People With Patellofemoral Pain Have Bilateral Deficits in Physical Performance Regardless of Pain Laterality.

CONTEXT: People with patellofemoral pain (PFP) may have lower performance during the forward step-down and single-leg hop with their painful (unilateral complaints) or most painful (bilateral complaints) limb when compared to pain-free controls. Yet, no study has investigated the appropriateness of using the pain-free/less painful limb as a reference standard in clinical practice or whether deficits might be present depending on the laterality of pain. OBJECTIVE: To compare performance scores and proportion of side-to-side limb symmetry during the forward step-down and single-leg hop tests among people with unilateral and bilateral PFP, and pain-free controls. DESIGN: Cross-sectional study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Fifty-two young adults (18-35 years old) with unilateral PFP, 72 with bilateral PFP, and 76 controls. MAIN OUTCOME MEASURE(S): Group-by-limb interactions on the performance during the step- down (repetitions) and hop test (distance [cm] normalized by the limb length) were investigated using a repeated-measures analysis of covariance controlling for sex. Pairwise comparisons were interpreted using effect sizes. A Chi-square test was used to compare the proportion of symmetry/asymmetry (cutoff point of ≥ 90% for symmetries indices) across groups and tests. RESULTS: Main effects for groups (small-to-medium effects) but not limbs indicated lower performance of both limbs of individuals with unilateral and bilateral PFP compared to controls during forward step-downs and single-leg hop tests. No significant differences for the proportion of symmetry/asymmetry were identified across groups (p ≥ 0.05), which further suggests an impaired physical performance of the contralateral limb. CONCLUSIONS: Our results indicate bilateral deficits in the physical performance of people with unilateral and bilateral PFP when compared to pain-free controls during the forward step-down and single-leg hop tests. Limb symmetries indices greater than 90% should be interpreted with caution, as they may overstate the physical performance by not assuming bilateral deficits.

Evolution of attack in handball when playing 7 vs. 6 with empty goal between 2020 and 2023: coaches' perception vs. observational results.

Introduction: Recently, several studies on the 7 vs. 6 "empty goal" (EG) in handball have produced different and even contradictory results. The aim of the present study was to investigate the behavior of teams and players in the 7 vs. 6 EG attack in the European (Euro) and World Championships (WCh) between 2020 and 2023 and characterize the coaches' perceptions. Methods: A mixed-methods approach was used, consisting of the following: (i) an observational methodology and instrument developed and validated to collect observational data on player and team behavior; and (ii) a developed and validated questionnaire to coaches on their perceptions of the 7 vs. 6 game. Observational data were collected during the Euro 2020 and 2022 games (n = 62) and the WCh 2021 and 2023 games (n = 70). A total of 132 games and 391 situations of 7 vs. 6 attacking sequences were observed. In total, 156 coaches participated (146 men), with a mean age 42.33 ± 11.87 years, 19 nationalities, and with 12.77 ± 9.45 years of experience. Results and discussion: The choice of 7 vs. 6 offensive play was mostly made in the second half (>73%). The effectiveness of 7 vs. 6 offensive sequences was higher in the top six teams than in the team's ranked 7th to 12th (Euro 2020 51.6%-50.0%; WCh 2021 52.0%-50.0%; Euro 2022 53.1%-41.7%; WCh 2023 50.0%-43.8%). Some patterns of association were found (p < 0.05 and with values >±1.96): (i) scoring a goal with a breakthrough shot was significantly associated with the effectiveness of the 7 vs. 6 attack (Euro 2020 2.61; WCh 2021 2.87; Euro 2022 2.68; WCh 2023 2.32); (ii) teams in the top six significantly used 7 vs. 6 when they were winning (Euro 2020 2.17; WCh 2021 3.52; Euro 2022 5.88; WCh 2023 2.54); and (iii) teams in the bottom six used it when they were losing by at least four goals (Euro 2020 7.56; Euro 2022 6.64; WCh 2023 4.37) or when they were winning by four goals or more (WCh 2021 2.58). Coaches that agree with the possibility of playing 7 vs. 6 (74.4%), rarely or never do so (55.6%) because it brings little or no advantage (52.6%). The results of the analysis confirmed the perception of the coaches, the low use of 7 vs. 6, the low advantage associated with it, and the influence of the result and the moment of the game on its use.

There is more to the knee joint than just the quadriceps: A systematic review with meta-analysis and evidence gap map of hamstring strength, flexibility, and morphology in individuals with gradual-onset knee disorders.

BACKGROUND: Impairments in hamstring strength, flexibility, and morphology have been associated with altered knee biomechanics, pain, and function. Determining the presence of these impairments in individuals with gradual-onset knee disorders is important and may indicate targets for assessment and rehabilitation. This systematic review aimed to synthesize the literature to determine the presence of impairments in hamstring strength, flexibility, and morphology in individuals with gradual-onset knee disorders. METHODS: Five databases ((MEDLINE, Embase, CINAHL, SPORTDiscus, and Web of Science) were searched from inception to September 2022. Only studies comparing hamstring outcomes (e.g., strength, flexibility, and/or morphology) between individuals with gradual-onset knee disorders and their unaffected limbs or pain-free controls were included. Meta-analyses for each knee disorder were performed. Outcome-level certainty was assessed using the Grading of Recommendations Assessment, Development, and Evaluation, and evidence gap maps were created. RESULTS: Seventy-nine studies across 4 different gradual-onset knee disorders (i.e., knee osteoarthritis (OA), patellofemoral pain (PFP), chondromalacia patellae, and patellar tendinopathy) were included. Individuals with knee OA presented with reduced hamstring strength compared to pain-free controls during isometric (standard mean difference (SMD) = -0.76, 95% confidence interval (95%CI) : -1.32 to -0.21) and concentric contractions (SMD = -0.97, 95%CI : -1.49 to -0.45). Individuals with PFP presented with reduced hamstring strength compared to pain-free controls during isometric (SMD = -0.48, 95%CI : -0.82 to -0.14), concentric (SMD = -1.07, 95%CI : -2.08 to -0.06), and eccentric contractions (SMD = -0.59, 95%CI : -0.97 to -0.21). No differences were observed in individuals with patellar tendinopathy. Individuals with PFP presented with reduced hamstring flexibility when compared to pain-free controls (SMD = -0.76, 95%CI : -1.15 to -0.36). Evidence gap maps identified insufficient evidence for chondromalacia patellae and hamstring morphology across all gradual-onset knee disorders. CONCLUSION: Our findings suggest that assessing and targeting impairments in hamstring strength and flexibility during rehabilitation may be recommended for individuals with knee OA or PFP.

Physical Fitness and Body Composition of Youth Referees in Invasion Games.

BACKGROUND: Referees' activity can be an instrument for training students with an impact on health-related physical fitness (PF). This study aimed to investigate the differences in PF and body composition between students without sports practice (G1), students with regular sports practice (G2), and student referees in team invasion games (G3). METHODS: This study followed a cross-sectional design. The sample comprised 45 male students between 14 and 20 years old (16.40 ± 1.85). Three groups (G1, G2, and G3) of 15 participants each were selected. PF was assessed by a 20 m shuttle run, change-of-direction test, and standing long jump. Body composition was determined by body mass index (BMI; kg/m2) and the percentage of body fat (%BF) predicted by skinfold. RESULTS: After controlling for age as a covariate, the block of variables used to characterize PF was statistically different between sports practice groups favoring student referees (p < 0.001; r = 0.26). Similar results were achieved for body composition (i.e., BMI and %BF) (p < 0.001; r = 0.17). However, when the dependent variables were evaluated separately, there were only differences between groups in %BF (p = 0.007; r = 0.21). Student referees had statistically significantly lower values than the remaining groups. CONCLUSION: Refereeing activity benefits PF related to health and performance, including body composition. This study confirms the benefits related to health in children and adolescents who are involved in refereeing activity.

Group- and sex-related differences in psychological and pain processing factors in people with and without patellofemoral pain: correlation with clinical outcomes.

BACKGROUND: People with patellofemoral pain (PFP) exhibit impaired psychological and pain processing factors (i.e., kinesiophobia, pain catastrophizing and pressure pain thresholds [PPTs]). However, it remains unclear whether these factors have different presentations in women and men with PFP, as well as whether their correlation with clinical outcomes differ according to sex. The aims of this study were to: (1) compare psychological and pain processing factors between women and men with and without patellofemoral pain (PFP); (2) investigate their correlation with clinical outcomes in people with PFP. METHODS: This cross-sectional study included 65 women and 38 men with PFP, 30 women and 30 men without PFP. The psychological and pain processing factors were assessed with the Tampa Scale of Kinesiophobia, Pain Catastrophizing Scale, and PPTs of shoulder and patella measured with an algometer. Clinical outcomes assessed were self-reported pain (Visual Analogue Scale), function (Anterior Knee Pain Scale), physical activity level (Baecke's Questionnaire), and physical performance (Single Leg Hop Test). Generalized linear models (GzLM) and effect sizes [Cohen's d] were calculated for group comparisons and Spearman's correlation coefficients were calculated to investigate correlations between outcomes. RESULTS: Women and men with PFP had higher kinesiophobia (d = .82, p = .001; d = .80, p = .003), pain catastrophizing (d = .84, p < .001; d = 1.27, p < .001), and lower patella PPTs (d = -.85, p = .001; d = -.60, p = .033) than women and men without PFP, respectively. Women with PFP had lower shoulder and patella PPTs than men with PFP (d = -1.24, p < .001; d = -.95, p < .001), but there were no sex differences in those with PFP for psychological factors (p > .05). For women with PFP, kinesiophobia and pain catastrophizing had moderate positive correlations with self-reported pain (rho = .44 and .53, p < .001) and moderate negative correlations with function (rho = -.55 and -.58, p < .001), respectively. For men with PFP, only pain catastrophizing had moderate positive correlations with self-reported pain (rho = .42, p = .009) and moderate negative correlations with function (rho = -.43, p = .007). CONCLUSIONS: Psychological and pain processing factors differ between people with and without PFP and between sexes, respectively. Also, correlations between psychological and pain processing factors with clinical outcomes differ among women and men with PFP. These findings should be considered when assessing and managing people with PFP.

Changes in Estimated Body Composition and Physical Fitness of Adolescent Boys after One Year of Soccer Training.

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.

School-Based Family-Oriented Health Interventions to Promote Physical Activity in Children and Adolescents: A Systematic Review.

OBJECTIVE: This study aimed to systematically review and analyse intervention programs in a school context centred on the family, focused on increasing youths' physical activity. DATA SOURCE: The research was carried out in the PubMed, Scopus and Web of Science databases. STUDY INCLUSION CRITERIA: Studies were included if participants were children or adolescents, focusing on school-based intervention studies with parental involvement and physical activity, sedentary behaviour or physical fitness outcomes. DATA EXTRACTION: The search was performed according to the PRISMA protocol. A total of 416 articles were identified. After being considered for eligibility and duplicates, 22 studies were identified as relevant for inclusion. DATA SYNTHESIS: Sample and intervention characteristics, objective, the role of the family, outcomes measures, main findings regarding the outcomes and risk of bias. RESULTS: Ten studies reported improvements in physical activity, 6 in sedentary behaviour and 9 in the components of physical fitness and/or skills related to healthy behaviours and lifestyles. Most of the interventions adopted a multidisciplinary and multi-component approach. CONCLUSIONS: Most interventions employed a school's multidisciplinary/multi-component approach to promoting physical activity, nutrition, and general education for healthier lifestyle behaviours. The impact of school-based interventions involving families on youth's physical activity levels is still a relatively emerging theme. Further research is needed given the diversity of the intervention's characteristics and the disparity in the results' efficacy.

Body composition variations between injured and non-injured professional soccer players.

Professional soccer is characterized by its physical demands, making players' exposure to high injury risks a growing problem. It is crucial to study the factors associated with injuries in professional soccer. This study aimed to investigate the relationship between age, body composition, and others variables related with the injury profile of professional soccer players of a specific Portuguese team. Also, it analyzed the impact of the injury profile on soccer's variations in body fat (BF%), skeletal muscle mass (SMM) and total body water (TBW) throughout the season. The sample comprised 31 male professional soccer players competing in the First Portuguese Soccer League. Older players had a higher prevalence of muscular injuries. Midfielders and forwards showed the highest number of muscular injuries during the season being quadriceps the most affected zone. Considering players' BF% [Wilks' Lambda = 0.42, F (7, 23) = 4.61, p = 0.002, r = 0.58], SMM [Wilks' Lambda = 0.59, F (6, 23) = 2.70, p = 0.039, r = 0.41] and TBW [Wilks' Lambda = 0.54, F (7, 23) = 2.80, p = 0.029, r = 0.46] there was a substantial main effect for the assessments performed throughout the season and the injury status. Age assumes relevance in explaining the injury profile. The impact of the injury profile on soccer's variations in BF%, SMM and TBW throughout the season must be analyzed considering the clinical relevance.

The Impact of Different Pedagogical Models on Moderate-to-Vigorous Physical Activity in Physical Education Classes.

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.

Body Composition and Physical Fitness in Madeira Youth.

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.

Association between the Duration of the Active Commuting to and from School, and Cognitive Performance in Urban Portuguese Adolescents.

This study aimed to analyze the differences between active commuting to school (ACS) and non-ACS in cognitive performance (CP), and the association of ACS duration with CP. This cross-sectional study included 370 adolescents (males n = 170), with a mean age of 15.28 ± 2.25 years. CP was assessed through an interview, and ACS, extracurricular physical activity, and socioeconomic status was assessed by self-report. Body composition was assessed using the FitnessGram test battery. One in two adolescents did ACS (51.6%). ACS was associated with boys (53.9%), younger adolescents (14.91 ± 2.15 vs. 15.69 ± 2.29), those having school social support (55.0%), and those doing one or more extracurricular physical activities (53.6%), compared to non-ACS participants (p < 0.05). The analysis of covariance, after controlling for age, sex, school social support, and participation in extracurricular physical activity, showed an effect of ACS on the total cognitive score (F(2,362) = 3.304, p < 0.05). The CP was higher in adolescents with more than 30 min of ACS than non-ACS (p < 0.05). The influence of ACS duration can be seen in the dimensions of inductive reasoning (ß = 0.134, t = 2.587, p < 0.05) and working memory (ß = 0.130, t = 2.525, p < 0.05). The role of ACS for CP, as well as guidelines for future research, are discussed.

Playing 7 vs. 6 with an empty goal: Is it really an option for coaches? A comparative analysis between Portugal and the other teams during the Men's European Handball Championship 2020.

The dynamic of changes in the rules in team games materialize from research and debate between experts and coaches before being implemented by the International Federations. In Handball, the last changes occurred in 2016, and one of them was to substitute the goalkeeper with an additional field player allowing teams to play "empty goal" while using the additional field player. This study aimed to analyze and characterize the use of the 7 vs. 6 strategical-tactical option for the attack in the 2020 Men's European Championship. We also analyzed whether the game time and partial score influenced the use of 7 vs. 6 and its efficiency. Observational methodology and a mixed ad hoc instrument combining field format and category systems validated by experts were used. Data were taken from 28 matches involving teams in the first 12 positions in the 2020 Men's European Championship. The total number of offensive sequences in an organized attack method in 7 vs. 6 with an empty goal (n = 123) were analyzed. Sequential analysis techniques with lags, prospective and retrospective, and polar coordinate analysis were used. The results showed that (a) these solutions had poor efficiency, except for the Portuguese National Team; (b) teams using the 7 vs. 6 tactic option had no negative consequences or increased risk with the opponent response; (c) partial score influenced the decision to use 7 vs. 6 strategic option, and (d) game time was associated with 7 vs. 6 play options and detected patterns.

Sports Injuries of a Portuguese Professional Football Team during Three Consecutive Seasons.

Professional football players are exposed to high injury risk due to the physical demands of this sport. The purpose of this study was to characterize the injuries of a professional football team in the First Portuguese League over three consecutive sports seasons. Seventy-one male professional football players in the First Portuguese Football League were followed throughout the sports seasons of 2019/2020, 2020/2021, and 2021/2022. In total, 84 injuries were recorded. Each player missed an average of 16.6 days per injury. Lower limbs were massively affected by injuries across all three seasons, mainly with muscular injuries in the quadriceps and hamstrings and sprains in the tibiotarsal structure. Overall, the injury incidence was considerably higher in matches than in training. The two times of the season that proved most conducive to injuries were the months of July and January. Our results emphasize the importance of monitoring sports performance, including injury occurrence, and assisting in identifying risk factors in professional football. Designing individualized training programs and optimizing prevention and recovery protocols are crucial for maximizing this global process.

Predictive Modeling of Injury Risk Based on Body Composition and Selected Physical Fitness Tests for Elite Football Players.

Injuries are one of the most significant issues for elite football players. Consequently, elite football clubs have been consistently interested in having practical, interpretable, and usable models as decision-making support for technical staff. This study aimed to analyze predictive modeling of injury risk based on body composition variables and selected physical fitness tests for elite football players through a sports season. The sample comprised 36 male elite football players who competed in the First Portuguese Soccer League in the 2020/2021 season. The models were calculated based on 22 independent variables that included players' information, body composition, physical fitness, and one dependent variable, the number of injuries per season. In the net elastic analysis, the variables that best predicted injury risk were sectorial positions (defensive and forward), body height, sit-and-reach performance, 1 min number of push-ups, handgrip strength, and 35 m linear speed. This study considered multiple-input single-output regression-type models. The analysis showed that the most accurate model presented in this work generates an error of RMSE = 0.591. Our approach opens a novel perspective for injury prevention and training monitorization. Nevertheless, more studies are needed to identify risk factors associated with injury prediction in elite soccer players, as this is a rising topic that requires several analyses performed in different contexts.

Colistin conditioning surfaces combined with antimicrobial treatment to prevent ventilator-associated infections.

Biofilm formation on endotracheal tubes (ETT) is an important factor in the development of ventilator-associated pneumonia (VAP). This work aimed to investigate the effectiveness of colistin (COL) against the early stages of biofilm formation by Pseudomonas aeruginosa. Two strategies were used: pre-conditioning the adhesion surfaces with COL before biofilm formation and growing biofilms in its presence. The combined effect of treating P. aeruginosa 24-hours old biofilms with Ciprofloxacin (CIP) or colistin (COL) on clean and COL-conditioned surfaces was also assessed. Random deposition of COL residues altered the physico-chemical properties of the adhesion surfaces and impaired biofilm formation. Moreover, as a consequence of the reduced amount of biofilms attached to COL conditioned surfaces, adhered cells became more exposed to the subsequent action of CIP or COL, suggesting a combined outcome of prophylactic and therapeutic COL-based strategies. Results highlighted the promising use of COL to prevent the establishment of biofilms on ETT.

Pathways for adapting tourism to climate change in an urban destination - Evidences based on thermal conditions for the Porto Metropolitan Area (Portugal).

The narrative of sustainable tourism transition in a context of adaptation to climate change is very relevant internationally. The availability and sharing of knowledge and information is a basic requirement for the successful planning of the tourism sector regarding this phenomenon. Planning adaptation in the urban tourism sector is widely regarded as a collectively-based process. However, collaborative planning is far from being the standard. This study reports the results of a Modified Delphi Approach (MDA) among experts about the future of urban tourism in a context of adaptation to climate change in Porto Metropolitan Area (Portugal), considering the outdoor thermal conditions perspective. Using an expert panel, the study gathered their opinions to analyze the degrees of responsibility of the main sectorial entities at different territorial levels, the conditions of action in the transformation agenda and the measures to be implemented in the adaptation and mitigation process - according to priority and time horizon. Two rounds were carried out to apply the methodology between January and April 2021. The first questionnaire had the participation of 47 professionals. 34 out of the 47 professionals of the 1st round participated in the second questionnaire. The evidence from different stakeholders demonstrates that there is an ambiguous process of understanding the problem, information needs, and a weak interaction between actors - resources - tasks. The effectiveness and efficiency of collaborative planning and outlined goals by 2050 for adaptation of urban tourism sector to climate change can be hampered. Experts consider the creation of structural (tangible) measures to be fundamental. Among other results, it was found that most participants consider that the intervention is dependent on the guidelines issued by the government and municipal councils when it comes to defining a proposal for adapting the urban tourism sector to climate change. Despite this, the options for more sustainable practices must be based on three axes: (i) solutions based on the energy sector in the hotel industry (e.g., energy certification, prioritization of the use of renewable energy); (ii) improvement and expansion of green infrastructure for tourist enjoyment [e.g., creation of green areas (small additional pockets), namely in the center of Porto; and pedestrianization of central areas of the city] and (iii) network participation through the collaboration of various stakeholders with relevance in tourism and urban planning.

The Relationship between Different Large-Sided Games and Official Matches on Professional Football Players' Locomotor Intensity.

Large-sided games (LSG) are commonly used in the training contexts for providing either technical/tactical or locomotor/physiological stimuli. Despite natural similarities with the official match, the locomotor profile seems to be different, which must be considered by the coaches to identify compensatory strategies for achieving the ideal dose of training. The aim of this study was two-fold: (1) to investigate the locomotor demands imposed by LSGs and the official matches; and (2) to compare the effect of different pitch sizes' LSG conditions in the locomotor demands. This study followed an observational design. Sixteen professional football players from the same team (26.3 ± 3.0 years old) were included. The study was conducted over four weeks. The same GK + 10 × 10 + GK play format with different pitch sizes (i.e., area per player ranging between 195 m2 to 291 m2) was analyzed. Three official matches were also collected in which the 10 most demanding minutes were considered for further comparisons. Only the same players who participated in matches were considered in comparison with the LSG. The data were obtained using a 10-Hz global positioning system technology. Total distance (TD) and mechanical work (MW) scores increased 20% and 23%, respectively, between the smallest and biggest pitch sizes (p < 0.001). There was a significant difference in locomotor intensity metrics between opponents from different positions on the table (p = 0.001). The biggest LSG (i.e., 291 m2 per player) was the only one that required similar levels of locomotor intensity as required in the official full match. The present study demonstrates that LSG pitch size variation requires different locomotor intensities. Bigger pitch sizes cause an increase in TD and MW. In addition, considering the position on the table, the level of opponents induces different TD covered. Finally, the largest LSG simulates the official match more accurately.

Speed and Agility Predictors among Adolescent Male Football Players.

This study aimed to examine the associations between lower-body explosive strength (squat jump-SJ, and countermovement jump-CMJ), speed (10- and 35-m linear sprints), and agility (t-test) capacities, after controlling for crucial predictors such as chronological age (CA) and body composition. The sample was composed of 164 adolescent male football players from under 19, under 17, and under 15 age groups. Body fat percentage (BF%) was significantly and positively related to body mass, speed, and agility. In contrast, BF% was a significant negative predictor of lower-body explosive strength. Sprint and t-test times were significantly and negatively correlated with lower-body explosive strength. After controlling for CA and body composition, SJ was the most significant predictor, accounting for 36 to 37% of the variance observed in the 35 m linear sprint and the t-test performance. Our main results suggest that lower-body explosive strength, particularly in the SJ, is a significant predictor of male adolescent male football players' speed and agility capacities. Conversely, detrimental relationships between BF% and these outcomes were observed. Sports agents should consider lower-body explosive strength development as part of the youth football training process, particularly to improve maximal sprint and change of direction times, which are crucial to game performance.

Model-guided development of an evolutionarily stable yeast chassis.

First-principle metabolic modelling holds potential for designing microbial chassis that are resilient against phenotype reversal due to adaptive mutations. Yet, the theory of model-based chassis design has rarely been put to rigorous experimental test. Here, we report the development of Saccharomyces cerevisiae chassis strains for dicarboxylic acid production using genome-scale metabolic modelling. The chassis strains, albeit geared for higher flux towards succinate, fumarate and malate, do not appreciably secrete these metabolites. As predicted by the model, introducing product-specific TCA cycle disruptions resulted in the secretion of the corresponding acid. Adaptive laboratory evolution further improved production of succinate and fumarate, demonstrating the evolutionary robustness of the engineered cells. In the case of malate, multi-omics analysis revealed a flux bypass at peroxisomal malate dehydrogenase that was missing in the yeast metabolic model. In all three cases, flux balance analysis integrating transcriptomics, proteomics and metabolomics data confirmed the flux re-routing predicted by the model. Taken together, our modelling and experimental results have implications for the computer-aided design of microbial cell factories.

Knee flexor strength, rate of torque development and flexibility in women and men with patellofemoral pain: Relationship with pain and the performance in the single leg bridge test.

OBJECTIVES: To investigate the relationship between: (1) knee flexor strength, rate of torque development (RTD), and flexibility with pain level; (2) knee flexor strength and RTD with the performance in the single leg bridge test (SLBT) in women and men with patellofemoral pain (PFP). DESIGN: Cross-sectional. SETTING: Laboratory-based study. PARTICIPANTS: 39 women and 36 men with PFP. MAIN OUTCOME MEASURES: Knee flexor strength, RTD, and flexibility; performance in the SLBT, current, and worst pain level. RESULTS: Moderate to strong significant negative relationships were identified between the current pain level with knee flexor strength (r = -0.57 to -0.34) and flexibility (r = -0.44 to -0.35); and between knee flexor strength and RTD with the performance in the SLBT (r = 0.34 to 0.57) in women and men with PFP. Knee flexor RTD was not related to any pain level and no significant relationships were identified between the worst pain level with knee flexor strength and flexibility in women and men with PFP. CONCLUSIONS: Our results support the potential value of assessing knee flexor strength and flexibility in women and men with PFP. The SLBT may be a useful tool to assess knee flexor muscle capacity in individuals with PFP in a clinical setting.