WIMU PROTM Research Articles

Is it safe to use sand surface during rehab when training basic skills in early stages? How sand surface and inertial sensor position affect Drop Jump landing's G-forces and it's application in injury recovery

In sports, the use of sand surface as a tool in the injury recovery process has received very good acceptance and an increased attention in recent years. Unfortunately, the number of studies in this area continues being scarce. Therefore, this study analyzes the existence of possible differences in the magnitude of the impact generated during a 45 cm Drop Jump (DJ), depending on the body area analyzed, the contact surface (sand or grass) and the height (thoracic spine and ankle) at which a jump is placed. To that purpose, 6 participants were analyzed by wearing 3 IMU sensors (WIMU PRO™) to measure G foreces in the landing phase of the DJ. The results suggest the existence of statistically significant differences when comparing surfaces (sand vs. grass), body area (ankle and lumbar) and location of device placement (thoracic area vs. ankle).

Does the Final Score Influence the Physical Demands of Women’s Handball Matches?

The purpose of this study was twofold: to analyze and compare the influence of the final score of the match (close, balanced and unbalanced) on physical demands during official competitions in women’s handball; and to investigate if the physical demands of each playing position are affected by the final score. Twenty-two semi-professional female players from the Spanish 2nd Division were monitored across 13 official matches. Total distance (TD), high-speed running (HSR), high-intensity braking distance (HIBD), accelerations (ACC), decelerations (DEC) and PlayerLoad (PL) were collected in absolute and relative values using a local positioning system (WIMU PRO™, Realtrack Systems S.L., Almería, Spain). Two-way ANOVA with partial Eta-squared and Cohen’s d were used to determine the differences between playing positions and match types. Unbalanced (16.4±4.1 n·min−1) and balanced matches (15.2±3.8 n·min−1) elicited higher DEC/min than close matches (13.1±2.8 n·min−1) (p<0.001, moderate effects). In relation to playing positions, wings covered the largest TD and registered the highest values of PL in balanced and unbalanced matches (p<0.001, large effects). Also, wings presented the highest values of HIBD, HSR and HSR/min regardless of the final score (p<0.05, moderate effects). Moreover, wings performed largely more number of ACC and DEC compared to pivots in unbalanced matches (p<0.05, large effects). In conclusion, this study showed that the final score of the match influences the physical demands experienced by female handball players during official competitions. This information should be considered by coaches to adapt and periodize the training load across the microcycle.

Neuromuscular Load in Professional Women's Handball: Segmentation of the Player Load and the Impacts at Group and Individual Level.

Handball is a team sport characterised by physical interaction with other opponents. This interaction produces a high load on the players that can manifest itself in various ways, from discomfort to prolonged injuries due to tears caused by excessive load. In order to establish correct protocols for application in women's teams, context- and gender-specific reference data must be available. For this reason, the present research aims to find out how women's teams in European competitions prepare for decisive matches during the match week, analysing the load in a segmented way and the level of specificity that should be achieved in training. Ex post facto research was used in which a total of 17 players belonging to a women's first division handball team in Spain participated. The variables player load and impacts extracted from the use of Wimu ProTM inertial devices were analysed. The results showed a high neuromuscular load in players at this competitive level, especially in the variable impacts, reaching values per session of up to 1000 impacts. The individuality analyses show that the load varies significantly depending on the subject, which is why it is considered essential to establish protocols for strength work and load control in the most specific way possible.

Sports Performance Analysis of Wheelchair Basketball Players Considering Functional Classification

Wheelchair basketball (WB) is a sport modality adapted for people with disabilities who present functional classification (FC) according to their mobility, from 1.0 for players with lesser functional capacity up to 4.5 for great mobility and trunk control players. This study aimed to analyze and compare the external load (EL) and the internal load (IL) of the WB players according to their FC in 5 × 5 simulation game tasks. The main objective of this task was to develop a simulated game in which two teams of five players faced each other to resemble the physical demands of an official match. The development of these tasks allowed for the players to learn the different systems of play, and to improve tactical skills. To conduct the study, 12 (male) national professional WB players (years: 30.7 ± 4.82 and WB experience: 5 ± 1.43) participated in the study and were grouped according to FC. WIMU PROTM devices monitored the EL manufactured by RealTrack Systems in Almería, Spain, and to measure the player’s IL, GarminTM Heart Rate (HR) bands were used (GarminTM in Olathe, KS, USA). The EL variables were divided as kinematic (distance, explosive distance, acc, dec, max. acc, max. dec, average speed, max. speed) and neuromuscular (player load, impact). The IL variables were average HR, max. HR and %max. HR. The main results show that players with greater functional capacity (FC = 4.0) developed higher values in the IL and neuromuscular variables analyzed (p < 0.05), as well as in some kinematic variables like distance, dec and average speed (p < 0.05). This information is relevant because it helps to personalize the training load based on competitive demands and create a gradual and adaptable training program. This information helps athletes to develop better performance during training and prevent injuries caused by overexertion.

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.

The impact of different game formats on players’ and team performance in youth soccer competitions

The study aimed to investigate the impact of game formats on the running and technical–tactical performance of young soccer players, as well as on players’ dynamics of spatial occupation during competitions. Eleven players of a U-11 team (11.10 ± 0.39 years old) participated in three competitions specifically designed to analyze the impact of different game formats: 5vs5 (F-5), 7vs7 (F-7) and 11vs11 (F-11). Players’ running performance and dynamics of spatial occupation were analyzed using the GPSs devices from WIMU PRO™ devices (10 Hz). Players’ and team's technical–tactical performance was also analyzed using the Team Sports Assessment Procedure (TSAP) and the Offensive Sequence Characterization System (SCSO), respectively. It was observed that the teams tended to adopt a less direct style in the F-11 ( LpW: F7 vs. F-11 p = 0.001 and F-5 vs. F-11 p = 0.002), with a lower rate of spatial exploration (F-7 vs. F-11 p = 0.001 and &amp;&amp;F-5 vs. F-11 p = 0.001) and lower running demand ( Sprint: F-7 vs. F-11 p = 0.001 and F-5 vs. F-11 p = 0.014; HSR: F-7 vs. F-11 p = 0.001 and F-5 vs. F-11 p = .001). In addition, the F-11 allowed the players to have less involvement during the match (F-7 vs. F-11 p = 0.003; F-5 vs. F-11 p = 0.001), as well as a lower technical–tactical performance (F-7 vs. F-11 p = .003 and F-5 vs. F-11 p = .005). Our results highlight the importance of adjusting the game formats used in youth competitive environments to players’ intrinsic dynamics.

Analysing the manipulation of the number of players on tactical, technical, and physical performance in youth futsal

ABSTRACT The aim of this study was to comprehensively describe and compare the effects of different practice tasks, specifically 4 × 4, 3 × 3, 2 × 2 with goalkeepers (GK) in a 40 × 20 m field court. Forty-two male U17 players (age = 15.62 ± 0.58 years) from three futsal teams participated in the study. The tactical-technical offensive and defensive actions were measured using Videobserver® software. To measure external load (EL) and internal load (IL) during futsal tasks, the WIMU PROTM Ultra-Wideband (UWB) tracking system was used. To compare the tasks, the ANOVA for repeated measures was used. Results revealed that the reduction on the number of players contributed to increase the number of passing and shooting actions, while a generalised increase in physical and physiological responses were observed. In general, the major differences were observed between GK + 2 × 2 + GK and GK + 3 × 3 + GK in relation to GK + 4 × 4 + GK while some differences in physical and tactical-technical actions were also observed between GK + 2 × 2 + GK and GK + 3 × 3 + GK. Thus, the reduction on the number of players in large games can be considered a pedagogical strategy to promote an increase in the tactical-technical actions, such as passing and shooting actions, increasing the physical intensity of players.

External load of different format small-sided games in youth football players in relation to age

Background Monitoring of training tasks allows coaches to have a better knowledge of the loads applied to their players. Objectives The aim of this study was to analyze the variations in external load in small-sided games (SSGs) with young players U-12, U-15, and U-23 and compare the external load between age categories in each of the SSGs. Methods A group of 24 male soccer players performed five consecutive different formats of four vs. four SSGs composed of 3 minutes of play/rest. GPS devices were used during the tasks (WIMU PRO™). The data were analyzed using IBM SPSS Statistics 28.0, using descriptive statistics, graphical statistics, and ANOVA to compare the results between SSGs and between age groups. Results The increase in field areas promotes the increase of distance (DIST) covered and the high metabolic load distance (HMLd), with and without a goalkeeper (GK). The SSGs with GK recorded fewer PL values compared to SSGs without GK. In the U-12 and U-15 age groups, GK use promotes more acceleration (AC) and deceleration (DEC) of high intensity (&gt;3 m/s2). The results also show that the larger areas are promoters of high-speed running (HSR). Age influences some external load variables (DIST, AC, DEC, HMLd) in the game formats studied. Conclusions The SSG formats analyzed using GK are promoters of high-intensity neuromuscular activity. Larger areas promote more high-speed displacement. Age is an influence on the external load in different SSGs.

A Preliminary Investigation about the Influence of WIMU PROTM Location on Heart Rate Accuracy: A Comparative Study in Cycle Ergometer.

Technological development has boosted the use of multi-sensor devices to monitor athletes' performance, but the location and connectivity between devices have been shown to affect data reliability. This preliminary study aimed to determine whether the placement of a multi-sensor device (WIMU PROTM) could affect the heart rate signal reception (GARMINTM chest strap) and, therefore, data accuracy. Thirty-two physical education students (20 men and 12 women) performed 20 min of exercise in a cycle ergometer based on the warm-up of the Function Threshold Power 20 test in laboratory conditions, carrying two WIMU PROTM devices (Back: inter-scapula; Bicycle: bicycle's handlebar-20 cm from the chest) and two GARMINTM chest straps. A one-dimensional statistical parametric mapping test found full agreement between the two situations (inter-scapula vs. bicycle's handlebar). Excellent intra-class correlation values were obtained during the warm-up (ICC = 0.99, [1.00-1.00], p < 0.001), the time trial test (ICC = 0.99, [1.00-1.00], p < 0.001) and the cool-down (ICC = 0.99, [1.00-1.00], p < 0.001). The Bland-Altman plots confirmed the total agreement with a bias value of 0.00 ± 0.1 bpm. The interscapular back placement of the WIMU PROTM device does not affect heart rate measurement accuracy with a GARMINTM chest strap during cycling exercise in laboratory conditions.

Same Training for Everyone? Effects of Playing Positions on Physical Demands During Official Matches in Women’s Handball

The purpose of this study was to analyze and compare the differences between playing positions on physical demands during official matches in women’s handball. Twenty-two semi-professional female players (4 wings, 14 backs and 4 pivots) from the Spanish 2nd Division were monitored across 13 official home matches. Total distance covered (TDC), high-speed running distance (HSR), high-intensity breaking distance (HIBD), accelerations (ACC), decelerations (DEC) and PlayerLoad™ (PL) were collected in absolute and relative values (normalized by playing time) using a local positioning system (WIMU PRO™, Realtrack Systems S.L., Almería, Spain). Playing positions differences were determined by variance analysis one-way ANOVA with partial Etasquared (ηp2) or epsilon-squared (ε²) and Cohen’s effect size (ES). Wings covered more TDC (3414.5±1710.1 m), HSR (492.7±280.0 m) and HIBD (171.2±104.7 m) compared to backs and pivots (p&lt;0.05; moderate-large effects). Wings also registered more total number of ACC (750.5±362.2) and PL (85.0±7.8 a.u.) compared to backs and pivots (p&lt;0.05; moderate-large effects), whereas backs performed more ACC/min (19.9±1.1 n·min−1) than wings (18.9±1.4 n·min−1) and pivots (18.4±3.9 n·min−1) (p&lt;0.05; moderate effects). In conclusion, physical demands differ between playing positions during official female competitions and these differences should be considered by practitioners to better prescribe and periodize training load and to design more individualized training programs.

Analysis of the External and Internal Load in Wheelchair Basketball Considering the Game Situation

The systematic and programmed control and evaluation of the external and internal load of high-performance athletes during training sessions and high-level competitions allows the coaching staff to know a great amount of information to evaluate the physical condition of the players and the tactical positioning as well as to identify optimal performance. Therefore, this study aimed to analyse the external and internal load of wheelchair basketball players during training and competition matches considering the functional classification of the players. WIMU PROTM inertial devices were used to collect the data. As independent variables, the sporting context and the functional classification were selected, and as dependent variables, the variables related to the external and internal load were established. The results reported significant differences between the contexts, with higher values in the competition than in the training sessions considering the internal and external load. Taking into account the functional classification, it is shown that the player with a higher functional classification obtained more differences and higher values. Understanding the external and internal load of the players during training and competitions is very important to personalise the training load according to the demands of the competition. It allows development of a progressive and modular training programme of loads to obtain the best performance. Consequently, injury risk of players due to overload will also be reduced.

Assessing the Amount of Data per Second to Measure Tactical Variables in Team Sports

Sampling frequency of microsensors that measure the position of the players in team sports is a variable that could affect the accuracy of the measurement. The aim of the present study was to assess the impact of the sampling frequency on the measurement of a collective tactical behaviour variable: the total area (TA). Sixteen young U16 male soccer players participated in the study. They carried out three controlled tasks. Tactical variable was measured by a radio ultra-wide band technology (IMU; WIMU PROTM, RealTrack Systems, Almeria, Spain). For TA different sampling frequencies were applied (i.e. 1 Hz, 2 Hz, 4 Hz and 10 Hz). Trivial differences (p 0.05) were found between the TA values across the different amounts of inserted data per second across Task 1 (ES= 0.04-0.08), Task 2 (ES= 0.01-0.09) and Task 3 (ES= -0.03-0.04). Also High to perfect ICCs (0.91-1) and linear correlations (r= 0.961-1; p 0.01) were found among the TA values obtained through all sampling frequencies. The sampling frequency (i.e. 1 Hz, 2 Hz, 4 Hz and 10 Hz) does not affect the measurement of total area during tactical behaviour analysis but does significantly affect the change in centroid position measurement. Thus, it is recommended the use of 1 Hz to measure TA, but further studies should analyse the impact of lower than 1 Hz and greater than 10 Hz sampling frequencies to measure this collective tactical behavior.

Cause-Effect: The Relationship between Role and Experience with Psychological and Physical Responses in the Competition Context in Soccer Referees.

This study analyzed the effects of psychological responses (impulsivity, self-esteem, self-confidence, and anxiety) in baseline and pre-competitive contexts of national soccer referees (SRs), their control of the game (yellow and red cards), and physical performance (PP) according to the role (assistant or main referee), and experience in the category. Twenty-seven national SRs from Spain participated in this study. Baseline and pre-competitive psychological data were collected through the Competitive State Anxiety Inventory-2 (CSAI-2 test), Urgency, Premeditation (lack of), Perseverance (lack of), Sensation Seeking, Positive Urgency, Impulsive Behavior Scale (UPPS-P test), and Rosenberg tests. Furthermore, WIMU PRO™ inertial devices were used to monitor PP. The results indicated that a lack of perseverance and self-esteem were higher in the main SRs and somatic anxiety in assistant SRs. Experience of SRs was related to anxiety, self-confidence, self-esteem, impulsivity dimensions, and PP metrics (p < 0.05). Finally, red cards were related to positive and negative urgency (r = 0.38 and r = 0.35, p < 0.05, respectively). In conclusion, the main SRs and SRs with more experience had better psychological characteristics and PP in a competitive context. However, yellow and red cards were not associated with these factors, although red cards were related with urgency. Based on these data, specific training programs could be incorporated to enhance emotional control in SRs with less experience to achieve greater performance and professional development.

Is Basketball a Symmetrical Sport?

Basketball, an intermittent sport with a high impact load, presents a strong probability of lower limb injuries. These injuries can be caused by poor quantification of loads, very intense training sessions or even asymmetries in the lower extremities. The main aim of the present study is to identify whether asymmetries exist in basketball. Specifically, asymmetries depending on: (i) type of task, (ii) type of game situation, (iii) specific positions while training and (iv) specific positions while competing. It is hypothesized that there will be no significant differences between the different conditions. For this purpose, all the training sessions and matches of a professional basketball team belonging to the First Spanish Division were monitored during the preseason. WIMU PROTM inertial devices were used for data collection. The statistical analysis compared the different cases with an ANOVA test. The results do not show significant differences in the values collected among the type of task, the game situation and the positions of the individual players. It can be concluded that basketball is a symmetrical sport. Despite this, the coaching staff should carefully monitor the training loads and asymmetries of the players to avoid the risk of injury.

Does the operating temperature of accelerometers affect data measurement during static and dynamic conditions in sports? A randomized-control trial

This study aimed to analyse the effect of two operating temperatures (optimal vs environmental) on IMU internal temperature and accelerometry-based data in two conditions of measurement: (a) static, no movement; and (b) dynamic, a U’16 game-based training soccer session with 14 players. Each session took a 60-min duration and followed an ecological design (no intervention in environmental conditions). Fifty-six WIMU PROTM inertial devices were randomly grouped in four conditions (two operating temperatures × two measurement conditions, 14 devices in each group) and recorded IMUs’ internal temperature, resultant acceleration vector and PlayerLoad (PLRT). Devices were placed in the manufacturer’s docking station at the static condition and in a specific harness at the interscapular level at the dynamic condition. Repeated measures t-tests were employed for between-group comparisons at 1-min average sections throughout the register. Between-group differences were found in the static and dynamic conditions in IMUs internal temperature (static: 0–31 min; dynamic: 0–20 min) and resultant acceleration vector (static: 0–29 min; dynamic: 0–19 min). Instead, no differences were found in PLRT dynamics and accumulated PLRT although values in the environmental group were overestimated. In conclusion, WIMU PROTM devices must achieve the optimal operating temperature (38–39°) to avoid measurement error, regardless of the application (short or long sessions).

Performance analysis of professional U-23 portuguese players in small-sided games

The aim of this study was to examine the influence of different small-sided games (SSGs) format on external, internal load and technical actions of professional U-23 portuguese soccer players. Eight players (20.1±0.8 years, 180.4±7.2 cm, 75.9±4.9 kg) performed three different 4 vs. 4 ball possession SSGs (3x3 min play/rest) in different pitch dimensions, SSG1 16x24 m, SSG2 20x30 m and SSG3 24x36 m. All SSGs were video recorded for technical actions analysis. WIMU PROTM (RealTrack Systems, Almeria, Spain) inertial devices were used for internal and external load data collection. The distribution normality was determined with the Shapiro-Wilk test. Parametric and nonparametric statistics were selected accordingly. Statistical Package for the Social Sciences (SPSS™ 25.0 version) was used for data analysis. No significant differences were observed comparing the different SSGs in total distance covered, acceleration/deceleration distance, as well as in maximal and mean heart rate. Regarding the technical actions, no significant differences were observed in successful passes, contrary to the observed from SSG1 to SSG3 in duels (7.00±2.13; 4.38±2.44; 4.25±1.98), number of balls lost (2.63±1.30; 1.00±0.53; 0.88±1.12) and in between SSGs in high-speed running (p&lt;0.05, ES=0.37). In senior and professional soccer players, the modification of the pitch size between 16x24 m and 24x36 m during 4 vs. 4 ball possession SSGs with 3x3 min play/rest promotes modifications in the dynamic of technical actions and internal and external training load variables Keywords: Small-sided games, Professional soccer, Technical actions, External and internal load, Performance.

Criterion validity and reliability of a new algorithm to detect jump performance in women’s volleyball players

The limitation of tracking systems to assess short high intensity efforts has led to an exponential growth of inertial measurement units (IMU), capable of recording jumps at a very high sampling rate. However, the validity and reliability of each of them should be tested. This study aimed to assess the criterion validity and reliability of a new algorithm to detect jump performance in professional women’s volleyball players during training using an IMU. A total of 1581 jumps performed by 13 players (17.31 ± 7.34 years’ experience, and 6.77 ± 7 years playing in the first league) were video recorded during two volleyball training sessions. Data were recorded with Realtrack Systems IMU (WIMU PRO™, RealTrack Systems, Almeria, Spain), and extracted data were compared against a video system (Sony HDR-CX240 high-definition camera, Sony Corporation, Tokyo, Japan) using an observational procedure (ICC = 0.99). The results showed that WIMU PRO™ identified 1569 from the total of 1581 jumps performed (i.e. 99.24%). Therefore, this wearable device proved to have excellent jump count accuracy in top-level women’s volleyball players, making its use feasible in this sport context. This finding supports the use of this IMU as a valid method to guide the monitoring of jump training load.

Applying Different Strategies of Task Constraint Manipulation in Small-Sided and Conditioned Games: How Do They Impact Physical and Tactical Demands?

This study aimed to investigate how different strategies of task constraint manipulation impact physical and tactical demands in small-sided and conditioned games (SSCG). Ten recreational U-17 soccer players participated in this study (16.89 ± 0.11 years). We used different strategies of task manipulation to design two 4 vs. 4 SSCG: Structural SSCG and Functional SSCG. In Structural SSCG, pitch format and goal sizes were manipulated, while in Functional SSCG, players were allowed to kick the ball twice and at least 5 passes to shoot at the opponent’s goal. Players participated in four Structural and Functional SSCG, of five minutes duration with a two-minute interval in between. Players’ physical performance and tactical behavior were assessed using the WIMU PROTM inertial device. Structural SSCG stimulated players to cover more distance in sprinting (p = 0.003) and high-speed running (p < 0.001). Regarding tactical behavior, Structural SSCG stimulated players to explore game space better (p < 0.001). Moreover, Functional SSCG stimulated players to be closer to the ball, decreasing the effective playing space (p = 0.008). We conclude that these strategies of task constraint manipulation impact physical and tactical demands of the game.

Characterization and sex-related differences in the multi-location external workload profile of semiprofessional basketball players. A cross-sectional study

ABSTRACT Commonly, the monitoring of external workload has been performed using a single device on player's scapulae. The human body is a complex multi-articular system and quantification in a single location is insufficient, being necessary the assessment in multiple body locations simultaneously. Therefore, this study aimed to characterize the multi-location external workload in men’s and women’s players and to analyze the sex-related differences during the most common movements in basketball. Twenty-six semi-professional basketball players (n = 13 men, n = 13 women) were evaluated in five tests: linear and curvilinear movements, changing of speed, jumping and in-game movements. PlayerLoadRT was evaluated at six anatomical locations simultaneously (scapulae, lumbar region, knees, and ankles) with WIMU PROTM inertial devices attached to the athlete using a full-body skinsuit. Statistical analysis was composed of a t-test of independent measures and Coheńs d effect size. The main results indicated: (1) the type of movement modified the external workload supported by the musculoskeletal structures; (2) sex-related differences were found in the vertical absorption of external workload (p < 0.05); (3) no sex-related differences were shown in the horizontal profile (p > 0.16). The multi-location monitoring will allow the identification of musculoskeletal structures with high vertical absorption of external load depending on sex (men > women: scapulae-lumbar and knee-ankle; women > men: lumbar-knee) and type of movement (scapulae-lumbar: decelerations; lumbar-knee: jumping; knee-ankle: in-game), just like horizontal differences in lower limb (outer > inner leg: curvilinear). Equally movements distribution throughout training sessions, strengthening and recovery programmes of high-workload muscle groups according to player’s characteristics could contributed to performance enhancement and reduce injury risk. HIGHLIGHTS Men’s and women’s basketball players presented different vertical musculoskeletal absorption of external workload. Men presented higher absorption in scapulae – lumbar and knee – ankle segments while women did so in the lumbar – knee segment. The type of movements had a direct effect in the multi-location external workload profile. A combined effect of sex and type of movement was found in the vertical musculoskeletal absorption of the external workload profile. No sex-related differences were found in the horizontal profile regarding the type of movement.

Physiological and physical effects associated with task constraints, pitch size, and floater player participation in U-12 1 × 1 soccer small-sided games

PurposeThe study aim was to analyse 1 × 1 small-sided games (SSGs) with and without floating players, in different pitch sizes.MethodsTen U-12 soccer players were divided into 2 groups. Group 1 (&lt;i&gt;n&lt;/i&gt; = 4) performed 1 × 1 SSG and group 2 (&lt;i&gt;n &lt;/i&gt;= 6) performed 1 × 1 + 1 SSG. Field sizes of 5 × 10 m (SSG1), 10 × 15 m (SSG2), and 15 × 20 m (SSG3) were used, all with small goals. The studied variables were heart rate (HR), total distance, explosive distance (&gt; 12 km/h), accelerations, decelerations, maximum sprint, player load (PL) intensity and volume. The data were collected through WIMU PROTM and analysed with IBM SPSS Statistics. Descriptive analyses and comparisons between the effects of internal and external PL and SSG were performed with the Mann-Whitney &lt;i&gt;U&lt;/i&gt; test.ResultsIncreasing the pitch size in 1 × 1 and 1 × 1 + 1 SSGs led to raised total distance, maximum sprint, and PL. In 1 × 1 and 1 × 1 + 1 SSGs, the time practice was predominantly associated with HR&lt;sub&gt;max&lt;/sub&gt; intervals above 90%. Statistically significant differences were observed between 1 × 1 and 1 × 1 + 1 SSGs in explosive distance (SSG2: 46.40 ± 5.07 / 28.99 ± 4.93, &lt;i&gt;p&lt;/i&gt; = 0.02, ES(r) = 0.82), PL intensity (SSG2: 2.03 ± 0.11 / 1.78 ± 0.12, p = 0.02, ES(r) = 0.82), HR&lt;sub&gt;max&lt;/sub&gt; (SSG1: 189.50 ± 1.91 / 199.50 ± 2.38, &lt;i&gt;p&lt;/i&gt; = 0.01, ES(r) = 0.82), and HR&lt;sub&gt;mean&lt;/sub&gt; (SSG1: 174.50 ± 3.31 / 181.75 ± 2.21, &lt;i&gt;p&lt;/i&gt; = 0.01, ES(r) = 0.82). Floating players’ physical and physiological demands were lower compared with the other athletes.ConclusionsThe pitch size influences the physiological and physical response of young soccer players in SSGs. The demand of 1 × 1 SSG is higher compared with 1 × 1 + 1. Floating player participation could result in a fruitful strategy to adjust the training intensity of specific soccer players.