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

Background: 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. Aim: 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. Methods: 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. Results: 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). Conclusion: 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.

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

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.

Hormonal Basis of Biological Sex Differences in Human Athletic Performance.

Biological sex is a primary determinant of athletic human performance involving strength, power, speed, and aerobic endurance and is more predictive of athletic performance than gender. This perspective article highlights 3 key medical and physiological insights related to recent evolving research into the sex differences in human physical performance: (1) sex and gender are not the same; (2) males and females exhibit profound differences in physical performance with males outperforming females in events and sports involving strength, power, speed, and aerobic endurance; (3) endogenous testosterone underpins sex differences in human physical performance with questions remaining on the roles of minipuberty in the sex differences in performance in prepubescent youth and the presence of the Y chromosome (SRY gene expression) in males, on athletic performance across all ages. Last, females are underrepresented as participants in biomedical research, which has led to a historical dearth of information on the mechanisms for sex differences in human physical performance and the capabilities of the female body. Collectively, greater effort and resources are needed to address the hormonal mechanisms for biological sex differences in human athletic performance before and after puberty.

High-dose short-term creatine supplementation without beneficial effects in professional cyclists: a randomized controlled trial.

BACKGROUND: Growing evidence supports the ergogenic effects of creatine supplementation on muscle power/strength, but its effects on endurance performance remain unclear. We assessed the effects of high-dose short-term creatine supplementation in professional cyclists during a training camp. METHODS: The study followed a double-blind, randomized parallel design. Twenty-three professional U23 cyclists (19 ± 1 years, maximum oxygen uptake: 73.0 ± 4.6 mL/kg/min) participated in a 6-day training camp. Participants were randomized to consume daily either a recovery drink (containing carbohydrates and protein) with a 20-g creatine supplement (creatine group, n = 11) or just the recovery drink (placebo group, n = 12). Training loads and dietary intake were monitored, and indicators of fatigue/recovery (Hooper index, countermovement jump height), body composition, and performance (10-second sprint, 3-, 6-, and 12-minute time trials, respectively, as well as critical power and W') were assessed as study outcomes. RESULTS: The training camp resulted in a significant (p < 0.001) increase of training loads (+50% for total training time and + 61% for training stress score, compared with the preceding month) that in turn induced an increase in fatigue indicators (significant time effect [p < 0.001] for delayed-onset muscle soreness, fatigue, and total Hooper index) and a decrease in performance (significant time effect [p = 0.020] for critical power, which decreased by -3.8%). However, no significant group-by-time interaction effect was found for any of the study outcomes (all p > 0.05). CONCLUSIONS: High-dose short-term creatine supplementation seems to exert no consistent beneficial effects on recovery, body composition or performance indicators during a strenuous training period in professional cyclists.

No additive effect of creatine, caffeine, and sodium bicarbonate on intense exercise performance in endurance-trained individuals.

BACKGROUND: Athletes commonly use creatine, caffeine, and sodium bicarbonate for performance enhancement. While their isolated effects are well-described, less is known about their potential additive effects. METHODS: Following a baseline trial, we randomized 12 endurance-trained males (age: 25 ± 5 years, VO2max: 56.7 ± 4.6 mL kg-1 min-1; mean ± SD) and 11 females (age: 25 ± 3 years, VO2max: 50.2 ± 3.4 mL kg-1 min-1) to 5 days of creatine monohydrate (0.3 g kg-1 per day) or placebo loading, followed by a daily maintenance dose (0.04 g kg-1) throughout the study. After the loading period, subjects completed four trials in randomized order where they ingested caffeine (3 mg kg-1), sodium bicarbonate (0.3 g kg-1), placebo, or both caffeine and sodium bicarbonate before a maximal voluntary contraction (MVC), 15-s sprint, and 6-min time trial. RESULTS: Compared to placebo, mean power output during 15-s sprint was higher following loading with creatine than placebo (+34 W, 95% CI: 10 to 58, p = 0.008), but with no additional effect of caffeine (+10 W, 95% CI: -7 to 24, p = 0.156) or sodium bicarbonate (+5 W, 95% CI: -4 to 13, p = 0.397). Mean power output during 6-min time trial was higher with caffeine (+12 W, 95% CI: 5 to 18, p = 0.001) and caffeine + sodium bicarbonate (+8 W, 95% CI: 0 to 15, p = 0.038), whereas sodium bicarbonate (-1 W, 95% CI: -7 to 6, p = 0.851) and creatine (-6 W, 95% CI: -15 to 4, p = 0.250) had no effects. CONCLUSION: While creatine and caffeine can enhance sprint- and time trial performance, respectively, these effects do not seem additive. Therefore, supplementing with either creatine or caffeine appears sufficient to enhance sprint or short intense exercise performance.

Effects of Plyometric Training on Physical Fitness Attributes in Handball Players: A Systematic Review and Meta-Analysis.

This meta-analysis aimed to examine the effects of plyometric training on physical fitness attributes in handball players. A systematic literature search across PubMed, SCOPUS, SPORTDiscus, and Web of Science identified 20 studies with 563 players. Plyometric training showed significant medium-to-large effects on various attributes: countermovement jump with arms (ES = 1.84), countermovement jump (ES = 1.33), squat jump (ES = 1.17), and horizontal jump (ES = 0.83), ≤ 10-m linear sprint time (ES = -1.12), > 10-m linear sprint time (ES = -1.46), repeated sprint ability with change-of-direction time (ES = -1.53), agility (ES = -1.60), maximal strength (ES = 0.52), and force-velocity (muscle power) (ES = 1.13). No significant impact on balance was found. Subgroup analysis indicated more pronounced agility improvements in players ≤ 66.6 kg compared to > 66.6 kg (ES = -1.93 vs. -0.23, p = 0.014). Additionally, greater improvements were observed in linear sprint and repeat sprint ability when comparing training durations of > 8 weeks with those ≤ 8 weeks (ES = -2.30 to -2.89 vs. ES = -0.92 to -0.97). In conclusion, plyometric training effectively improves various physical fitness attributes, including jump performance, linear sprint ability, maximal strength, muscle power and agility.

Effects of Caffeinated Coffee on Cross-Country Cycling Performance in Recreational Cyclists.

The ergogenic effects of acute caffeine intake on endurance cycling performance lasting ~1 h have been well documented in controlled laboratory studies. However, the potential benefits of caffeine supplementation in cycling disciplines such as cross-country/mountain biking have been rarely studied. In cross-country cycling, performance is dependent on endurance capacity, which may be enhanced by caffeine, but also on the technical ability of the cyclist to overcome the obstacles of the course. So, it is possible that the potential benefits of caffeine are not translated to cross-country cycling. The main objective of this study was to investigate the effects of acute caffeine intake, in the form of coffee, on endurance performance during a cross-country cycling time trial. Eleven recreational cross-country cyclists (mean ± SD: age: 22 ± 3 years; nine males and two females) participated in a single-blinded, randomised, counterbalanced and crossover experiment. After familiarisation with the cross-country course, participants completed two identical experimental trials after the ingestion of: (a) 3.00 mg/kg of caffeine in the form of soluble coffee or (b) 0.04 mg/kg of caffeine in the form of decaffeinated soluble coffee as a placebo. Drinks were ingested 60 min before performing a 13.90 km cross-country time trial over a course with eight sectors of varying technical difficulty. The time to complete the trial and the mean and the maximum speed were measured through Global Positioning System (GPS) technology. Heart rate was obtained through a heart rate monitor. At the end of the time trial, participants indicated their perceived level of fatigue using the traditional Borg scale. In comparison to the placebo, caffeine intake in the form of coffee significantly reduced the time to complete the trial by 4.93 ± 4.39% (43.20 ± 7.35 vs. 41.17 ± 6.18 min; p = 0.011; effect size [ES] = 0.300). Caffeine intake reduced the time to complete four out of eight sectors with different categories of technical difficulty (p ≤ 0.010; ES = 0.386 to 0.701). Mean heart rate was higher with caffeine (169 ± 6 vs. 162 ± 13 bpm; p = 0.046; ES = 0.788) but the rating of perceived exertion at the end of the trial was similar with caffeinated coffee than with the placebo (16 ± 1 vs. 16 ± 2 a.u.; p = 0.676; ES = 0.061). In conclusion, the intake of 3 mg/kg of caffeine delivered via soluble coffee reduced the time to complete a cross-country cycling trial in recreational cyclists. These results suggest that caffeine ingested as coffee may be an ergogenic substance for cross-country cycling.

Recovery following exercise-induced fatigue: Influence of a single heart rate clamped cycling session under systemic hypoxia.

We investigated whether a single heart rate clamped cycling session under systemic hypoxia affects the recovery of physical and psycho-physiological responses from residual fatigue compared to normoxia. On separate occasions, twelve trained males performed a 3-d acute training camp scenario. On days 1 and 3, participants cycled for 60 min at a constant heart rate (80% of ventilatory threshold). On day 2, fatigue was induced through a simulated team game circuit (STGC), followed by a 60-min intervention of either: (1) heart rate clamped cycling in normoxia; (2) heart rate clamped cycling in hypoxia (simulated altitude ~ 3500 m); or (3) no cycling. Countermovement jump height and leg stiffness were assessed before and after every session. Perceptual fatigue was evaluated daily. Compared to baseline, jump height decreased at all timepoints following the STGC (all p < 0.05). Leg stiffness and cycling power output only decreased immediately following the STGC, with a 48% further decrease in cycling power output in hypoxia compared to normoxia (p < 0.05). Perceived fatigue, decreased sleep quality, and increased muscle soreness responses occurred on day 3 (p < 0.05). A single heart rate-clamped cycling session in hypoxia reduced mechanical output without affecting recovery of physical performance and perceptual measures from residual fatigue induced through team sport activity.

Recovery in elite youth basketball players: The responsiveness of the psychophysiological measurements and the role of testosterone concentration.

This study investigated the recovery responses to the Total Quality Recovery (TQR), Well-Being questionnaire (WBQ), and Heart Rate (HR) responses to Submaximal Running Test (SRT), and the influence of salivary testosterone concentration (TEST) on these responses in 25 elite youth (U15) male basketball players. TQR, WBQ, and HR measurements were assessed after 48 hours of rest (T1), 24 hours after the 1st day of training (T2) and 24 hours after the 2nd day of training (T3). Salivary sampling was conducted at T1 and T3. A significant decrease was observed for TQR (F = 4.06; p = 0.01) and for WBQ (F = 5.37; p = 0.008) from T1 to T3. No difference among the three-time points was observed for HR and HR Recovery, and the TEST concentration did not influence the results. These results show that TQR and WBQ are sensitive to acute transient alterations in training loads (TL) and may be utilized to monitor recovery in elite youth basketball players. The HR related measurements presented limited responsiveness, and the TEST seems not to influence the recovery of these players who are competing at highest performance level.

A Single Dose of Beetroot Juice not Enhance Performance during Intervallic Swimming Efforts.

Despite the numerous scientific evidence on the topic, there is no clear and consistent answer that clarifies the true effects of beetroot juice (BJ) supplementation on different types of physical performance. This study examined whether an acute intake of BJ improves swimming performance, physiological variables of anaerobic metabolism, or subjective measures during high-intensity interval exercise with incomplete rest in competitive swimmers. Eighteen competitive swimmers (nine females and nine males) participated in this cross-over randomized, placebo-controlled, double-blind and counterbalanced study. In two trials, swimmers ingested BJ (70 mL, 6.4 mmol/400 mg NO3-) or placebo (PLA) (70 mL, 0.04 mmol/3 mg NO3-) three hours before a 2×6×100 m maximal effort with 40 seconds rest between repetitions and three minutes between blocks. The 100 m times showed no differences between groups (p > 0.05), but there was an interaction between block×repetition×condition (F5 = 3.10; p = 0.046; ηp2 = 0.54), indicating that the BJ group decreased the time of the sixth repetition of block2 compared to block1 (p = 0.01). Lactate concentration showed no differences between conditions (p > 0.05), but there was a main effect of block (ηp2 = 0.60) and a block×repetition interaction (ηp2 = 0.70), indicating higher values in block2 and increasing values between repetitions in block1. The subjective scales, perception of exertion (RPE) and Total Quality Recovery (TQR), showed no effects of condition (p > 0.05), but BJ swimmers had a greater TQR in the last repetitions of each block. In conclusion, a single dose of BJ did not enhance intermittent swimming performance or modified the physiological (lactate and heart rate) or subjective (RPE and TQR) variables; although there was a possible positive effect on the exercise tolerance at the end of effort.

Gender-Specific Effects of Short Sprint Interval Training on Aerobic and Anaerobic Capacities in Basketball Players: A Randomized Controlled Trial.

This study compared the effects of a 6-week short sprint interval training (sSIT) on male and female basketball players' bio-motor abilities, aerobic fitness, and anaerobic power. Using a randomized controlled trial design, 40 basketball players of similar training backgrounds were randomly assigned to two training groups of females (n = 10) and males (n = 10) or two control groups of females and males (each of 10). The training groups performed 3 sets of 10 × 5-second all-out interval running, with a 1:3 work-to-recovery ratio, and a 3-minute rest between sets. The players were evaluated for bio-motor abilities, including muscular power assessed through the vertical jump, agility measured using a T-test and Illinois change of direction (COD) test, and maximal sprint speed measured by a 20-meter sprint test. Also, aerobic fitness was assessed by evaluating maximum oxygen consumption (V̇O2max) through the Yo-Yo intermittent recovery test level 1 (Yo-Yo IR 1) test before and after the 6-week training period. After the intervention, both training groups (females and males) demonstrated significant improvements in vertical jump (effect size [ES] = 1.29, 1.06, respectively), peak power output (ES = 1.27, 1.39), T-test (ES = -0.56, -0.58), Illinois COD test (ES = -0.88, -1.1), 20-m sprint (ES = -1.09, -0.55), Yo-Yo IR1 performance (ES = 2.18, 2.20), and V̇O2max (ES = 2.28, 1.75). Gender did not exhibit any significant impact on the extent of changes observed over time. The results of this study suggest that adaptations in aerobic fitness and bio-motor abilities measured in this experiment in response to sSIT are similar across genders, and gender differences should not be a major concern when implementing sSIT in basketball players.

TacticAI: an AI assistant for football tactics.

Identifying key patterns of tactics implemented by rival teams, and developing effective responses, lies at the heart of modern football. However, doing so algorithmically remains an open research challenge. To address this unmet need, we propose TacticAI, an AI football tactics assistant developed and evaluated in close collaboration with domain experts from Liverpool FC. We focus on analysing corner kicks, as they offer coaches the most direct opportunities for interventions and improvements. TacticAI incorporates both a predictive and a generative component, allowing the coaches to effectively sample and explore alternative player setups for each corner kick routine and to select those with the highest predicted likelihood of success. We validate TacticAI on a number of relevant benchmark tasks: predicting receivers and shot attempts and recommending player position adjustments. The utility of TacticAI is validated by a qualitative study conducted with football domain experts at Liverpool FC. We show that TacticAI's model suggestions are not only indistinguishable from real tactics, but also favoured over existing tactics 90% of the time, and that TacticAI offers an effective corner kick retrieval system. TacticAI achieves these results despite the limited availability of gold-standard data, achieving data efficiency through geometric deep learning.

Building Individual Player Performance Profiles According to Pre-Game Expectations and Goal Difference in Soccer.

Soccer player performance is influenced by multiple unpredictable factors. During a game, score changes and pre-game expectations affect the effort exerted by players. This study used GPS wearable sensors to track players' energy expenditure in 5-min intervals, alongside recording the goal timings and the win and lose probabilities from betting sites. A mathematical model was developed that considers pre-game expectations (e.g., favorite, non-favorite), endurance, and goal difference (GD) dynamics on player effort. Particle Swarm and Nelder-Mead optimization methods were used to construct these models, both consistently converging to similar cost function values. The model outperformed baselines relying solely on mean and median power per GD. This improvement is underscored by the mean absolute error (MAE) of 396.87±61.42 and root mean squared error (RMSE) of 520.69±88.66 achieved by our model, as opposed to the B1 MAE of 429.04±84.87 and RMSE of 581.34±185.84, and B2 MAE of 421.57±95.96 and RMSE of 613.47±300.11 observed across all players in the dataset. This research offers an enhancement to the current approaches for assessing players' responses to contextual factors, particularly GD. By utilizing wearable data and contextual factors, the proposed methods have the potential to improve decision-making and deepen the understanding of individual player characteristics.

The effects of anti-doping measures on sports performance in weightlifting.

BACKGROUND: Evaluating anti-doping measures is essential to optimise their effectiveness. Comparing sporting results that have a higher doping prevalence, such as weightlifting, before and after the implementation of anti-doping measures may serve as an effectiveness indicator. METHODS: The results of the most successful weightlifters of both sexes in two time periods, 2009-2015 and 2016-2022 were analysed. The Sinclair Total (ST) to compare the relative strength of weightlifters from different weight categories was calculated. RESULTS: A significant decrease in the ST during 2016-2022 (p < 0.001) in athletes of all ages and both sexes overall was reported. When analysed by age, there was a decrease in ST in juniors and seniors of both sexes (p = 0.010 and p < 0.001, respectively), but not in youth. There was a decrease in the ST in senior men (p < 0.001), junior women (p < 0.001) and senior women (p < 0.001). CONCLUSION: In elite weightlifting, adult athletic results declined during 2016-2022, which may partly be explained by the implementation of new methods to detect long-term anabolic androgenic steroid metabolites as well as other policies. This may highlight the effectiveness of these methods both in the prevention and detection of anti-doping rule violations.

Composite rating method: Application to European basketball leagues.

This paper introduces the Composite Rating Method (CRM), a novel approach for the integrated evaluation of basketball player and team performances across multiple leagues. Utilizing data from Euroleague, EuroCup, and Basketball Champions League, the presented method provides comprehensive and accurate rankings, including accounting for actions not included in personal statistics. Drawing inspiration from established methodologies such as ELO, PER, Offensive and Defensive ratings, CRM offers a balanced assessment of player and team capabilities. The paper delineates the data collection and preprocessing procedures, details the algorithmic framework of CRM, and showcases its predictive capacity. By presenting a well-rounded approach to ranking, this paper aims to contribute to the advancement of performance evaluation methods in basketball and sports in general.

Lower and upper extremity contributions to propulsion and resistance during semi-tethered load-velocity profiling in front crawl swimming.

The study estimated lower and upper extremity contributions to whole-body front crawl swimming using semi-tethered load-velocity profiling. Nine female and 11 male (inter)national-level swimmers performed 20 m semi-tethered sprints, each with five progressive loads for lower (leg kicking), upper (arm stroke), and whole-body front crawl movements. The theoretical maximal speed (v0) and load (L0), and active drag (Da) were expressed as a percentage of the sum of both extremities for the movements of each extremity to calculate their contributions. The difference of whole-body values minus the sum of both extremities was used to estimate whole-body reserves. Lower (upper) body contributions were 43.8 ± 2.8% (56.2%) for v0, 37.3 ± 7.1% (62.7%) for L0, and 39.6 ± 5.6% (60.4%) for Da. Statistically significant whole-body reserves were found for v0 (-30.9 ± 3.9%, p < 0.001) and Da (-5.7 ± 11.7%, p = 0.04). V0 reserves correlated very highly with whole-body v0 in males (r = 0.71, p = 0.014) and moderately in females (r = 0.47, p = 0.21). The lower extremities contribute substantially to front crawl load-velocity profiles of highly trained swimmers. Higher sprint swimming speeds are associated with an efficient speed transfer from lower- and upper- to whole-body movement.

Practices and perceptions of strength and conditioning training in female golf: A cross-sectional survey study of high-level amateur players.

This study aims to ascertain an in-depth understanding of current practices and perceptions of S&C training in high-level amateur female golfers. A cross-sectional, explorative survey study was constructed which asked questions relating to four key areas: i) general participant information, ii) current strength and conditioning (S&C) practices, iii) the perceived influence of S&C training on golf performance, and iv) knowledge and awareness of S&C. Results showed that the majority of female players had participated in some form of S&C training in the past, with the majority believing that clubhead speed and carry distance were the primary golfing metrics which could be positively impacted. More specifically, 91-97% of the players "Strongly agreed" or "Agreed" that the key physical characteristics for golf were strength and power for the lower and upper body, and flexibility. Interestingly, 58% of the players believed that S&C training should mimic the movement of the golf swing, which based off current evidence, is not how drive metrics and ultimately shots gained, can be maximised. This survey study provides useful information relating to the practices and perceptions of S&C training in high-level female amateur players and areas where education may be able to further advance player understanding of physical preparation.

Development of the Talent Identification Questionnaire in Soccer for Outfield Players (TIDQ-OP): Coaches' perceptions of the key attributes for player recruitment.

Talent identification in sports is a complex process, whereby the aim is to identify, select and promote players who are considered to have the necessary skills and competencies (e.g., technical, tactical, and physical attributes) to succeed in senior adult competition. To support this process, this study focused on the development of a questionnaire to assist in the identification of talent among South African youth soccer players. This will establish a measure of the attributes coaches consider important when making talent identification decisions for outfield soccer players. The questionnaire was constructed following established instrument development phases. In phase 1, 61 questionnaire items were generated based on a review of the relevant literature. In phase 2, a panel of experts examined the content validity of the preliminary items. In phase 3, the provisional 59-item questionnaire (Talent Identification Questionnaire in Soccer for Outfield Players; TIDQ-OP) was administered to 173 experienced South African soccer coaches (130 males and 43 females) who ranged in age from 18 to 64 years. In phase 3, the factorial structure of the questionnaire was established through principal component analysis. The final questionnaire consisted of 58 items. These preliminary analyses indicate the usefulness of the TIDQ-OP as a tool to assist South African coaches in the identification and selection of talented players.

Evaluation of multi-directional speed qualities throughout adolescence in youth soccer: The non-linear nature of transfer.

Training and assessment of agility is often prioritised by soccer coaches and practitioners aiming to develop multi-directional speed. Although the importance of agility is advocated throughout childhood and adolescence, limited data evidence agility performance at different stages of adolescence. The purpose of this study was to examine differences in multi-directional speed performance in youth soccer players spanning an entire soccer academy. A total of 86 male junior-elite soccer players volunteered to participate. Anthropometric data were collected, alongside performance data from a battery of physical tests including sprinting, jumping, change of direction, reaction time, and agility. Bayesian models using log-likelihoods from posterior simulations of parameter values displayed linear or curvilinear relationships between both chronological and biological age and performance in all tests other than agility and reaction time. For agility and reaction time tests, performance improved until ~14 years of age or the estimated age of peak height velocity whereby arrested development in performance was observed. Our results demonstrate that while most performance skills improve as chronological or biological age increases, measures of agility and reaction time may not. These findings support the notion that agility performance is complex and multifaceted, eliciting unique, challenging physical demands and non-linear development.

More than metrics: The role of socio-environmental factors in determining the success of athlete monitoring.

The perceived value of athlete monitoring systems (AMS) has recently been questioned. Poor perceptions of AMS are important, because where practitioners lack confidence in monitoring their ability to influence programming, and performance is likely diminished. To address this, researchers have primarily sought to improve factors related to monitoring metrics, e.g., validity rather than socio-environmental factors, e.g., buy-in. Seventy-five practitioners (response rate: n = 30) working with Olympic and Paralympic athletes were invited to take part in a survey about their perceptions of AMS value. Fifty-two per cent (n = 13) was confident in the sensitivity of their athlete self-report measures, but only 64% (n = 16), indicated their monitoring was underpinned by scientific evidence. A scientific base was associated with improved athlete feedback (rS (23) = 0.487, p =0.014*) and feedback correlated with athlete monitoring adherence (rS (22) = 0.675, p = <0.001**). If athletes did not complete their monitoring, 52% (n = 13) of respondents felt performance might be compromised. However, most respondents 56% (n = 14), had worked with internationally successful athlete(s) who did not complete their monitoring. While AMS can be a useful tool to aid performance optimisation, its potential value is not always realised. Addressing socio-environmental factors alongside metric-factors may improve AMS efficacy.