Older Players Research Articles

Perceived competence in ice hockey and its associations with relative age, early sport specialization, and players’ position

IntroductionIce hockey is a sport that has gained much attention in recent times, particularly concerning the development of young players. In the domain of youth sport development, one significant factor that must be considered is the perceived competence of players. This variable is closely linked to positive psychological outcomes and sustained practice. However, there is a lack of understanding about how other important developmental factors such as age, early sport specialization, players’ position and relative age affect players’ perceived competence. Therefore, the objective of this study is to explore the relationships between these developmental factors, perceived ice hockey competence and a global measure of perceived sport competence.MethodsData was drawn from 971 players (14.78 ± 1.61 mean age), who completed on-line questionnaires, from which we conducted path analyses involving all variables.ResultsYounger players tend to display higher perceived competence scores than older players. Additionally, players who opted to specialize earlier also reported higher perceived competence. Furthermore, forwards and defensemen had differing perceptions of their competence, which was in line with their respective roles on the ice. The study also showed relative age effects, in which players who were born earlier relative to the selection period tend to perceive themselves more advantageously in three components of perceived competence.DiscussionBased on these findings, several recommendations are proposed for coaches and decision-makers to encourage the positive development of ice hockey players. The study highlights that ice hockey-specific competencies are influenced by various factors, such as early sport specialization, relative age effect, player age, and position.

Differences between U23 and older semi-professional soccer players in perfectionism and passion: exploring determinant relationship between variables.

Abundant studies have pointed out that perfectionism and passion are interrelated and that they both can influence performance in a variety of contexts, including sports, however, research on how these variables interact and might affect performance in team sports, such as soccer, is still scarce. The aim of this study is to analyze differences in perfectionism and passion between under-23 years-old (U23) and older semi-professional soccer players, as well as to study the possible relationship between these two psychological variables. Participants (N = 130 healthy semi-professional Spanish soccer players) were divided into two equivalent groups according to the participants age, U23 (N = 65; 21.58 ± 1.91 years) and older than 24 years (N = 65; 30.03 ± 3.72 years) and completed self-reports on perfectionism and passion. Independent samples t-test determined significant differences between the U23 Group and the >24 Group in perfectionism global score and concern over mistakes (maladaptive perfectionism), and in time, value, and passion. Multiple regression analyses revealed that obsessive passion predicted maladaptive subdimensions of perfectionism, while harmonious passion predicted adaptive perfectionism. U23 soccer players show higher levels of maladaptive perfectionism, time, value, and passion in relation with soccer than older players, probably because at this stage pressure to become professionals and to develop their technical, tactical, and physical skills is higher than in later stages. Identifying differences between different age groups can help professionals in tailoring their interventions and strategies to address the specific needs of athletes at different stages of development more effectively, and to optimize mental focus, reduce stress, to promote a healthy mindset for optimal performance in soccer players, furthermore, the study of moderating effects of factors such as team dynamics or coaching styles on these constructs is advised.

Analysis on Marketing Strategies of Mihoyo Games Take Honkai Star Rail as an Example

Mihoyo Games has grown to be the third-largest mobile game company in China in 2 decades, so a deep analysis of Mihoyos marketing strategies can be used as good references for new game companies. However, less research has been done on Mihoyos newly released game, Honkai Star Rail. In this paper, the 4Ps model is used to analyze Honkai Star Rails marketing strategies from product, price, promotion, and place perspectives and tries to find out why it can be so popular and successful. It turns out that the product and promotion strategies of Honkai Star Rail especially stand out. Product strategies can be concluded to the following points: innovative game style to attract new players; various product terminals support all devices; and the enhancement of the user experience to retain older players. Also, Honkai Star Rail used many different kinds of promotion methods, including various online and on-site promotion activities both before and after its release. Moreover, Mihoyo uses innovative methods to strengthen the relationship between players and games. By using these strategies, Mihoyo gained loyal players who are strongly tied to the games.

Design and Validation of a New Water Polo Test of Anaerobic Endurance: Preliminary Study of Junior Male Players

Water polo is a team sport in which anaerobic capacity plays a significant role, but there is a lack of ecologically valid tests of water polo-specific anaerobic capacity. Therefore, the purpose of this study was to design and validate a method for evaluating the anaerobic capacity of water polo players. The sample of participants included 10 male junior water polo players (16.70 ± 1.06 years, 186.11 ± 6.06 cm, 81.18 ± 6.88 kg). Measurements included power output in the Wingate anaerobic test (WAnT) and the newly designed eggbeater kick anaerobic test (EKAT). WAnT included peak power (PP), average power (AP), minimal power (MP), and power drop (PD), and EKAT included the same four parameters as well as anaerobic capacity (AC). The results of this study show a significant correlation between test and retest values of power output (Pearson’s correlation: 0.63, 0.87, 0.85, and 0.90 for PP, AP, MP, and AC, respectively). T-test calculation showed no significant differences between test and retest values for EKAT. Correlation analysis between EKAT and WAnT showed no significant correlation between corresponding power outputs. In conclusion, our results suggest that EKAT has proper metric characteristics, indicating the practical applicability of this test for male water polo players. Further studies on older players and female players are warranted.

Anthropometric and physical characteristics in U16, U18 and U20 elite French youth rugby union players.

The aims of this study in elite youth French players were to 1) describe the anthropometric and physical characteristics of international and non-international players from U16 to U20, and 2) compare these characteristics across age categories and playing standard (international or non-international). Altogether, 1423 players from the French Rugby Federation's academies participated in a physical testing battery, part of its national young player development pathway. From seasons 2010 to 2020, players were assessed for anthropometric (body mass and height), off-field (bench press; isometric squat, vertical jump) and on-field physical characteristics (aerobic capacity: maximal aerobic speed [MAS]; speed: 10-m, 50-m sprint). A 2-way mixed model analysis of variance (ANOVA) was used to compare physical characteristics across age categories and playing standards. Two separate models were used for forwards and backs. A main statistical effect was observed for age category and playing standard (range p < 0.05 -p < 0.001). Pair-wise category comparisons showed that older players were generally taller, heavier, stronger, faster and demonstrated better aerobic qualities than younger peers. The same results were observed for INT compared with NI players while INT forwards were also taller and heavier than NI peers (range p < 0.01 -p < 0.001). Findings revealed a clear progression in anthropometric characteristics and physical qualities throughout the age development pathway in elite young French rugby players. Findings also identified certain physical qualities (strength, power and speed) necessary at younger levels to achieve international standard.

Female basketball game performance is influenced by menstrual cycle phase, age, perceived demands and game-related contextual factors

ABSTRACTThis study evaluated the influence of physical and perceived game demands, menstrual cycle phase, perceived recovery, individual and game-related contextual factors on competitive performance in professional, female basketball players.11 professional female players (age: 20.6 ± 2.7 years) were monitored for game-related statistics (Performance Index Rating, PIR; rebounds, REB; effective field goal %, eFG%; turnovers, TO), objective (PlayerLoad per minute, PL·min−1) and subjective (RPE) game loads, pre-game perceived recovery (Total Quality Recovery, TQRpre), menstrual phase (follicular; luteal) and game-related contextual factors (game location; game outcome; score differential; opponent level) during 12 official games. Separate linear mixed models were used to evaluate the influence of RPE, PL·min−1, TQRpre, menstrual phase, contextual factors, and individual characteristics (age; playing position) on game-related statistics.Higher PIR and eFG% were found for older players and those who reported higher RPE (all p < 0.05). Higher age also led to less TO (p = 0.042). eFG% was higher when players reported higher TQRpre ;(p = 0.010). Better shooting (eFG%) and rebounding (REB) performances were found during the follicular menstrual phase (p < 0.05). More REB were collected in won games (p = 0.002).This study suggests that the co-influences of perceptual, menstrual-related, individual and game-related contextual factors should be considered to optimise female basketball players’ performance.

Physical fitness in young top level table tennis players: differences between sex, age and playing style

Understanding the physical fitness of table tennis (TT) players could be interesting in improving the training process and evaluating talent. This study aimed to assess the physical fitness of U14 TT players and differentiate between sex, age and playing style. A total of 352 players (203 males and 149 females) aged between 9 and 13 years participated in the present study. Furthermore, the sample was divided according to playing style: offensive (OFF) and mixed + defensive (M + D). A battery of tests was carried out to assess cardiorespiratory capacity, speed, strength, flexibility and power. Both sexes reported significant differences in cardiorespiratory capacity and speed (p &amp;lt; 0.05). Concerning age, there were substantial differences in cardiorespiratory capacity, speed, strength and power, with older players obtaining better results (p &amp;lt; 0.05). Finally, concerning playing style, differences were reported in cardiorespiratory capacity, higher in OFF style group, and flexibility, higher in the M + D style group. Finally, there were relationships between playing style and cardiorespiratory fitness and flexibility. Physical fitness evolves with increasing age as a function of sex. This is the first study to assess fitness in a large sample of TT players as a function of playing style.

Upper limb biomechanical differences in volleyball spikes among young female players

The performance assessment of relevant biomechanical factors is essential for appropriate age-related training progression in volleyball spike (VS). This study aimed to investigate the differences in upper limbs’ (a) range of motion (ROM), (b) angular velocities, and (c) muscular activity during VS among under 16- (U-16), under 18- (U-18), and under 20- (U-20) year-old female volleyball players. The kinematic variables of the spike performances were recorded using six optoelectronic cameras (Vicon Motion system, UK). Additionally, the wireless Trigno system (Delsys, USA) was used to record the electromyographic signals. The one-way ANOVA (1d SPM analysis) exhibited a significantly greater wrist internal rotation ( p &lt; .001), wrist adduction velocity (p &lt; .001), and palmaris longus activity ( p &lt; .001) in the acceleration phase in U-20, compared to the U-16 group. Additionally, the U-20 and the U-18 players portrayed a significantly greater shoulder external rotation ( p &lt; .001) and internal angular velocity ( p = .035) relative to the U-16 group. A significantly greater pectoralis major (p &lt; .001), biceps brachii ( p &lt; .001), and anterior deltoid ( p &lt; .001) activity was observed in the U-20 group, compared to younger groups. This study suggests that older players employ more upper limb muscular activities during spike with the presence of blocks, which enables them to hit the ball with greater velocities and direct the ball in their desired direction through increased wrist ROMs.

Prevalence of sports supplements consumption and its association with food choices among female elite football players

ObjectivesThe present study aimed to 1) investigate the consumption of Sports Supplements (SSs) among female elite football players, 2) evaluate the influence of age on SS consumption, and 3) determine the relationship between the consumption of SSs and dietary choices among elite football players. MethodsA total of 126 female football players of Primera Iberdrola and Reto Iberdrola who participated in this descriptive, observational, and cross-sectional study completed a self-administered questionnaire on SSs and the Athletes’ Food Choices Questionnaire. ResultsOverall, 84.1% of participants consumed supplements, mainly for improved sports performance (68.3%) and health (34.1%). The main sources of purchase were the Internet (34.9%) and specialized shops (23.8%), and players were commonly advised by a dietitian-nutritionist to use SSs (56.3%). The SSs most often consumed included whey protein (30.2%), sports drinks (28.6%), creatine monohydrate (28.6%), sports bars (27.8%), and caffeine (27.8%). Older players consumed more supplements at the time of data compilation. Players predominantly acquired these supplements by using the Internet and reported benefits from their use (all P ≤ 0.036). Additionally, players who consumed SSs conveyed more concern about their food choices. ConclusionsA high prevalence of female football players consumed SSs, particularly SSs supported by robust scientific evidence. Older players had higher supplement consumption rates. The use of SSs was related to food choices through nutritional characteristics of foods, knowledge about health and nutrition, weight control with the help of food, and the performance benefits players could acquire.

Relationship between relative age measured through decimal age, physical variables and anthropometry in elite youth soccer players

ABSTRACT Introduction Age differences between athletes born in the same year, as well as an over-representation of older players, are known as the Relative Age Effect (RAE). Players born at the beginning of the selection year have a physical and anthropometric advantage over their younger peers. Experts keep looking for new prediction variables for talent identification. Objectives The aim of the study is to correlate anthropometric, strength and power variables with the relative age (RA) and the level of the teams in which players played in each age category. Methods All players (N = 366) from an elite soccer academy of a Spanish club volunteered to participate in the study (U23-U10). Results There was a significant correlation between the RA of the players and the level of the team in which they played in each age category but no correlation between trimester of birth and level of the team. We found significant correlations between the players’ physical capacities, anthropometry, RA and the level of the team in which they played for the same age category, mainly from U16 to U10. U23 did not show any correlation between RA and physical or anthropometric variables. Conclusion Coaches should be cautious of choosing players based only on anthropometric or physical attributes.

Investigating Player Selection within UK Academy Soccer: The Application of Objective and Subjective Assessments in Detecting Talent

Talent selection and development in academy soccer is highly dependent on coach intuition. Given such reliance upon subjective inputs, a greater understanding towards the utility of coach intuition may prove invaluable. The present study investigated coach agreement, the associations between subjective and objective outcomes and prominent traits highlighted within player (de)selection. Academy players (n = 45, age = 14 ± 2yrs) and coaches (n = 10, age = 31 ± 5yrs) were recruited from a professional soccer academy. Objective assessments included tactical and psychological surveys, physical assessments (linear sprints, change of direction and jumping tasks) and performance analysis (performance assessment for team sports). Coach subjective player gradings were collected using a visual analogue scale aligned to the objective assessments. Lead and assistant coaches demonstrated poor-to-moderate agreements in perceived player skills (ICC = 0.48 to 0.76) and fair to almost perfect agreement in player (de)selection (ICC= 0.23-1.00, P &lt;.001 to .26). However, coach agreement reduced as players aged. Likewise, a maturation related bias was present whereby biologically older players were selected over their lesser mature players. Moreover, coach intuition demonstrated a strong predictive capability to select players, whilst the study was incapable of distinguishing exclusive traits related to selection outcome.

Head Acceleration Events in Male Community Rugby Players: An Observational Cohort Study across Four Playing Grades, from Under-13 to Senior Men

ObjectivesThe aim of this study was to examine the cumulative head acceleration event (HAE) exposure in male rugby players from the Under-13 (U13) to senior club level over 4 weeks of matches and training during the 2021 community rugby season.MethodsThis prospective, observational cohort study involved 328 male rugby players. Players were representative of four playing grades: U13 (N = 60, age 12.5 ± 0.6 years), U15 (N = 100, age 14.8 ± 0.9 years), U19 (N = 78, age 16.9 ± 0.7 years) and Premier senior men (N = 97, age 22.5 ± 3.1 years). HAE exposure was tracked across 48 matches and 113 training sessions. HAEs were recorded using boil-and-bite instrumented mouthguards (iMGs). The study assessed the incidence and prevalence of HAEs by ages, playing positions, and session types (match or training).ResultsFor all age grades, weekly match HAE incidence was highest at lower magnitudes (10–29 g). Proportionally, younger players experienced higher weekly incidence rates during training. The U19 players had 1.36 times the risk of high-magnitude (> 30 g) events during matches, while the U13 players had the lowest risk compared with all other grades. Tackles and rucks accounted for the largest HAE burden during matches, with forwards having 1.67 times the risk of > 30 g HAEs in rucks compared with backs.ConclusionsThis study provides novel data on head accelerations during rugby matches and training. The findings have important implications for identifying populations at greatest risk of high cumulative and acute head acceleration. Findings may guide training load management and teaching of skill execution in high-risk activities, particularly for younger players who may be exposed to proportionally more contact during training and for older players during matches.

Higher age and present injury at the start of the season are risk factors for in-season injury in amateur male and female football players—a prospective cohort study

PurposeTo describe the injury prevalence, injury pattern, and potential baseline risk factors for injuries in male and female adolescent and adult amateur football players.MethodsThis prospective study followed adolescent and adult amateur football players over one season March–October 2020. The study was completed by 462 players (130 men, age 20.0 ± 5.7, 14–46 years) who answered a baseline survey and a weekly web survey during the season. A total of 1456 weekly surveys were registered from males and 5041 from females. Injuries were recorded with the Oslo Sports Trauma Research Center Overuse Injury Questionnaire (OSTRC-O2). Potential baseline risk factors (age, performance of strength/conditioning training, participation in other sports, perceived importance of sporting success, self-rated training and match load, perceived balance between training/match load and recovery, previous/present injury at start of season, and injury beliefs) and their association with injury were analysed with Poisson regressions within each sex.ResultsMales reported 95 injuries (262 injury weeks, weekly prevalence 18.0% (95% CI 16.1–20.1)) and females 350 injuries (1206 injury weeks, weekly prevalence 23.9% (95% CI 22.8–25.1)). Gradual-onset injuries accounted for 57% of the injuries in males and 66% in females. For males, substantial injuries were most common in the hip/groin (weekly prevalence 3.8%), ankle (2.1%), posterior thigh (2.0%), and knee (2.0%); and for females, in the knee (4.3%), ankle (2.5%), and lower leg/Achilles tendon (2.0%). Significant risk factors for injury were higher age (rate ratio males 1.05 per year increase (95% CI 1.02–1.08), females 1.03 (95% CI 1.01–1.05)), and present injury at baseline (males 1.92 (95% CI 1.27–2.89), females 1.58 (95% CI 1.19–2.09)).ConclusionAt any given week, almost one in five male and one in four female amateur football players reported new or ongoing injuries. Hip/groin injuries were more frequent in males, while female players had a higher prevalence of knee injuries. Older players and those with an existing injury at the start of the season were more prone to new injury during the season. Rehabilitation of pre-season injury and complaints are key to reduce the injury burden in amateur football.Level of evidenceLevel II.Trial registration number NCT04272047, Clinical trials

Market exit and re-entry in a volatile emerging economy: a case study of Yamaha motorcycles in Pakistan

PurposeThis study aims to understand the dynamics underpinning the exit and re-entry strategies adopted by multinational enterprises (MNEs) in an emerging market, Pakistan.Design/methodology/approachThis study undertook an in-depth historical case study of Yamaha Motorcycles, which had initially entered Pakistan as a joint venture but had then exited and re-entered as a wholly owned subsidiary.FindingsThis study found that, despite its status as a market leader and one of the older players in the Pakistani market, changing market dynamics in the 2000s – especially the increased competition brought by more affordable (inexpensive) Chinese motorcycles and the weak enforcement of industrial policies – had pushed Yamaha Motorcycles to exit. Another factor that had contributed to its exit were differences in risk perception and strategies with its local joint venture partner (a Pakistani business group). Hence, both firm-level and institutional factors had played significant roles in Yamaha’s market exit. This study further found that re-entering in a wholly owned subsidiary operation mode had been beneficial for the firm, as it gained a significant market share due to its focus on innovation and on capturing a market niche, which had earlier not been its main focus. The findings also suggest that opportunity logics and multiple forms of learning can be important for a firm’s re-entry into a host market – such as experiential (i.e. learning from experience) and vicarious learning (i.e. learning from other organizations, including suppliers and competitors) in an emerging market context, in which institutions evolve amid political and policy uncertainty. Finally, this study found that exit and re-entry timing is an important factor for the development of competitive advantage in a host market.Originality/valueThis study is among the few to have investigated the exit and re-entry strategies of MNEs in emerging markets. The relatively short time during which Yamaha Motorcycles had been out of the market had benefited it on its re-entry, as the firm had been able to capitalize on its prior learning and ties to suppliers’ networks.

Return to Play and Performance After Anterior Cruciate Ligament Reconstruction in the National Women's Soccer League.

The anterior cruciate ligament (ACL) is commonly injured in elite-level female athletes, which usually requires ACL reconstruction (ACLR). To analyze return to play (RTP) and changes in performance of players in the National Women's Soccer League (NWSL) after ACLR. Descriptive epidemiology study. NWSL players who sustained an ACL tear and underwent surgery between the 2013 and 2020 seasons were identified by multiple online resources. Players were classified as forwards, defenders, midfielders, and goalkeepers. RTP was assessed according to games played, games started, percentage of minutes played, plus/minus net per 90 minutes (a measure of a player's contribution to their team's performance while on the field), goals scored, and assists. A subanalysis was performed based on the median age at the time of the injury (≤24 vs ≥25 years). Nonparametric testing methods were used throughout the analysis. A total of 30 NWSL athletes were included. Midfielders had the highest percentage of injuries (n = 11; 36.7%), followed by forwards (n = 10; 33.3%). Overall, 27 players returned to the NWSL at a median of 12.1 months (IQR, 10.9-14.3 months), constituting a 90.0% RTP rate. There was a significant decrease in the percentage of minutes played from 1 year before the injury to 1 year after the injury (median, 87.9% [IQR, 80.7%-90.6%] vs 25.1% [IQR, 16.3%-57.2%], respectively; P = .031). Forwards and midfielders had a significant decrease in the number of assists from 1 year before the injury to 1 year after the injury (median, 3.0 [IQR, 1.0-3.0] vs 0.0 [IQR, 0.0-1.0], respectively; P = .037) as well as the number of goals scored when averaging across 2 seasons before the injury to 2 seasons after the injury (median, 3.0 [IQR, 1.5-5.5] vs 1.0 [IQR, 0.5-3.5], respectively; P = .031). On subanalysis, older players started in significantly more games (median, 12.0 [IQR, 3.8-18.5] vs 3.0 [IQR, 0.5-6.0], respectively; P = .048) and had a higher percentage of minutes played (median, 63.0% [IQR, 18.8%-77.3%] vs 14.9% [IQR, 2.0%-21.2%], respectively; P = .046) at 1 year after the injury versus younger players. There was a 90.0% RTP rate after ACLR in the NWSL. Players who returned to the NWSL had a lower percentage of minutes played in their first year after RTP, with older players starting in more games and having a greater percentage of minutes played. Compared with preinjury performance, forwards and midfielders had a significant decrease in the number of assists at 1 year after the injury as well as the number of goals scored at 2 years after the injury.

Anthropometric Characteristics and Specific Functional Swimming Capacities in Youth U12 Water Polo Players

Introduction: Water polo is a physically high-demanding team sport, therefore players’ physical abilities and anthropometric characteristics are important factors to achieve a good level of quality in technical-tactical actions. The aim of this study was to determine the association of the chronological age with the anthropometric characteristics and specific functional swimming capacities in youth U12 male water polo players. Methods: There were 170 youth U12 water polo players who attended the Croatian Water Polo Federation training camps included in this cross-sectional study. Measurements included anthropometric characteristics and specific functional swimming capacities. Results: Players were divided according to their chronological age: Q1 (January- March) – 59 players (34.7%), Q2 (April-June) – 35 players (20.6%), Q3 (July-September) – 46 players (27.1%) and Q4 (October-December) – 30 players (17.6%). Older players born in Q1 presented higher values of body height and weight than their younger peers born in Q4 (Q1 165.96±7.88 cm vs. Q4 159.46±5.44 cm, P=0.001; Q1 60.14±13.99 kg vs. Q4 51.35±7.09 kg, P=0.023), while there were no statistically significant differences in specific functional swimming tests between different age groups. Discussion: Contrary to what was hypothesized, older water polo players presented only better anthropometric characteristics than their younger peers, probably due to the biological maturity influence on functional skills, as well as small range of chronological age differences. Conclusion: Such data might provide an understanding of the general and specific water polo player’s development process, which should be considered by coaches of youth players to improve their skills as a result of developing better training programs.

Lumbar Bone Stress Injuries and Nonunited Defects in Elite Australian Cricket Players.

To describe the presentation and management of lumbar bone stress injuries (LBSI), recurrent LBSI, and lumbar nonunited defects in elite Australian male and female cricket players. Retrospective case series. Professional domestic and international cricket teams over 13 seasons. Elite Australian cricket players. Symptomatic LBSI requiring time off cricket and lumbar nonunited defects, both confirmed by imaging. Incidence, presentation, history, healing, and management. 211 LBSI were identified at an average incidence of 5.4 per 100 players per season. LBSI were most common in male pace bowlers younger than 20 years of age (58.1 per 100 players per season), however, were also observed in older players, females, and non-pace bowlers. Recurrent LBSI accounted for 33% (27%-40%) of all LBSI. Median days to return to match availability was 182 (128-251) days for all LBSI, with a shorter time frame observed for new and less severe injuries, and male spin bowlers. Healing was demonstrated in 87% (81%-91%) of all LBSI cases. 29 nonunited defects were identified and predisposed subsequent pain, LBSI, and spondylolisthesis. LBSI are experienced by approximately 5.4 in every 100 elite Australian cricket players per season, with a high time cost of approximately 4 to 8 months. Nonunited defects also have a high time cost with associated subsequent lumbar spine issues. The findings of this study reinforce the importance of early detection and conservative management of LBSI, particularly for younger male pace bowlers and players with recurrent LBSI, which may be supported by MRI.

Air pollution and indoor work efficiency: Evidence from professional basketball players in China

Previous studies analysing the effects of air pollution on work efficiency did not pay much attention to indoor impacts. This paper attempts to fill this gap by using technical data from Chinese Basketball Association (CBA) players. For the first time, we present personal work efficiency using a comprehensive evaluation index, the player efficiency rating (PER). The information is then combined with daily air quality data. We find that air pollution reduces work productivity: for every 10% increase in the air quality index (AQI), the average PER decreases by 0.4221, and the effects vary by air pollutant. Heterogeneity analysis shows that at the level of competition venues, the negative impact of air pollution on work efficiency can be weakened at home, while the rising temperature in the competition city can amplify the negative impact of air pollution on work efficiency. At the level of individual players, older players and foreign players are less affected by air pollution. Moreover, we find that air pollution affects work efficiency by reducing total work output and work accuracy.Our research constructs a comprehensive evaluation index for work efficiency, enriches research on the influence of air pollution on work efficiency, and provides a policy basis for identifying groups that are sensitive to air pollution, which might help with air pollution control policy making.

The Assessment of Body Composition and Nutritional Awareness of Football Players According to Age.

The optimal body composition for health is an individual trait and is determined by genetic factors, sex, age, somatotype, physical activity, and individual variability. The present study aims to assess how professional football players' body composition has changed over the training macrocycle in various age groups and to determine the correlation between nutritional awareness and body composition maintenance. Thirty-eight football players participated in the study, with 16 players classified in the younger age group (19-25) and 22 in the older age group (26-31). Using the direct segmented multi-frequency electrical impedance analysis technique, the athletes' body composition was assessed six times across a training macrocycle made up of preparatory, competitive, and transitional periods. The Sports Nutrition Knowledge Questionnaire was used to evaluate nutrition knowledge. The above correlations show that both younger and older athletes with higher awareness are better able to adjust their nutrition to meet the goals of the preparation period and can achieve greater gains in muscle mass and greater reductions in body fat. According to the study's results, athletes who are better conscious of their nutritional needs during competition experience less muscle loss and exhibit more consistent body weight and BMI levels. Football players' body composition suffers detrimental alterations throughout the transition period. Higher body mass, lean body mass content, and skeletal muscle mass are traits of older players. Higher nutritional knowledge reduces the negative modifications of body composition consisting of muscle mass reduction and fat gain. Nutritional knowledge influences the stability of body composition in both age groups during all the analyzed periods: Preparation, competition, and transition.

Characterization of Static Strength, Vertical Jumping, and Isokinetic Strength in Soccer Players According to Age, Competitive Level, and Field Position.

Muscular strength is strongly related to speed and agility tasks, which have been described as the most decisive actions preceding goals in the soccer game. This study aimed to characterize the players' strength indicators and to analyze the variation associated with age, competition level, and positional role. Eighty-three male soccer players from A team (n = 22), B team (n = 17), U-23 (n = 19), and U-19 (n = 25) participated in this study. Handgrip strength was assessed using a hand dynamometer (Jamar Plus+), countermovement jump (CMJ) and the squat jump (SJ) were evaluated using Optojump Next, and a Biodex System 4 Pro Dynamometer was used to assess the isokinetic strength of knee extension/flexion. Team A players showed increased lower-body strength compared to their peers, mainly through their increased vertical jumping capacity (i.e., CMJ and SJ; ps < 0.019), and superior performance in isokinetic assessments (i.e., peak torque, total work, and average power). Overall, older players outperformed their younger peers regarding vertical jumping, static strength, and average power in isokinetic strength (ps < 0.005). This study emphasizes the superior strength levels of professional soccer players compared with their lower-division peers, even after controlling by age. This information is of great value to sports agents and coaches, underlining the need to design and include strength-specific content during soccer training.