WIMU PRO Research Articles

Is Match Playing Time a Potential Tool for Managing Load in Women's Handball?

García-Sánchez, C, Navarro, RM, Nieto-Acevedo, R, and de la Rubia, A. Is match playing time a potential tool for managing load in women's handball? J Strength Cond Res XX(X): 000-000, 2024-The aim of this study was to explore the external load experienced by female handball players according to the time played in official matches (≥40, <40, and ≤20 minutes) and in relation to playing positions (backs, pivots, and wings). Twenty-two female players from the Spanish second Division were monitored across 13 matches. Total distance covered, high-speed running distance (HSR), accelerations, decelerations, and PlayerLoad were collected in absolute and relative values using a local positioning system (WIMU PRO, Realtrack Systems SL, Almería, Spain). One-way ANOVA with partial eta-squared and Cohen's d were used to determine the differences between playing time groups and between playing positions. This study revealed that players with more match playing time had a higher absolute values in all external load variables (p < 0.001; very large effects), except in HSR where only wings showed higher values according to the time played (p < 0.001; very large effects). However, these differences between playing time groups disappear when the external load values were normalized according to the effective playing time (p > 0.05). In relation to playing positions, wings covered more HSR/minutes than the other playing positions regardless of the playing time (p < 0.05; large effects). In addition, backs performed more ACC/minutes than wings in the high playing time group and more than pivots in the low playing time group (p < 0.05, moderate effects). In addition, backs performed more DEC/minutes than wings in the low playing time group (p < 0.05, moderate effects). Therefore, handball coaches should consider the playing time as an effective tool to optimize the weekly load distribution.

Analysis of external load and internal load in AirBadminton

The aim of this study was to compare internal load and external load between AirBadminton and traditional indoor badminton. The research was conducted with 8 badminton players from the Alicante Technification Centre, including both men and women. The study was carried out based on the recommendations and guidelines of the International Badminton Federation. The procedure included competitions in both 1vs1 and 2vs2 formats, first on sand and then on hard court. Various variables related to players' internal and external load were analysed, using devices such as WIMU PRO for external load and Polar H7 transmitters for internal load. Data analysis was performed using statistical tests such as T-Student and Wilcoxon. Results showed significant differences between indoor badminton and AirBadminton in terms of internal and external load. In the 1vs1 format, indoor badminton was found to be more demanding, with higher intensity efforts, greater distance covered, and higher heart rate compared to AirBadminton. Similar results were observed in the 2vs2 format, confirming that indoor badminton involves greater effort. AirBadminton may be a healthier and more accessible alternative, suitable for different age groups, as it is less explosive and lighter in terms of internal and external load. Future research should focus on technical, tactical, and full-match duration aspects of this new modality.

Kinetic and Kinematic Characteristics Underpinning Change of Direction Performance in Basketball: A Comparative Study Between Sexes and Tests.

Baena-Raya, A, Díez-Fernández, DM, Martínez-Rubio, C, Conceição, F, and López-Sagarra, A. Kinetic and kinematic characteristics underpinning change of direction performance in basketball: A comparative study between sexes and tests. J Strength Cond Res 38(4): e182-e188, 2024-This study (a) evaluated the sex-specific kinetic and kinematic outcomes underpinning change of direction (COD) performance, (b) compared these outcomes across 3 different COD tests, and (c) examined the sex-specific and test-specific outcome most strongly related to COD performance in basketball players. Thirty young basketball players (17 males and 13 females) competing at the national level were assessed for the modified 505 test, modified T test, and V-cut test. The Local Positioning System technology (WIMU PRO, Realtrack Systems S.L., Almería, Spain) was used to measure the maximum values of acceleration (ACC max ), deceleration (DEC max ), velocity (VEL max ), and centripetal force (CentF max ) in each COD test. Male players displayed greater ACC max , VEL max , DEC max , and CentF max outputs for each section of the 505 test, T test, and V-cut test (all p < 0.05), resulting in a faster COD performance than females across tests (all ES > -1.42; 95% CI = -3.45 to -0.57). The 505 test demanded significantly greater kinematic outputs than T test and V-cut test for both sexes ( p < 0.01). The ACC max explained ∼26-58% of the variability in COD time for males across tests ( p < 0.05) and 40% in females' modified 505-test time ( p < 0.05). Likewise, in females, DEC max explained 38% of the modified T -test time variability, whereas VEL max explained 53% in the V-cut test time (both p < 0.05). These findings suggest that (a) COD data should not be used interchangeably across sexes, (b) test specificities should be considered for designing COD training, and (c) the kinematic outcomes explaining COD performance might vary across sexes.

Do all matches require the same effort? Influence of contextual factors on physical demands during official female handball competitions.

Understanding the influence of contextual factors on physical demands is essential to maximize performance in handball. The purpose of this study was to explore and compare the influence of contextual factors (halves of the match, level of the opponent, match outcome and player role) on external load during official matches in women's handball. Twenty-two semi-professional female players 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). HSR, HSR/min and HIBD/min decreased during the second half (p < 0.05; small effects). Regarding the level of the opponent, high-level and middle-level teams elicited higher TDC/min, HIBD/min and PL/min than low-level teams (p < 0.05; small-moderate effects). Additionally, starter players exhibited higher absolute values of external load (TDC, HSR, HIBD, ACC, DEC and PL) compared to non-starters (p < 0.05; moderate-large effects). Match outcome did not affect the physical demands (p > 0.05). The study indicated that halves of the match, level of the opponent, and player role influenced external load experienced by players during official matches; specifically, starter players showed higher absolute values of external load compared to non-starters. This information should be considered in managing load and developing strategies to minimize fatigue and enhance performance during matches.

Possession or position games: What is the key in soccer?

The aims of this study were to compare the running performance of possession and position games and to describe the external load of the same position game played on pitches of different dimensions. Using a GPS system (WIMU Pro, RealTrack Systems, Almería, Spain), the running demands of 25 professional soccer players were monitored during 18 possession (without a standardized role position) and 18 positional (with a specific role position) games of 9 vs. 9 + 2 floaters. Each format was developed in small (< 60 m2 per payer), medium (60-90 m2 per player) and large (> 90 m2 per player) sizes. Position games obtained significantly lower distance covered, peak speed and player load values than possession games (all p < 0.05). However, position games obtained significantly higher values of maximal acceleration, maximal deceleration, accelerations higher than 3 m · s-2 and decelerations lower than -3 m · s-2 than possession games (all p < 0.05). Likewise, large position games obtained significantly higher values of distance covered, distance covered > 21 km · h-1, peak speed and player load than small and medium sizes. Large size also showed significantly higher values of maximal acceleration and deceleration than small size, significantly fewer accelerations and decelerations, and fewer accelerations lower than 3 m · s-2 and decelerations higher than -3 m · s-2 compared to medium and small size (all p < 0.05). Practitioners should keep in mind the use of these games and their size to modify the external load of the players during their training.

NERYO-CHAGI KINEMATIC CHARACTERISTICS EVALUATION IN IMPACT SINGLE COMBATS BY EXAMPLE OF WTF TAEKWONDO VIA FEEDBACK TECHNOLOGIES

This article is dedicated to topical issues related to feedback information technologies. As of now, there is not enough research on the topic of studying the kinematic characteristics of athletes in full-contact martial arts using tracking feedback systems. Research methodology: To test the hypothesis concerning the practicability of modern information technologies application, there was held an experiment with WTF taekwondo martial arts athletes. The researchers examined 4 athletes: 2 highly qualified athletes (elite) and 2 sub-elite athletes. The GPS/LPS RealTrack System by Wimu Pro Spain, was chosen to record the motion parameters. Neryo-Chagi was randomly chosen to assess the kinematic characteristics (exploratory study). Neryo-Chagi was considered as an integral motor action, which consists of two types of movement: 1) swing and 2) shock movement (strike). Research results: At the moment of Neryo-Chagi strike, there is a linear increase in the angular velocity (degrees/sec) from low to maximum. When performing a swing and a shock movement (strike), the angular velocity (deg / s) is different. The maximum angular speed during the swing is observed when strikes the way they are in a fight are compared to the maximum, medium and slow intensity. Swing time (s) with elite athletes is higher compared to sub-elite ones, while the time to perform a strike movement does not differ. Elite athletes have higher maximum angular velocity during the swing and strike movement. Evaluation of the main motor actions of athletes, classified by kinematic characteristics, allows a new assessment of their effectiveness.&lt;p&gt; &lt;/p&gt;&lt;p&gt;&lt;strong&gt; Article visualizations:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;img src="/-counters-/soc/0009/a.php" alt="Hit counter" /&gt;&lt;/p&gt;

Inter-system and inter-unit reliability of Polar Team Pro and WIMU PRO devices during external load measurements indoors

The aim was to examine inter-system and inter-unit reliability of both WIMU PRO (UWB) and Polar Team Pro devices in measuring indoor sport-specific movements. Seventeen active and healthy adults (age: 21.4 ± 5.2 years; height 170.3 ± 8.2 cm; body mass: 71.2 ± 4.5 kg) completed one repetition of an indoor team sport circuit (i.e. accelerations, decelerations, change of direction, jumps and arc runs). Participants carried two 10-Hz Polar Team Pro GPS and wore two 20-Hz GPS (UWB) WIMU PRO chest- and back-mounted devices, respectively. Distance (absolute, relative and in different speed thresholds), mean and peak speed, accelerations and decelerations at different intensities and jumps were recorded. A repeated-measures two-way analysis of variance and ICC and CV were utilised. There was a significant ( p ≤ 0.001) main effect of the system for all variables except the total distance, mean speed and distance covered during low- and high-intensity running. There were significant differences ( p &lt; 0.05) between the two Polar Team Pro units for all external load variables except for distance covered during submaximal speed, moderate-intensity accelerations (ACC), and moderate-intensity and total decelerations (DCC). No significant differences ( p &gt; 0.05) between the two WIMU PRO units were detected. Poor inter-system reliability was ascertained, with inter-unit reliability being moderate-excellent for most variables of both systems.

Novel Curvilinear Sprint Test in Basketball: Reliability and Comparison With Linear Sprint.

Baena-Raya, A, Díez-Fernández, DM, López-Sagarra, A, Martínez-Rubio, C, Soriano-Maldonado, A, and Rodríguez-Pérez, MA. Novel curvilinear sprint test in basketball: reliability and comparison with linear sprint. J Strength Cond Res 37(9): e535-e540, 2023-This study (a) evaluated the reliability of a curvilinear sprint (CS) test to assess kinetic and kinematic outcomes in basketball players, (b) compared the kinetic and kinematic outcomes derived from curvilinear vs. linear sprints (LS), and (c) examined the association of both the CS and LS with change of direction (COD) performance. Thirty young basketball players (17 men and 13 women) competing at the national level (i.e., Spanish Basketball National League) performed a novel CS test around the 3-point line (the 3-point line CS test) to the right and left sides. The maximum and average values of acceleration (ACC), velocity (VEL), and centripetal force (CentF) were measured using Local Positioning System technology (WIMU PRO, Realtrack Systems S.L., Almería, Spain). All outcomes showed a high relative (intraclass correlations coefficient ≥ 0.90) and absolute (coefficient of variation [CV] < 5%) reliability, except the maximal CentF to the right (CV = 5.41%) and left sides (CV = 7.72%). Linear sprints displayed higher ACC and VEL outputs compared with the 3-point line CS test (all p < 0.001). Both sprinting tests were very large to nearly perfect associated with COD performance (LS r range from -0.71 to -0.86; CS r range from -0.68 to -0.94; p < 0.001), and the curvilinear ACC max was the kinematic outcome most strongly associated with COD performance ( r range from -0.73 to -0.94). In conclusion, the 3-point line CS test is reliable to measure CS performance in basketball and presents different kinetic and kinematic features than LS.

Validity of a new tracking device for futsal match

Purpose: The purpose of this study was to to evaluate the validity of a new tracking device that allows measuring different performance factors in futsal real game situations. Methods: 10 high elite futsal players performed a typical futsal training task, this is, a 4v4 in 28×20m with a duration of 180 seconds, where players wore two tracking devices, the new one (OLIVER) and the already validated device (WIMU PRO). Data recorded by the OLIVER and WIMU PRO systems were compared after the training session. Descriptive analysis was performed for each variable, and a one-way ANOVA was developed to calculate the validity of OLIVER compared with WIMU PRO report. Results: The results reported good validity for most of the variables analysed, such as the total distance (P = .385), the distance traveled at high intensity (P = .786) and maximum intensity (P = .460), as well as the number of accelerations (P =.690) and decelerations (P = .073) and maximum speed (P = .114). However, the distance traveled at low speed (P = .013) and the number of high accelerations (P = .028) reported statistical differences from OLIVER to WIMU PRO. Conclusions: The OLIVER system can be stated as a valid technology for monitoring most of the external load variables in specific training tasks in futsal, which ensures an improvement in the monitoring training process. Keywords: inertial measurement unit; acceleration; max speed; metrics; team sports.

Using wireless inertial measurement units for measuring hip range of motion through commonly used clinical tests

Hamstring extensibility is a crucial component of athletic performance and spinal health. In this regard, hip range of motion analysis through standardized clinical tests has been used as a valid and reliable method for measuring hamstring extensibility. Consequently, new inertial devices have been designed for this purpose. The aims of this study were to: (i) analyze the concurrent validity of inertial sensors for measuring hamstring extensibility through the Active Straight Leg Raise (ASLR) and Passive Straight Leg Raise (PSLR) tests; and (ii) analyze the test-retest reliability of inertial sensors for measuring hamstring extensibility through the ASLR and PSLR tests. A total of 18 healthy participants took part in this cross-sectional study. The hamstring extensibility was measured through the range of motion of the left and right hip in the Active Straight Leg Raise (ASLR) and Passive Straight Leg Raise (PSLR) tests. Data were collected by inertial sensors (WIMU Pro) and an ISOMED bi-level inclinometer, which was used as the reference instrument. The inertial sensors reported a standard error of the measurement (SEM) below 0.6° in all measurements. The R2 correlation and the intraclass correlation coefficient (ICC) were very close to 1 in all measurements. Regarding the reliability analysis, there were no significant differences ( p &gt; 0.05) between test and retest measures, and the SEM were below 0.8° in both instruments. The ICC were close to 1 in all cases as well. The coefficients of variation (CV) were below 2.7% in the inertial device and 2.2% in the inclinometer. This study showed that using microtechnology through WIMU Pro may be a valid and reliable method for measuring hip range of motion during the ASLR and PSLR tests.

External training load by accelerometery analysis during pick and roll in male amateur basketball

Accelerations and decelerations appear continuously in basketball. Limit and control how and when they occur and the relation with external load can be very useful.The objective of this study is to determine the type of accelerations and decelerations produced by the offensive players during screens situations. Secondly to determine if there are any relationships between players.389 screens situations (n = 389) were recorded using WIMU PRO® technology and a video camera. Each screen was classified according to six criteria. The following variables were analysed: accelerations 1 m / s² and 2 m / s² (Accel LOW), decelerations -1 m / s² -2 m / s² (Decel LOW), accelerations +2 m / s² (Accel HI), decelerations -2 m / s² (Decel HI), ∑ Accel and Decel LOW (Total LOW), ∑ Accel and Decel HI (Total HI), ∑ Accel and decel LOW and HI (Totals). Subsequently, a normality test and the Krurskal-Wallis non-parametric test was performed.Significant differences (p &lt;0.05) were obtained in all the variables analysed from the position, screen and player criteria. No differences were observed in any of the variables in the exercise, continuation and defense criteria.

Physical Persistency across Game Quarters and during Consecutive Games in Elite Junior Basketball Players.

Given the intermittent nature of basketball and the different demands that occur during playing time that are specific to every level of competition, the ratio of accelerations/decelerations and the intensity level across quarters were evaluated in female elite junior basketball players (n = 48; age: 16.8 ± 0.7 years; height: 1.76 ± 0.07 cm; body mass: 67.2 ± 6.2 kg). The following variables were analyzed to determine physical persistency across game quarters:(a) total distance covered (m), (b) high-intensity running (HIR) (14–21 km·h−1) distance covered (m), (c) sprint (21–30 km·h−1) distance covered (m), (d) total accelerations (n), (e) total decelerations (n), (f) relative accelerations (n·min−1), (g) relative decelerations (n·min−1), (h) ratio of acceleration/deceleration (A/D), (i) total jumps (j) relative jumps (n·min−1) (k) player load (AU). using the WIMU PRO® system. Higher but shorter acceleration intensity occurred during the last quarters due to the tight results of the matches. The results suggest that high-intensity efforts such as sprints and HIR seem to increase the A/D ratio (guard and forward positions). Therefore, specific conditioning, as well as eccentric strength training, could be included by practitioners in training programs to improve the performance of these positions during competition, especially as a prior preparation to a game-congested event. Centers seem to have a more variable performance through quarters than do other positions, perhaps highlighting the need for specific conditioning strategies.

Analysis of the Objective Internal Load in Portuguese Skydivers in the First Jump of the Day.

The general objective of this study was to identify the variation in heart rate (HR) of Portuguese skydivers during 6 moments in their first jump of the day, bearing in mind the variable level of experience. Thirty-one Portuguese skydivers, 28 men and 3 women, aged between 19 and 62, participated in the study, 12 had A and B licenses (less experienced) and 19 had C and D licences (more experienced). The instrument used to record the heart rate of the skydivers at the different moments of their first jump of the day was the WIMU PRO. A repeated measures analysis of variance was used to analyse HR at different moments in the jump and its relation with the variables level of experience. Bonferroni multiple comparisons were performed to study the importance of the differences observed in HR at the different moments. The effect size was evaluated with partial eta squared. The results showed that average HR in this group of skydivers was 130 bpm, in the different moments of the jump. HR increases from the value recorded at rest until the moment of jumping from the plane and opening the parachute, reaching the highest average at that moment, then decreasing until contact with the ground. Comparing the variable, we found that the less experienced had higher HR than the more experienced at all moments during the jump. Statistically significant differences were found at the different moments of the jump, regarding HR (Max: p < 0.001, ƞ2p = 0.820; Min: p < 0.001, ƞ2p = 0.821; AVG: p < 0.001, ƞ2p = 0.834) Level of experience with jumping moment interaction, we only verified differences related to HR Min (p = 0.007, ƞ2p = 0.056),. With regard to experience, the identified differences were not statistically significant. Skydiving triggers an acute adaptive cardiovascular response which is reflected in the increase in the HR, between the moment of boarding the plane and the moment at which the parachute opens, thereafter decreasing until contact with the ground. The most experienced parachutists recorded the highest HR at the moment of landing and the least experienced at the moment of free fall.

Exploring the Use of Player Load in Elite Soccer Players.

The aims of this study were to (1) analyze the distribution of the player load (PLTOTAL) in 3 axes of movement (PLAP, anterior-posterior; PLML, medial-lateral; PLV, vertical) during elite soccer matches, (2) investigate the effect of playing position on PL-related variables, and (3) explore the association between PLTOTAL and distance covered by the players. Despite different load distribution between axes of movement, PLTOTAL might be used as a body load indicator for all playing positions. Longitudinal study. Level 3. Data were collected from elite soccer players using WIMU Pro tracking systems, which included inertial sensors. The axis of movement had a significant effect on the distribution of the load (P < 0.001; conditional R2 = 0.91), with the greatest contribution from the PLV (P < 0.001; d = 5.41-5.86). Moreover, no effect of playing position on PLTOTAL, PLV, PLML, or PLAP was observed (P > 0.05). Finally, a large correlation was found between PLTOTAL and distance covered, and the linear mixed model showed that distance may be predicted by the PLTOTAL (conditional R2 = 0.81; P < 0.001). Differences in load distribution were based on the axis of movement, although playing position had no effect on any variable. The selection of either distance covered, which is representative of a 2-dimensional analysis, or PLTOTAL, which is representative of a 3-dimensional analysis, may be adequate for monitoring locomotor demands or accelerometer-derived load. Training strategies that focus on the vertical component of match play should be adopted. In addition, given that PLTOTAL is an accelerometry-based metric, which combines the accelerations in anterior-posterior, medial-lateral, and vertical planes, strength and conditioning coaches may use this parameter as a measure of total body load.

Mandatory lockdown impairs performance in professional soccer players.

COVID-19 caused a total halt in sport competition during 2020. The purpose of this study was to analyze the changes between pre- and post-lockdown competitive periods in the players’ workload variables in competition. Seventeen professional football players were monitored using a WIMU PRO® inertial device throughout the 2019-20 season. Anthropometric and physical fitness were assessed with the aim to relate possible associations between these characteristics and the workload changes in the pre- and post-lockdown periods. During the lockdown, players carried out an 8-week guided self-training. There was a general decrement in the players’ physical workload demands in competition, and the parameters related to high-intensity actions as accelerations and decelerations (-8.96% [ES: 0.64] and -11.04% [ES: 0.77] respectively; p &lt; .05), Ind HSR (-35.57% [ES: 0.92]; p = .002), HMLD (-8.58% [ES: 0.66]; p = .016), PLOAD (-7.03% [ES: 0.54]; p = .047) and Vmax (-3.80% [ES: 0.65]; p = .016) can be highlighted. The results showed high negative correlations between match workload variables prior to the lockdown and the percentage of change in these variables after the lockdown period. Individual percentages of change showed high variability in players’ changes. Individual self-training programs should be reviewed to minimize the impact of a “detraining” period in players’ physical performance during possible new lockdown periods.

Integrating video tracking and GPS to quantify accelerations and decelerations in elite soccer

The aim of this study was to analyze the degree of agreement comparing number and distance covered in different acceleration and deceleration sections registered by a video tracking system (MEDIACOACH) and a GPS device (WIMU PRO) during official competition. Data from a Spanish professional club were registered over the course of a season. First, the descriptive statistics presented more bursts of accelerations and decelerations in WIMU PRO than in MEDIACOACH, whereas the distances covered recorded by both systems were similar. Second, negative relationships were found (i.e., negative bias) comparing WIMU PRO to MEDIACOACH in the number of accelerations and decelerations between 0/1 m/s2 and ½ m/s2 (p < 0.05), and in the distances covered in accelerations and decelerations (p < 0.05) between 0/1 m/s2 and in accelerations and decelerations registered between 2/3 m/s2 and more than 3 m/s2. Moreover, the differences in means (i.e., standardized mean bias) across the two devices were trivial (> 0.19) and small (0.2–0.59) for most variables. The standardized typical errors in the estimate (TEE) were moderate (0.3–0.59) and small to moderate (0.1–0.29 to 0.3–0.59), respectively. Also, the Intra class Correlation Coefficients (ICCs) for agreement and consistency between systems showed good and excellent values (> 0.90). The magnitude of change in means (%) between systems, defined as the percentage change between the numbers or values, was below 14% and 7% for number and distances covered, respectively. All scores in the smallest worthwhile change were lower than 9% and in the coefficients of variation were lower than 95% and 15%, respectively. Thus, both systems demonstrated an acceptable degree of agreement and could be useful in analyzing players’ acceleration demands in professional soccer. However, caution is required when interpreting the results and a comparison with a gold standard is required in order to validate both systems.

Effects of Pitch Size and Goalkeeper Participation on Physical Load Measures during Small-Sided Games in Sub-Elite Professional Soccer Players

This study sought to examine the variations of internal and external load measures in soccer players when performing different types of 4 vs. 4 small-sided games (SSGs). Ten U-23 professional and sub-elite soccer players, eight outfield players (age: 20.1 ± 1.5 years old; height: 1.83 ± 0.04 m; total body mass: 76.1 ± 3.6 kg) and two goalkeepers (GK) (age: 20.5 ± 2.1 years old; height: 1.91 ± 0.04 m; total body mass: 77.0 ± 1.4 kg) participated in the study. Five SSGs were performed with 3 min duration and 3 min rest interval. SSG1, SSG2 and SSG4 aimed for ball possession play, while in SSG3 and SSG5, two GK were added, defending regular-size goals. The pitch size changed from SSG1 (16 × 24 m) to SSG2 and SSG3 (both 20 × 30 m) and SSG4 and SSG5 (both 24 × 36 m). All players were monitored using WIMU Pro device during the tasks. Anova One-Way and the post hoc Tukey honestly significant difference were used for analysis of statistically significant differences (p &lt; 0.05) and effect sizes were determined by calculating partial eta-squared. The framework was associated with relevant but steady state internal load fatigue and induce a considerable external load stimulus. GK participation in SSGs should be carefully considered as it seems to have a greater impact on physical load measures when compared to the pitch size manipulation.

Training Load in Different Age Category Soccer Players and Relationship to Different Pitch Size Small-Sided Games.

This study sought to evaluate the training load in different age category soccer players associated with distinct pitch size small-sided games (SSGs). Twenty-four soccer players (eight in each age category: U-12, U-15, and U-23) performed three consecutive 4 vs. 4 ball possession SSGs (SSG1: 16 × 24 m; SSG2: 20 × 30 m; and SSG3: 24 × 36 m) all with 3 min duration and 3 min rest. Subjects carried ultra-wideband-based position-tracking system devices (WIMU PRO, RealTrack System). Total distance covered increased from SSG1 to SSG3 in all age categories and predominantly in running speeds below 12 km·h−1. Moreover, distance covered in 12–18 km·h−1 running speed was different in all performed SSGs and age categories. Residual or null values were observed at 18–21 km·h−1 or above running speed, namely in U-12, the only age category where metabolic power and high metabolic load distance differences occurred throughout the performed SSGs. Edwards’ TRIMP differences between age categories was only observed in SSG2 (U-12 < U-15). The design of SSGs must consider that the training load of the players differs according to their age category and metabolic assessment should be considered in parallel to external load evaluation in SSGs. Wearable technology represents a fundamental support in soccer.

Comparing Sampling Frequencies to Measure Collective Tactical Variables During Soccer Training.

Rico-González, M, Pino-Ortega, J, Rojas-Valverde, D, and Arcos, AL. Comparing sampling frequencies to measure collective tactical variables during soccer training. J Strength Cond Res 36(10): 2862-2867, 2022-The 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 this study was to assess the impact of the sampling frequency on the outcomes of tactical behavior variables during soccer training. Sixteen U16 male soccer players participated in the study. Three tactical variables (change in the geometrical center position [cGCp], mean distance between players [mean-DbP], and total area [TA]) were measured at 4 different sampling frequencies (i.e., 10, 4, 2, and 1 Hz) during a 7+goalkeeper-a-side soccer match by a time motion tracking system using inertial measurement units (IMU; WIMU PRO, RealTrack Systems, Almeria, Spain). Significant (p < 0.01) and substantial (ES = moderate-large) differences were found in the cGCp values across all sampling frequencies. Several significant (p < 0.05) and substantial (ES = small-moderate) differences were found in the mean-DbP values between 10 data per second and the rest of the sampling frequencies. There were no significant (p > 0.05) and substantial (ES = trivial) differences in the TA values across all sampling frequencies. The sampling frequency affects the outcomes of cGCp and mean-DbP but does not affect the values of TA. The outcomes of the studies that assess collective tactical behavior should be compared with caution if GC-related and distance variables were measured using different sampling frequencies. In addition, it seems that a smaller amount of data could be sufficient to measure area variables with greater magnitudes.

Strength and Speed Profiles Based on Age and Sex Differences in Young Basketball Players.

Team sports are in continuous evolution, and physical performance is acquiring greater importance in the game. The assessment of physical fitness is the most reliable method for knowing if the athlete’s physical fitness is appropriate. Therefore, the objectives of this research were to identify profiles of physical-physiological demands with different specific tests of physical fitness related to the maximum strength of the lower body and speed. Moreover, some differences based on the sex and age of the players were identified. One hundred and forty-nine basketball players were analyzed (men n = 103 vs. women n = 46, weight: 74.74 ± 11.65 kg vs. 56.89 ± 3.71 kg, height: 184.66 ± 11.67 vs. 164 ± 4 and BMI: 21.7 ± 0.83 vs. 21.6 ± 0.90). The players performed an Abalakov test, a multi-jump test, and a repeat sprint ability test. Each player was equipped with a WIMU PRO device, and photoelectric cells were used. A MANOVA was performed to discover the differences between ages, and a t-test was used regarding sex. The results showed significant differences based on age and sex in variables related to time and Player Load/min (p < 0.001). The variables related to steps (contact, step, flight) also showed significant differences as a function of age (p < 0.001) and sex (p < 0.05). The multi-jump test showed differences based on age (p < 0.05 except in between jumps), but not on sex. These results confirm the importance of working together on lower body strength and speed skills. In addition, the planning of the work on these abilities must be individualized and according to the characteristics of the athlete.