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 vertical and horizontal plyometric training on jump performances and sprint force-velocity profile in young elite soccer players.

PURPOSE: During a soccer match, horizontal acceleration ability during short sprints is determinant for performance. Development of sprint force and velocity qualites have been reported after plyometric training. However, orientation of plyometric training exercises can influence the functional performance. The purpose of this study was to compare the horizontal and vertical orientation of plyometric training on explosiveness performances and sprint force-velocity profile in young soccer players. METHODS: Twenty-eight soccer players were recruited and divided in two groups: vertical (VG, n = 14) and horizontal (HG, n = 14) groups. Tests including jumps and sprint performances were conducted before and after the 8 week training period. Sprint force-velocity profile (FVP) was evaluated during a 30 m sprint test. RESULTS: The results demonstrated significant improvements in both VG and HG for jump performances (from + 4.9% to + 9.0%), sprint times (from -5.5% to -8.7%) and FVP parameters. Higher relative changes for the HG than for the VG were observed in 5 m and 15 m sprint times, horizontal jump lengths, and also in FVP parameters, especially improvements in maximal power (VG: + 16.4% vs. HG: + 28.1%) and in the decrease rate of horizontal orientation of force with increasing speed (HG: + 22.9%) during the 30 m sprint. CONCLUSIONS: Both horizontal and vertical plyometric training can be either used in young soccer players to improve vertical and horizontal performances in jump and sprint. However, horizontal plyometric training may result in a greater improvement in horizontal ballistic actions while similarly developing vertical jump qualities compared to vertical plyometric training in young soccer players.

Influence of trajectory and contrast on dynamic visual acuity in elite team sports players.

Dynamic visual acuity (DVA) is considered an essential component for studying the visual function, especially in challenging environments like team sports. Beyond frequent comparative studies, much information is still lacking about the mechanisms underlying DVA and possible differences in stimulus presentation. It is crucial to understand the performance of DVA under different conditions of contrast and trajectories to achieve more specific data and better ecological validity of measurements. Fifty-five top professional male Spanish athletes, including 23 soccer, 14 basketball, and 18 water polo players were selected. Static visual acuity (SVA) was evaluated at 5 m. DVA was determined at 2 m under combined conditions of velocity (52°/s), three trajectories (horizontal, diagonal 45° and 135°) and two contrasts (99.7% and 13%). Significant differences in most DVA conditions measurements show that the best scores correspond to horizontal, over diagonal trajectories, and high contrast. The correlation between SVA and DVA showed a different relationship depending on the contrast conditions. Professional soccer, basketball, and water polo players have similar characteristics with reference to all the DVA evaluated conditions.

Influence of contextual factors on match running performance of starters and non-starters in elite youth male soccer players.

This study investigated the effects of match location, quality of opposition (classified into: strong [1st to 4th position]; intermediate [5th to 15th position]; weak [16th to 20th position]), and match outcome on the match running performance of starters and non-starters from a top elite Brazilian soccer team. Absolute measures were calculated using total distance, high-speed (19.8-25.2 km·h-1), sprinting (≥ 25.2 km·h-1), total distance high-acceleration (> 2m·s2), and deceleration (< -2m·s2) were recorded by GPS units from a sample of young soccer players (N = 25) in a total of 17 matches. Relative measures were calculated by dividing absolute measures by the total duration of the matches. Non-starters covered greater total distance (p = 0.02), sprinting (p = 0.02), high-acceleration and deceleration (p = 0.04), sprinting distance relative per minute played (p = 0.005), and high-acceleration and deceleration relative per minute played (p < 0.001) when the team plays at home, strong opponents, and wins the matches. Starters covered greater total distance in high-speed running (p = 0.04), high-acceleration and deceleration (p = 0.03), and high-speed running relative per minute played (p = 0.04) when the team plays strong opponents and wins the matches. These findings highlight the impact of contextual factors during matches on the locomotor performance of young soccer players.

In-Season Training Load Variation - Heart Rate Recovery, Perceived Recovery Status, and Performance in Elite Male Water Polo Players: A Pilot Study.

BACKGROUND: Increased training and competition demands of the in-season period may disturb athlete fatigue and recovery balance. The aim of this study was to describe the training load distribution applied in a competitive period and the training adaptations and fatigue/recovery status of elite water polo players. HYPOTHESIS: Effective workload management during tapering (TAP) would restore player recovery and enhance performance. STUDY DESIGN: Case series. LEVEL OF EVIDENCE: Level 4. METHODS: Training load, perceived recovery, maximal speed in 100- and 200-meter swim, heart rate (HR) during submaximal swimming (HRsubmax) and HR recovery (HRR) were assessed in 7 outfield water polo players a week before starting a normal training microcycle (NM), after NM, and after congested (CON) and TAP training blocks in the lead-up to the Final Eight of the European Champions League. RESULTS: Training load was higher in NM compared with CON and TAP by 28.9 ± 2.6% and 42.8 ± 2.1% (P < 0.01, d = 11.54, and d = 13.45, respectively) and higher in CON than TAP by 19.4 ± 4.2% (P < 0.01, d = 3.78). Perceived recovery was lower in CON compared with NM and TAP (P < 0.01, d = 1.26 and d = 3.11, respectively) but not different between NM and TAP (P = 0.13, d = 0.62). Both 100- and 200-meter swim performance was improved in TAP compared with baseline (P < 0.01, d = 1.34 and d = 1.12, respectively). No differences were detected among other training blocks. HRsubmax and most HRR were similar among the training periods. CONCLUSION: Effective management of training load at TAP can restore recovery and improve swimming performance without affecting HR responses. CLINICAL RELEVANCE: Despite lower workloads, CON training impairs perceived recovery without affecting performance; however, a short-term training load reduction after a CON fixture restores recovery and improves performance.

Effect of repeated post-resistance exercise cold or hot water immersion on in-season inflammatory responses in academy rugby players: a randomised controlled cross-over design.

PURPOSE: Uncertainty exists if post-resistance exercise hydrotherapy attenuates chronic inflammatory and hormone responses. The effects of repeated post-resistance exercise water immersion on inflammatory and hormone responses in athletes were investigated. METHODS: Male, academy Super Rugby players (n = 18, 19.9 ± 1.5 y, 1.85 ± 0.06 m, 98.3 ± 10.7 kg) participated in a 12-week programme divided into 3 × 4-week blocks of post-resistance exercise water immersion (either, no immersion control [CON]; cold [CWI]; or hot [HWI] water immersion), utilising a randomised cross-over pre-post design. Fasted, morning blood measures were collected prior to commencement of first intervention block, and every fourth week thereafter. Linear mixed-effects models were used to analyse main (treatment, time) and interaction effects. RESULTS: Repeated CWI (p = 0.025, g = 0.05) and HWI (p < 0.001, g = 0.62) reduced creatine kinase (CK), compared to CON. HWI decreased (p = 0.013, g = 0.59) interleukin (IL)-1ra, compared to CON. HWI increased (p < 0.001-0.026, g = 0.06-0.17) growth factors (PDGF-BB, IGF-1), compared to CON and CWI. CWI increased (p = 0.004, g = 0.46) heat shock protein-72 (HSP-72), compared to HWI. CONCLUSION: Post-resistance exercise CWI or HWI resulted in trivial and moderate reductions in CK, respectively, which may be partly due to hydrostatic effects of water immersion. Post-resistance exercise HWI moderately decreased IL-1ra, which may be associated with post-resistance exercise skeletal muscle inflammation influencing chronic resistance exercise adaptive responses. Following post-resistance exercise water immersion, CWI increased HSP-72 suggesting a thermoregulatory response indicating improved adaptive inflammatory responses to temperature changes, while HWI increased growth factors (PDGF-BB, IGF-1) indicating different systematic signalling pathway activation. Our data supports the continued use of post-resistance exercise water immersion recovery strategies of any temperature during in-season competition phases for improved inflammatory adaptive responses in athletes.

Starters vs. non-starters differences in vertical jump force-time metrics in female professional volleyball players.

As one of the fundamental volleyball skills, countermovement vertical jump (CMJ) has been commonly implemented in the applied sports setting as a non-invasive and time-efficient assessment of athletes' lower-body neuromuscular function. The purpose of the present study was to examine the differences in CMJ characteristics between starters and non-starters within a cohort of professional female volleyball players. Nineteen athletes competing in one of the top European leagues (i.e., SuperLeague) volunteered to participate in the present investigation. Following the completion of a warm-up protocol, each athlete performed three maximal-effort CMJs with no arm swing while standing on a uni-axial force plate system sampling at 1,000 Hz. The following force-time metrics were used for performance analysis purposes: braking phase duration and impulse, eccentric and concentric duration, mean and peak force and power, contraction time, jump height, and reactive strength index-modified. Mann-Whitney U and independent t-tests revealed no statistically significant differences (p > 0.05) during both eccentric and concentric phases of CMJ between the players included in the starting lineup (n = 9) and their substitutions (n = 10), with the effect sizes being small to moderate in magnitude (g = 0.053-0.683). While further research is warranted on this topic, these results suggest that securing a position in a starting lineup at the professional level of volleyball play may be more contingent on the player's ability to proficiently execute sport-specific skills (e.g., blocking, attacking), rather than the performance on the CMJ assessment, considering that the observed values for both groups fall within the desired ranges for this specific population of athletes.

Tell me how much your opponent team runs and I will tell you how much you should run: A predictive model applied to Spanish high-level football.

The aim of this study was to predict a team's accumulated distance (TotDisTea) and accumulated distance at > 21 km/h (TotDis21Tea) in the Spanish Football First Division. 2,946 team physical performances (out of 3040 possible) during four seasons (from 2016-17 to 2019-20) were analysed. The outcome variables were the TotDisTea and TotDis21Tea when the ball was in play. Eight predictor variables were used: the distance accumulated and accumulated at > 21 km/h by the opponent (TotDisOpp and TotDis21Opp) were registered in km, the effective playing (EffPlaTim) and possession (BalPos) time were recorded in min, match location (MatLoc) had two levels (home and away), match outcome (MatOut) had three levels (lost, drawn, and won), and the teams were grouped in four levels (Champions League, Europa League, remained, and relegation) distinguishing the observed team (TeaLev) and the opponent team (OppLev) in the match. A total of 127 models were estimated from the all-possible regressions procedure for each outcome variable. The model with six predictor variables was selected as the best model to predict the TotDisTea (R2adj = .82). The predictor variables TotDisOpp, EffPlaTim, and BalPos had a greater contribution to the mean outcome value than the predictors OppLev, TeaLev, and MatLoc. All models estimated to predict TotDis21Tea had little predictive power (R2adj < .38). The findings of this study have both theoretical and practical implications for practitioners. The interaction between teams has a great effect on the conditional response. Before the match, teams could use this information to anticipate the physical demand expected in the next match, and after the match, be able to assess whether the physical response was similar to expected, and make decisions.

Gender-Related Disparities in Sport, Physical Activity, and Physical Activity Lessons in Minnesota From 2016 to 2019.

PURPOSE: To leverage multi-year panel data to determine statewide trends of participation in team sports, physical activity (PA) lessons, and overall PA among transgender and gender diverse (TGD) adolescents in 2016 and 2019. METHODS: Frequencies and percentages for TGD adolescents' team sport and PA lesson involvement, as well as mean number of days of ≥ 60 minutes of PA in the previous week, were compared in 2016 and 2019 to cisgender youth. RESULTS: In both years, cisgender students were about twice as likely to participate in sports and engaged in an average of one additional full day per week of PA for ≥ 60 minutes. Students unsure of their gender identity participated slightly more than those identifying as transgender, genderqueer, genderfluid, or nonbinary. DISCUSSION: We extend previous literature by demonstrating how gender-related participation gaps existed for Minnesotan high school students in 2016 and persisted into 2019, and we added distinctions for identities within the TGD umbrella (e.g., unsure).

Negotiating periodised training programmes in youth soccer development: A social process.

The purpose of the study was to develop new knowledge about the everyday realities when implementing periodised training programmes in professional soccer Academies. Specifically, this project enhances understanding in relation to 1) those stakeholders involved in periodised training programmes in professional soccer Academies, 2) factors that facilitate and constrain the design, implementation, and monitoring of periodised programmes, 3) the extent to which practitioners perceive that education programmes adequately prepared them for this aspect of their work. Academy managers, coaches and sport science support staff were approached to complete an online survey, with 30 individuals (33.6 ± 9.5 years old) agreeing to do so. Findings highlight that practitioners "have" to adapt their practices accordingly in response to contextually constraining factors. Here, the importance of developing richer insights into the social aspects of work in applied settings, greater recognition of facilitating and constraining factors, and an improved awareness and development of the educational interventions that can prepare practitioners in applied practice is emphasised.

ACTN3 XX Genotype Negatively Affects Running Performance and Increases Muscle Injury Incidence in LaLiga Football Players.

The aim of this study was to investigate the association of the ACTN3 rs1815739 polymorphism with match running performance and injury incidence in top-level professional football players. A total of 315 top-level professional football players from the first division of Spanish football (i.e., LaLiga) participated in this prospective and descriptive study. The ACTN3 rs1815739 genotype was identified for each player using genomic DNA samples. During LaLiga 2021-2022, players' performance was obtained through a validated camera system in all official matches. Additionally, the incidence of non-contact injuries was obtained by each team's medical staff according to the International Olympic Committee (IOC) statement. From the study sample, 116 (36.8%) players had the RR genotype, 156 (49.5%) had the RX genotype, and 43 (13.7%) had the XX genotype. The anthropometric characteristics of the players were similar across genotypes. However, the total running distance (p = 0.046), the distance at 21.0-23.9 km/h (p = 0.042), and the number of sprints (p = 0.042) were associated with the ACTN3 genotype. In all these variables, XX players had lower match performance values than RR players. Additionally, total and match injury incidences were higher in XX players than in RR players (p = 0.026 and 0.009, respectively). The rate of muscle injuries was also higher in XX players (p = 0.016). LaLiga football players with the ACTN3 XX genotype had lower match running performance and a higher incidence of non-contact injuries over the season.

Acute pre- and post-competitive soccer match-play changes in neuromuscular factors, physical performance, and muscle response in youth male players.

There is a paucity of literature analyzing the impact of fatigue from actual competitive soccer match-play on measures of neuromuscular function and muscle damage markers in youth players. Aims The main purpose was to analyze the acute pre- and post-competitive soccer match-play changes in measures of landing mechanics, stretch-shortening cycle capability, physical performance, muscle damage, and match intensity. A secondary purpose was to explore whether the players' maturity status and chronological age were associated with post-soccer match-play responses. Methods Thirty-two male youth outfield soccer players from two chronological competition age groups (U14 and U16) were assessed pre-and post-competitive soccer match-play for 2D dynamic knee valgus at landing (DKV), leg stiffness, reactive strength index, 20 m sprint time, CMJ-Abalakov jump height, creatine kinase and urea activity and visual analogue scale for muscle soreness (VAS). Players' maturity status was also estimated using a previously validated regression equation. Results There were statistically significant (p < 0.05) post-competitive soccer match-play impairments in all measures of stretch-shortening cycle capability and muscle damage markers assessed irrespective of the age group. Likewise, significant post-match play alterations in landing mechanics (DKV of the dominant leg) and physical performance (sprint time and jump height) scores were documented for the U14 players. Significant interactions between maturity and landing mechanics and VAS responses to competitive soccer match-play were also found whereby more mature players demonstrated larger post-match changes. Conclusion The findings of this study suggest the existence of a negative influence of competitive match-play on neuromuscular function and muscle damage in youth soccer.

Optimizing Short-Term Maximal Exercise Performance: The Superior Efficacy of a 6 mg/kg Caffeine Dose over 3 or 9 mg/kg in Young Female Team-Sports Athletes.

Caffeine (CAF) is among the most extensively researched dietary supplements worldwide. However, little is known about the relationship between dosage and performance enhancement, particularly in female athletes. This study aimed to explore the effects of three different CAF dosages (3 mg·kg-1, 6 mg·kg-1, and 9 mg·kg-1) on high-intensity exercise and the prevalence of undesirable side effects related to these doses among female team-sports athletes. All participants (n = 16; age: 16.9 ± 0.6 y; height: 1.64 ± 0.1 m; BMI: 21.6 ± 1.5 kg·m-2) were mild CAF consumers. This study had a randomized, crossover, double-blind design in which each athlete performed four experimental sessions after ingesting either a placebo (PLAC), 3 mg·kg-1 CAF (CAF-3), 6 mg·kg-1 CAF (CAF-6), or 9 mg·kg-1 of CAF (CAF-9), with an in-between washout period of at least 72 h. In each experimental session, 60 min after ingesting the capsules, participants underwent a countermovement jumps test (CMJ), modified agility t-test (MATT), repeated sprint ability (RSA) test, and a rating of perceived exertion (RPE) and completed the CAF side effects questionnaire. Our findings revealed that in comparison to the PLAC condition, the MATT, RSAmean, and RSAbest performances were significantly greater only under the CAF-6 and CAF-9 conditions. Although the RPE scores remained unchanged, CMJ performance improved under all CAF conditions. All the performance outcomes were better for the CAF-6 and CAF-9 conditions than for the CAF-3 condition. Notably, no significant difference between the CAF-6 and CAF-9 conditions was observed for any of these parameters despite the highest incidence of side effects being noted for the CAF-9 condition. In summary, our findings highlight the recommendation for a moderate CAF dosage of 6 mg·kg-1 rather than 3 or 9 mg·kg-1 to enhance various aspects of short-term maximal performance in mild-CAF-consumer female team-sports athletes while mitigating the occurrence of adverse CAF side effects.

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.

Exploring countermovement jump variables across competitive levels and playing positions in futsal.

Introduction: The aims of this study were to compare several countermovement jump (CMJ) kinetic variables between professional (PRO) and semi-professional (SEMI-PRO) futsal players and examine the differences amongst playing positions. Methods: CMJ performance from 56 male futsal players (25.2 ± 4.8 years; weight: 74.4 ± 6.4 kg) was analysed. Players were separated into PRO (n = 29; 27.0 ± 4.4 years; 75.4 ± 6.0 kg) and SEMI-PRO (n = 27; 22.7 ± 4.3 years; 73.1 ± 6.8 kg), and according to playing position: defenders (n = 16; 25.4 ± 3.7 years; 75.2 ± 6.0 kg), wingers (n = 26; 23.5 ± 4.5 years; 72.0 ± 6.9 kg), and pivots (n = 14; 28.0 ± 5.6 years; 77.8 ± 4.3 kg). Linear mixed models and effect sizes were used for the analyses based on the mean of two jumps for each variable. Results: PRO players presented a deeper center of mass (COM) displacement (p = 0.002, ES = 0.83), greater eccentric (Ecc) absolute (p = 0.019, ES = 0.61) and relative peak power (p = 0.046, ES = 0.52), and achieved greater Ecc peak velocities (p = 0.004, ES = 0.76) when compared to SEMI-PRO. Non-significant and trivial-to-small differences were observed in all the other CMJ variables according to the competitive level and playing position. Discussion: Ecc capabilities (i.e., deeper COM displacement, greater Ecc absolute and relative peak power, and peak velocity) during vertical jump seem to differentiate PRO and SEMI-PRO players. However, CMJ variables do not discriminate amongst playing positions in futsal players.

Chronological age-based vs. Bio-banded friendly football tournament: Effects on physical performance and spatial exploration behaviour in 7v7 match play.

Biological age-based competitions have been suggested to mitigate maturation bias among youth football players. This study analysed the physical demands and spatial exploration behaviour when playing football matches against biological or chronological age-based opposition. One-hundred and sixteen U-13 and U-14 male regional-level football players were recruited from five Portuguese football academies. Each player completed eight games, four per condition (chronological and biological-based), on the same day. Games were played in 7 vs. 7 formats, with 20-min duration, and conformed to standard officiating and rule procedures. The following variables were considered from GPS-data in each game: distance covered, high-intensity accelerations and decelerations, body impacts, and average and peak speeds. Furthermore, average, and peak heart rates (HRpeak) and spatial exploration index were collected. Players covered significantly less distance (ES = 1.11), performed fewer decelerations (ES = 0.82), achieved lower average speeds (ES = 1.15), had fewer body impacts (ES = 0.94), and recorded lower HRpeak (ES = 0.56) in the biological age-based competition compared to the chronological-age-based. No significant differences were found between the two formats in spatial exploration. Both game formats offer distinct physical demands at the external and internal levels. Finally, practitioners can manipulate the type of opposition to get distinct physical demands to mitigate the effect of maturation bias during development.

Selection-Dependent Differences in Youth Elite Basketball Players' Relative Age, Maturation-Related Characteristics, and Motor Performance.

Purpose: The aim of the present study was to investigate the influence of players' relative age, maturation-related characteristics, and motor performance tests on two different stages of talent selection (regional and national level) in youth elite basketball. Methods: Relative age, maturation-related variables (height, weight, maturity offset, maturity timing) and motor performance (Countermovement jump, Standing long jump, Modified agility T-test, Linear sprint 20 m) of N = 68 male youth basketball players (Mage = 14.39 ± 0.28 years) were assessed during the initial selection tournament for the German U15 national team. Pre-selection biases regarding relative age and maturity timing on the regional level were investigated utilizing one-sample t-tests. Differences in relative age, maturation-related characteristics and motor performance between players selected (n = 27) and non-selected (n = 41) for the youth national team were examined via independent samples' t-tests and logistic regression analyses. Results: Strong pre-selection biases toward early-born and early-maturing players were confirmed on the regional level. Significant advantages in height and weight and higher values in maturity offset and maturity timing were found for selected players. Among the motor variables, only Countermovement jump performance was significantly better in selected players. When controlling for relative age and biological maturation regression models including motor performance variables did not significantly discriminate players' selection status. Conclusion: Coaches working in national, but also preceding selection stages (regional and club level) should raise their awareness to relative age and biological maturation when evaluating players' potential and current (motor) performance.

Optimization of training for professional rugby union players: investigating the impact of different small-sided games models on GPS-derived performance metrics.

Introduction: Professional rugby union players can improve their performance by engaging in small-sided games (SSGs), which simulate the movement patterns of the game. This study collected metrics related to running performance and mechanical workload and their relative values from both forward and back positions, aiming to explore the impact of different SSGs factors on athlete workload, as well as the workload difference between official games (OGs) and SSGs. Methods: The monitored GPS data were collected from SSGs with different player numbers and pitch sizes (five sessions), SSG rules (5 weeks, four sessions per week), and OGs conducted throughout the year. Additionally, the study compared changes in players' sprinting performance before and after two SSG sessions. Results: Backs had greater workload than forwards. Less space and number of players SSG (4 vs. 4, 660 m2) was conducive to facilitating training for players in acceleration and deceleration. Conversely, larger spaces were associated with improved running performance. However, the introduction of a floater had no significant impact on performance improvement. Additionally, the 7 vs. 4 model (seven players engaged with four opponents) resulted in the greatest workload during medium-hard accelerations (F = 52.76-88.23, p < 0.001, ηp 2 = 0.19-0.28). Japan touch model allowed for more high-speed running training (F = 47.93-243.55, p < 0.001, ηp 2 = 1.52). The workload performed by SSGs can almost cover that of OGs (F = 23.36-454.21, p < 0.05, ηp 2 = 0.03-0.57). In the context of ηp 2, values around 0.01, 0.06 and 0.14 indicate small, medium and large effects respectively. Discussion: However, given the significantly higher workload of SSGs and the slight decrease in sprinting performance, further research is required to examine the training patterns of SSGs. This study provided insight into the impact of player numbers, pitch size, and rules on rugby-specific SSGs. Coaches should optimize SSG setups for enhanced training outcomes, ensuring the long-term development of physical capacity, technical and tactical skills.

Comparative Effects of Two High-Intensity Intermittent Training Programs on Sub-Elite Male Basketball Referees' Fitness Levels.

This study aimed to compare the effects of an 8-week short-term training program, comprising repeated sprints or running-based high-intensity intermittent training (HIIT), on the aerobic fitness and repeated sprint ability (RSA) performance of sub-elite basketball referees. Twenty male referees participated in supervised training sessions twice a week. They were randomly assigned to either the RSA-based group (RSAG) or the running-based HIIT group (HIITG). The RSAG conducted 3-4 sets of 8 × 20-m all-out sprints, while the HIITG performed 2-3 sets of 6 × 20-s runs at 90% of their maximal velocity achieved in the 30-15 intermittent fitness test (30-15IFT). Referees underwent a graded exercise test on a treadmill, the 30-15IFT, and an RSA test before and after the training program. Both groups showed significant improvement (~3%) in the fastest (22.6 ± 1.4 vs. 23.4 ± 1.7 and 22.0 ±1.9 vs. 22.4 ± 1.7 km·h-1 in RSAG and HIITG, respectively) and mean (21.5 ± 1.2 vs. 22.4 ± 1.4 and 21.3 ± 1.8 vs. 21.7 ± 1.6 km·h-1 in RSAG and HIITG, respectively) sprint velocity of the RSA test (p < 0.05). Moreover, positive changes (p < 0.05) were observed in the 30-15IFT maximal velocity (18.6 ± 1.1 vs. 19.3 ± 1.0 and 19.4 ± 0.9 vs. 20.5 ± 0.9 km·h-1 in RSAG and HIITG, respectively). In conclusion, an 8-week training intervention using either RSA or running-based HIIT led to similar improvements in referees' RSA performance and specific aerobic fitness measures. These findings could assist in devising tailored training programs for basketball referees.