Impact of temperature on physical and cognitive performance in elite female football players during intermittent exercise.

There is limited research on female football players, especially related to their physical and cognitive performance under different climactic conditions. We analyzed the impact of a hot environmental temperature on physical performance and anticipation in elite female football players during a fatigue-inducing intermittent protocol. Elite female players (n = 21) performed the countermovement jump (CMJ) and responded to filmed sequences of offensive play under two distinct environmental temperatures (i.e., mild environment temperature- 20°C and 30% rh versus hot environment temperature- 38°C and 80% rh), interspersed by 1-week interval. Linear mixed models were used. CMJ performance declined following the intermittent protocol on both temperature conditions (p < 0.05). Moreover, there were significant main effects for protocol on CMJ speed (m/s) (p = 0.001; ηp 2 = 0.12), CMJ power (p = 0.002; ηp 2 = 0.11), and CMJ Heightmax (p = 0.002; ηp 2 = 0.12). After performing the intermittent protocol, exposure to a hot temperature caused a greater decline in anticipation accuracy (mild temperature = 64.41% vs. hot temperature = 53.44%; p < 0.001). Our study shows impaired performance in elite female football players following an intermittent protocol under hot compared with mild environmental conditions. We report decreased performance in both CMJ and anticipation performance under hotter conditions. The results reveal that exposure to hot temperatures had a negative effect on the accuracy of their anticipatory behaviors. We consider the implication of the work for research and training interventions.

What is the visual behaviour and attentional effort of football players in different positions during a real 11v11 game? A pilot study.

Background: Visual perception has been defined as the first step to a football player's decision-making process and it plays an important role in performance in sport. The skill of focussing to prioritize relevant cues has been also considered crucial in sport. This pilot study aims to explore the visual behaviour and attentional effort of three football players (mean age 19 ± 0 years old) in specific-role positions; Right-winger (RW), Centre-Midfielder (CM) and Left-Back (LB), in the five seconds before receiving the ball from their teammate. Methods: Twenty-two male football players performed an 11v11 game, where 24 game sequences (trials) from which 166 fixations were recorded and analysed via the Tobii Pro eye-movement registration glasses and software. The gaze behaviour dependent variables were the mean of fixation duration (FD), time to first fixation (TTF), both measured in milliseconds (ms), and the number of fixations (NF) on eight areas of interest (AOIs). AOIs include teammate with and without the ball, opponent without the ball, space around teammate with and without the ball, space around opponent without the ball, ball and undefined. The mean pupil diameter (PD) correlates to the attentional effort and was measured in millimetres (mm). Results: Descriptive statistics showed nonregular search rate data between the participants in FD, TTF, NF on the AOIs. Mean FD on the ball: (CM, 270 ms), (RW, 570 ms), (CM, 380 ms). They also presented differences in the mean PD during play; (CM: 2.90 mm ± 0.26), (RW: 2.74 mm ± 0.30), (LB 2.77mm ± 0.27). Conclusions: Albeit the sample size was small, the findings demonstrated a promising way to measure the on-field perceptual-cognitive abilities of football players according to their specific positions, since different playing roles revealed to present distinctive visual and attentional patterns. This could potentially assist in tailoring players 'visual and focus training.

The Effects of Massage Guns on Performance and Recovery: A Systematic Review.

The use of massage guns has become increasingly popular in recent years. Although their use is more and more common, both in a clinical and sports context, there is still little information to guide the practitioners. This systematic review aimed to determine the effects of massage guns in healthy and unhealthy populations as pre- and post-activity or part of a treatment. Data sources used were PubMed, PEDro, Scopus, SPORTDiscus, Web of Science and Google Scholar, and the study eligibility criteria were based on "healthy and unhealthy individuals", "massage guns", "pre-activity, post-activity or part of a treatment" and "randomized and non-randomized studies" (P.I.C.O.S.). Initially, 281 records were screened, but only 11 could be included. Ten had a moderate risk of bias and one a high risk of bias. Massage guns could be effective in improving iliopsoas, hamstrings, triceps suralis and the posterior chain muscles' flexibility. In strength, balance, acceleration, agility and explosive activities, it either did not have improvements or it even showed a decrease in performance. In the recovery-related outcomes, massage guns were shown to be cost-effective instruments for stiffness reduction, range of motion and strength improvements after a fatigue protocol. No differences were found in contraction time, rating of perceived exertion or lactate concentration. Massage guns can help to improve short-term range of motion, flexibility and recovery-related outcomes, but their use in strength, balance, acceleration, agility and explosive activities is not recommended.

Relationship between Bioelectrical Impedance Phase Angle and Upper and Lower Limb Muscle Strength in Athletes from Several Sports: A Systematic Review with Meta-Analysis.

The phase angle (PhA) of bioelectrical impedance is determined by primary factors such as age, body mass index and sex. The researchers' interest in applying PhA to better understand the skeletal muscle property and ability has grown, but the results are still heterogeneous. This systematic review with a meta-analysis aimed to examine the existence of the relationship between PhA and muscle strength in athletes. The data sources used were PubMed, Scielo, Scopus, SPORTDiscus, and Web of Science and the study eligibility criteria were based on the PECOS. The searches identified 846 titles. From those, thirteen articles were eligible. Results showed a positive correlation between PhA and lower limb strength (r = 0.691 [95% CI 0.249 to 0.895]; p = 0.005), while no meta-analysis was possible for the relationships between PhA and lower limb strength. Furthermore, GRADE shows very low certainty of evidence. In conclusion, it was found that most studies showed a positive correlation between PhA and vertical jump or handgrip strength. The meta-analysis showed the relationship between PhA and vertical jump, however, little is known for the upper limbs as was not possible to perform a meta-analysis, and for the lower limbs we performed it with four studies and only with vertical jump.

The Effects of Physiological Demands on Visual Search Behaviours During 2 vs. 1 + GK Game Situations in Football: An in-situ Approach.

We examined the effect of physiological workload on gaze behaviour during defensive performance in 2 vs. 1 +goalkeeper game situations in football. Twenty-two players were assigned to either a high- or low-performing group based on a validated measure of tactical performance. A total of 12 game sequences (trials) were presented under high- and low-workload conditions. At the end of each sequence, participants were asked to indicate their perceived exertion using the Rating Scale of Mental Effort and the Borg Scale. The low- and high-workload conditions were defined when the players achieved 60 and 90% of their maximal heart rate, respectively, as per their performance in the Yo-Yo Intermittent Recovery Test. Visual search behaviours were recorded using Tobii Pro eye-movement registration glasses. Players reported higher rates of perceived exertion on the high- compared to low-workload condition. Participants in the low-performing group increased their average fixation duration and decreased the number of fixations and number of fixation locations from the low- to high-workload conditions. The low- and high-performing groups displayed different visual search strategies with regards the areas of interest fixated upon. Participants in the high-performing group focused on the SpaceFrontPlayer, followed by Ball, and AnotherOpponent. The low-performing group spent more time focusing on the SpaceFrontPlayer and SpacePlayer than Ball and AnotherOpponent. It appears that physiological workload and tactical expertise interact in constraining visual search behaviours in football players. Coaches and practitioners should consider ways to manipulate individual and task constraints while attending to the close interplay between physiological workload, visual behaviour, and tactical performance during practise.

How Task Constraints Influence the Gaze and Motor Behaviours of Elite-Level Gymnasts.

Perception-action coupling is fundamental to effective motor behaviour in complex sports such as gymnastics. We examined the gaze and motor behaviours of 10 international level gymnasts when performing two skills on the mini-trampoline that matched the performance demands of elite competition. The presence and absence of a vaulting table in each skill served as a task-constraint factor, while we compared super-elite and elite groups. We measured visual search behaviours and kinematic variables during the approach run phase. The presence of a vaulting table influenced gaze behaviour only in the elite gymnasts, who showed significant differences in the time spent fixating on the mini-trampoline, when compared to super-elite gymnasts. Moreover, different approach run characteristics were apparent across the two different gymnastic tasks, irrespective of the level of expertise, and take-off velocity was influenced by the skill being executed across all gymnasts. Task constraints and complexity influence gaze behaviours differed across varying levels of expertise in gymnastics, even within a sample of international level athletes. It appears that the time spent fixating their gazes on the right areas of interest during the approach run is crucial to higher-level performance and therefore higher scores in competition, particularly on the mini-trampoline with vaulting table.

Visual search strategy and anticipation in tactical behavior of young soccer players.

The aim of the present study was to compare the visual search strategy (VSS) and anticipation between two groups of young players of different efficiencies in tactical behavior (TB). A total of 44 Brazilian male soccer players aged 14.00 (± 1.06) years from three regional clubs participated in the study. TB was assessed using FUT-SAT; anticipation score was obtained by a video-based assessment, while VSS was performed using the Mobile Eye-XG® system. The soccer players were divided into two groups based on their TB results into those more efficient and those less efficient. The results showed that soccer players with higher efficiency in TB were better at anticipating and performed a higher number of shorter visual fixations and a greater average amount of fixations per location. They were also able to adjust their VSS in performing a longer fixation time on the player in possession of the ball. Therefore, there is support for an integration of visual search strategy and anticipation within tactical behavior. Visual search strategy and anticipation seem to contribute to the efficiency of tactical behavior in young soccer players.

The attention as a key element to improve tactical behavior efficiency of young soccer players / La atención como elemento clave para mejorar la eficiencia del comportamiento táctico de los futbolistas jóvenes / A atenção como elemento chave para melhorar a eficiência do comportamento tático de jovens jogadores de futebol

The aim of this study was to examine the associations between attention and tactical behavior efficiency of young soccer players with similar formal practice time and competitive level. The sample consisted of 80 young male soccer players from Brazilian clubs. The Vienna Test System was used to assess players' attention. The System of Tactical Assessment in Soccer (FUT-SAT) was used to assess players' tactical behavior efficiency. The Generalized Linear Models were used to verify the associations between attention and tactical behavior efficiency. The results showed that attention is positively associated with tactical behavior efficiency of young soccer players. Based on the results, high levels of attention will enable young soccer players with similar formal practice time and competitive level to display better responses regarding the tactical actions of the game

El objetivo del estudio fue verificar las asociaciones entre la atención y la eficiencia del comportamiento táctico de jóvenes jugadores de fútbol con tiempo de práctica formal y nivel competitivo similares. La muestra consistió en 80 jugadores de fútbol jóvenes del sexo masculino de clubes de Brasil. El Vienna Test System fue utilizado para evaluar la atención de los jugadores. El Sistema de Evaluación Táctica en el Fútbol (FUT-SAT) fue utilizado para evaluar la eficiencia del comportamiento táctico de los jugadores. Los Modelos Lineales Generalizados se utilizaron para verificar las asociaciones entre la atención y la eficiencia del comportamiento táctico. Los resultados revelaron que la atención está positivamente asociada a la eficiencia del comportamiento táctico de jóvenes jugadores de fútbol. Basado en estos resultados, altos niveles de atención permitirán que los jóvenes jugadores con tiempo de práctica formal y nivel competitivo similares presenten mejores respuestas en relación a las acciones tácticas en el juego

O objetivo deste estudo foi verificar as associações entre a atenção e a eficiência do comportamento tático de jovens jogadores de futebol com tempo de prática formal e nível competitivo similares. A amostra foi composta por 80 jogadores de futebol jovens do sexo masculino de clubes do Brasil. O Vienna Test System foi utilizado para avaliar a atenção dos jogadores. O Sistema de Avaliação Tática no Futebol (FUT-SAT) foi utilizado para avaliar a eficiência do comportamiento tático dos jogadores. Os Modelos Lineares Generalizados foram utilizados para verificar as associações entre a atenção e a eficiência do comportamento tático. Os resultados mostraram que a atenção está positivamente associada à eficiência do comportamento tático de jovens jogadores de futebol. Baseado nesses resultados, altos níveis de atenção irão permitir que jovens jogadores com tempo de prática formal e nível competitivo similares apresentem melhores respostas em relação às ações táticas no jogo

Multivariate Profiles of Selected versus Non-Selected Elite Youth Brazilian Soccer Players.

This study determined whether a multivariate profile more effectively discriminated selected than non-selected elite youth Brazilian soccer players. This examination was carried out on 66 youth soccer players (selected, n = 28, mean age 16.3 ± 0.1; non-selected, n = 38, mean age 16.7 ± 0.4) using objective instruments. Multivariate profiles were assessed through anthropometric characteristics, biological maturation, tactical-technical skills, and motor performance. The Student's t-test identified that selected players exhibited significantly higher values for height (t = 2.331, p = 0.02), lean body mass (t = 2.441, p = 0.01), and maturity offset (t = 4.559, p < 0.001), as well as performed better in declarative tactical knowledge (t = 10.484, p < 0.001), shooting (t = 2.188, p = 0.03), dribbling (t = 5.914, p < 0.001), speed - 30 m (t = 8.304, p < 0.001), countermovement jump (t = 2.718, p = 0.008), and peak power tests (t = 2.454, p = 0.01). Forward stepwise discriminant function analysis showed that declarative tactical knowledge, running speed -30 m, maturity offset, dribbling, height, and peak power correctly classified 97% of the selected players. These findings may have implications for a highly efficient selection process with objective measures of youth players in soccer clubs.

Effects of prolonged intermittent exercise on perceptual-cognitive processes.

PURPOSE: The visual search behaviors and thought processes underpinning anticipation and how these are influenced by intermittent exercise were examined in high- and low-level soccer players. METHODS: High-level (n = 8) and low-level (n = 8) players completed a soccer-specific, intermittent exercise protocol that simulated the demands of a match while responding to filmed sequences of offensive play. HR, blood lactate concentrations, anticipation performance, visual search behaviors, and immediate retrospective verbal reports were assessed. RESULTS: High-level players demonstrated superior anticipation compared with low-level counterparts, but both groups showed reduced accuracy across the exercise protocol. Mean HR and blood lactate values increased significantly from the beginning to the end of each half of the match (P < 0.05). Visual search data revealed significant group-test session interactions for the number of locations (P < 0.0001), mean fixation durations (P = 0.003), and number of fixations (P < 0.0001). When compared with low-level participants, high-level players used more fixations of shorter duration to more locations at the beginning of each half; whereas at the end of the exercise protocol, they used fewer fixations of longer duration to a lower number of locations. There was a significant group-type of statement-test session interaction (P = 0.001) for the verbal report data. High-level participants generated a great number of evaluation, prediction (in the beginning of the second half), and deep planning statements (during the first and the last test sessions). In contrast, low-level players used more superficial cognition statements than high-level individuals in both halves. CONCLUSION: The intermittent exercise induced changes in perceptual-cognitive processes in both groups, although high-level players exhibited superior anticipation across test sessions accompanied by more effective search behaviors and elaborate thought processes.