Genetic Associations With Acceleration, Change of Direction, Jump Height, and Speed in English Academy Football Players.

ABSTRACT: McAuley, ABT, Hughes, DC, Tsaprouni, LG, Varley, I, Suraci, B, Bradley, B, Baker, J, Herbert, AJ, and Kelly, AL. Genetic associations with acceleration, change of direction, jump height, and speed in English academy football players. J Strength Cond Res 38(2): 350-359, 2024-High-intensity movements and explosive actions are commonly assessed during athlete development in football (soccer). Although many environmental factors underpin these power-orientated traits, research suggests that there is also a sizeable genetic component. Therefore, this study examined the association of 22 single-nucleotide polymorphisms (SNPs) with acceleration, change of direction, jump height, and speed in academy football players. One hundred and forty-nine, male, under-12 to under-23 football players from 4 English academies were examined. Subjects performed 5-, 10-, 20-, and 30-m sprints, countermovement jumps (CMJs), and the 5-0-5 agility test. Simple linear regression was used to analyze individual SNP associations, whereas both unweighted and weighted total genotype scores (TGS; TWGS) were computed to measure the combined influence of all SNPs. To control for multiple testing, a Benjamini-Hochberg false discovery rate of 0.05 was applied to all genotype model comparisons. In isolation, the GALNT13 (rs10196189) G allele and IL6 (rs1800795) G/G genotype were associated with faster (∼4%) 5-, 10-, and 20-m sprints and higher (∼16%) CMJs, respectively (p < 0.001). Furthermore, the TGS and TWGS significantly correlated with all performance assessments, explaining between 6 and 33% of the variance (p < 0.001). This study demonstrates that some genetic variants are associated with power-orientated phenotypes in youth football players and may add value toward a future polygenic profile of physical performance.

Bio-Banding in Handball: Academy Players' Perceptions Based on Maturity Status and Gender.

The purpose of this study was to evaluate young male and female handball players' perceptions of the bio-banding concept. The estimated biological maturity status was assessed in a sample of 46 male and 40 female handball players (aged 14.06±1.40 years), who competed in both an annual age-group and bio-banded tournament. To test the players' perception of bio-banding, a post-competition questionnaire was conducted. A series of ANOVA and one-sample t-tests were used in order to examine the differences in perception between the different maturity groups. An inductive thematic analysis of the qualitative data recorded in the open-ended questions was also carried out. The results showed that early-maturing boys enjoyed the bio-banding tournament more than late-maturing boys (p<0.05). Conversely, no differences were found in girls (p>0.05). Furthermore, discussions were conducted based on the qualitative analysis of the players' written comments regarding their overall experience, finding individual variance in biological maturity may be less relevant in female sports contexts due to gender-related differences. Thus, a greater influence on play and leadership in late maturing boys and early maturing girls, a greater physical challenge in early maturing boys and an opportunity to express themselves technically and tactically in late maturing boys and on-time maturing girls were observed. Therefore, stakeholders must consider the different consequences of bio-banding in order to maximize the athlete's sport development process.

Selection into youth cricket academies: The influence of relative age and maturity status.

The aim of the study was to examine the birth quartile and maturity status distributions of male academy cricketers. Participants included 213 junior cricket players, aged between 9 and 18 years. Players were separated into birth quartiles and also grouped as early, average or late maturers. For the whole cohort, there was a medium effect bias towards players born in BQ1, but the number of early, average and late maturers was as expected. However, there were significantly more early maturers in the U10 and U11 groups than expected, and maturity distributions of the BQ groups showed that there was a small effect size bias towards early maturers in BQ4. Selection biases towards cricketers who are born earlier in the competitive year are consistent from U9 to U16, but more prevalent in the U12 and U14 age groups. There is a bias towards early maturers at U10 and U11, but this reduces as age increases. Practitioners working in academy pathways should be encouraged to assess the maturity status of players to assist in the retention and progression of players. Relative age effects should also be considered, and strategies may be required to identify players born later in the year.

The association of the ACTN3 R577X and ACE I/D polymorphisms with athlete status in football: a systematic review and meta-analysis.

The aim of this review was to assess the association of ACTN3 R577X and ACE I/D polymorphisms with athlete status in football and determine which allele and/or genotypes are most likely to influence this phenotype via a meta-analysis. A comprehensive search identified 17 ACTN3 and 19 ACE studies. Significant associations were shown between the presence of the ACTN3 R allele and professional footballer status (OR = 1.35, 95% CI: 1.18-1.53) and the ACE D allele and youth footballers (OR = 1.18, 95% CI: 1.01-1.38). More specifically, the ACTN3 RR genotype (OR = 1.48, 95% CI: 1.23-1.77) and ACE DD genotype (OR = 1.29, 95% CI: 1.02-1.63) exhibited the strongest associations, respectively. These findings may be explained by the association of the ACTN3 RR genotype and ACE DD genotype with power-orientated phenotypes and the relative contribution of power-orientated phenotypes to success in football. As such, the results of this review provide further evidence that individual genetic variation may contribute towards athlete status and can differentiate athletes of different competitive playing statuses in a homogenous team-sport cohort. Moreover, the ACTN3 R577X and ACE I/D polymorphisms are likely (albeit relatively minor) contributing factors that influence athlete status in football.

Disentangling Gender and Relative Age Effects in Women's and Girls' Rugby Union.

Relative age effects (RAEs) within sports refer to the overrepresentation of athletes born earlier in the selection year and the underrepresentation of those born later in the selection year. Research examining RAEs in women's and girls' rugby union remains limited in comparison to the male literature, whilst the impacts of RAEs on the youth-senior transition are yet to be explored in a female sport context. As such, the purpose of this study was to examine RAEs during entry into the women's and girls' premiership and international rugby union pathways in England, as well as to compare them to their respective senior cohort (n = 1367): (a) U18 England Rugby Centre of Excellence Player (n = 325) vs. Senior Premiership Player (n = 868), and (b) U18 England Player (n = 49) vs. Senior England Player (n = 125). Chi-square (χ2) analyses compared birth quarter (BQ) distributions against expected distributions. The findings revealed no significant difference in BQ distributions at either youth or senior levels, as well as no significant differences in the BQ distributions of those who were likely to transition from youth to senior levels (all p > 0.05). Importantly, though, descriptive statistics showed a skewed birthdate distribution in both U18 England Rugby Centre of Excellence Player (BQ1 = 30% vs. BQ4 = 20%) and U18 England Player cohorts (BQ1 = 33% vs. BQ4 = 18%). We highlight the gender-specific mechanisms that potentially explain the variations between male and female RAEs in rugby union, including developmental differences, sport popularity, and sociocultural norms. We also warn against a 'copy and paste' template from the male provision to ensure the recent growth of female rugby union does not fall victim to the same RAEs in the future.

Birth Advantages in Male Italian Soccer: How They Influence Players Youth Career and Their Future Career Status.

Soccer organizations generally adopt deterministic models within their talent pathways. In this framework, early ability and results are emphasized, leading to selection biases, such as birth advantages (i.e., relative age effects and birthplace effects), which research has shown affect both early developmental experiences and continued sporting involvement. Accordingly, this study aimed to (a) provide further test of birth advantages in Italian youth soccer by exploring the birth quarter (BQ) and birthplace (BP) distribution of 1050 male Italian players born between 1999 and 2001 who competed in the national U17 championship throughout the 2015-16 season and (b) investigate how birth advantages influenced selected players' future career status. Chi-square goodness-of-fit tests revealed early born players, and players born in North Italy were overrepresented at the youth level (p-values < 0.0001). Successive prospective analysis revealed only 18% of players developed into professional-level soccer players. Chi-square tests of independence indicated that players' BP was associated with their future career status (p < 0.0001), whereas their BQ was not (p = 0.459). Odds ratios showed players born in North Italy were five times more likely to complete the youth-to-senior transition than those born in South Italy. These findings highlighted environmental factors influence Italian players' early developmental experiences and their future career status.

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

This study provides insight into the current fitness testing practices in elite male soccer. One hundred and two practitioners from professional soccer leagues across 24 countries completed an online survey comprising 29 questions, with five sections: a) background information, b) testing selection, c) testing implementation, d) data analysis, and e) data reporting. Frequency analysis was used to evaluate the responses to fixed response questions and thematic analysis was used for open-ended questions to generate clear and distinct themes. Strength (85%) and aerobic capacity (82%) represent the most frequently assessed physical qualities. Scientific literature (80%) is the most influential factor in testing selection and practitioners conduct fitness testing less frequently than their perceived ideal frequency per season (3.6 ± 2 vs. 4.5 ± 2). Time and competitive schedule were the greatest barriers to fitness testing administration. Practitioners mostly used a 'hybrid' approach (45%) to fitness testing, blending 'traditional' (i.e., a day dedicated to testing) and 'integrated' (i.e., testing within regular training sessions) methods. Microsoft Excel is the most used software for data analysis (95%) and visualization (79%). An equal use of the combination of best and mean scores of multiple trials (44%) and the best score (42%) was reported. Comparing a player's test performance with previous scores (89%) was the most common method for interpreting test results. However, only 38% considered measurement error. Digital displays and verbal feedback are the most common data reporting methods, with different data reporting processes for coaches and players. Practitioners can use data and findings from this study to inform their current testing practices and researchers to further identify areas for investigation, with the overarching aim of developing the field of fitness testing in elite male soccer.

The relative age effect in the Gaelic Athletic Association (GAA): a mixed methods approach.

BACKGROUND: Background: In the Gaelic Athletic Association (GAA), Talent Academies (TAs) and senior teams cater for high-performing players. However, only two previous studies have quantified the relative age effect (RAE; i.e., a selection bias favouring those born near the beginning of the cut-off date) in these cohorts. Additionally, no studies have explored stakeholder understanding of the RAE using qualitative methods. AIM: This study aimed to: (a) quantify the RAE in TAs and senior teams, and (b) investigate stakeholder perspectives of the talent development environment, providing practical insight into the RAE. METHODS: A mixed methods sequential explanatory study design was employed. Phase one involved a retrospective analysis of longitudinal data for the frequency and distribution of births using TA (n = 12,445) and senior (n = 8,752) players. Phase two comprised two focus groups of key stakeholders [coaches (n = 4) and Talent Development Leaders (n = 4)] at TA and senior level. RESULTS: Analysis revealed a significant difference between TA birth quarter (BQ) distributions compared with expected distributions (P < 0.001; BQ1 = 30.4% vs. BQ4 = 17.6%), whereas at senior level, there were no significant differences observed (χ2 (df = 3) = 3.812, P = 0.282). In phase two, inductive analysis revealed three higher-order themes: (a) understanding of the RAE, (b) selection criteria, and (c) player characteristics. CONCLUSION: The GAA are encouraged to reflect on the practice of chronological age band grouping, investigate possible solutions to limit the effects of the RAE, and offer support programmes to educate key stakeholders.

Language games and blurry terminology: Can clarity enhance athlete development?

This perspective focuses on the need for researchers and practitioners to carefully consider the clarity and consistency of their language in the context of athlete development. Evidence supporting a lack of congruency in the way certain terms and expressions are defined, understood, and operationalized continues to accumulate, highlighting the importance of this area for sport stakeholders and the potential looming crises. In systems that regularly rely on precision and accuracy, it will be critical that all involved in the co-creation of knowledge generation and application carefully consider terms that may further complicate athlete development practices. We highlight some potentially blurry terms and draw attention to potential avenues for future research.

Relative age effects and the youth-to-senior transition in Italian soccer: the underdog hypothesis versus knock-on effects of relative age.

Relative Age Effects (RAEs) appear largely throughout youth soccer. However, little is known about how RAEs at youth levels can impact transition at senior levels. Accordingly, this study aimed to: (a) provide further test of RAEs by exploring the birth quarter (BQ) distribution of 2,030 Italian players born from 1975 to 2001 who have played in any of the Youth National Italian Soccer Teams; and (b) investigate how RAEs influence future career outcomes, by exploring the BQ distribution of players who completed the transition from youth squads to the Senior National Team (n = 182). Chi-square statistics revealed significantly skewed BQ distributions for all Youth squads (P values <0.0001), and for the cohort of players who completed the transition (P = 0.003). In contrast, results from the Odds Ratios highlighted how BQ4s were more likely to transition from youth-to-senior compared to BQ1s. Results showed BQ1s remained overrepresented at senior level due to a residual bias effect. Whereas BQ4s who were able to overcome selection processes at youth levels recorded the highest likelihood of competing at senior levels. Involving players' career trajectories in RAEs studies is needed to understand how RAEs impacts career outcomes of early selected players.

Nutritional Supplement Use in a UK High-Performance Swimming Club.

The aim of this study was to observe the nutritional supplement practices of highly trained swimmers on a national talent pathway, since it is often reported that swimmers engage in widespread supplement use at the elite level. Thus, this study employed a validated supplement intake questionnaire with forty-four swimmers from a high-performance swimming club, which had three distinct talent stages: development (aged 11-14 years, n = 20), age-group (aged 13-17 years, n = 13), and national level (aged ≥ 16 years, n = 11). Ninety-eight percent of the interviewed swimmers reported using at least one supplement, with performance (34%) and recovery (19%) cited as the primary reasons. National swimmers used more total supplements (8.1 ± 3.4 supplements) compared to age-group (4.8 ± 2.0 supplements, p = 0.003, g = 1.17) and development (3.9 ± 1.7 supplements, p < 0.001, g = 1.69) swimmers, mostly because of a greater intake of ergogenic aids (2.4 ± 1.4 supplements vs. age-group: 0.5 ± 0.5 supplements, p < 0.001, g = 1.12; vs. development: 0.1 ± 0.2 supplements, p < 0.001, g = 1.81). Parents/guardians were the primary supplement informants of development swimmers (74%, p < 0.001, V = 0.50), whereas performance nutritionists informed ~50% of supplements used by age-group and national swimmers (p < 0.001, V = 0.51). Based on these results, supplement education and greater focus on basic sport nutrition practices may be required for parents/guardians at the development level. Moreover, further research is needed to support the high number of ergogenic aids used by national swimmers, with the efficacy of these supplements currently equivocal in the applied setting.

Analysis of the most demanding passages of play in elite youth soccer: a comparison between congested and non-congested fixture schedules.

This study aimed to examine the most demanding passages of play in elite youth soccer for congested and non-congested fixture schedules. Seventeen elite youth male soccer players (18.2 ± 1.3 years old) participated in this study across 30 competitive matches. Assessed matches included congested (n = 12, three matches within eight consecutive days or less) and non-congested matches (n = 18, at least 5 days between matches). The players' activity profiles during matches were analysed using global positioning measurement units (GPS). Players activity included: distance covered, distance covered at different velocities, high-intensity accelerations and decelerations, and player load. The most demanding passages (MDP) of match play was calculated using a moving average method within three-time windows (i.e., 1, 5, and 10 min). Data were analysed using a Bayesian ANOVA. During congested fixtures, the players' distance covered and player load declined, with the former decreasing across all the MDP time windows, whereas the latter exclusively into the long-time windows (i.e., 5 and 10 min). Conversely, statistical differences in the remaining variables were anecdotal and in favour of the null hypothesis (i.e., Bayes factor <1), suggesting a non-influence of the competition fixture schedule. These findings provide insight into the MDP of youth soccer, helping practitioners to periodize training and recovery strategies during different competitive fixture schedules.

Genetic associations with technical capabilities in English academy football players: a preliminary study.

BACKGROUND: Technical capabilities have significant discriminative and prognostic power in youth football. Although, many factors influence technical performance, no research has explored the genetic contribution. As such, the purpose of this study was to examine the association of several single nucleotide polymorphisms (SNPs) with technical assessments in youth football players. METHODS: Fifty-three male under-13 to under-18 outfield football players from two Category 3 English academies were genotyped for eight SNPs. Objective and subjective technical performance scores in dribbling, passing, and shooting were collated. Simple linear regression was used to analyse individual SNP associations each variable, whereas both unweighted and weighted total genotype scores (TGSs; TWGSs) were computed to measure the combined influence of all SNPs. RESULTS: In isolation, the ADBR2 (rs1042714) C allele, BDNF (rs6265) C/C genotype, DBH (rs1611115) C/C genotype, and DRD1 (rs4532) C allele were associated with superior (8-10%) objective dribbling and/or shooting performance. The TGSs and/or TWGSs were significantly correlated with each technical assessment (except subjective passing), explaining up to 36% and 40% of the variance in the objective and subjective assessments, respectively. CONCLUSIONS: The results of this study suggest inter-individual genetic variation may influence the technical capabilities of youth football players and proposes several candidate SNPs that warrant further investigation.

Maturity-Associated Polygenic Profiles of under 12-16-Compared to under 17-23-Year-Old Male English Academy Football Players.

The purpose of this study was to examine polygenic profiles previously associated with maturity timing in male academy football players across different age phases. Thus, 159 male football players from four English academies (U12-16, n = 86, aged 13.58 ± 1.58 years; U17-23, n = 73, aged 18.07 ± 1.69 years) and 240 male European controls were examined. Polygenic profiles comprised 39 single nucleotide polymorphisms and were analysed using unweighted and weighted total genotype scores (TGSs; TWGSs). There were significant differences in polygenic profiles between groups, whereby U17-23 players had more genetic variants associated with later maturity compared to U12-16 players (TGS, p = 0.010; TWGS, p = 0.024) and controls (TGS, p = 0.038; TWGS, p = 0.020). More specifically, U17-23 players had over two-times the odds of possessing >36 later-maturing alleles than <30 compared to U12-16 players (odds ratio (OR) = 2.84) and controls (OR = 2.08). These results suggest there was a greater proportion of relatively later-maturing players as maturation plateaus towards adulthood, which may be explained by the 'underdog hypothesis'. This study provides the first known molecular evidence that supports the notion that a maturity selection bias exists within male academy football.

Exploring the role of socioeconomic status and psychological characteristics on talent development in an English soccer academy.

Social factors and psychological characteristics can influence participation and development in talent pathways. However, the interaction between these two factors is relatively unknown. The aim of this study was to investigate the implications of socioeconomic status and psychological characteristics in English academy soccer players (n=58; aged 11 to 16 years). To assess socioeconomic status, participants' home postcodes were coded according to each individual's social classification and credit rating, applying the UK General Registrar Classification system and CameoTM geodemographic database, respectively. Participants also completed the six factor Psychological Characteristics for Developing Excellence Questionnaire (PCDEQ). A classification of 'higher-potentials' (n=19) and 'lower-potentials' (n=19) were applied through coach potential rankings. Data were standardised using z-scores to eliminate age bias and data were analysed using independent sample t-tests. Results showed that higher-potentials derived from families with significantly lower social classifications (p=0.014) and reported higher levels for PCDEQ Factor 3 (coping with performance and developmental pressures) (p=0.007) compared to lower-potentials. This study can be used to support the impetus for researchers and practitioners to consider the role of social factors and psychological characteristics when developing sporting talent. For example, facilitating player-centred development within an academy and, where necessary, providing individuals with additional support.

Talent identification and development in an English Premiership rugby union club: the perspectives of players and coaches.

The pathway towards senior professional status in sport is affected by a multitude of factors. An abductive examination of the talent identification and development processes at an English Premiership rugby union (RU) club was undertaken for the present study. Part one examined the perspectives on the selection and development processes of senior academy male players (n = 8), whereas part two explored the perceptions of male coaches (n = 7). A total of three focus groups were used. Three main themes were confirmed by players and coaches: (a) task constraints, (b) performer constraints, and (c) environmental constraints. Specifically, although athletes and coaches believed that performer constraints were highly impactful on players' career in RU, there were inconsistencies surrounding the task and environmental constraints. Despite an indication that three common themes impacted an players path, this preliminary study shows an imbalance in the understanding of some of the key factors perceived to be important for talent progression in the present rugby academy. More research using similar qualitative methods is recommended to better understand the differences in opinions between players and coaches. Meanwhile, practitioners should consider implementing objective and holistic strategies to improve the talent pathway in English RU academies.

Relative Age Effects in Male Cricket: A Personal Assets Approach to Explain Immediate, Short-Term, and Long-Term Developmental Outcomes.

The purpose of this study was to adopt the Personal Assets Framework (PAF) to examine the immediate, short-term, and long-term developmental outcomes associated with relative age effects (RAEs) in male cricket. As such, this study was comprised of three aims: (a) examine the birth quarter (BQ) distribution of players throughout the England and Wales Cricket Board (ECB) national talent pathway (i.e., Regional U15, Regional U17, England U19, England Lions, England T20, England ODI, and England Test; n = 1800; immediate timescale), (b) explore the youth-to-senior transitions based on BQ and skill-set (i.e., batters and bowlers; short-term timescale), and (c) analyse the average number of games played at senior levels based on BQ and skill-set (i.e., long-term timescale). A chi-square goodness of fit test, Cramer's V, odds ratios, and 95% confidence intervals were used to compare the BQ distributions of each cohort against the expected BQ distributions. In the immediate timescale, results showed that relatively older players were overrepresented throughout all the youth levels (p < 0.05, V = 0.16−0.30), whereas there were no differences at senior levels (p > 0.05, V = 0.05−0.15). In the short-term timescale, when the senior cohorts were compared to the expected BQ distributions based on the Regional U15 cohort, relatively younger players were more likely to transition from youth to senior levels (p < 0.05, V = 0.22−0.37). In the long-term timescale, relatively older batters were selected for more games (p < 0.05, V = 0.18−0.51), whereas relatively younger bowlers were selected for more games (p < 0.05, V = 0.17−0.39). Moving forward, it is important for researchers and practitioners to better understand how (bi)annual-age grouping shapes developmental outcomes in across different timescales (i.e., immediate, short-term, and long-term), as well as consider alternative grouping strategies and RAE solutions.

The relative age effect in male and female English age-grade rugby union: Exploring the gender-specific mechanisms that underpin participation.

The relative age effect (RAE) is a phenomenon that represents how young athletes who are born early in the selection year are often overrepresented within youth sport settings. The contact nature of rugby union may further magnify the physiological advantages of those athletes who are chronologically older. Thus, the purpose of this study was to examine the RAE within English age-grade rugby union. Male (n = 228,206) and female (n = 23,563) English age-grade rugby union participants were allocated into their 12-month annual age-category (under-7 to under-18). Data was analysed using a chi-square goodness-of-fit test to compare the observed and expected distributions. Significant differences were revealed in all male (p < 0.001) and nine out of twelve female (p < 0.05) annual-age categories. From a male perspective, a higher relative difference became present at under-14 onwards, suggesting that there may be further implications due to the onset of puberty and the introduction of 15-a-side competition. Further female analysis revealed that there was a within-2-year effect in their 24-month age groups (under-13 and under-15). Interestingly, there was an inverse within-3-year effect (i.e., an overrepresentation of younger players) within the female 36-month age group (under-18). The key findings indicate a RAE has become ingrained in English age-grade rugby union, as well as outlining important gender-specific considerations.

A Multidisciplinary Investigation into the Talent Development Processes in an English Premiership Rugby Union Academy: A Preliminary Study through an Ecological Lens.

(1) Background: The progression of youth rugby union (RU) players towards senior professional levels can be the result of various different constraints. The aim of this study was to examine characteristics that differentiated playing positions and player rankings in an English Premiership RU academy. (2) Methods: Thirty players (mean age = 18.5 ± 2.8 years) were divided by playing positions (forwards = 18, backs = 12) and ranked (one to thirty) by coaches based on their potential to achieve senior professional status. Players were analysed across 32 characteristics from eight overreaching factors based on task, environmental, and performer constraints. MANOVA and ANOVA were used to calculate differences among variables in players' positions (i.e., forwards vs. backs) and ranks (i.e., top 10 vs. bottom 10), with a Welch's t-test applied to identify individual differences amongst groups and effect sizes calculated. (3) Results: Large effect sizes were found between groups for socioeconomic, sport activity, anthropometric, physical, and psychological factors. Moreover, environmental and performer constraints differentiated playing positions, whereas task and environmental constraints discriminated player ranks. (4) Conclusion: Present findings showed that playing positions and player ranks can be distinguished according to specific constraints.

No independent or synergistic effects of carbohydrate-caffeine mouth rinse on repeated sprint performance during simulated soccer match play in male recreational soccer players.

The study examined the synergistic and independent effects of carbohydrate-caffeine mouth rinse on repeated sprint performance during simulated soccer match play. Nine male soccer players (21 ± 3 years, 1.75 ± 0.05 m, 68.0 ± 9.0 kg) completed four trials with either 6 mg·kg-1 caffeine + 10% maltodextrin (CHO+CAFMR), 6 mg·kg-1 caffeine (CAFMR), 10% maltodextrin (CHOMR), water (PLA) in a block randomised, double-blinded, counterbalanced and crossover manner separated by minimum 96 h. All solutions were taste-matched and a carbohydrate-rich meal (2 g·kg-1body mass) was provided 2 h before each trial. Each trial consisted of a 90-min soccer-specific aerobic field test (SAFT90) and two bouts of repeated sprint ability tests (RSAT; 6 × 6 s sprints with 24 s recovery) completed at 0 min and 75th min of SAFT90. A 25 ml solution of either CHO+CAFMR, CAFMR, CHOMR or PLA was rinsed immediately before the second RSAT (75 min). Mean power output, peak power output (PPO) or fatigue index (FI) was not impacted by any treatment during the 75th min RAST (p > 0.05). These results suggest that carbohydrate and/or caffeine mouth rinses do not have an ergogenic effect during simulated soccer exercise after a high carbohydrate meal.