Players Age Research Articles

Talent Identification in Football: Different Effects of Maturation on Sprinting, Change of Direction and Jumping in 13-Year-Old Players

The aim of this cross-sectional study was to assess the influence of the maturity status on speed, explosive power and change of direction (COD) in 13-year-old football players. Ninety-eight male players (age: 13.1 ± 1.0 y) were divided into late, average and early-maturation groups. Physical fitness testing included the following variables: 10 and 30 m sprint time and maximum speed in the 20–30 m segment of the 30 m sprint test, the T-test time, countermovement jump height and horizontal distance in the triple jump. The data showed a significant effect of maturity status on performance in three parameters: at maximum speed in the 20–30 m section (p = 0.024), but the only significant differences were found between the early-maturation group and average-maturation group (p = 0.033); in the COD (p = 0.024), where significant differences were confirmed between the late-maturation group and the average-maturation group (p = 0.033); and in the unilateral triple jump distance of the dominant and non-dominant (p = 0.007 and p = 0.001, respectively) lower limb. For both limbs, significant differences between the late-maturation group and average-maturation group (p = 0.005 and p = 0.013, respectively) as well as the late-maturation group and early-maturation group (p = 0.007 and p = 0.045, respectively) were shown. These results indicate that maximal speed, COD speed and unilateral lower limb reactive strength are moderated by biological age in football players aged 13 years.

A Comparison of Glutathione and Malondialdehyde Concentrations in Athletes Engaged in Certain Sports

Sports stimulate the body to adapt to physical activity, causing biochemical and functional metabolic changes in various systems and organs of the body due to exercise. Antioxidants and free radicals affect the biological activity of living organisms, leading to physiological changes in all body systems due to exercise. This study, conducted from December 2023 to February 2024, included 120 blood samples from male basketball (40), football (40), and volleyball (40) players ages 18-27 years, from the College of Physical Education and Sports Sciences at Tikrit University. Blood samples were collected ten minutes before and ten minutes after 70 minutes of exercise on the same day. The study found no significant differences in glutathione (GSH) and malondialdehyde (MDA) concentrations before and after exercise among the groups. The findings suggest that the type of sport (football, basketball, or volleyball) with an anaerobic system does not significantly affect antioxidant and fat peroxidation levels, though slight variations due to increased lactic acid in muscles were noted, leading to muscle fatigue and minor changes in GSH and MDA concentrations.

Effect of 2 weeks rest-pause on oxidative stress and inflammation in female basketball players

Intense exercise leads to increased production of free radicals, resulting in an inflammatory response in athletes. For this reason, it was decided to investigate whether a single intensive exercise until exhaustion applied after a 2-week rest period would result in a violation of the pro-oxidant-antioxidant balance. Twenty-seven trained female basketball players (age: 16.55 ± 0.96 years, body mass: 66.40 ± 13.68 kg, height: 173.45 ± 5.14 cm) were enrolled to the study following the application of inclusion and exclusion criteria. Study was conducted at the end of the competitive training phase. Participants underwent incremental treadmill exercise, with blood samples collected before the test, immediately post-exercise, and after a 3-h restitution period. Total antioxidant capacity (TAC) levels increased significantly after exercise and remained unchanged after 3 h. Concentration of interleukin-10 (IL-10) and creatine kinase (CK) significantly increased after exercise and then decreased. Concentration of interleukin-2 (IL-2) was significantly reduced immediately and 3 h after exercise, while interleukin-13 (IL-13), interleukin-1α (IL-1α), and tryptophan (TRP) decreased 3 h after exercise. No significant changes were observed in other biochemical parameters. Obtained results show an increased antioxidant capacity which reduced oxidative stress and inflammation in response to intense exercise indicating that rested athletes have a high adaptation and elevated tolerance to effort.

Differences in anthropometric and vertical jump force-time characteristics between U16 and U18 female basketball players.

Considering the importance of body composition and lower-body strength and power for basketball players' on-court performance, as well as a lack of sports science research focused on female athletes, the purpose of the present investigation was to record the anthropometric and countermovement vertical jump (CMJ) characteristics of top-tier U16 and U18 female basketball players and examine between-group differences in the aforementioned tests. Thirty-two athletes who were a part of the national basketball academy volunteered to participate in the present investigation. Following the body composition assessment conducted via a segmental multifrequency bioimpedance analyzer, athletes performed three CMJs while standing on a force plate system sampling at 1000 Hz. Independent t-test and Mann-Whitney U-test were used to examine between-group differences. The findings reveal significant differences in body composition and lower-body neuromuscular performance characteristics between female basketball players ages 16 and 18. Although no differences were observed in muscle and body fat percentages, the U18 group had significantly greater height, overall body mass (both muscle and fat mass), as well as greater segmental fat-free mass (trunk, both legs and arms), intracellular and extracellular water, and body mass index when compared to their U16 counterparts. On the other hand, the U18 group demonstrated longer eccentric, concentric, and braking phase duration, as well as overall contraction time when compared to the U16 players. In addition, the U18 athletes exhibited higher eccentric mean force and power, concentric impulse, peak power, and mean and peak force.

Compensating wage differentials: Evidence from the National Hockey League

Using data for 1,471 unrestricted free agent player contracts in the NHL, this paper finds evidence that players are willing to sacrifice earnings to play on a higher quality team, and this tradeoff increases with player age. This result, which is consistent with the theory of compensating wage differentials, is robust to multiple specifications and estimation methodologies.

Normalization of rapid force to peak force in an isometric hamstring assessment using force plates

PurposeThe aim of this investigation was to determine the reliability of normalizing rapid force (RF) production to peak force assessed during an isometric knee flexor assessment, and to present a novel method of classifying athletes' potential training needs within the 90–90 isometric hamstring assessment. ProceduresTwenty elite female soccer players (age: 20.7 ± 4.7 years; height: 168.2 ± 5.5 cm; body mass: 62.8 ± 7.0 kg), with no recent (>6 months) history of hamstring strain injury, volunteered to participate in the study. Following a standardized warm-up, each participant performed three maximal isometric hamstring contractions, with their heel resting on a force plate, elevated on a box, to ensure that their hips and knees were at 90° Data was analyzed to determine peak for (PF), RF was established as force expressed at 100 ms (F100) and force expressed at 200 ms (F200), with force at each time-point subsequently normalized to a percentage of PF. FindingsF100 and F200 normalized to PF demonstrated good absolute reliability (%CV = 6.12–7.62) and moderate relative reliability (ICC = 0.689–0.703). Concurrently observing PF and normalized F100 and F200 could provide clear training and monitoring goals. ConclusionsNormalizing measures of RF production, including F100 and F200, to PF can be performed reliability. Therefore, could be tracked overtime to identify changes as an effect of training or for fatigue monitoring purposes. However, further research is required to determine how knee flexor force-time characteristics change in relation to focused training and how these characteristics change in response to fatiguing activities.

Epidemiology of lateral ankle sprain focusing on indirect contact mechanism in male and female soccer players: An 18.5-month cohort study

BackgroundEpidemiological research highlights the need to understand sports injuries for effective prevention. Yet, detailed knowledge about lateral ankle sprain (LAS) in soccer, especially related to indirect contact mechanisms and specific sports movements, remains scarce. This study aimed to determine the prevalence of LAS by examining injury mechanisms, focusing on indirect contact, and analyzing sports-related movements. Study designProspective study. MethodsIn this prospective study, 304 high-school and college soccer players (age: 19.0 ± 2.2 years, height: 168.3 ± 10.6 cm, weight: 64.2 ± 11.1 kg) were monitored for 18.5 months. Attendance and LAS incidents were recorded daily. Injury details, including movement at the time of injury, contact presence, and direction, were collected through interviews conducted on the injury day. LAS were categorized into direct contact, indirect contact, and non-contact mechanisms. Direct contact injuries were due to external forces on the lower leg or foot. Indirect contact injuries resulted from impacts on areas other than the lower leg or foot, and non-contact injuries involved no interaction with the ball or opponent. Incidence rates per 1,000 athlete exposures and 95 % confidence intervals (CIs) were calculated, along with rate ratios (RR) to assess sex differences. ResultsThe study recorded 59 LAS injuries. Indirect injuries were predominant, accounting for 47.5 % (n = 28) of the cases. Men experienced a higher incidence of indirect injuries, with an RR of 2.29 (95 % CI: 1.06–4.96). Outward contact was the most common (77.8 %; n = 21), while inward contact occurred in 22.2 % of the cases (n = 6). ConclusionHigh school and college soccer players primarily sustained injuries through indirect contact mechanisms, with a significant number of injuries occurring during lateral contact. Men were more prone to indirect contact injuries. Furthermore, 47.5 % of LAS incidents involved reactive movements, and injuries frequently occurred during specific sports actions, such as ball interception.

Effects of 5-week detraining period on body composition of professional soccer players

Purpose. The aim of the study was to examine the effects of five weeks detraining period on body composition changes in elite professional Indonesian male soccer players. Material and methods. The body composition of 24 top-level male soccer players (age: 26.33 ± 4.06 years) competing in First League of Indonesia was measured before and after the 5-weeks detraining period. Body composition variables, including body mass, body fat percentage, fat-free mass, and total body water percentage, were measured using the bioelectrical impedance method. The results. The paired samples T-test showed significant changes in the means of body composition variables for body fat percentage, fat-free mass, and total body water percentage. Mean values for body fat percentage increased during the detraining period from 10.87 ± 2.47% to 11.98 ± 2.75% (10.3%). A decrease in mean values for fat-free mass (61.34 ± 5.74 kg to 59.80 ± 6.22; 2.49%) and total body water percentage (from 65.13 ± 1.84% to 64.40 ± 1.99%; 1.12%) was observed. No significant changes occurred in body mass (from 69.05 ± 8.07 kg to 69.05 ± 8.48 kg; 0.04%) from initial to final testing. Conclusions. Since there was a significant difference in body fat percentage, fat-free mass, and total body water percentage% before and after detraining period., it is suggested that 5 weeks of detraining period. for the professional soccer players may not be necessary, and the duration should be shortened to maintain body composition status.

Impacto de ejercicios bilaterales y unilaterales en la potenciación aguda del salto horizontal en futbolistas profesionales

Objective: To analyze the effect of activation through bilateral or unilateral strength and plyometric exercises on horizontal jump performance. Methodology: The study involved 15 highly trained male soccer players (age, 24.7 ± 3.1 years; height, 181.2 ± 4.7 cm; weight, 79.7 ± 3.4 kg) from the same team competing in the national league. Their regular training routine consisted of 4 sessions and 1 competitive match per week. Participants performed 1 control protocol (CON) and 3 activation protocols following a counterbalanced design based on specific soccer exercises (SIN), bilateral (BIL), and unilateral (UNI) strength and plyometric exercises. After each protocol, players underwent the horizontal jump test (HZB). Results: The repeated measures ANOVA revealed significant positive effects on HZB for the SIN (p<0.01; diff = 2.95(2.00) %), BIL(p<0.01; diff = 3.22(2.61) %), and UNI (p<0.01; diff = 6.80(3.40) %) protocols compared to CON. Furthermore, HZB was significantly higher after the UNI protocol than after SIN (p<0.01; diff = 3.74(2.62) %) and BIL (p<0.01; diff = 3.47(1.94) %). Individual response analysis reflected positive effects on HZB for SIN, BIL, and UNI compared to CON, while 89 % of players showed better HZB performance after UNI than after BIL. Conclusions: Activation incorporating unilateral strength and plyometric stimuli has a greater positive effect on horizontal jump capacity than activation involving general, soccer-specific, and bilateral exercises.

Correlation between acute muscle damage and oxidative protection enzymes during different aerobic exercises

Different types of aerobic exercise can cause different disorders of homeostasis. This cross-over experiment aimed to determine the muscle fatigue and the antioxidative protection of female basketball players following a load caused by three different aerobic-type exercises (low-intensity continuous, high-intensity continuous, and high-intensity interval training). Twelve female basketball players (age 17.7±4.3 years; weight 67.3±9.8 kg; height 178.0±7.4 cm) voluntarily participated in the study. A wash-out period of 7 days between single sessions of different training was provided. Venous blood was drawn right before and immediately after each exercise session. The parameters that were analyzed are markers of muscle damage and enzymes of antioxidant protection. As a marker of muscle damage, myoglobin (F=2.884; p=0.065) and lactates (F=5.254; p=0.008) have higher values and statistically significant differences between training types. Creatinine shows higher values after each training session (F=4.053; p=0.022). Results of enzyme activity for oxidative protection show statistically significant differences between groups for catalase (F=5.811; p=0.005) with different types of training intervention. At the beginning of the preparatory period, parameters of acute muscle damage values are high. During the season, in response to different types of training, those parameters decrease in response to the body's adaptation to exercise-induced stress. Training leads to maintenance of physiological balance in the body and oxidative stress is not a necessary phenomenon of high aerobic training load. The inclusion of antioxidant protection enzymes decreases as the body adapts to a certain type of exercise.

Handcycling with concurrent lower body low-frequency electromyostimulation significantly increases acute oxygen uptake in elite wheelchair basketball players: an acute crossover trial.

Wheelchair basketball (WCB) demands high-intensity training due to its intermittent nature. However, acute oxygen uptake (V˙O2) in handcycling is restricted. Combining handcycling with low-frequency electromyostimulation (LF-EMS) may enhance V˙O2 in elite WBC athletes. Randomized crossover trail. Twelve German national team WCB players (age: 25.6 [5.6] years, height: 1.75 [0.16] m, mass: 74.0 [21.7] kg, classification: 2.92 [1.26]). Participants underwent 2×5 min of handcycling (60 rpm, ¾ bodyweight resistance in watts) (HANDCYCLE) and 2×5 min of handcycling with concurrent LF-EMS (EMS_HANDCYCLE). LF-EMS (4Hz, 350µs, continuous stimulation) targeted gluteal, quadriceps, and calf muscles, adjusted to individual pain thresholds (buttocks: 69.5 [22.3] mA, thighs: 66.8 [20.0] mA, calves: 68.9 [31.5] mA). Significant mode-dependent differences between HANDCYCLE and EMS_HANDCYCLE were found in V˙O2 (17.60 [3.57] vs 19.23 [4.37] ml min-1 kg-1, p = 0.001) and oxygen pulse (16.69 [4.51] vs 18.41 [5.17] ml, p = 0.002). ΔLactate was significantly lower in HANDCYCLE (0.04 [0.28] vs 0.31 [0.26] mmol l-1). Although perceived effort did not differ (p = 0.293), discomfort was rated lower in HANDCYCLE (1.44 [1.28] vs 3.94 [2.14], p = 0.002). LF-EMS applied to the lower extremities increases oxygen demand during submaximal handcycling. Thus, longitudinal application of LF-EMS should be investigated as a potential training stimulus to improve aerobic capacity in wheelchair athletes.

Seasonal variation of physical, perceptual, and cognitive function measures in professional academy soccer players

Soccer match play and training have been documented to significantly impair players' physical function and affect their perceptual wellness, indicating the necessity of evaluating the response to mixed-content training across a soccer season (Deely et al., 2022, Front Physiol, 13, 911009; Brownstein et al., 2017, Front Physiol, 8, 831; Thomas et al., 2017, Med Sci Sports Exer, 49, 955-964). This study aimed to assess seasonal variation in physical, perceptual, and cognitive functions in response to training among professional academy soccer players, to identify whether players develop increased physical robustness or encounter greater physiological and psychological impairments due to the demanding training and match schedule. Ethical approval was granted for sixteen academy players (age: 18 ± 1 years) to undergo a range of tests at three seasonal points - early, mid, and late - at baseline, immediately post-strenuous training, and at 24, 48, and 72 h. The testing regime encompassed physical performance (countermovement jump [CMJ], ten-to-five repeated jump test [10/5 RJT]), cognitive function (Stroop task, Four-Choice Reaction Time [FCRT] test, Corsi Block Test), and perceptual responses via an adapted Short Questionnaire of Fatigue (SQF). Linear mixed modelling (LMM) was employed to analyse the impact of season phase and testing time-points on training response, incorporating testing measures as dependent variables. Jump performance varied across time-points, with performance maintained immediately post-training, although displaying decrements at 24 h (P < 0.001), 48 h (P < 0.01), and remained unresolved at 72 h (P < 0.05). Season phase exerted a fixed effect on physical function, with vertical jumps decreasing from both early- (P = 0.033, CMJ; P < 0.001, 10/5 RJT) and mid-season (P < 0.001, CMJ; P < 0.001, 10/5 RJT) to late-season. Perceptual measures—soreness, fatigue, and readiness to train—varied across the week, with immediate post-session impairments recovering by 48 and 72 hours. Cognitive function remained relatively stable across the training week, with only a decline in Corsi Block performance noted immediately post-session. An improvement in FCRT from early to mid-season was observed, though accuracy decreased from early to late-season. No interaction between season phase and training week time-points was found across any variable, indicating a consistent training response throughout the season, despite substantial impairments in physical function and declines in perceptual wellness observed post-training. The decrease in physical function during the late-season phase underscores the need for enhanced recovery focus and training load monitoring as the season progresses.

Retirements of professional tennis players in second- and third-tier tournaments on the ATP and WTA tours.

The demands of professional tennis, including physical and psychological aspects, contribute to the frequency of retirements at elite levels of the sport. The aim of this study was to analyze epidemiological patterns and risk factors associated with retirements in previous ATP and WTA Tour tournaments. A retrospective cohort study was conducted. This study focused on previous ATP and WTA Tour tournaments. The ATP database encompassed 584,806 matches, while the WTA database included 267,380 matches. To assess retirements, potential risk factors such as playing surface, tournament category, match round, and player age were analyzed. Incidence rates were calculated for the period between 1978-2019 for men and 1994-2018 for women. The overall incidence rate was 1.56 (95%CI: 1.54, 1.59) and 1.36 (95%CI: 1.33, 1.39) retirements per 1000 games played in male and female competitions, respectively. Retirements increased over the years. Higher incidence rates were observed on hard (1.59 [95%CI: 1.56, 1.63] and 1.39 [95%CI: 1.34, 1.44]) and clay (1.60 [95%CI: 1.57, 1.63] and 1.36 [95%CI: 1.32, 1.41]) compared to grass courts (0.79 [95%CI: 0.65, 0.94] and 1.06 [95%CI: 0.88, 1.27]). Risk factors differed by gender, with tournament category significant in males (IRR: 1.23 [95%CI: 1.19, 1.28] in ITF vs ATP) and match round in females (IRR: 0.92 [95%CI: 0.88, 0.98] in preliminary vs final). This study provides valuable insights for coaches, players, support teams, and epidemiologists regarding retirements and associated risk factors in previous ATP and WTA Tour tournaments, contributing to injury prevention strategies.

The effect of weighted vest use during in-season, small-sided games training on young soccer players’ performance

ABSTRACT The aim of the present study was to investigate the effect of weighted vest on-field small-sided games (SSG) soccer training, during the in-season period, on body composition and soccer-specific performances, in young, trained soccer players. A counterbalance study design was adopted, in which the fourteen well-trained players (age: 19.1 ± 0.5 yrs, body mass: 70.3 ± 5.3 kg, body height: 180.3 ± 3.0 cm, body fat: 9.2 ± 4.1%) performed both the Interventional (Vest) and Control (Con) training routines (6 weeks/season; 5 training sessions/week; 1 match/week), in different occasions (winter/spring period). Con group followed a regular weekly training plan. When the Con group performed their intense training sessions, Vest group performed only the on-field SSGs training wearing a vest (12.5% of athletes’ body mass). All the evaluations were performed one week before and after each training period. Statistical analyses include repeated ANOVA and T-test (p < 0.05). Significant increases in sprinting, jumping, change of direction (COD), aerobic and anaerobic performances were observed only after Vest intervention (−4.7 ± 2.2% to 11.2 ± 4.2%; p < 0.05). Significant changes were observed only after Vest training, compared to Cont (p < 0.05). These results suggest that using a weighted vest, during the in-season, onfield SSG training two times/week induces greater increases in young soccer players’ sprinting, jumping, COD, aerobic and anaerobic performances.

Descriptive epidemiology study of hand injuries sustained in Gaelic football referred to a hand therapy service over 1 year

ObjectivesGaelic football requires ball handling, such as bouncing, fist passing and catching. To date, no research has examined the types of injuries sustained to the hand in this sport. This...

Validity of the Hawkin Dynamics Wireless Dual Force Platform System Against a Piezoelectric Laboratory Grade System for Vertical Countermovement Jump Variables.

Dos'Santos, T, Evans, DT, and Read, DB. Validity of the Hawkin dynamics wireless dual force platform system against a piezoelectric laboratory grade system for vertical countermovement jump variables. J Strength Cond Res 38(6): 1144-1148, 2024-The aim of this study was to determine the criterion validity of the Hawkin Dynamics (HD) wireless dual force platform system for assessing vertical countermovement jump (CMJ) variables, compared with those derived from a Kistler piezoelectric laboratory grade force platform system. During a single testing session, HD force platforms were placed directly on top of 2 adjacent Kistler force platforms to simultaneously collect vertical ground reaction forces produced by 2 male recreational soccer players (age: 29.0 ± 2.8 years, height: 1.79 ± 0.01 m, mass: 85.6 ± 4.7 kg) that performed 25 vertical CMJs each. Sixteen vertical CMJ variables pertaining to jump height (JH), flight time (FT), time-to-take off (TTT), countermovement depth, body weight (BW), propulsive and braking mean, and peak powers, forces, and impulses were compared between systems. Fixed bias was observed for 6 of 16 variables (peak and mean braking power, mean propulsion force, TTT, FT, and BW), while proportional bias was present for 10 of 16 variables (peak and mean propulsive and braking force, TTT, FT, peak and mean braking power, mean propulsive power, and BW). For all variables regardless of fixed or proportional bias, percentage differences were ≤3.4% between force platform systems, with near perfect to perfect correlations (r or ρ = 0.977-1.000) observed for 15 of 16 variables. The HD dual wireless force platform system can be considered a valid alternative to a piezoelectric laboratory grade force platform system for the collection of vertical CMJ variables, particularly outcome (i.e., JH, reactive strength index modified) and strategy variables (countermovement depth).

The Effect of Plyometric Exercises on Physical Fitness and Technical Skills of Football Players

Background: Football is a physically demanding sport requiring players to possess a balance of strength, endurance, agility, and speed. Plyometric exercises have gained popularity among football players due to their potential to enhance explosive strength and speed, crucial for successful performance on the field. Objective: The purpose of this study was to evaluate the impact of plyometric exercises on the technical and physical skill sets of football players in Quetta, Balochistan. Methods: A randomized, triple-blinded clinical trial was conducted involving 32 football players who were randomly assigned to either a plyometric training group or a conventional training group. Both groups participated in upper and lower body exercises over an eight-week period. Data collection included assessments at baseline, 2nd, 4th, 6th, and 8th weeks of the intervention. Physical fitness was evaluated using tests such as the vertical jump, 505 agility, and three-hop test, while technical skills were assessed using head juggling, figure 8 dribbling, controlled speed dribbling, power shooting, and pass and receiving tests. Statistical analysis was performed using SPSS version 25, employing one-way and mixed ANOVA to analyze the interaction and main effects. Results: The mean age of players in the plyometric group was 25.31 ± 5.05 years, and in the conventional group, it was 24.68 ± 4.81 years. The plyometric group showed significant improvements in all physical and technical tests compared to the conventional group. Specifically, the vertical jump improved from 18.33 ± 1.03 cm at baseline to 29.00 ± 2.21 cm at the 8th week (F=123.1, p&lt;0.001) in the plyometric group, while the conventional group improved from 18.31 ± 2.44 cm to 25.56 ± 1.68 cm (F=75.90, p&lt;0.001). Similar trends were observed in agility, dribbling, and power shooting tests, where the plyometric group outperformed the conventional group significantly. Conclusion: Plyometric exercises significantly improved the technical and physical skills of football players. These exercises enhance explosive power, speed, agility, and coordination, all of which are essential for football performance. Incorporating plyometric training into regular practice sessions is recommended for optimizing player performance.

Space and players' number constrains the external and internal load demands in youth futsal.

The aim of this study was to analyze the effects of space and number of players manipulation on the external and internal load demands of youth futsal athletes. Forty-two male U17 players (age = 15.62 ± 0.58 years) from three futsal teams participated in the study. In this cross-sectional study that lasted 8-week, the player's sample practiced six futsal tasks (T1-T6) and a futsal game played under the official rules (T7). From T1-T6, two task constraints were manipulated: (i) the number of players and, (ii) the space of play. The WIMU PRO™ Ultra-Wideband (UWB) tracking system was used to measure the external and internal load during the futsal tasks. External load was quantified using kinematic and mechanical variables extracted from positional data and, the internal load was quantified using Heart rate (HR) and rating of perceived exertion (RPE). Repeated measures ANOVA was used for comparison purposes. In general, the results showed high external (total distance, distance 18.1-21, above 21 Km/h, and high intensity acceleration and deceleration, p < 0.001) and internal load (heart rate average and rating of perceived exertion, p < 0.001) in the tasks with low number of players and high area. In relation to the match, the tasks with small relative area per player (GK + 2 vs. 2 + GK and GK + 3 vs. 3 + GK in 20 × 20 m) promoted low external load. It was concluded that increasing the relative area by reducing the number of players involved in the tasks in the form of small-sided games (GK + 2 vs. 2 + GK and GK + 3 vs. 3 + GK), in relation to the futsal game (GK + 4 vs. 4 + GK), can be considered a pedagogical strategy to increase the external and internal load demands of young futsal players.

Loading or Unloading? This Is the Question! A Multi-Season Study in Professional Football Players.

This study examined the impact of training load periodization on neuromuscular readiness in elite football players using the Locomotor Efficiency Index (LEI) as a measure of performance optimization. Throughout the 2021/22 and 2022/23 seasons, 106 elite male players (age: 19.5 ± 3.9 years) from an Italian professional football club were monitored using Global Positioning Systems (GPS) external load data. The LEI was derived from a machine learning model, specifically random forest regression, which compared predicted and actual PlayerLoad™ values to evaluate neuromuscular efficiency. Players were categorized by weekly LEI into three readiness states: bad, normal, and good. Analysis focused on the variation in weekly LEI relative to weekly load percentage variation (large decrease, moderate decrease, no variation, moderate increase, large increase), which included total distance, high-speed distance (above 25.2 km/h), and mechanical load, defined as the sum of accelerations and decelerations. Statistical analysis showed significant differences only with variations in total distance and mechanical load. Specifically, reducing weekly loads improved LEI in players in lower readiness states, while maintaining or slightly increasing loads promoted optimal readiness. This approach enables coaches to tailor training prescriptions more effectively, optimizing workload and recovery to sustain player performance throughout a demanding season.

Changes in Countermovement Jump Height in Elite Volleyball Players in Two Competitive Seasons: Consideration on the Technique of Execution of the Jump

Monitoring athletes’ well-being during the competitive season is a common practice in team sports, and countermovement jump (CMJ) is often introduced to monitor neuromuscular fatigue of the players. In this pilot observational study, we aimed to evaluate changes in jump performance in professional volleyball players during their two competitive seasons after introducing different executions of the jump test. Different execution of the flight phase of the jumps was introduced as a differentiating factor. Nine professional volleyball players (age: 23.3 ± 1.9 years; volleyball training experience: 10.4 ± 1.9 years; body height: 192.3 ± 8.3) performed CMJ measurements 1–2 times a week on a contact mat during two competitive seasons, and a total number of 1008 jumps (540 in season 1 and 468 in season 2) was collected. Players’ CMJ height significantly decreased (p &lt; 0.05) in season 2 by approximately 4%, and standard deviation of the data reduced by approximately 30%. Our study confirms that the testing procedures need to be rigorous as different execution of the jump may be associated with changes in CMJ height. Execution of the jump should not be interchangeable using the same measurement device, and the technique introduced in season 2 seems to be more appropriate for this measurement device.