soccer-Can It Predict Injury Mechanism and Return to Play? A Pilot Study"
Reference: Foot Ankle Orthop. 2023 Aug 11;8(3):24730114231195048. doi: 10.1177/24730114231195048. eCollection 2023 Jul.
Authors: Neil Jain, David Murray, Steve Kemp, James Calder
Summary: Ankle syndesmosis injuries in professional soccer may lead to an unpredictable and prolonged recovery. This injury has been investigated in anatomical and radiologic studies but the precise mechanism leading to syndesmosis injury is not well understood and remains debated. The 2 goals of this study were to (1) evaluate the relationship between the mechanism of syndesmosis injury as determined by high-speed video analysis and the injured structures identified by clinical and radiologic examination and to (2) investigate the relationship between mechanism of injury and time of return to play. This pilot study prospectively reviewed high-speed video analysis of 12 professional soccer players who sustained syndesmosis injuries. The mechanism of injury was compared with the clinical and MRI evaluation and the time taken to return to play. Higher-grade syndesmosis injuries occurred during ankle external rotation with dorsiflexion. Supination-inversion injuries with a standard lateral ankle sprain (rupture of the anterior talofibular ligament) may extend proximally, causing a lower-grade syndesmosis injury. These may present with signs of a high ankle sprain but have a quicker return to sport than those following a dorsiflexion-external rotation injury (mean 26 days vs 91 days). Video analysis confirmed that at least 2 mechanisms may result in injury to the ankle syndesmosis. Those "simple" ankle sprains with signs of syndesmosis injury had a quicker return to play. This new finding may be used by club medical teams during their initial assessment and help predict the expected time away from soccer in players with suspected high ankle sprains.
#5 A Schatzker Type III Tibial Plateau Fracture in a Soccer Player: A Case Report
Reference: Cureus. 2023 Jul 17;15(7):e42015. doi: 10.7759/cureus.42015. eCollection 2023 Jul.
Authors: Kevin Do, Alan A Zakaria, Tais G O Bertasi, Raphael A O Bertasi, Rock P Vomer, Jeffrey Nadwodny, George G A Pujalte
Summary: The tibial plateau is an important load-bearing surface in the knee, and when fractured, there is subsequent loss of motion and stability. These fractures typically result from axial loading and twisting. Our case outlines a tibial plateau fracture in a 15-year-old soccer player. The physical examination was positive for a decreased range of motion, pain with valgus stress, and positive ballottement. Radiography of the knee revealed joint effusion but no definite fracture. MRI revealed a Schatzker Type III fracture and a partial medial collateral ligament (MCL) tear. Our patient was referred for open repair and internal fixation. The Schatzker classification system is divided by type and location of fracture. Types I through III are located laterally, Type IV is medial, Type V identifies bicondylar fractures, and Type VI identifies tibial diaphysis separation from the metaphysis. These fractures are managed both nonoperatively and operatively. Nonoperative management is recommended for minimally displaced fractures that will heal without notable deformity. Operative management is indicated for displaced and unstable fractures, which include all fracture Types IV through VI, and certain Type I through III fractures that have valgus alignment or large articular surface involvement. Recovery time is lengthy and largely dependent on the fracture type. The first six weeks usually involve non-weightbearing, the second six weeks include weightbearing as tolerated, with knee range of motion exercises and muscle strengthening. Although open repair and internal fixation usually provide good results, some athletes cannot return to their previous levels of activity.
#6 The relationship between locus of control and pre-competitive anxiety in highly trained soccer players
Reference: Front Psychol. 2023 Aug 3;14:1227571. doi: 10.3389/fpsyg.2023.1227571. eCollection 2023.
Authors: Imen Ben Amar, Chiraz Gomni, Oussema Gaied, Aymen Khmiri, Rania Ghouaiel, Julien S Baker
Summary: Previous studies have not considered the potential association between locus of control and precompetitive anxiety in elite soccer players. Accordingly, this cross-sectional study examined The prediction of locus of control on precompetitive anxiety in highly trained cadet soccer players. Based on a literature review, our research question was: can the locus of control be considered as an explanatory element of precompetitive anxiety? Thirty-five Tunisian highly trained soccer players licensed from two regional soccer clubs aged between 15 and 16 years participated in the resent study. All participants were evaluated using the Competitive State Anxiety Inventory-2 (CSAI-2) and the Internal-External Locus of Control Scale. The relationship between measures of anxiety, self-confidence and the locus of control scores were analyzed using Pearson's product-moment correlation coefficient. Further, multiple linear stepwise multiple regression models were calculated to determine the most robust predictors of the locus of control. Based on our findings, the regression analysis explains up to 21.3% of the total variation of our independent variable (locus of control) and explains only 21.3% of the variability of our dependent variable somatic anxiety. Furthermore, locus of control explains 61.9% of the variability in self-confidence. The locus of control can be used for the detection and selection of young athletic talent to identify individuals with the best psychological aptitude to cope with psychological problems related to sports performance. Preparing highly trained soccer players on how to deal with their anxiety could prevent them from becoming overwhelmed when they feel powerless to change their situation during competition.
#7 The effects of a smartphone game training intervention on executive functions in youth soccer players: a randomized controlled study
Reference: Front Sports Act Living. 2023 Aug 3;5:1170738. doi: 10.3389/fspor.2023.1170738. eCollection 2023.
Authors: Florian Heilmann, Damiano Formenti, Athos Trecroci, Franziska Lautenbach
Summary: Cognitive training primarily aims to improve executive functions (EFs). It has become a popular research topic, as previous studies have provided preliminary evidence that EFs relate to sports performance. However, whether a domain-generic cognitive training intervention can improve EFs in high-performance athletes is still unclear. The present randomized controlled study aimed to examine the effects of an eight-week (5 min/day, 5 days/week) smartphone-based domain-generic cognitive training intervention (i.e., the smartphone game "Fruit Ninja") on EFs in youth soccer athletes (N = 33; intervention: n = 15, passive control: n = 18; German youth soccer academy). We assessed working memory (3-back task), inhibition (Flanker & Go/NoGo task), and cognitive flexibility (number-letter task) in a pre-post design with computerized tasks. The results showed no significant time x group differences attributable to the cognitive training between the intervention group and the control group, except for a response time variable of the Go/NoGo task. These preliminary results do not suggest an application of CT as a smartphone-based game to improve EFs performance in soccer players. However, more research is needed to establish the efficacy of domain-specific interventions in high-level team sport athletes.
#8 Posterior hip fracture dislocation from a non-contact injury while playing soccer. "A Case Report"
Reference: Trauma Case Rep. 2023 Aug 7;47:100885. doi: 10.1016/j.tcr.2023.100885. eCollection 2023 Oct.
Authors: Jared A Nowell, Stefan Coombs, Abhishek Tippabhatla, Basilia O Nwankwo
Summary: 35-Year old male presented with acute right hip pain after a pivoting motion while playing soccer. This was a non-contact injury. Imaging revealed a posterior hip dislocation with an associated posterior wall acetabular fracture. He was treated with closed reduction of the hip followed by subsequent open reduction internal fixation of the acetabular fracture. Posterior hip fracture dislocations can occur in adults following low energy non-contact injuries. Successful outcomes can be achieved if they are treated in a timely fashion, but unrecognized injuries can lead to devastating consequences.
#9 Identifying Soccer Players' Playing Styles: A Systematic Review
Reference: J Funct Morphol Kinesiol. 2023 Jul 26;8(3):104. doi: 10.3390/jfmk8030104.
Authors: Spyridon Plakias, Serafeim Moustakidis, Christos Kokkotis, Marina Papalexi, Themistoklis Tsatalas, Giannis Giakas, Dimitrios Tsaopoulos
Summary: Identifying playing styles in football is highly valuable for achieving effective performance analysis. While there is extensive research on team styles, studies on individual player styles are still in their early stages. Thus, the aim of this systematic review was to provide a comprehensive overview of the existing literature on player styles and identify research areas required for further development, offering new directions for future research. Following the PRISMA guidelines for systematic reviews, we conducted a search using a specific strategy across four databases (PubMed, Scopus, Web of Science, and SPORTDiscus). Inclusion and exclusion criteria were applied to the initial search results, ultimately identifying twelve studies suitable for inclusion in this review. Through thematic analysis and qualitative evaluation of these studies, several key findings emerged: (a) a lack of a structured theoretical framework for player styles based on their positions within the team formation, (b) absence of studies investigating the influence of contextual variables on player styles, (c) methodological deficiencies observed in the reviewed studies, and (d) disparity in the objectives of sports science and data science studies. By identifying these gaps in the literature and presenting a structured framework for player styles (based on the compilation of all reported styles from the reviewed studies), this review aims to assist team stakeholders and provide guidance for future research endeavors.
#10 Female Soccer Periodization on Anaerobic Power/Capacity
Reference: J Strength Cond Res. 2023 Aug 22. doi: 10.1519/JSC.0000000000004555. Online ahead of print.
Authors: Troy M Purdom, Kyle S Levers, Gregory A Ryan, Lindsey Brown, Jacob Giles, Chase McPherson
Summary: The purpose of this study was to observe changes in anaerobic power and capacity (resistance to fatigue) over an annual training cycle (ATC) in 14 Division I female soccer athletes (19.4 ± 1.0 years, 60.8 ± 5.4 kg, 164.9 ± 6.2 cm, 19.5 ± 3.2% body fat, and 48.9 ± 3.9 kg fat free mass). All subjects were evaluated across the ATC at 5 testing blocks (B1-B5) representing seasonal transitions: postcompetition I (B1), prespring (B2), postspring training (B3), precompetition (B4), and postcompetition II (B5) using 3 tests: countermovement vertical jump to measure peak vertical power (PVP), 40-yard sprint to measure peak horizontal power (PHP), and 35-m running anaerobic sprint test to measure anaerobic capacity via fatigue index (FI). Repeated measures analysis of variance was used with the Bonferroni post hoc test when relevant along with Cohen's d to evaluate effect size. Data are represented as mean ± SD; significance set to p < 0.05. Significant performance increases were observed from postseason I to spring season training (B1-B3) in PVP (6.61 ± 3.18 and 7.71 ± 3.20; p < 0.01, d = 1.12) while changes occurred from prespring season to postspring season (B2-B3) in PVP (6.84 ± 3.15 and 7.71 ± 3.20; p = 0.03, d = 0.93) and PHP (6.65 ± 0.97 and 7.55 ± 1.26; p < 0.01, d = 1.06) with no change in body composition. No other significant changes were observed across the ATC (p > 0.05). Increases in PHP and PVP occurred with directed training after B3 and then declined remaining so across the competitive season. Peak horizontal power and PVP may be more sensitive to coaching style and seasonal transition compared with FI and body composition changes.
#11 Leadership cycles, styles, and antecedent factors: the perspective of coaches and young soccer athletes from national Slovak leagues
Reference: Front Psychol. 2023 Aug 7;14:1218290. doi: 10.3389/fpsyg.2023.1218290. eCollection 2023.
Authors: Elena Lisá, Jacinta Sousa, Catarina Morais, António Rui Gomes
Summary: Building positive relationships and interactions between coaches and athletes is critical to an athlete's success. The current study aimed to overview how coaches and their young athletes perceive three elements of the Leadership Efficacy Model (philosophy, practice, and criteria). The aim was examined with four goals of analysis: the perceptions of coaches and athletes about coaches' leadership philosophy, practice, and criteria (1); the differences between athletes' and coaches' perceptions of leadership cycles (2); the differences between athletes' and coaches' perceptions of leadership styles (3); and the differences between athletes' and coaches' perceptions of leadership antecedent factors (4). The study involved 304 athletes and 20 coaches competing in the youth national leagues U15, U16, U17, and U19. Two-source data collection was applied: coaches completed the questionnaires from their point of view, and so did athletes. The coaches were paired then with their athletes to compare the answers. Coaches fulfilled Leadership Cycles Questionnaire (LEQ), Multidimensional Scale of Leadership in Sport (MSLS), and Leadership Antecedent Factors Questionnaire (LAFQ). Athletes completed the same questionnaires as the coaches did and also fulfilled the Sport Performance Perception Questionnaire (SPPQ). Athletes' age and SPPQ served as control variables. Both athletes (37.5%) and coaches (40%) perceived that the philosophy of the leadership efficacy model should be increased. Coaches evaluated their philosophy (F = 4.43; p = 0.036; η2 = 0.014), support in MSLS (F = 5.05; p = 0.025; η2 = 0.016) and active management in MSLS (F = 4.08; p = 0.044; η2 = 0.013) higher than their athletes. The athletes assessed the maturity of the team members (LAFQ dimension) (F = 13.98; p <0.001; η2 = 0.044), negative feedback in MSLS (F = 6.02; p = 0.015; η2 = 0.020), and passive management in MSLS (F = 4.95; p = 0.027; η2 = 0.016) higher than their coaches. The tendency of coaches to have a more positive perception of their leadership behavior compared to their athletes represents the coach-athlete perception gap of leadership. Future research can examine the efficacy of congruent perceptions of leadership between athletes and coaches during the sports season and the impact produced by objective performance indicators.
#12 Changes in Physical Performance Throughout Professional Soccer Match-Play
Reference: J Strength Cond Res. 2023 Aug 23. doi: 10.1519/JSC.0000000000004579. Online ahead of print.
Authors: José M Oliva-Lozano, Paulino Granero-Gil, Marco Panascì
Summary: The aim of this study was to explore the changes in physical performance by playing position throughout professional soccer match-play. Global Positioning Systems were used for the collection of external load measures during 35 matches. Each match was divided into 15-minute periods. Physical performance varied according to the period in distance covered (F = 25.69; p < 0.001; partial eta-squared [ηp2] = 0.11), sprinting distance (SPD, F = 4.35; p < 0.001; ηp2 = 0.02), sprinting actions (SPAs, F = 5.19; p < 0.001), high-intensity accelerations (Acc+3, F = 2.18; p = 0.05; ηp2 = 0.01), high-intensity decelerations (Dec+3, F = 4.51; p < 0.001; ηp2 = 0.02), and high-metabolic load distance (HMLD, F = 5.59; p < 0.001; ηp2 = 0.03). The period with the greatest mean physical performance was usually from the first half of the matches: 0-15 minutes (distance, Acc+3, and Dec+3) and 30-45 minutes (HMLD, SPA, and SPD). However, the lowest mean physical performance compared with the rest of 15-minute periods was observed in the 60-75-minute period (distance, HMLD, Acc+3, and Dec+3), except for SPA and SPD (15-30 minutes and 75-90 minutes). Overall, no significant differences (p > 0.05) were observed in the physical performance between the extratime periods. In addition, the playing position had a significant effect on all performance variables (F = 39.99-133.29; p < 0.001; ηp2 = 0.14-0.34). Central defenders showed the lowest physical performance throughout the periods of match-play, whereas wide midfielders showed the greatest physical performance in all variables, except for distance covered, in which midfielders had the greatest performance. In conclusion, there were changes in physical performance during the matches depending on the period of match-play and playing position.
#13 Toward a New Conceptual Approach to "Intensity" in Soccer Player's Monitoring: A Narrative Review
Reference: J Strength Cond Res. 2023 Sep 1;37(9):1896-1911. doi: 10.1519/JSC.0000000000004503.
Authors: Guglielmo Pillitteri, Filipe M Clemente, Marco Petrucci, Alessio Rossi, Marianna Bellafiore, Antonino Bianco, Antonio Palma, Giuseppe Battaglia
Summary: In the last decade, monitoring physiological and match-related demands in soccer has become an increasingly common practice in sports sciences. One of the great challenges during monitoring process is the identification of key indicators that permit to generalize evidence and sustain decision-making process during training prescription. Actually, one of the major debates in the scientific community and among practitioners is the identification of the "intensity" concept. Defining a given training session or exercise based on "intensity" is difficult due to the fact that a huge amount of indicators are available (related both to the performed activities and to the athletes' psychophysiological responses). These indicators can lead to specific outcomes with different interpretations. The current narrative review aims to discuss the different measures approaches used in soccer to describe the intensity for both internal and external demands. In addition, a second purpose of this review is to propose general recommendations for combining intensity indicators with the aim of defining an overall intensity score of a training session or drill.
#14 SARS-CoV-2 Infection Increases the Risk of Muscle Injury in Professional Male Soccer Players-A Retrospective Analysis of the Italian and Spanish Major Leagues
Reference: Infect Dis Rep. 2023 Jul 26;15(4):425-435. doi: 10.3390/idr15040043.
Authors: Sandra Miccinilli, Marco Bravi, Giorgio Conti, Federica Bressi, Silvia Sterzi, Fabio Santacaterina, Massimo Ciccozzi
Summary: A retrospective cohort study on professional soccer players from the Serie A and LaLiga was conducted to investigate the correlation between SARS-CoV-2 infection and muscle injuries. Players were divided into two groups based on whether they contracted the SARS-CoV-2 infection (C+) or not (C-) during the 2020/2021 season. In the 2019-2020 season, both championships showed a similar number of muscular injuries (MI) between C+ and C- (Serie A: p = 0.194; 95% CI: -0.044 to 0.215, LaLiga p = 0.915; 95% CI: -0.123 to 0.137). In the 2020-2021 season, C+ had a significantly higher number of MI compared to C- in both championships (Serie A: p < 0.05; 95% CI 0.731 to 1.038; LaLiga: p < 0.05; 95% CI: 0.773 to 1.054). Multiple linear regression analysis confirmed that belonging to C+ in the season 2020/2021 was the variable that most strongly influenced the probability of having a muscle injury. Survival analysis revealed a hazard ratio of 3.73 (95% CI 3.018 to 4.628) and of 5.14 (95% CI 3.200 to 8.254) for Serie A and LaLiga respectively. We found an association between SARS-CoV-2 infection and increased risk of muscle injury, emphasizing the importance of carefully considering the infection in the decision-making process for returning to sport. Therefore, SARS-CoV-2 infection should be judged as a real injury requiring specific assessment and training programs.
#15 Is there a relationship between executive functions and resilience in youth elite soccer players?
Reference: Brain Behav. 2023 Aug 25;e3122. doi: 10.1002/brb3.3122. Online ahead of print.
Authors: Jennifer Lehmann
Summary: While the relationship between cognitive performance and sport performance in youth elite soccer players has proponents as well as opponents, many aspects of this relationship remain unclear. Therefore, this quasi-experimental study wants to contribute to this relationship including the psychological aspect of resilience when investigating youth elite soccer players during an assessment selection for a representative team. Questionnaires as well as computer-based tests were conducted. Results of this study showed no relationship between resilience and executive function in youth elite soccer players. Furthermore, no differences in executive functions or in resilience were found between those players who are selected for a representative team and those who were not selected. The results indicate that further research needs to be conducted to clarify possible relationships in more detail.
#16 Soccer, Sleep, Repeat: Effects of Training Characteristics on Sleep Quantity and Sleep Architecture
Reference: Life (Basel). 2023 Aug 2;13(8):1679. doi: 10.3390/life13081679.
Authors: Patricia Frytz, Dominik P J Heib, Kerstin Hoedlmoser
Summary: Due to the high demands of competitive sports, the sleep architecture of adolescent athletes may be influenced by their regular training. To date, there is no clear evidence on how training characteristics (intensity, time of day, number of sessions) influence sleep quality and quantity. 53 male soccer players (M = 14.36 years, SD = 0.55) of Austrian U15 (n = 45) and U16 elite teams (n = 8) were tested on at least three consecutive days following their habitual training schedules. Participants completed daily sleep protocols (7 a.m., 8 p.m.) and questionnaires assessing sleep quality (PSQI), chronotype (D-MEQ), competition anxiety (WAI-T), and stress/recovery (RESTQ). Electrocardiography (ECG) and actigraphy devices measured sleep. Using sleep protocols and an ECG-based multi-resolution convolutional neural network (MCNN), we found that higher training intensity leads to more wake time, that later training causes longer sleep duration, and that one training session per day was most advantageous for sleep quality. In addition, somatic complaints assessed by the WAI-T negatively affected adolescent athletes' sleep. Individual training loads and longer recovery times after late training sessions during the day should be considered in training schedules, especially for adolescent athletes. MCNN modeling based on ECG data seems promising for efficient sleep analysis in athletes.