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The assessment of biological maturation is a central topic in pediatric exercise sciences. Skeletal age (SA) reflects changes in each bone of the hand and wrist from initial ossification to the adult state. This study examined intra-observer and inter-examiner agreement is Greulich-Pyle (GP) assessments of SA in 97 male tennis players 8.6-16.8 years of age. Two observers independently examined all films on two occasions using the GP method. The SA of each bone was evaluated. The mean and median of SAs assigned for each bone was the individual SA for each participant. The calculation was exclusively based on the bones that were not skeletally mature. Intra-observer mean differences were significant for several bones with better results by the experienced examiner (observer B). Comparisons between SA values of the two independent observers indicated significant differences for the ulna, metacarpals II and III, and distal phalanx V. Nevertheless, the magnitude of the bone-specific differences was small, perhaps trivial. Differences in individual SA values of the tennis players based on the non-mature bones of the hand-wrist were negligible based on the mean (0.04±0.39, t = 0.321, p = 0.749) or the median (0.05±0.58, t = 0.007, p = 0.994). Nevertheless, the current study confirmed examiners as a source of error in the estimation of SA using the Greulich-Pyle method and highlighted the importance of calculating SAs based on non-mature bones among adolescent players.

Background This study aimed to determine the agreement between fat-free mass (FFM) estimates from bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA) and their use in estimating resting metabolic rate (RMR) in men undergoing resistance training.Methods Thirty healthy resistance-trained men (22.7 ± 4.4 years, 70.0 ± 8.7 kg, 174.6 ± 6.7 cm, and 22.9 ± 2.3 kg/m2) were evaluated. The equation developed by Tinsley et al. (RMR = 25.9 × fat-free mass [FFM] + 284) was adopted to calculate the RMR. DXA was used as the reference method for FFM.Results Furthermore, FFM was also estimated by BIA using a spectral device. No significant difference (p > 0.05) was observed between DXA (1884.2 ± 145.5 kcal) and BIA (1849.4 ± 167.7 kcal) to estimate RMR. A positive and significant correlation (r = 0.89, p

Background The purpose of the review was to evaluate the literature exploring nutritional habits and practices in female soccer players.Methods The PRISMA-ScR Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews were followed. Searches of Web of Science, PubMed and Scopus databases were conducted for studies exploring the nutritional habits and practices of female soccer players.Results A total of 72 studies were included in the scoping review. Studies on female soccer players mainly focused on daily energy expenditure, daily energy and macronutrient intake and hydration status. A negative energy balance was consistent across studies, and the ingestion of CHO appears below the current recommendations. Female soccer players are predominately in negative energy balance, which may indicate that they are at risk of low energy availability. A high use of nutritional supplements is apparent in female soccer, whilst a large proportion of players commence training dehydrated.Conclusions The current findings have implications for practitioners relating to the planning, management, monitoring, and implementation of nutritional intake and training and competition schedules.

Abstract Introduction: Exercise is being incorporated into the treatment of patients on hemodialysis; however, little is known about the major characteristics of these interventions. Objective: To describe the exercise protocols prescribed for hemodialysis patients in Brazil. Methods: A scoping review was conducted following JBI and Prisma-ScR guidelines. Searches were carried out in Medline, Embase and three other databases until May 2024. Other sources (websites, books and guidelines) were also investigated. Evidence from patients on hemodialysis describing exercise protocols in all settings and designs in Brazil was included. Results: Forty-five pieces of evidence were found, resulting in 54 exercise protocols from 16 Brazilian states. Strength exercises (33.3%), followed by aerobic exercises (22.2%), were the most prescribed, mainly to be performed during dialysis (85.2%). The most prevalent professionals supervising the programs were physiotherapists and exercise physiologists (37.0% and 18.5%, respectively). All protocols implemented the principles of type and frequency training, while progression was adopted in only 53.7%. The main prescription was three times per week (88.9%). Exercise intensity was predominantly determined by subjective methods (33.3%). Conclusion: Aerobic and strength exercises during dialysis were the most commonly prescribed modalities in Brazil, with the majority of programs being properly supervised by qualified professionals. However, existing protocols have not employed systematic progression throughout the intervention, which would be appropriate for providing better physiological responses and adaptations.

Background:Running is one of the simplest and most popular forms of exercise. Biomechanical evaluation of running is one of the elements of evaluating running technique and, consequently, improving sports performance. Running uphill and downhill is one of the components of daily running but also an element of training used by recreational runners. The aim of this study is to optimize running training and minimize the risk of injury by identifying changes in the spatiotemporal structure of running at different inclinations. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. The protocol has been registered on the international platform INPLASY under the number INPLASY202430094U2. The search was conducted up to 30 March 2024 using the Scopus, PubMed, and Web of Science databases. Results: Spatiotemporal parameters were most frequently analyzed at 2.8–3.35 m/s velocities and inclinations in the range of −11% to 11%. Decreases in stride length (SL) and flight time (FT), and increases in step frequency (SF) were the most frequently reported changes from all parameters analyzed as a function of inclination and velocity. Significant increases or decreases in individual parameters were more often observed for positive inclination values than negative ones. Conclusions: The heterogeneous results of the study limit the possibility of determining the changes that occur in the spatiotemporal structure of the run under the impact of different inclinations. The variation in the results for negative inclination values indicates the different characteristics of running uphill and downhill. However, for uphill running, SF, SL, and FT are closely related to the increase in inclination.

Most paints contain pigments that absorb light and fade over time. A robust alternative can be found in nature, where structural coloration arises from the interference of light with submicron features. Plant‐derived, cellulose nanocrystals (CNCs) mimic these features by self‐assembling into a cholesteric liquid crystal that exhibits structural coloration when dried. While much research has been done on CNCs in aqueous solutions, less is known about transferring CNCs to apolar solvents that are widely employed in paints. This study uses a common surfactant in agricultural and industrial products to suspend CNCs in toluene . Surprisingly, a stable liquid crystal phase is formed within hours, even with concentrations of up to 50 wt%. Evaporating the apolar CNC suspensions results in photonic films with peak wavelengths ranging from 660 to 920 nm. The resulting flexible films have variable mechanical properties with surfactant content, allowing for an optical response with applied force. The films also act as humidity sensors, with increasing relative humidity swelling the films, yielding a redshift in the reflected wavelength. With the addition of a single surfactant, CNCs can be made compatible with existing production methods of industrial coatings, while improving the strength and responsiveness of structurally colored films to external stimuli.

Abstract Background The purpose of this scoping review was to evaluate the current use of technologies in sports settings for training adaptation and injury prevention. The review aimed to map the existing literature, identify key concepts and themes, and highlight gaps in research, thus offering guidance for future studies. Methods This study followed the guidelines of the PRISMA extension for scoping reviews and a search in four major databases was conducted. Results A total of 21 studies were included. The findings highlighted the widespread use of various technologies, including wearable devices and force plates, to monitor athletes’ performance and inform evidence-based decision-making in training and injury prevention. Variables such as Player Load, changes of direction, and acute chronic workload ratio were identified as key metrics in injury prediction. Conclusions This review uncovers a dynamic field of research in athlete injury prevention, emphasizing the extensive use of varied technologies. A key finding is the pivotal role of Player Load data, which offers nuanced insights for customizing training loads according to sport-specific demands, player positions, and the physical requirements of various activities. Additionally, the review sheds light on the utility of tools like force plates in assessing fatigue, aiding recovery, and steering injury rehabilitation, particularly in sports prone to knee and ankle injuries. These insights not only enhance our understanding of injury prevention but also provide a strategic direction for future research, aiming to boost athlete safety, performance, and career longevity.

Purpose: This cohort study aimed to investigate the relationship between subjective (wellness and internal training load [ITL]) and objective (neuromuscular fatigue) monitoring markers and performance aspects (reception quality [RQ] and attack efficiency [AE]) in professional female volleyball players. Methods: The study was conducted over an 8-week period during the final mesocycle of the competitive phase. A total of 24 training sessions and 10 matches were included in the analysis. Subjective measures of wellness and ITL were assessed, and neuromuscular fatigue was evaluated using countermovement-jump (CMJ) height. RQ and AE were determined based on game statistics. Results: The study found a positive relationship between wellness and RQ, particularly affecting outside hitters and liberos. ITL showed a positive association with AE, primarily impacting outside hitters, opposite hitters, and middle blockers. Additionally, ITL demonstrated a negative correlation with RQ, mainly affecting outside hitters and liberos. CMJ performance was associated with AE, where a decrease in CMJ height was linked to reduced AE. Conclusions: The findings highlight the importance of considering players' wellness scores in training and match strategies for different positions. Careful management of training loads, considering both physical and technical demands, is crucial for optimizing performance outcomes. Monitoring neuromuscular fatigue, as indicated by CMJ performance, is particularly relevant for outside hitters, opposite hitters, and middle blockers involved in attack actions. Coaches, trainers, and sports practitioners can use these insights to develop position-specific training protocols and implement effective strategies for maintaining or improving performance metrics under various stressors. [ABSTRACT FROM AUTHOR]

Purpose: The monitoring of training loads and quantification of physical performance are common practices in youth soccer academies to support coaches in prescribing and programming training for individuals. The interaction between training load and physical performance is unknown during a preseason period in youth soccer players. The current study assessed changes in training load and physical assessments across a 4-week preseason period. The relationship between physical performance and match playing time in youth male soccer players was also investigated. Methods: The training loads of 25 professional youth academy male soccer players were monitored throughout a 4-week preseason period. Assessments of power, agility, speed, and aerobic capacity were undertaken in the first training session. Session ratings of perceived exertion (sRPE) and well-being questionnaires were collected during all training sessions and preseason matches. Playing time during subsequent competitive matches was recorded. Results: T test and 30-m-sprint assessments, conducted on the first day of preseason, were predictors of sRPE throughout preseason (t test χ2/df = 2.895, poor adjustment; 30-m sprint χ2/df = 1.608, good adjustment). YoYo Test performance was related with changes in perceived fatigue (χ2/df = 0.534, very good adjustment). Faster players reported higher values of sRPE, and players with higher aerobic capacity reported higher levels of fatigue across preseason. Well-being, perceived fatigue and soreness, and sRPE decreased across preseason. Greater match durations were related to higher levels of fatigue during preseason (P <.05). Conclusion: The current study highlights the relationship between training load, physical assessments, and playing time. Coaches and practitioners can use physical test data at the start of preseason as an indication of players that report higher sRPE, perceived fatigue, and reduced well-being across preseason, supporting decisions around individualized training prescriptions. [ABSTRACT FROM AUTHOR]

Background and purpose: Hemodialysis patients have chronic systemic inflammation, musculoskeletal impairments, and body composition changes from several factors and exercise may attenuate. We evaluated the effects of an intradialytic resistance training program on body composition, physical function, and inflammatory markers in patients under short daily hemodialysis treatment.Materials and methods: A quasi-experimental study in clinical routine was conducted over eight months. Measures of physical function (handgrip strength, five-time sit-to-stand, timed-up and go, and gait speed), body composition (by bioelectrical impedance), and inflammatory markers (interleukin [IL]-1 beta, IL-6, IL-8, IL-10, IL-12p70, and tumor necrosis factor-α) were assessed at baseline as well as at four and eight months past continued intervention. Patients underwent two intradialytic resistance training sessions per week supervised by exercise professionals.Results: A total of 18 patients (62 ± 14 years; 55.6% ≥ 60 years; 44% female) were included. Significant increases in body mass index and basal metabolic rate were found at four and eight months compared to baseline. For physical function, timed-up and go performance improved at four and eight months compared to baseline. The other body composition and physical function measures, as well as all inflammatory markers, did not significantly change over time.Conclusion: A supervised intradialytic resistance training program for patients on short daily hemodialysis treatment, as part of the clinical routine, may induce modest changes in body mass index, basal metabolic rate, and timed-up and go performance.

The assessment of biological maturation is a central topic in pediatric exercise sciences. Skeletal age (SA) reflects changes in each bone of the hand and wrist from initial ossification to the adult state. This study examined intra-observer and inter-examiner agreement is Greulich-Pyle (GP) assessments of SA in 97 male tennis players 8.6–16.8 years of age. Two observers independently examined all films on two occasions using the GP method. The SA of each bone was evaluated. The mean and median of SAs assigned for each bone was the individual SA for each participant. The calculation was exclusively based on the bones that were not skeletally mature. Intra-observer mean differences were significant for several bones with better results by the experienced examiner (observer B). Comparisons between SA values of the two independent observers indicated significant differences for the ulna, metacarpals II and III, and distal phalanx V. Nevertheless, the magnitude of the bone-specific differences was small, perhaps trivial. Differences in individual SA values of the tennis players based on the non-mature bones of the hand-wrist were negligible based on the mean (0.04±0.39, t = 0.321, p = 0.749) or the median (0.05±0.58, t = 0.007, p = 0.994). Nevertheless, the current study confirmed examiners as a source of error in the estimation of SA using the Greulich-Pyle method and highlighted the importance of calculating SAs based on non-mature bones among adolescent players. [ABSTRACT FROM AUTHOR]

Background:Running is one of the simplest and most popular forms of exercise. Biomechanical evaluation of running is one of the elements of evaluating running technique and, consequently, improving sports performance. Running uphill and downhill is one of the components of daily running but also an element of training used by recreational runners. The aim of this study is to optimize running training and minimize the risk of injury by identifying changes in the spatiotemporal structure of running at different inclinations. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. The protocol has been registered on the international platform INPLASY under the number INPLASY202430094U2. The search was conducted up to 30 March 2024 using the Scopus, PubMed, and Web of Science databases. Results: Spatiotemporal parameters were most frequently analyzed at 2.8–3.35 m/s velocities and inclinations in the range of −11% to 11%. Decreases in stride length (SL) and flight time (FT), and increases in step frequency (SF) were the most frequently reported changes from all parameters analyzed as a function of inclination and velocity. Significant increases or decreases in individual parameters were more often observed for positive inclination values than negative ones. Conclusions: The heterogeneous results of the study limit the possibility of determining the changes that occur in the spatiotemporal structure of the run under the impact of different inclinations. The variation in the results for negative inclination values indicates the different characteristics of running uphill and downhill. However, for uphill running, SF, SL, and FT are closely related to the increase in inclination. [ABSTRACT FROM AUTHOR]

Abstract Background Puberty is a period of intense changes in human body and, additionally, participation in sports is viewed as prominent form of physical activity among male adolescent athletes. The current study was aimed to examine the intra-individual changes in body composition and bone tissue during years of maximal growth and the effect of 12-month participation in sports contrasting in mechanical impact. Methods The sample included 40 male adolescent athletes (soccer: n = 20; swimming: n = 20) aged 12.57 ± 0.37 years who were followed for 12 months. Stature and body mass were measured, bone mineral content (BMC), areal bone mineral density (aBMD), lean soft and fat tissues assessed using DXA. Food intake was estimated using a questionnaires and training sessions individually monitored. Repeated measures ANOVA tested the differences between sports and 12-month intra-individual variation (time moments: TM1, TM2). The analyses on aBMD for total body and total body less head were repeated controlling for variation in stature at baseline. Results Soccer players completed 63 ± 31 sessions (95 ± 47 h). Respective values for swimmers were 248 ± 28 sessions and 390 ± 56 h. In general, the analysis of aBMD as dependent variable evidenced significant effect of sport-associated variation (F = 5.254, p

IntroductionThere has been an abundance of dietary analysis research conducted on adult male soccer players, while studies on youth players are lacking. Furthermore, the daily distribution of energy and macronutrient intake throughout the day has been reported to influence training adaptations, but this is often not considered in the literature. This study aims to quantify daily energy and macronutrient intake and assess their distribution over 5 days, and compare daily energy intakes and predicted daily energy expenditure in under-16 male soccer players.MethodsThe sample included 25 soccer participants aged 14.8–15.7 years. Five-day self-reported food diaries were used to record the food/drink consumption. Intake was analyzed for total daily energy, macronutrient intakes, and distribution among meals (breakfast, lunch, dinner, and snacks). Daily energy expenditure was predicted by resting energy expenditure and physical activity levels developed for youth sports participants.ResultsThe mean total energy intake was 1,928 ± 388 kcal∙day−1, whereas the estimated daily energy expenditure was 3,568 kcal∙day−1. Relative daily protein intakes were lower at breakfast, morning snack, afternoon snack, and night snack compared to lunch and dinner.DiscussionYouth soccer players do not appear to meet energy requirements and daily CHO guidelines. Fluctuations in protein intake throughout the day were noted and may influence training adaptations (i.e., muscle protein synthesis and recovery).

X-ray free electron lasers deliver photon pulses that are bright enough to observe diffraction from extremely small crystals at a time scale that outruns their destruction. As crystals are continuously replaced, this technique is termed serial femtosecond crystallography (SFX). Due to its high pulse repetition rate, the European XFEL enables the collection of rich and extensive data sets, which are suited to study various scientific problems, including ultra-fast processes. The enormous data rate, data complexity, and the nature of the pixelized multimodular area detectors at the European XFEL pose severe challenges to users. To streamline the analysis of the SFX data, we developed the semiautomated pipeline EXtra-Xwiz around the established CrystFEL program suite, thereby processing diffraction patterns on detector frames into structure factors. Here we present EXtra-Xwiz, and we introduce its architecture and use by means of a tutorial. Future plans for its development and expansion are also discussed.

Abstract Background End-stage Kidney Disease patients have a high mortality and hospitalization risk. The association of these outcomes with physical activity is described in the general population and in other chronic diseases. However, few studies examining this association have been completed in end-stage Kidney Disease patients, raising the need to systematically review the evidence on the association of physical activity with mortality and hospitalization in this population. Methods Electronic databases (EBSCO, Scopus and Web of Science) and hand search were performed until March 2020 for observational studies reporting the association of physical activity with mortality or hospitalization in adult end-stage Kidney Disease patients on renal replacement therapy (hemodialysis, peritoneal dialysis and kidney transplant). Methodological quality of the included studies was assessed using the Quality in Prognosis Studies tool. The review protocol was registered in PROSPERO (CRD42020155591). Results Eleven studies were included: six in hemodialysis, three in kidney transplant, and two in hemodialysis and peritoneal dialysis patients. Physical activity was self-reported, except in one study that used accelerometers. All-cause mortality was addressed in all studies and cardiovascular mortality in three studies. Nine studies reported a significant reduction in all-cause mortality with increased levels of physical activity. Evidence of a dose-response relationship was found. For cardiovascular mortality, a significant reduction was observed in two of the three studies. Only one study investigated the association of physical activity with hospitalization. Conclusions Higher physical activity was associated with reduced mortality in end-stage Kidney Disease patients. Future studies using objective physical activity measures could strengthen these findings. The association of physical activity with hospitalization should be explored in future investigations.

Ribeiro, N, Martinho, DV, Pereira, JR, Rebelo, A, Monasterio, X, Gonzalo-Skok, O, Valente-dos-Santos, J, and Tavares, F. Injury risk in elite young male soccer players: a review on the impact of growth, maturation, and workload. J Strength Cond Res 38(10): 1834–1848, 2024—The long-term development of young male soccer players involves a prolonged period of significant adjustments, highlighting the importance of studying the complex interaction between dynamic variables, including workload, and inherent elements like growth and maturity. This analysis examines the intricate connections involving the development, maturity, workload, and susceptibility to injuries among adolescent male soccer players. Significantly, these connections become prominent at the peak height velocity (PHV) period, a crucial moment in maturation. Growth rates vary among individuals, and higher rates have been associated with an increased risk of injury in young soccer players, particularly during periods of rapid growth. Identifying possible risk factors and understanding the complex connections between them is crucial to developing specific methods for reducing the risk of injury. Sharing this valuable information with essential stakeholders is crucial for guaranteeing young athletes' comprehensive growth and maturation process. Furthermore, this review emphasizes the immediate need for long-term studies and thorough injury analyses to comprehend better the dynamic interactions that influence injury patterns in young male soccer players. This review will allow practitioners to better understand the main modifiable and nonmodifiable risk factors for injury and provide essential information focusing on practical strategies, facilitating more informed decision making by all stakeholders. The review aims to clarify these complexities and offer crucial insights that can assist in designing and implementing efficient strategies to reduce the risk of injury, specifically for the challenges faced during PHV and within the broader framework of long-term athletic development in young soccer. [ABSTRACT FROM AUTHOR]

Abstract Background Skeletal age (SA) is considered the best method of assessing biological maturation. The aim of this study was to determine intra-observer (reproducibility) and inter-observer agreement of SA values obtained via the Greulich-Pyle (GP) method. In addition, the variation in calculated SAs by alternative GP protocols was examined. Methods The sample was composed of 100 Portuguese female soccer players aged 12.0–16.7 years. SAs were determined using the GP method by two observers (OB1: experience 2000 exams using several methods). The radiographs were examined using alternative GP protocols: (wholeGP) the plate was matched to the atlas as an overall approach; (30-boneGP) bone-by-bone inspections of 30-bones; (GPpmb) bone-by-bone inspections of the pre-mature bones only. For the 30-boneGP and GPpmb approaches, SA was calculated via the mean (M) and the median (Md). Results Reproducibility ranged 82–100% and 88–100% for OB1 and OB2, respectively. Inter-observer agreement (100 participants multiplied by 30 bones) was 92.1%. For specific bones, agreement rates less than 90% were found for scaphoid (81%), medial phalange V (83%), trapezium (84%) and metacarpal V (87%). Differences in wholeGP SAs obtained by the two observers were moderate (d-cohen was 0.79). Mean differences between observers when using bone-by bone SAs were trivial (30-boneGP: d-cohen less than 0.05; GPpmb: d-cohen less than 0.10). The impact of using the mean or the median was negligible, particularly when analyses did not include bones scored as mature. Conclusion The GP appeared to be a reasonably reproducible method to assess SA and inter-observer agreement was acceptable. There is evidence to support a recommendation of only scoring pre-mature bones during later adolescence. Further research is required to examine whether these findings are consistent in younger girls and in boys.

Abstract Background Chronic Kidney Disease (CKD) patients frequently develop life-impairing bone mineral disorders. Despite the reported impact of exercise on bone health, systematic reviews of the evidence are lacking. This review examines the association of both physical activity (PA) and the effects of different exercise interventions with bone outcomes in CKD. Methods English-language publications in EBSCO, Web of Science and Scopus were searched up to May 2019, from which observational and experimental studies examining the relation between PA and the effect of regular exercise on bone-imaging or -outcomes in CKD stage 3–5 adults were included. All data were extracted and recorded using a spreadsheet by two review authors. The evidence quality was rated using the Cochrane risk of bias tool and a modified Newcastle-Ottawa scale. Results Six observational (4 cross-sectional, 2 longitudinal) and seven experimental (2 aerobic-, 5 resistance-exercise trials) studies were included, with an overall sample size of 367 and 215 patients, respectively. Judged risk of bias was low and unclear in most observational and experimental studies, respectively. PA was positively associated with bone mineral density at lumbar spine, femoral neck and total body, but not with bone biomarkers. Resistance exercise seems to improve bone mass at femoral neck and proximal femur, with improved bone formation and inhibited bone resorption observed, despite the inconsistency of results amongst different studies. Conclusions There is partial evidence supporting (i) a positive relation of PA and bone outcomes, and (ii) positive effects of resistance exercise on bone health in CKD. Prospective population studies and long-term RCT trials exploring different exercise modalities measuring bone-related parameters as endpoint are currently lacking.

Abstract Background The aim of the study was to examine the contribution of chronological age (CA), skeletal maturation, training experience and concurrent body size descriptors, to inter-individual variance in left ventricular mass (LVM) among female adolescent soccer players. Methods The sample included 228 female soccer players 11.8–17.1 years. Training experience defined as years of participation in competitive soccer (range 2–9 years), was obtained by interview. Stature, body mass and skinfolds (triceps, medial calf) were measured. Fat mass was estimated; Fat-free mass was derived. LVM was assessed by echocardiography. Skeletal maturity status was as the difference of skeletal age (SA, Fels method) minus CA. Results Fat-free mass was the most prominent single predictor of LVM (R2 = 36.6%). It was associated with an allometric coefficient close to linearity (k = 0.924, 95%CI: 0.737 to 1.112). A significant multiplicative allometric model including body mass, fat-free mass, CA, training experience and skeletal maturity status was also obtained (R = 0.684; R2 = 46.2%). Conclusion Stature has limitations as a valid size descriptor of LVM. Body mass, fat-free mass, training experience, CA, body mass and skeletal maturity status were relevant factors contributing to inter-individual variability in LVM.

Purpose: Most high-intensity bouts of exercise in volleyball consist of jumping activities, which are responsible for inducing muscle damage, high levels of fatigue, and muscle soreness. Therefore, the aim of the current study was to quantify and analyze the training loads, neuromuscular fatigue, and perceptual well-being of a 5-week in-season mesocycle carried out by a professional male volleyball team. Methods: Fifteen volleyball players (age 28.51 [5.39] y; height 193.19 [9.87] cm; body mass 88.46 [13.18] kg) participated in this study. Internal training load assessed through the rating of perceived exertion, external training load (ETL; evaluated using an inertial motion unit), countermovement jump (CMJ) height and peak power, and wellness questionnaire responses were obtained from all athletes. Results: Results indicated a progressive decrease of the internal training load during the week and by the undulatory pattern of the ETL during the microcycles. Moreover, training monotony increased across the microcycles and was negatively associated with CMJ peak power (r = −.681, P <.05). Finally, sleep quality (ρ = −.747, P <.01) and fatigue (ρ = −.789, P <.01) were negatively associated with weekly ETL. Conclusions: This study indicated that sleep quality and fatigue were negatively associated with weekly ETL. Therefore, decreases in weekly ETL might be needed to improve sleep quality and decrease fatigue in professional volleyball players. Plus, higher values of training monotony were associated with lower values of CMJ peak power. Consequently, avoiding training monotony might be important to improve jumping performance in professional volleyball athletes. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine intra- and inter-observer agreement for the three skeletal ages derived from the TW2 method among male pubertal soccer players. The sample included 142 participants aged 11.0-15.3 years. Films of the left hand-wrist were evaluated twice by each of two observers. Twenty bones were rated and three scoring systems used to determine SA adopting the TW2 version: 20-bone, CARPAL and RUS. Overall agreement rates were 95.1% and 93.8% for, respectively, Observer A and Observer B. Although, agreement rates between observers differed for 13 bones (5 carpals, metacarpal-I, metacarpal-III, metacarpal-V, proximal phalanges-I, III and V, distal phalanx-III), intra-class correlationa were as follows: 0.990 (20-bone), 0.969 (CARPAL), and 0.988 (RUS). For the three SA protocols, BIAS was negligible: 0.02 years (20-bone), 0.04 years (CARPAL), and 0.03 years (RUS). Observer-associated error was not significant for 20-bone SA (TEM = 0.25 years, %CV = 1.86) neither RUS SA (TEM = 0.31 years, %CV = 2.22). Although the mean difference for CARPAL SAs between observers (observer A: 12.48±1.18 years; observer B: 12.29±1.24 years; t = 4.662, p

Sports participation is one of the most popular forms of physical activity among youngsters. This study aimed to examine the changes in the estimated body composition, strength, and flexibility of adolescent boys after 12 months of soccer training compared with those of age-matched controls with non-sports participation. We assessed 137 boys (62 soccer players and 75 controls) at baseline (TM1) and 12 months later (TM2). The differences in estimated body composition, strength, and flexibility were investigated using a repeated measure analysis of variance. The analysis revealed a significant main effect of soccer training on fat mass (F = 73.503, p ≤ 0.01, η2 = 0.59) and fat-free mass (F = 39.123, p ≤ 0.01, η2 = 0.48). Over time, the soccer group decreased their fat mass and increased their fat-free mass, while the opposite results were observed for the controls. Among physical fitness tests, a substantial effect of soccer training was evidenced for the sit-up performance (F = 16.224, p ≤ 0.01, η2 = 0.32). Regarding the time factor, significant effects were noted for height and handgrip strength. No significant differences were detected for flexibility. Overall, the benefits of soccer training were exhibited by the larger improvements in fat mass, fat-free mass, sit-ups, and handgrip strength performance, underlining the important role of soccer participation during adolescence.

The aims of this study were twofold: (i) to examine differences in physical activity (PA) variables regarding the length of Physical Education (PE) lessons (45 vs. 90 min) and teaching methodology (Teaching Games for Understanding (TGfU) or hybrid TGfU-sports education (SE)); and (ii) to estimate the percentage of time spent in moderate-to-vigorous (MV) PA assessed via an accelerometer based on total step count, BMI, age, and sex, considering the pedagogical models and the class length. This study was carried out in three classes of invasion games in PE. Two classes were taught based on TGfU (44 students, 18 males, 12.6 ± 0.55), and one was taught based on a hybrid TGfU-SE (17 students, 9 males, 13.7 ± 0.90). The same students were assessed twice, first in a 45 min class and then in a 90 min class. The students’ MVPA was assessed using the Actigraph GT3X Activity Monitor. The results revealed significant differences in PA intensity regarding the length of the PE lesson (45 vs. 90 min) and the teaching methodology. The 45 min classes using TGfU were more intense and had less sedentary time than the 90 min classes. When using a hybrid TGfU-SE, the 90 min classes had higher intensities than the 45 min classes. Generally, when comparing the two types of pedagogical intervention, the TGfU model provided more active lessons and less sedentary time in class than a hybrid TGfU-SE. The TGfU model is more profitable for increasing MVPA in class. Due to the issues related to the organization and management of sports practice in class, several recommendations for maximizing MVPA in a hybrid TGfU-SE class must be considered.

Background: Research on composition and physical fitness is lacking in school-aged children from Madeira. This study aimed to examine the frequencies of overweight and obese participants and, in addition, to compare the fitness levels of Madeira youth with reference data. Methods: The sample comprised 521 participants (n = 258 boys; n = 263 girls) aged 10.0–18.9 years old. Methods: Height and weight were measured. Body mass index (BMI) was calculated, and percent fat was derived from skinfolds. Tests detailed on FITESCOLA battery were performed. BMI was plotted against U.S. reference data and physical assessment contrasted with the cut-off points of FITESCOLA protocol and corresponding data developed in Portuguese youth. Results: The percentages of overweight and obesity were 15% (overweight) and 14% (obesity) for boys and 16% (overweight) and 6% (obesity) for girls. The median values of fat mass percentage were closely related to the cut-off standards; however, substantial variation was noted. Boys and girls tended to be below the recommendations of cardiorespiratory fitness. Conclusions: Sport participation should be promoted in Madeira to attain acceptable values of body composition and physical fitness levels.