Is test specificity the issue in assessing aerobic fitness and performance of runners? A systematic review.

INTRODUCTION: Various tests have been developed to evaluate aerobic fitness and performance of runners. However, a systematic understanding of which methods are more accurate is necessary to provide coaches and the sports sciences community with useful and confident outcomes. This study aims to summarize the evidence regarding the validity, reliability and sensitivity of tests for measuring aerobic fitness and performance in runners of several background of training. EVIDENCE ACQUISITION: A systematic search was conducted of Web of Science, PubMed and Scopus up to 31st December 2022 according to PRISMA statement guidelines. Studies that reported findings about tests covering maximal aerobic speed, final velocity achieved during the test, average running speed or other method of evaluating the reference speed during the test were included. We evaluated the risk of bias in the included articles using the Risk of Bias Assessment Tool for Nonrandomized Studies (RoBANS). The tests were categorized into continuous incremental tests, intermittent tests and time-trial test. EVIDENCE SYNTHESIS: A total of 23 studies met eligibility criteria. These studies contained three background of training: track and road runners (N.=15), trail runners (N.=7) and inexperienced runners (N.=1). Criterion validity was assessed in 73% of the studies, while only 41% of studies examined convergent validity. The majority of the reviewed studies (87%) ignored test-retest reliability. Test sensitivity was not reported in any study. CONCLUSIONS: At least one aerobic fitness and performance test was identified for each types of background of training. However, some methodological aspects were not provided in the included articles. Most studies examined at least one aspect of validity (i.e., criterion or convergent-related validity), whilst few studies investigated test-retest reliability. Researchers and practitioners can use the information provided in this systematic review to select appropriate tests.

Toward a New Conceptual Approach to "Intensity" in Soccer Player's Monitoring: A Narrative Review.

ABSTRACT: Pillitteri, G, Clemente, FM, Petrucci, M, Rossi, A, Bellafiore, M, Bianco, A, Palma, A, and Battaglia, G. Toward a new conceptual approach to "intensity" in soccer player's monitoring: A narrative review. J Strength Cond Res 37(9): 1896-1911, 2023-In the last decade, monitoring physiological and match-related demands in soccer has become an increasingly common practice in sports sciences. One of the great challenges during monitoring process is the identification of key indicators that permit to generalize evidence and sustain decision-making process during training prescription. Actually, one of the major debates in the scientific community and among practitioners is the identification of the "intensity" concept. Defining a given training session or exercise based on "intensity" is difficult due to the fact that a huge amount of indicators are available (related both to the performed activities and to the athletes' psychophysiological responses). These indicators can lead to specific outcomes with different interpretations. The current narrative review aims to discuss the different measures approaches used in soccer to describe the intensity for both internal and external demands. In addition, a second purpose of this review is to propose general recommendations for combining intensity indicators with the aim of defining an overall intensity score of a training session or drill.

Recovery of kicking kinematics and performance following repeated high-intensity running bouts in the heat: Can a rapid local cooling intervention help young soccer players?

The effects of a cooling strategy following repeated high-intensity running (RHIR) on soccer kicking performance in a hot environment (>30ºC) were investigated in youth soccer players. Fifteen academy under-17 players participated. In Experiment 1, players completed an all-out RHIR protocol (10×30 m, with 30s intervals). In Experiment 2 (cross-over design), participants performed this running protocol under two conditions: (1) following RHIR 5 minutes of cooling where ice packs were applied to the quadriceps/hamstrings, (2) a control condition involving passive resting. Perceptual measures [ratings of perceived exertion (RPE), pain and recovery], thigh temperature and kick-derived video three-dimensional kinematics (lower limb) and performance (ball speed and two-dimensional placement indices) were collected at baseline, post-exercise and intervention. In Experiment 1, RHIR led to small-to-large impairments (p < 0.03;d = -0.42--1.83) across perceptual, kinematic and performance measures. In experiment 2, RPE (p < 0.01; Kendall's W = 0.30) and mean radial error (p = 0.057; η2 = 0.234) increased only post-control. Significant small declines in ball speed were also observed post-control (p < 0.05; d = 0.35). Post-intervention foot centre-of-mass velocity was moderately faster in the cooling compared to control condition (p = 0.04; d = 0.60). In youth soccer players, a short cooling period was beneficial in counteracting declines in kicking performance, in particular ball placement, following intense running activity in the heat.

Warm-up optimization in amateur male soccer players: A comparison of small-sided games and traditional warm-up routines on physical fitness qualities.

The aim of this study was to compare the effects of small-sided soccer games (SSSGs) and traditional warm-up (TWU) routines on physical fitness qualities in soccer players. Following a between-subject, randomized design, amateur-level soccer players were assigned to a SSSG warm-up (n = 10; age: 19.3 ± 2.8 years) or TWU group (n = 10; age: 19.3 ± 2.4 years). Players completed multiple trials of 10-m and 30-m linear sprints, change-of-direction speed (CODS) tests, and countermovement jumps (CMJ) prior to and following the warm-up routine. Separate mixed ANOVAs were performed to assess group effects (SSSG vs. TWU), time effects within each group (pre- vs. post-warm-up), and their interaction for each physical fitness quality. No significant interaction effects were observed for any dependent variable. Significant improvements were evident between baseline and follow-up measurements for 10-m sprint time (p = 0.002, Hedges' g effect size [g] = 0.59) and CMJ variables (height: p = 0.016, g = 0.20; power: p = 0.003, g = 0.19; force: p = 0.002, g = 0.14) in the TWU group and for CODS performance time (p = 0.012, g = 0.51) and CMJ variables (height: p < 0.001, g = 0.46; power: p = 0.002, g = 0.35; force: p = 0.001, g = 0.27) in the SSSG warm-up group. Both SSSG and TWU protocols improved selected physical fitness qualities with SSSG more effective at improving CODS and CMJ performance, and TWU more effective at improving linear speed. Soccer coaches may choose between SSSG or traditional warm-up activities according to player needs and preferences; however, the superior effects of SSSG suggest it might offer greater benefits than TWU in preparing players for optimal physical output.

Web-based exercise interventions for patients with depressive and anxiety disorders: a systematic review of randomized controlled trials

Objective: The number of people suffering from depression and/or anxiety has increased steadily due to the coronavirus disease 2019 (COVID-19) pandemic. In this context, web-based exercise interventions have emerged as a potential treatment strategy. The objective of this study was to synthetize evidence from randomized controlled trials regarding the effects of web-based exercise interventions on patients with depressive and/or anxiety disorders. Methods: Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Six databases were searched (Cochrane Library, EBSCO, PubMed, SciELO, Scopus, and Web of Science), and eligible articles were identified according to a PICOS inclusion-exclusion approach (participants with depressive or anxiety disorders; web-based exercise interventions; active or passive control group; assessment of changes in depressive or anxiety disorders; randomized design). Primary outcomes were depressive and/or anxiety symptoms. The quality of evidence was assessed with Grading of Recommendations Assessment, Development, and Evaluation. Results: Of 7,846 search results, three studies met the inclusion criteria (172 participants between 18 and 65 years of age, 95.9% women). The web-based exercise interventions lasted 8-12 weeks and involved endurance training, yoga, or combined endurance and strength training. The comparators involved non-exercise controls or active controls. Compliance rates were low. Web-based exercise interventions were not superior to controls regarding anxiety symptoms, and only one study found benefits for depressive symptoms (p ≤ 0.05). The quality of the cumulative evidence was low. Conclusion: The available data regarding the effects of web-based exercise interventions on depression and/or anxiety symptoms is scarce, the risk of bias is high, and the quality of the cumulative results is low. Currently, no clear recommendations can be provided. Registration number: PROSPERO CRD42021225938.

Assessing the Relationship Between External and Internal Match Loads in Elite Women's Rugby Sevens.

PURPOSE: To assess the relationship between external and internal load during official women's rugby seven matches. METHODS: Six backs (age = 24.2 [3.2] y; height = 161.5 [7.3] cm; body mass = 59.5 [5.0] kg; playing experience = 5.3 [1.5] y) and 8 forwards (age = 22.4 [2.7] y; height = 167.0 [4.8] cm; body mass = 70.6 [5.6] kg; playing experience = 5.0 [1.5] y) belonging to the women's rugby seven Brazilian national team were monitored across 3 international tournaments during the 2019-20 season, with 2 players excluded from the analysis since they did not participate in any investigated match. Total distance (TD), distance during high-intensity running 18.1 to 20.0 km·h-1 and >20 km·h-1 (sprinting), number of accelerations >1.8 m·s-2 (ACC), and of decelerations <1.8 m·s-2 were used as match load volume measures, while their relative values (TD per minute, high-intensity running per minute, sprinting per minute, ACC per minute, and decelerations per minute) were used as external load match intensity measures. Internal load intensity and volume were assessed using the session rating of perceived exertion (sRPE) and its value multiplied by match duration (sRPE-ML), respectively. Spearman correlations and linear mixed models were used to assess the relationships between internal and external load measures. RESULTS: A very large relationship (ρ = .830, P < .001) was found between sRPE-ML and TD, with linear mixed models showing that TD statistically affected sRPE-ML (P < .001). Linear mixed models analysis showed that ACC per minute was also affecting the sRPE-ML (P = .017), while sprinting (P = .007) and ACC per minute (P = .005) were the only 2 measures statistically affecting sRPE. However, weak relationships (trivial to large) were found for these and all other measures. CONCLUSIONS: These results highlight that TD is the main external load measure able to anticipate the internal load responses measured via sRPE-ML in elite women's rugby sevens.

Quantification of training and match load in elite youth soccer players: a full-season study.

BACKGROUND: The present study aimed to quantify training and match load in elite young soccer players over the course of an entire season. METHODS: Using a longitudinal design, session-rate of perceived exertion (s-RPE) and its metrics (weekly acute workload [wAW], acute to chronic workload ratio [wACWR], training monotony and training strain) were examined in twenty-one elite young soccer players (mean±standard deviation; age: 16.1±0.2 years; height: 176.8±5.6 cm; body mass: 67.3±5.7 kg; BMI: 21.5±1.4 kg/m2; V̇O2max: 47.6±3.8 mL.kg-1.min-1) during the whole season containing 4 meso-cycles: preseason (Pre-S), early-season (Ear-S), mid-season (Mid-S), and end-season (End-S). RESULTS: Repeated-measures analysis of variance examined variations in s-RPE load data across the 4 meso-cycles and 1-week of microcycle. Analyzing data revealed the End-S had a significant greater wAW compared to Early-S (P=0.002, g=0.96) and Mid-S (P<0.001, g=1.09). However, no differences between in-season periods were observed in wACWR (P=0.524). The within-week variations revealed significant lower wAW in prematch a day (MD-1) (P<0.001), 1 day after match (MD+1) (P<0.001) and 2 days after match (MD+2) (P<0.001) compared to match day (MD) for overall team analysis. Additionally, analyses by playing position showed that fullbacks have a significant lower AW in MD+2 compared to MD (P<0.029). CONCLUSIONS: The periodization of training load indicated variations across the whole season in young elite players. The weekly microcycle perceived load could be identified as follows; there are higher training loads on MD-3 and MD-2 which was similar to intensities experienced by players throughout the match play and, furthermore, lower overall WL on the MD+1 and MD+2 in order to ensure the optimal recovery of the players.

Web-based exercise interventions for patients with depressive and anxiety disorders: a systematic review of randomized controlled trials.

OBJECTIVE: The number of people suffering from depression and/or anxiety has increased steadily due to the coronavirus disease 2019 (COVID-19) pandemic. In this context, web-based exercise interventions have emerged as a potential treatment strategy. The objective of this study was to synthetize evidence from randomized controlled trials regarding the effects of web-based exercise interventions on patients with depressive and/or anxiety disorders. METHODS: Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Six databases were searched (Cochrane Library, EBSCO, PubMed, SciELO, Scopus, and Web of Science), and eligible articles were identified according to a PICOS inclusion-exclusion approach (participants with depressive or anxiety disorders; web-based exercise interventions; active or passive control group; assessment of changes in depressive or anxiety disorders; randomized design). Primary outcomes were depressive and/or anxiety symptoms. The quality of evidence was assessed with Grading of Recommendations Assessment, Development, and Evaluation. RESULTS: Of 7,846 search results, three studies met the inclusion criteria (172 participants between 18 and 65 years of age, 95.9% women). The web-based exercise interventions lasted 8-12 weeks and involved endurance training, yoga, or combined endurance and strength training. The comparators involved non-exercise controls or active controls. Compliance rates were low. Web-based exercise interventions were not superior to controls regarding anxiety symptoms, and only one study found benefits for depressive symptoms (p ≤ 0.05). The quality of the cumulative evidence was low. CONCLUSION: The available data regarding the effects of web-based exercise interventions on depression and/or anxiety symptoms is scarce, the risk of bias is high, and the quality of the cumulative results is low. Currently, no clear recommendations can be provided. REGISTRATION NUMBER: PROSPERO CRD42021225938.

Lateral Preference and Inter-limb Asymmetry in Completing Technical Tasks During Official Professional Futsal Matches: The Role of Playing Position and Opponent Quality.

This study had the purpose of analyzing dominant and non-dominant limb performances (frequency of use and accuracy) during match-play technical actions with ball possession (receiving, passing, and shooting a ball) in professional futsal and also check for the possible influence of playing position and the quality of opponent. We have analyzed data pertaining to eight matches of the FIFA Futsal World Cup Thailand 2012™ in which 76 male professional senior futsal players participated (44 right-footed and 32 left-footed). In total, we coded 5,856 actions (2,550 ball receptions, 3,076 passes, and 230 shoots). Our main findings were that (a) players used the dominant limb more frequently than the non-dominant limb for all actions considered [p < 0.001; effect size (ES) medium-to-large]; (b) accuracy was generally greater when using the dominant limb, regardless of the quality of opponent (p < 0.01; ES large); and (c) in shooting actions, pivots showed similar accuracy between dominant and non-dominant limbs (p = 0.51; ES small). The study suggested that when completing technical actions with the ball in futsal, high-level players depended to a greater extent on the use of their dominant lower limb during official matches. Excepting a similarity detected between limbs on shooting performance of pivots, players from all positional roles generally showed a higher accuracy rate in receiving, passing, and shooting a ball when using their dominant limb as compared to their non-dominant one during match-play and the limb usage and accuracy seemed to be independent of the quality of opponents.

The Hamstrings: Anatomic and Physiologic Variations and Their Potential Relationships With Injury Risk.

The incidence and recurrence of hamstrings injuries are very high in sports, posing elevated performance and financial-related costs. Attempts to identify the risk factors involved in predicting vulnerability to hamstrings injury is important for designing exercise-based programs that aim to mitigate the rate and severity of hamstrings injuries and improve rehabilitation strategies. However, research has shown that non-modifiable risk factors may play a greater role than modifiable risk factors. Recognizing non-modifiable risk factors and understanding their implications will afford the prescription of better suited exercise programs, i.e., that are more respectful of the individual characteristics. In a nutshell, non-modifiable risk factors can still be acted upon, even if indirectly. In this context, an underexplored topic is how intra and inter- individual anatomic and physiologic variations in hamstrings (e.g., muscle bellies, fiber types, tendon length, aponeurosis width, attachment sites, sex- and age-related differences) concur to alter hamstrings injuries risk. Some anatomic and physiologic variations may be modifiable through exercise interventions (e.g., cross-sectional area), while others may not (e.g., supernumerary muscle bellies). This apparent dichotomy may hide a greater complexity, i.e., there may be risk factors that are partially modifiable. Therefore, we explored the available information on the anatomic variations of the hamstrings, providing a deeper insight into the individual risk factors for hamstrings injuries and contributing with better knowledge and potential applications toward a more individualized exercise prescription.

Effects of 8-Week FIFA 11+ for Kids Intervention on Physical Fitness and Attention in Elementary School Children.

BACKGROUND: The psychological and physiological adaptations in response to the FIFA 11+ for kids (FIFA11+kid) program has not been examined in school children. This study aimed to investigate the effects of 8-week FIFA11+kid intervention on physical fitness and attentional capacity in elementary school children. METHODS: A total of 55 elementary school students voluntarily participated in the study. Participants were assigned to either the FIFA11+kid (n = 28, 5 times per week) or the control (n = 27) group. At baseline and after 8 weeks, all participants were asked to perform a battery of physical fitness tests (sit-and-reach, broad jump, sit-up test, and 800-m run) and the Attention Scale for Elementary School Children, including 5 subscales: focused, sustained, selective, alternating, and divided attentions. RESULTS: The FIFA11+kid group demonstrated larger pre-post change in sit-and-reach (P < .001) and sit-up test (P < .001) than that of control group. Moreover, the FIFA11+kid group demonstrated large improvements pre-post change in Attention Scale for Elementary School Children scores of total score (P < .001), focused (P < .001), sustained (P < .001), and selective attentions (P < .001) compared with the control group. CONCLUSION: A total of 8 weeks of FIFA11+kid exercise intervention can improve general physical fitness and attentional capacities in elementary school children.

Injury prevention of hamstring injuries through exercise interventions.

INTRODUCTION: Hamstring injuries are the most prevalent time-loss injuries in sport, mainly in those modalities characterized by high-intensity and short-term actions, especially accelerations and decelerations during high-speed running. Expanding the knowledge about this type of injury and its preventive programs could be a key strategy to reduce the hamstring injury incidence. Thus, this review aimed to study the effectiveness of different preventive programs based on exercise interventions on reducing the hamstring injury incidence in athletes. EVIDENCE ACQUISITION: An umbrella review was conducted through of PubMed/MEDLINE, Scopus, SPORTDiscus, Web of Science, Cochrane Library and Physiotherapy Evidence Database databases. The methodological quality of the included systematic reviews was assessed through the Assessing the Methodological Quality of Systematic Reviews 2 and the quality of the evidence was evaluated using the modified Grading of Recommendations Assessment, Development and Evaluation principles. EVIDENCE SYNTHESIS: Eight systematic reviews and meta-analysis (40 primary studies) met the inclusion criteria, which included interventions based on eccentric strength, Nordic hamstring, proprioceptive training, stretching, FIFA11 and combined programs. From the qualitative synthesizes, three studies showed that eccentric-based training programs were effective; seventeen studies reported that Nordic hamstring-based programs were effective; three studies observed that stability training-based interventions were effective; two studies indicated that flexibility were effective; three studies claimed that FIFA11+based programs were effective; and two studies reported that combined programs were effective. CONCLUSIONS: Exercise is a key strategy to reduce the hamstring injury incidence, being programs based on eccentric strength mainly by means of Nordic hamstring exercise, and on stability training, those programs which reported greater effectiveness.

Quantification of Respiratory and Muscular Perceived Exertions as Perceived Measures of Internal Loads During Domestic and Overseas Training Camps in Elite Futsal Players.

BACKGROUND: The rating of perceived exertion (RPE) scales with respiratory and muscular illustrations are recognized as simple and practical methods to understand individual psychometric characteristics in breathing and muscle exertion during exercise. However, the implementation of respiratory and muscular RPE to quantify training load in futsal training camps has not been examined. This study investigates respiratory and muscular RPE relationships during domestic training camps (DTC) and overseas training camps (OTC) in an under 20 futsal national team. METHODS: Data collected from eleven field players were used for comparison in this study (age = 18.7 ± 0.7 years, height = 171.9 ± 6.1 cm, body weight = 64.2 ± 8.4 kg). All players reported Borg CR10 RPE (RPECR10) and 7-scales respiratory RPE (RPErespiration) and muscular RPE (RPEmuscle) (Dalhousie pictorial scales) after training sessions and matches. Additionally, total distance covered (TD) and training impulse (TRIMP) were used to quantify external and internal loads via the Polar Team Pro system. Paired-sample t-tests were used to compare the RPECR10, RPErespiration, RPEmuscle, TD, and TRIMP between DTC and OTC. Furthermore, linear regression was performed to determine the relationships among all RPE scales, TD, and TRIMP. RESULTS: The RPECR10 (p = 0.047), TD (p < 0.001), and TRIMP (p < 0.001) showed significant difference between DTC and OTC. Furthermore, linear regression analyses showed significant correlation between RPErespiration and RPEmuscle (DTC: r = 0.857, p = 0.006; OTC: r = 0.924, p < 0.001), RPECR10 and RPErespiration (DTC: r = 0.857, p = 0.001; OTC: r = 0.863, p = 0.001), and RPECR10 and RPEmuscle (DTC: r = 0.906, p < 0.001; OTC: r = 0.900, p < 0.001). CONCLUSION: Pictorial RPErespiration or RPEmuscle can be used as an alternative to quantify perceived measures of internal loads during DTC and OTC in futsal players. Interpretation of perceived measures of training load and cardiac-related responses in association with external training loads during short-term training camps would be useful in further understanding the demands of futsal players' experience in these circumstances.

Running-related injuries in Portuguese trail runners: a retrospective cohort study.

BACKGROUND: The purpose of this study was to characterize trail running injuries within a cohort of Portuguese male and female recreational trail running athletes. METHODS: The study was retrospective (12 months), with data collected through an online survey. A total of 719 athletes participated (529 male and 190 female, average age: 38.01±7.78 years). A valid questionnaire was used to collect: 1) demographic information; 2) general information; 3) training typology; 4) physical information; 5) injuries (body location, number, type, reason, treatment, time without practice); and 6) general information concerning the effects of injuries on respondents' daily lives. RESULTS: The results revealed that 87.8% of the sample contracted an injury resulting from this practice, with the toenails (24.8%), knees (17.5%), and ankles (14.5%) being the most-often reported locations of injuries and blisters (20%), irritation (chafing) (14%), superficial wounds (12%), sprains (11%), and iliotibial band syndrome (7%) being the most common injuries. The result of 10.0 injuries per 1000 h was found, with a negative and medium correlation (r=-0.344; P=0.000) between total exposure time and injuries per 1000 h. It was also found that those who do not perform warm-up have a significantly increased injury rate (P<0.05). CONCLUSIONS: The gathered evidence demonstrated a large number of dermatological and musculoskeletal injuries, and these tended to have higher incidences in athletes with less exposure time and who devalue warm-up exercises.

The effect of two types of combined training on bio-motor ability adaptations in sedentary females.

BACKGROUND: The purpose of this study was to compare the effects of combined training of high-volume/low intensity vs. low volume/high intensity on different bio-motor adaptations in sedentary women. METHODS: Thirty sedentary healthy females (mean age, 22.1±3.3 years), were randomly assigned into: control group (CG; N.=10), High-Volume/low-intensity training group (HV; N.=10); or high-intensity/low-volume training group (HI; N.=10). Training protocols were performed for 8 weeks, on three non-consecutive days a week. RESULTS: Post-intervention, there were significant main effects of time and a group by time interaction for all body composition and performance variables (P≤0.001), while no significant differences were found for changes in maximum heart rate. Pairwise comparisons revealed significant decreases in body fat percentage and speed test in HV and HI (P≤0.001) after intervention, while anaerobic power significantly increased in HV and HI (P≤0.001). The rating of perceived exertion (RPE) was significantly superior in HI than HV (P≤0.05). Additionally, there were significant main effects of time and a group by time interaction for all one-repetition maximum tests (P≤0.001). CONCLUSIONS: Combined interval training and resistance training were effective for improving bio-motor parameters in sedentary young women. HV training produced less RPE than HI training, which may potentially increase adherence to training protocols post-intervention.

Effects of Plyometric Jump Training in Female Soccer Player's Physical Fitness: A Systematic Review with Meta-Analysis.

We aimed to assess the effects of plyometric jump training (PJT) on female soccer player's physical fitness. To this aim, a systematic review with meta-analysis (SRMA) was conducted. The electronic databases PubMed, MEDLINE, Web of Science, and SCOPUS were used. To qualify for inclusion, peer-reviewed studies must have included (i) a PJT programme of ≥2 weeks, (ii) healthy athletes, (iii) a control group, and (iv) physical fitness outcomes (e.g., jump; sprint). Studies were excluded if (i) they incorporated injuried female soccer players, (ii) did not involve PJT or an active control group, (iv) lack of baseline and/or follow-up data. Data was meta-analyzed using the inverse variance random-effects model. Ten moderate-to-high quality studies were included in the analyses, comprising 13 training groups (n = 140) and 10 control groups (n = 110). Small to large (ES = 0.60-2.24; p = 0.040 to <0.001) effects were noted for countermovement jump, drop jump, kicking performance, linear sprint, change of direction speed, and endurance. The moderator analyses (i.e., PJT duration, age groups, competitive level, and soccer experience) revealed no significant differences between groups. In conclusion, PJT may improve the physical fitness of female soccer players. Such improvements might be expected after PJT interventions with six or more weeks of duration, and in players with different chronological ages, competitive levels and soccer experience.

A Survey to Assess the Quality of the Data Obtained by Radio-Frequency Technologies and Microelectromechanical Systems to Measure External Workload and Collective Behavior Variables in Team Sports.

Electronic performance and tracking systems (EPTS) and microelectromechanical systems (MEMS) allow the measurement of training load (TL) and collective behavior in team sports so that match performance can be optimized. Despite the frequent use of radio-frequency (RF) technology (i.e., global positioning navigation systems (GNSS/global positioning systems (GPS)) and, local position systems (LPS)) and MEMS in sports research, there is no protocol that must be followed, nor are there any set guidelines for evaluating the quality of the data collection process in studies. Thus, this study aims to suggest a survey based on previously used protocols to evaluate the quality of data recorded by RF technology and MEMS in team sports. A quality check sheet was proposed considering 13 general criteria items. Four additional items for GNSS/GPS, eight additional items for LPS, and five items for MEMS were suggested. This information for evaluating the quality of the data collection process should be reported in the methods sections of future studies.

Tactical Analysis According to Age-level Groups during a 4 vs. 4 Plus Goalkeepers Small-sided Game.

This study aimed to compare the collective dynamics of three different age-level groups (i.e., U13, U15 and U18) during a 4 vs. 4 plus goalkeepers small-sided game (SSG). Fifty-four male outfield soccer players aged between 13 and 18 years took part in the study. Team tactical behaviors were assessed by measuring (a) the area occupied by players of each team, (b) the distance between both teams' centroids, (c) the players' distance to their own team and d) the stretch index during a 4 vs. 4 plus goalkeepers SSG format. The main results revealed that larger areas were occupied by the older players (P < 0.001; Effect size (ES) = 0.44-0.25, small). Additionally, the mean distance between teams' centroids was greater in older groups (P < 0.001; ES = 0.44-0.81, large-small). Finally, the distance between players (P < 0.001; ES = 0.75-0.81, moderate-large) and the stretch index (P < 0.001; ES = 0.44-0.47, small) were also greater in older age categories. The evidence provided in the present study might help coaches identify the influence of age on collective dynamics during SSGs and help them find task conditions that could help to improve the behaviors and positioning of younger players.

Analyzing the effects of combined small-sided games and strength and power training on the fitness status of under-19 elite football players.

BACKGROUND: The purpose of this study was twofold: 1) to characterize a common microcycle considering both internal and external training loads; and 2) to identify the effects of small-sided games (SSGs) and of power and strength training on the fitness status of football players. METHODS: Fifteen male football players (age: 18.55±0.39 years) participated in this study. Ninety-two consecutive training sessions were monitored and analyzed over a period of nineteen weeks. Rating of perceived exertion (RPE ) was used as an internal load marker, and the distances covered at different speed thresholds and accelerations/decelerations were used as external load markers to characterize the common microcycle. Participants' body composition, vertical jumping ability, maximal strength, speed, and agility were assessed twice before and after the training monitoring process. RESULTS: The results revealed that match day -5 (MD-5) and MD-1 were associated with the lowest RPE scores (4.2 and 3.8 A.U., respectively). MD-4 and MD-3 were associated with the highest RPE values (9.2 and 8.8 A.U., respectively). Meaningful changes in RPE were found between training days. External load monitoring revealed that MD-4 had the highest values of accelerations and decelerations >2 m/s2/min (4.22 and 3.17, respectively) and MD-3 had the highest values of distance covered at high intensity (6.11 m/s2/min). Meaningful moderate improvements in jumping performance (d=0.90) and maximal strength parameters (d=0.83) were also found between assessments. CONCLUSIONS: It was identified that the concurrent approach had meaningful impacts on the fitness development of players and should be considered by coaches for future training interventions.

Analyzing the Seasonal Changes and Relationships in Training Load and Wellness in Elite Volleyball Players

PURPOSE: The purposes of this study were to (1) analyze the variations of acute and chronic training load and well-being measures during 3 periods of the season (early, mid, and end) and (2) test the associations between weekly training load and well-being measures during different periods of the season. METHODS: Thirteen professional volleyball players from a team competing in the Portuguese Volleyball First Division (age 31.0 [5.0] y) were monitored during an entire season. Weekly acute (wAL) and chronic load (wCL), acute to chronic workload ratio (wACWL), and training monotony (wTM) were calculated during all weeks of the season. The weekly values of muscle soreness (wDOMS), stress (wStress), fatigue (wFatigue), sleep (wSleep), and Hooper index (wHI) were also obtained across the season. RESULTS: The midseason had meaningfully low values of wAL (-26.9%; effect size [ES]: -1.12) and wCL (-28.0%; ES: -2.81), and greater values of wACWL (+38.9%; ES: 2.81) compared with early season. The wCL (+10.6%; ES: 0.99), wStress (44.6%; ES: 0.87), and wHI (29.0%; ES: 0.62) were meaningfully greater during the end of season than in midseason. Overall, wAL presented very large correlations with wDOMS (r = .80), wSleep (r = .72), and wFatigue (r = .82). CONCLUSIONS: The results of this study suggest that the load was meaningfully higher during early season; however, stress was higher during the final stages of the season. Overall, it was also found that the acute load is more highly correlated with well-being status and its variations than chronic load or training monotony.