Retirements of professional tennis players in ATP and WTA tour events.

Professional tennis competition at the highest levels requires high physical, technical, tactical, and mental demands. Player retirement is a scenario that often occurs at the highest echelons of the game. The objective of this study was to descriptively determine which factors influence retirement of matches in tennis. Matches from the Women's Tennis Association (WTA) and Association of Tennis Professionals (ATP) tours played over 44 and 46 years were included in the study, respectively. The results showed an increasing trend in the incidence of retirements in both ATP and WTA events, especially in recent years. Factors associated with the match characteristics, such as the type of surface, the type of tournament, and the round of the draw, were shown to influence retirement. Variables associated with player characteristics, such as the age difference between players, did not show to influence retirement, whereas the ranking difference did. When comparing ATP and WTA matches, similar results were observed in which surfaces and tournaments had the highest or lowest incidence of retirements. On the other hand, as per the rounds, the results are not conclusive. The findings highlight the growing trend of match retirements in professional tennis and emphasize the relevant influence of match characteristics such as surface type, tournament type, and round of the draw. These insights can guide coaches, players, and tournament organizers in developing strategies to mitigate retirements and inform future research on enhancing player longevity and performance in tennis.

Determinants of Performance in Professional Soccer Players at 2 and 5 Years After ACL Reconstruction.

BACKGROUND: A number of studies have investigated return to play after anterior cruciate ligament reconstruction (ACLR) in professional soccer players, but it is unclear which factors are associated with a return to the preinjury performance and ability to play over time. PURPOSE: To identify factors that contribute to a professional soccer player's return to preinjury performance after ACLR, as well as to report their playing performance at 2 and 5 years after ACLR compared with their preinjury performance. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A consecutive cohort of professional soccer players undergoing primary ACLR were analyzed between 2005 and 2019. A minimum 2-year follow-up was required. The effect of patient, surgical, and postoperative factors on performance rates, defined as a combination of league level and playing time, was evaluated with univariate and multivariate logistic regression models. RESULTS: A total of 200 male professional soccer players were included. When combining league level and playing time, 30% of athletes returned to their preinjury performance at 2 years and 22% at 5 years. However, 53% of athletes returned to their preinjury performance for at least 1 season by year 5. At 2 years, a chondral lesion of grade 3 or 4 decreased the odds of return to preinjury performance (odds ratio [OR], 0.37; P = .010). Athletes receiving an ACLR with the addition of a lateral extra-articular tenodesis procedure were 2.42 times more likely to return to preinjury performance at 2 years than athletes with ACLR alone (P = .004). By 5 years after ACLR, athletes aged ≥25 years at the time of reconstruction were 3 times less likely to be performing at their preinjury performance (OR, 0.32; P < .001), and those with a grade ≥3 chondral lesion were >2 times less likely to be performing at their preinjury performance (OR, 0.43; P = .033). CONCLUSION: The presence of >50% thickness chondral pathology, ACLR without lateral extra-articular tenodesis, and age >25 years at the time of surgery were all significant risk factors of worse performance rates after ACLR. Significant decreases in performance rates were noted at 2 and 5 years postoperatively.

The influence of selected anthropometric parameters on psychomotor abilities among professional Rugby Union players.

BACKGROUND: One of the most popular varieties of rugby is Rugby Union, in which a team consists of 15 players. Rugby Union is a full-contact sport, and players must demonstrate strength, endurance, speed and agility. During the match, players participate in multiple physical collisions and tackles, short-duration and high-intensity sprinting efforts. In addition, one of the elements affecting the effectiveness of the player's game can be the reaction time of the rugby player to the visual stimulus and the ability to read the game and react to the situations on the pitch. The level of psychomotor abilities of a person or a player practising sports can be influenced by various factors, including age, body height, body weight, type of sport practised or level of training. The study aimed to analyse the psychomotor abilities of professional rugby union players, investigate the relationship between the selected anthropometric characteristics and psychomotor abilities, and compare obtained results with the control group. METHODS: The study covered 22 players of the Polish National Team (age: 29.3 ± 5.4) and 27 students in the control group (age: 24.3 ± 3.9). The tests were carried out using the Test2Drive computer system of tests. For psychomotor abilities analysis, four tests were used: Simple Reaction Test, Choice Reaction Time Test, Hand-Eye Coordination Test and Spatial Orientation Test. The statistical analysis compares groups using basic statistical measures, and statistically significant differences between groups were checked. In addition, multiple linear regression was used. RESULTS: The analysis showed statistically significant differences between the groups in the simple reaction time test and the movement time for the test assessing reaction time with choice and eye-hand coordination. Multiple regression analysis conducted for both groups showed a statistically significant influence of some anthropometric parameters on the examined psychomotor abilities. The calculated multiple regression models had a high fit. CONCLUSIONS: The analysis showed that professional Rugby Union players have shorter movement time than the control group. For reaction time, statistically significant differences were observed only for simple reaction time. Moreover, linear regression analysis showed that body height and weight affect the selected psychomotor abilities.

Effects of Nutrition Interventions on Athletic Performance in Soccer Players: A Systematic Review.

BACKGROUND: More than 270 million participants and 128,893 professional players play soccer. Although UEFA recommendations for nutrition in elite football exist, implementing these guidelines among professional and semiprofessional soccer players remains suboptimal, emphasizing the need for targeted and individualized nutritional strategies to improve adherence to established recommendations. METHODS: We conducted a comprehensive search in PubMed, Scopus, Web of Science, and clinical trial registers. Inclusion criteria focused on professional or semiprofessional soccer players, nutrition or diet interventions, performance improvement outcomes, and randomized clinical trial study types. We assessed quality using the Risk of Bias 2 (RoB 2) tool. We identified 16 eligible articles involving 310 participants. No nutritional interventions during the recovery period effectively improved recovery. However, several performance-based interventions showed positive effects, such as tart cherry supplementation, raw pistachio nut kernels, bicarbonate and mineral ingestion, creatine supplementation, betaine consumption, symbiotic supplements, and a high-carbohydrate diet. These interventions influenced various aspects of soccer performance, including endurance, speed, agility, strength, power, explosiveness, and anaerobic capacity. CONCLUSIONS: Specific strategies, such as solutions with bicarbonate and minerals, high carbohydrate diets, and supplements like creatine, betaine, and tart cherry, can enhance the performance of professional soccer players. These targeted nutritional interventions may help optimize performance and provide the competitive edge required in professional soccer. We did not find any dietary interventions that could enhance recovery.

Predictors of linear sprint performance in professional football players.

The purpose of this study was to analyze the relationship between sprint performance (time), and strength and power capabilities in football players. A total of 33 professional Portuguese football players performed isokinetic strength assessments, countermovement jumps (CMJ), squat jumps (SJ), and 10, 20 and 30 m sprints. Pearson's correlation (r) was used to determine the relationships between variables. Concentric knee extensor torque at 180° · s-1 was largely-to-very largely correlated with 10 m (r = -0.726), 20 m (-0.657) and 30 m sprints (r = -0.823). Moderate inverse correlation were observed between CMJ (r = -0.425 and r = -0.405) and SJ height (r = -0.417 and r = -0.430), and 20 m and 30 m sprint performance, respectively. Multiple linear regression combining KEcon 180° · s-1 and KFcon 180° · s-1 demonstrated that the model was significant for predicting 10 m sprint time (F (2, 8) = 5.886; R 2 = 0.595). The model combining SJ, CMJ and KEcon 180° · s-1 was also significant for predicting 20 and 30 m sprint times (F (3, 7) = 2.475; R 2 = 0.515 and F (3, 7) = 5.282; R 2 = 0.562; respectively). In conclusion, peak torque at higher velocities and vertical jump performance correlates significantly with linear sprint performance (time). For practitioners seeking to improve linear sprint performance in football players, evaluation of high speed strength and vertical jump indices should be undertaken.

Eye injuries in badminton - players' perspective toward the usage of personal protective equipment.

OBJECTIVE: We conducted a survey between April to September 2021 to understand the perspective of badminton players on the usage of personal protective equipment to avoid eye injuries. METHODS: The survey was conducted online. It was disseminated through various social media platforms and via e-mail. The survey was initially shared with university-level badminton players. Both recreational and professional players were included. They were further encouraged to circulate the survey questionnaire among their colleagues. RESULTS: In total, the survey received 372 responses. After removing possible duplicates and incomplete responses (n = 28), 92.5% (n = 344) of the responses were included in the final analysis. Among the 344 included responses, recreational and professional players accounted for 77.6% (n = 267) and 22.4% (n = 77), respectively. The mean age ± SD of the recreational and professional players were 24.1 ± 6.3 years (range 14-60 years) and 25.7 ± 6.0 years (range 14-61 years), respectively. A significant difference was noted for self-reported eye injuries between recreational and professional players while playing badminton (χ2 value = 5.321, p = 0.02). Among the recreational and professional players, 93.6% (n = 250) and 88.3% (n = 68) did not use protective eyewear while playing badminton. Professional players were at higher risk of eye injuries than recreational players (OR = 2.9, 95% CI = 1.1-7.8). CONCLUSION: The majority of badminton players in both groups agreed that PPE usage would lower the risk of sustaining eye injuries; however, they are ambiguous about the usage of protective eyewear. In contrast, players with self-reported eye injuries were aware of its impacts and encouraged the usage of PPEs associated with badminton. Further studies are warranted to understand and educate badminton players about the causes and impacts of eye injuries in badminton.

Are there differences in the attention of elite football players concerning playing positions?

PURPOSE: This study aimed to compare the attention performance, by playing position, in elite Brazilian football players. METHODS: A total of 66 professional players competing in the first division of the Brazilian Championship were evaluated. They were grouped according to their playing positions into 7 goalkeepers, 8 defenders, 15 fullbacks, 8 defensive midfielders, 13 attacking midfielders, and 15 forwards. The attention was evaluated using the QuotientTM ADHD System equipment. The group performances were compared using the Kruskal-Wallis Test and the post-hoc analysis using the Mann-Whitney Test. RESULTS: Fullbacks showed less attentive behavior than defenders (U = 9.000, p = 0.001), defensive midfielders (U = 12.500, p = 0.002), offensive midfielders (U = 48.000, p = 0.007) and forwards (U = 27.000, p = 0.001). Fullbacks also had impulsive behavior longer than defenders (U = 10.500, p = 0.001) and defensive midfielders (U = 12.000, p = 0.002), as well as offensive midfielders had impulsive behavior longer than defenders (U = 16.0000, p = 0.004) and defensive midfielders (U = 19.500, p = 0.009). CONCLUSION: Players of defensive positions, as defenders and defensive midfielders, were more attentive and less impulsive than players of hybrid positions, responsible for both defensive and offensive actions, such as fullbacks and attacking midfielders. The present finding indicates that the defenders were the players who maintained the attention level for more time, while the fullbacks maintained for less time. Players in offensive playing positions (fullbacks and attacking midfielders) maintained their impulsive behavior for longer when compared to defensive positions (defenders and defensive midfielders).

Studying professional and recreational female footballers: A bibliometric exercise.

OBJECTIVES: Research directed at soccer has seen dramatic growth in the last decade. While published research on soccer has shown exponential growth, the proportion of articles addressing females is lagging behind research addressing males. The purpose of this paper is to explore how the literature on soccer, female soccer, and professional female soccer has changed over time. METHODS: The Web of Science (WoS) was queried for all "articles" about soccer and association football from 1970 to 2019. This set of records was then queried to collect subsets of papers about females, professional/elite, and female professional/elite. Each of these data subsets was then queried for a number of characteristics and topics. The results were submitted to bibliometric analysis. RESULTS: WoS returned 16,822 "articles" about soccer from 1970 to 2019, 3242 of which addressed females. A total of 5924 "articles" about professional players was found, of which 919 had a female focus. Articles about anterior cruciate ligament injuries and concussion were the topics with the highest proportion of papers involving females. Articles directed at selective areas of training and performance were relatively infrequent. Prominent journals, authors, affiliations, and influential papers are presented. CONCLUSIONS: A bibliometric analysis of the published research presents a high-level overview of trends in soccer research. Overall, studies about women accounted for around 20% of all soccer research and about 15% of studies on professional players. There were a number of topics where studies on females account for less than 10%-15% of the research on all professionals, and opens opportunities for future study.

The use of recovery strategies by Spanish first division soccer teams: a cross-sectional survey.

OBJECTIVES: different active and passive post-exercise recovery techniques such as massage, foam rolling, stretching or ice baths among others, are used by elite athletes to promote effective physiological, physical, and mental restoration. However, limited research is available investigating the use of recovery strategies in professional soccer. As such, we aimed to explore and describe the use of strategies by professional teams throughout the season, describing competitive and preparatory phases. METHODS: the present study collected data from all professional Spanish soccer teams who played in 'LaLiga' (The Spanish first division), during the season 2018-2019 (n = 20) and the ones promoted for the season 2019-2020 (n = 3). A six-section online survey was responded once. RESULTS: teams used different recovery protocols and combinations, although natural and physical strategies such as sleep/nap, food/fluid replacement, cold/ice bath/shower/immersion, and massage were always present. However, there is no agreement in the protocols and timings employed. Three physical strategies showed a higher presence in the recovery protocols after competition: cold/ice bath/shower/immersion, massage and foam rolling; always used by seventeen teams (74%), sixteen (70%) and thirteen (57%) respectively. The design and supervision of recovery are multidisciplinary tasks in 87% of the teams. Our findings also demonstrate that although there is a body of scientific evidence on recovery, a gap between theory and practice exists with 13% of the teams acknowledging that insufficient logistics and economic resources limit the use of some strategies, and two teams (9%) not periodizing or individualizing recovery. CONCLUSION: the investigation provided insight into the current use of recovery strategies by 'LaLiga' teams, highlighting that all clubs used them to one extent or another, but also that significant variability responding to individualized perceptions exists. Moreover, this study provides relevant contextual information that may be useful for professional soccer staff concerning the use of recovery strategies.

Psychomotor Abilities of Professional Handball Players.

The main purpose of the paper was to evaluate selected psychomotor abilities of handball players depending on the competition class (league), position on the court, training seniority and the dominant hand. The study covered a group of 40 handball players (age: 24.02 ± 3.99), while 50 non-training men (age: 22.90 ± 1.13) formed the control group. Studies were performed using Test2Drive computer tests. The following four tests were used for measuring psychomotor fitness: simple reaction time test, choice reaction time test, hand-eye coordination test and spatial anticipation test. An analysis revealed that handball players had better reaction times and movement times than the control group. The league, position on the court, training seniority and the dominant upper limb were analysed for their impact on the reaction time and movement time in handball players. An analysis of psychomotor abilities of handball players with regard to the league revealed that in the majority of tests the Superliga players had a shorter reaction time than players in lower leagues.

A systematic review on small-sided games in football players: Acute and chronic adaptations.

Small-sided games (SSG) are played on a small pitch, often using modified rules and involving a smaller number of players. This article aimed to critically analyse the literature to determine how small-sided games affect the performance of football players in the short- and long term. Electronic databases were searched for literature dating from January 2000 to July 2018. The methodological quality of the studies was evaluated using the modified Downs and Black Quality Index (cross-sectional studies) and the Physiotherapy Evidence Database (PEDro) scale (intervention studies). Fifty-three studies, 44 cross-sectional and 9 intervention studies, met the inclusionary criteria for review. Most of the cross-sectional studies focused on describing the differences between SSG protocols, whereas 4 studies focused on making a comparison between "interval" and "continuous" SSG training regimes. On the other hand, intervention studies focused on making a comparison between SSG-based protocols and high-intensity intermittent training (HIIT)-based running protocols, in addition to determine the effect of a SSG-based training programme alone. SSG-based football plans (2 to 4 SSG sessions per week) show athletic performance improvements in football players by improving sprint, repeated sprint ability (RSA) and change of direction (COD) along with muscular and physiological adaptation.

Alternative assessment of knee joint muscle balance of soccer players through total work-based hamstring: quadriceps ratios.

Isokinetic hamstring-to-quadriceps (H:Q) ratios are frequently used to assess knee muscle strength imbalances and risk of injuries/re-injuries. The use of peak torque (PT) or total work (TW) to estimate joint stability may lead to different results because of the differences between these two neuromuscular variables. Thus, the current study aimed to compare the conventional and functional H:Q ratios calculated by PT and TW. Ninety-three male professional soccer players from Brazilian first division teams performed isokinetic concentric and eccentric contractions of the quadriceps and the hamstrings at 60°/s. Muscle strength balance was calculated using the conventional torque ratio (CTR) and conventional work ratio (CWR), functional torque ratio (FTR) and functional work ratio (FWR) were highly and moderately correlated between them (r = 0.83 and r = 0.73, respectively). The Wilcoxon statistical test revealed significant differences between CTR and CWR, as well as FTR and FWR (p < 0.05). T-test demonstrated significant differences in mean CTR-CWR and FTR-FWR, whereas Bland-Altman plots showed non-consistent bias. In addition, the chi-square test demonstrated significant differences between players below the conventional reference values and functional reference values (p < 0.001). In conclusion, TW ratios seem to provide distinct and additional information regarding the H:Q strength balance in professional soccer players. Moreover, taking into account that TW captures torque information throughout the entire range of motion, it is possible that TW ratios represent a more comprehensive assessment of muscle strength imbalance.

Relative Age Effect in UEFA Championship Soccer Players.

Relative Age Effect (RAE) is the breakdown by both age grouping and dates of birth of athletes. In the past 20 years the existence of this effect has been shown with higher or smaller impact in multiple sports, including soccer. The purpose of this study was to identify the existence of RAE in European soccer players. The sample included 841 elite soccer players who were participants in the UEFA European Soccer Championship in different categories. The professional category (n = 368), U-19 (n = 144) and U-17 (n = 145) were in 2012, and U-21 was in 2011 (n = 184). The Kolmogorov-Smirnov test and the Levene test recommended the use of nonparametric statistics. The results obtained by the square test ( the Kruskal-Wallis test and Cohen's effect sizes revealed the existence of RAE (χ(2) = 17.829, p < 0.001; d = 0.30), with the size of their different effects depending on their category or qualifying round achieved by the national team and the existence of significance in the observed differences by category. Therefore, we could continue examining RAE which is present in elite soccer, and could be considered a factor that influences performance of the national teams tested. RAE was not evident in the professional teams analysed, however it was present in the three lower categories analysed (youth categories), with its influence being greater on younger age categories (U-17).

Medical reasons behind player departures from male and female professional tennis competitions.

BACKGROUND: The number of retirements, withdrawals, and "lucky losers" (the replacement of a player who withdraws before the start of the tournament by a losing player from the qualifying round) from professional tennis tournaments has increased, but the reasons behind such departures have not yet been analyzed. An official consensus statement has been conducted to allow a general categorization of injuries in tennis. PURPOSE: To determine the reasons for departure and injury rates in professional tennis. STUDY DESIGN: Descriptive epidemiology study. METHODS: All reasons for departures were collected from official Association of Tennis Professionals (ATP) and Women's Tennis Association (WTA) web pages. All tournaments apart from the 4 major competitions (the Australian Open, French Open, Wimbledon, and US Open) were included for the period 2001-2012 for men and women. Personal data, tournament information, surface, match setting, date, and reason were obtained for each departure scenario. RESULTS: Variations in departure and injury rates were seen throughout the season. Women left and were injured significantly more than men. Women mainly left because of thigh injuries, whereas men left mainly because of back injuries. Playing surface only had an influence on the risk of lower back injuries. Only women's departures were affected by the tournament round. CONCLUSION: A high number of departures from tournaments have occurred during the past 10 years on the ATP and WTA circuits. Injuries were the main reasons of these departures, regardless of the type of departure and player sex. The back and thigh were the main locations of injuries for men and women, respectively.