Fatigue-Related Changes in Running Technique and Mechanical Variables After a Maximal Incremental Test in Recreational Runners.

Understanding the changes in running mechanics caused by fatigue is essential to assess its impact on athletic performance. Changes in running biomechanics after constant speed conditions are well documented, but the adaptive responses after a maximal incremental test are unknown. We compared the spatiotemporal, joint kinematics, elastic mechanism, and external work parameters before and after a maximal incremental treadmill test. Eighteen recreational runners performed 2-minute runs at 8 km·h-1 before and after a maximal incremental test on a treadmill. Kinematics, elastic parameters, and external work were determined using the OpenCap and OpenSim software. We did not find differences in spatiotemporal parameters and elastic parameters (mechanical work, ankle, and knee motion range) between premaximal and postmaximal test conditions. After the maximal test, the runners flexed their hips more at contact time (19.4°-20.6°, P = .013) and presented a larger range of pelvis rotation at the frontal plane (10.3°-11.4°, P = .002). The fatigue applied in the test directly affects pelvic movements; however, it does not change the lower limb motion or the spatiotemporal and mechanical work parameters in recreational runners. A larger frontal plane motion of the pelvis deserves attention due to biomechanical risk factors associated with injuries.

Energetic responses of head-out water immersion at different temperatures during post-exercise recovery and its consequence on anaerobic mechanical power.

PURPOSE: While exercise recovery may be beneficial from a physiological point of view, it may be detrimental to subsequent anaerobic performance. To investigate the energetic responses of water immersion at different temperatures during post-exercise recovery and its consequences on subsequent anaerobic performance, a randomized and controlled crossover experimental design was performed with 21 trained cyclists. METHOD: Participants were assigned to receive three passive recovery strategies during 10 min after a Wingate Anaerobic Test (WAnT): control (CON: non-immersed condition), cold water immersion (CWI: 20 â„ƒ), and hot water immersion (HWI: 40 â„ƒ). Blood lactate, cardiorespiratory, and mechanical outcomes were measured during the WAnT and its recovery. Time constant (τ), asymptotic value, and area under the curve (AUC) were quantified for each physiologic parameter during recovery. After that, a second WAnT test and 10-min recovery were realized in the same session. RESULTS: Regardless the water immersion temperature, water immersion increased [Formula: see text] (+ 18%), asymptote ([Formula: see text]+ 16%, [Formula: see text] + 13%, [Formula: see text] + 17%, HR + 16%) and AUC ([Formula: see text]+ 27%, [Formula: see text] + 18%, [Formula: see text] + 20%, HR + 25%), while decreased [Formula: see text] (- 33%). There was no influence of water immersion on blood lactate parameters. HWI improved the mean power output during the second WAnT (2.2%), while the CWI decreased 2.4% (P < 0.01). CONCLUSION: Independent of temperature, water immersion enhanced aerobic energy recovery without modifying blood lactate recovery. However, subsequent anaerobic performance was increased only during HWI and decreased during CWI. Despite higher than in other studies, 20 °C effectively triggered physiological and performance responses. Water immersion-induced physiological changes did not predict subsequent anaerobic performance.

Vertical ground reaction force responses to different head-out aquatic exercises performed in water and on dry land.

The purpose was to analyse the vertical ground reaction forces (Fz) of head-out aquatic exercises [stationary running (SR), frontal kick (FK), cross-country skiing (CCS), jumping jacks (JJ), adductor hop (ADH) and abductor hop (ABH)] at two cadences in both aquatic and dry land environments. Twelve young women completed two sessions in each environment, each consisting of three exercises performed at two cadences (first and second ventilatory thresholds - C1 and C2, respectively). Two-way and three-way repeated measures analysis of variance were used to the statistical analysis. The results showed that the peak Fz and impulse were significantly lower in the aquatic environment, resulting in values from 28.2% to 58.5% and 60.4% to 72.8% from those obtained on dry land, respectively. In the aquatic environment, the peak Fz was lower and the impulse was higher at the C1 than at the C2. Furthermore, it was observed that SR and FK (0.9-1.1 BW) elicited a significantly higher peak Fz values compared to the ADH and JJ exercises (0.5-0.8 BW). It can be concluded that the aquatic environment reduces the Fz during head-out aquatic exercises. It should be noted that its magnitude is also dependent on the intensity and the identity of the exercise performed.

Association of Physical and Emotional Parameters with Performance of Firefighters: A Systematic Review.

Firefighting requires a high level of physical fitness and causes substantial psychological stress, engendering musculoskeletal, mental, and cardiac issues. Consequently, it is necessary to measure the preparation of the firefighters daily through the Firefighting Physical Ability Tests (FPATs). According to the literature, some variables are more important for performance in the FPAT. Therefore, we aimed to summarize evidence that relates physical and mental aspects to the FPAT performance. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) method, screening 1055 records from databases and selecting 15 that met inclusion criteria. No emotional and psychological variables were correlated with the FPAT. Most research shows significant correlations between the FPAT performance and the following: aerobic fitness, upper body endurance and strength, anaerobic capacity, body fat, and age. Lower body endurance and strength, as well as anaerobic power, had a low number of investigations and need to be further explored. Abdominal endurance showed weak correlations, while flexibility did not show any correlations in most studies, although these should be considered for injury prevention. We recommend that fitness programs and evaluations include a global analysis considering the evidence presented for methodological improvements.

Modelling 5-km Running Performance on Level and Hilly Terrains in Recreational Runners.

Incline and level running on treadmills have been extensively studied due to their different cardiorespiratory and biomechanical acute responses. However, there are no studies examining the performance determinants of outdoor running on hilly terrains. We aimed to investigate the influence of anthropometrics, muscle strength, and cardiorespiratory and gait spatiotemporal parameters during level (0%) and inclined (+7%) running on performance in level and hilly 5-km races. Twenty male recreational runners completed two 5-km outdoor running tests (0% vs. +7% and −7%), and two submaximal (10 km·h−1) and incremental treadmill tests at 0 and 7% slopes, after complete laboratory evaluations. The velocity at maximal oxygen consumption (VO2max) evaluated at 7% incline and level treadmill running were the best performance predictors under both hilly (R2 = 0.72; p < 0.05) and level (R2 = 0.85; p < 0.01) conditions, respectively. Inclusion of ventilatory and submaximal heart rate data improved the predictive models up to 100%. Conversely, none of the parameters evaluated in one condition contributed to the other condition. The spatiotemporal parameters and the runners' strength levels were not associated to outdoor performances. These results indicate that the vVO2max evaluated at similar slopes in the lab can be used to predict 5-km running performances on both level and hilly terrains.

Cardiorespiratory, neuromuscular and kinematic responses to stationary running performed in water and on dry land.

The purpose of this study was to analyze the cardiorespiratory, neuromuscular and kinematic responses obtained during the stationary running in aquatic and dry land environments. Twelve women took part in the experimental protocol. Stationary running was performed for 4 min at three submaximal cadences and for 15 s at maximal velocity, with the collection of kinematic (peak hip angular velocity (AV)), cardiorespiratory (oxygen uptake (VO(2))) and neuromuscular variables (electromyographic (EMG) signal from the rectus femoris (RF), vastus lateralis (VL), semitendinosus (ST) and short head of the biceps femoris (BF) muscles) in land-based and water-based test protocols. Factorial ANOVA was used, with an alpha level of 0.05. AV was significantly higher when the exercise was performed on land, and became significantly higher as the execution cadence increased. Similarly, VO(2) was significantly higher in the land-based exercise and rose as cadence increased. With the increase in the submaximal execution cadences, there was no corresponding increase in the EMG signal from the VL, BF, RF and ST muscles in either environment, though such a significantly increase was seen between the submaximal cadences and the maximal velocity. Dry land presented significantly greater EMG signal responses for all muscles at the submaximal cadences, except for the ST muscle. However, at the maximal velocity, all the analyzed muscle groups showed similar responses in both environments. In summary, for both environments, cardiorespiratory responses can be maximized by increasing the submaximal cadences, while neuromuscular responses are only optimized by using maximal velocity.

Correlation between rating of perceived exertion and physiological variables during the execution of stationary running in water at different cadences.

The purpose of the present study was to correlate the rating of perceived exertion (RPE) with cardiorespiratory and neuromuscular variables during the execution of stationary running in water at different cadences. The sample consisted of 12 apparently healthy women (age: 22.33 ± 0.57 years). During the assessment session, the subjects performed the stationary running exercise in water at 3 different cadences: 60, 80, and 100 bpm. The heart rate (HR), oxygen uptake (V(O2)), ventilation (Ve), and electromyographic (EMG) signal of the vastus lateralis (VL), biceps femoris (BF), rectus femoris (RF), and semitendinosus (ST) muscles were measured during the exercise, and the overall body RPE was measured immediately following the end. Pearson's linear correlation and multiple linear regression were used, with p < 0.05. The analyses demonstrate a high and significant relationship between RPE and HR (r = 0.65; p < 0.001), RPE and %HR maximal (r = 0.65; p < 0.001), RPE and V(O2) (r = 0.60; p = 0.001), RPE and %V(O2) maximal (r = 0.71; p < 0.001), and RPE and Ve (r = 0.77; p < 0.001). However, there was no relationship between the RPE and the EMGs of the VL, BF, RF, and ST muscles. With regard to the regression, the model was significant (p < 0.001) with an r2 = 0.79, whereas the variables that explained better the RPE were %V(O2) maximal and Ve. Hence, these results suggest an association between the perception of exertion and cardiorespiratory variables, which was not the case with the neuromuscular variables evaluated in this study. Therefore, the Borg scale of RPE can be used when prescribing stationary running exercise in water for young women.

Neuromuscular economy, strength, and endurance in healthy elderly men.

Declines in muscular strength resulting from reduced neural activity may influence the reduction in aerobic capacity in older men. However, there has been little investigation into the relationship between muscular strength and economy of movement during aerobic exercise in elderly subjects. Thus, the purpose of this study was to investigate the possible relationship between strength, aerobic performance, and neuromuscular economy in older men. Twenty-eight aged men (65 ± 4 years old) were evaluated in dynamic (1 repetition maximum test), isometric strength (maximal voluntary contraction), and rate of force development. Peak oxygen uptake, maximal workload, and ventilatory threshold were determined during a ramp protocol on a cycle ergometer. Throughout the same protocol, the neuromuscular economy (electromyographic signal) of the vastus lateralis was measured. Significant correlations were found between muscular strength, cardiorespiratory fitness, and neuromuscular economy (r = 0.43-0.64, p < 0.05). Our results suggest that cardiorespiratory capacity and economy of movement are associated with muscular strength during aging.

Female students are the most psychologically affected by the COVID-19 outbreak: a case study in an academic community in Brazil.

OBJECTIVE: The study evaluates psychological responses to the COVID-19 outbreak in the students, professors, and staff due to the social distancing and transition of the classroom activities through online learning. METHODS: 518 participants from a University community in Brazil answered an online survey with questions related to demographic data, psychological responses, and preventive measures. Absolute and relative frequencies described the sample, Chi-square and z-test tested associations between the variables, adopting p<0.05. RESULTS: Female (71.20%), young age -18 to 35 years (82.60%), students (76.10%), living in a family with 1 to 3 members during quarantine (55.40%) were more prevalent respondents. Women, young age, and students had a significantly higher rate of negative feelings in all psychological questions. Curiously, negative feelings during social distances affect the participants, independent of living quarantine alone or with family/friends during the COVID-19 outbreak. CONCLUSIONS: Our findings demonstrated that the COVID-19 outbreak affected the psychological responses in the Brazilian academic community, also, women, young age, and students appear to be a risk group to negative psychological responses. The long-term quarantine due to the COVID-19 pandemic may cause further worsening in the psychological responses, especially in those in the risk group.

Characterization of Reproductive and Morphological Variables in Female Elite Futsal Players.

We aimed to characterize the age of onset of training, age at menarche, menstrual periodicity, and performance perception during the menstrual cycle and examined the impact of these reproductive variables on body composition, morphology, and body weight satisfaction in Brazilian elite futsal players. The study consisted of 115 female Brazilian elite futsal players from the top national teams. Data were collected during the twentieth Women's Brazil Futsal Cup. Players were interviewed and self-reported their age of onset of training, age at menarche, menstrual periodicity, and the menstrual period, where they performed best. We also asked for what they considered to be their ideal body weight as well as information related to their training (i.e., volume and frequency). Subsequently, anthropometric measurements (i.e., body mass, height, circumferences, diameters, and skinfold thickness) were performed to estimate the body composition and determine morphological characteristics (e.g., somatotype). Fifty-nine (53.2%) players were postmenarche-trained and 52 (46.8%) were premenarche-trained. Eighteen (16.2%), 65 (58.6%), and 28 (25.2%) were classified as early, normal, and late menarche, respectively. Only 11 (9.6%) and 1 (0.9%) had irregular menstrual cycles and were amenorrheic, respectively. Seventy-three (69.5%), 23 (21.9%), and 9 (8.6%) reported that their game performance was the best at the follicular phase, menses, and luteal phase of the menstrual cycle, respectively. No associations between the four reproductive-related variables were found. Postmenarche-trained players had significant lower age at menarche and higher percentage body fat. The somatotype profile registered lower ectomorphy rate for the postmenarche-trained participants after controlling for covariates. Early menarche group presented higher sum of six skinfold thickness and endomorphy rate compared to normal and late menarche groups. No differences were found when menstrual periodicity groups and best performance groups were compared, except for higher femur width in the regular menstrual cycle group compared to the irregular one. The association between body weight satisfaction and the four reproductive-related variables were not observed. Premenarche-trained Brazilian elite futsal players had the menarche later than the postmenarche-trained athletes. Most of the participants had menarche age classified as "normal," presented "regular" menstrual cycles and perceived to perform better during the follicular phase of the menstrual cycle.

Horizontal ground reaction forces to stationary running performed in the water and on dry land at different physiological intensities.

The aim of the present study was to compare the peak anterior-posterior (Fy) and medio-lateral (Fx) ground reaction forces (GRFs) of women performing stationary running at different intensities in aquatic and dry land environments. Fourteen young women performed the stationary running exercise at three cadences (first ventilatory threshold, second ventilatory threshold and maximum effort, as determined during exercise in water) in aquatic and dry land environments. Two-way repeated measures ANOVA was used to analyse the data (α = .05). As a result, significantly lower peak Fy anterior, Fy posterior, Fx medial and Fx lateral values were observed for the aquatic environment, except for the Fy posterior at the first ventilatory threshold. Significant differences were observed between cadences in the peak Fy anterior, Fy posterior, Fx medial and Fx lateral values, with higher values for the cadence corresponding to maximum effort compared to the first ventilatory threshold, except for the Fy posterior and Fx medial in the aquatic environment. The results indicate that the horizontal GRFs are reduced in the aquatic environment and depend on the intensity of stationary running exercise performance.

[Characterization of the physical environment and practice of physical activities in Primary Health Care Units in Guarapuava, Paraná State, Brazil, 2011-2012]. / Caracterização do ambiente físico e prática de atividades físicas em unidades básicas de saúde de Guarapuava, Paraná, 2011-2012.

OBJECTIVE: to characterize the physical environment and physical activity (PA) in Primary Health Care Units (PHU) in the urban area of Guarapuava-PR, Brazil, 2011-2012. METHODS: this is a descriptive study in which the coordinators of the municipality's 27 PHUs were interviewed about violence, crime and physical space and safety conditions for PAs inside and outside the PHUs; the streets surrounding the area were visited to evaluate environmental factors categorized as favorable or unfavorable to PA deployment and practice. RESULTS: the most common places for PA were grass areas (n=18) and churches (n=24); three fifths of PHUs presented factors favorable to PA deployment/practice; lack of sidewalks (14 PHUs) or uneven sidewalks (13 PHUs) surrounding the PHUs are conditions that could jeopardize the practice of walking. CONCLUSION: despite the identification of favorable factors for PA practice, at PHUs should be focused by health service managers.

Kinesiological Analysis of Stationary Running Performed in Aquatic and Dry Land Environments.

The purpose of the present study was to analyze the electromyographic (EMG) signals of the rectus femoris (RF), vastus lateralis (VL), semitendinosus (ST) and short head of the biceps femoris (BF) during the performance of stationary running at different intensities in aquatic and dry land environments. The sample consisted of 12 female volunteers who performed the stationary running exercise in aquatic and dry land environments at a submaximal cadence (80 beats·min(-1) controlled by a metronome) and at maximal velocity, with EMG signal measurements from the RF, VL, ST and BF muscles. The results showed a distinct pattern between environments for each muscle examined. For the submaximal cadence of 80 beats·min(-1), there was a reduced magnitude of the EMG signal in the aquatic environment, except for the ST muscle, the pattern of which was similar in both environments. In contrast to the submaximal cadence, the pattern of the EMG signal from all of the muscles showed similar magnitudes for both environments and phases of movement at maximal velocity, except for the VL muscle. Therefore, the EMG signals from the RF, VL, ST and BF muscles of women during stationary running had different patterns of activation over the range of motion between aquatic and dry land environments for different intensities. Moreover, the neuromuscular responses of the lower limbs were optimized by an increase in intensity from submaximal cadence to maximal velocity.

Rating of Perceived Exertion and Physiological Responses in Water-Based Exercise.

The aim of the present study was to relate the overall rating of perceived exertion (RPE-overall) with cardiorespiratory and neuromuscular variables during stationary running with the elbow flexion/extension performed with water-floating equipment. The sample consisted of eleven women that performed the water-based exercise at submaximal cadences. The heart rate, oxygen uptake, ventilation, and electromyographic signal (EMG) from biceps brachii (%EMG BB), triceps brachii (%EMG TB), biceps femoris (%EMG BF) and rectus femoris (%EMG RF) muscles were measured during the exercise, and the overall RPE was measured immediately following its completion. The Pearson product-moment linear correlation was used to investigate associations between the variables analyzed in the present study. Significant relationships were observed between the RPE-overall and all the cardiorespiratory variables, with the r values ranging from 0.60 to 0.70 (p<0.05). In addition, the RPE-overall showed a significant (p<0.05) relationship with %EMG BB (r=0.55) and %EMG BF (r=0.50). These results suggest an association between the RPE-overall with all cardiorespiratory and two neuromuscular variables during the execution of a water-based aerobic exercise using water-floating equipment.

Relative age in female futsal athletes: implications on anthropometric profile and starter status / Idade relativa em atletas de futsal feminino: implicações no perfil antropométrico e titularidade / Edad relativa en atletas de futsal femenino: implicaciones en el perfil antropométrico y titularidad

ABSTRACT Introduction: Evidence suggests that a higher distribution of elite athletes have birth dates in the first few months of the year. However, the advantages of birth month on performance related to starter status, structure and body composition in female futsal (5-a-side football played on a hard court, mainly indoors), are unknown. Objective: To determine the effect of relative age (ERA) on competitive female futsal athletes, and its influence on anthropometric profile and starter status. Methods: One hundred and fifteen athletes, participants in the 20th Brazilian Cup of Adult Futsal Clubs, special division, were submitted to measurements of body mass, height, skinfold thickness, body perimeters and bone diameters, in order to characterize the anthropometric profile and determine the body somatotype. The athletes were distributed in semesters and quartiles of the months of the year, according to their birth dates. Differences in the distribution of expected and observed birth dates were tested using Chi-square tests (χ2). Comparisons between semesters and birth quartiles were performed using parametric and non-parametric tests. Results: There was no ERA in distribution (p=0.248), anthropometric profile (p=0.872 to 0.912), or starter status between athletes born from January to June (p=0.352) and those born between July and December (p=0.744). On the other hand, those born in the first months of the year showed longer practice times than those born in the latter months of the year. Conclusion: Although the ERA in this study reveals longer practice times favoring female futsal athletes born in the first quartile of the year, it did not influence the starter status, the distribution in the teams, or any advantage in anthropometric profile. Level of evidence III, Case-Control Study.

RESUMO Introdução: Evidências sugerem maior distribuição de atletas de elite com data de nascimento nos primeiros meses do ano. Entretanto, as vantagens que o mês de nascimento exerce no desempenho relacionado à titularidade, estrutura e composição corporal no futsal feminino são desconhecidas. Objetivo: Determinar o efeito da idade relativa (EIR) em atletas de futsal feminino competitivo e sua influência no perfil antropométrico e na titularidade. Métodos: Cento e quinze atletas, participantes da XX Taça Brasil de Clubes de Futsal Feminino Adulto, divisão especial, foram submetidas a medidas de massa corporal, estatura, espessuras de dobras cutâneas, perímetros corporais e diâmetros ósseos, a fim de caracterizar o perfil antropométrico e determinar o somatotipo corporal. As atletas foram distribuídas em semestres e quartis dos meses do ano, de acordo com suas datas de nascimento. Diferenças na distribuição das datas de nascimento esperadas e observadas foram comparadas utilizando o teste de qui-quadrado (χ2). As comparações entre os semestres e os quartis de nascimento foram realizadas utilizando os testes paramétricos e não paramétricos. Resultados: Não houve EIR na distribuição (p=0,248), no perfil antropométrico (p=0,872 a 0,912) ou na titularidade entre as atletas nascidas de janeiro a junho (p=0,352) e as nascidas entre julho a dezembro (p=0,744). Por outro lado, as atletas nascidas nos primeiros meses do ano demonstraram maior tempo de prática do que as nascidas nos últimos meses do ano. Conclusão: Apesar do EIR neste estudo revelar maior tempo de prática favorecendo atletas de futsal feminino nascidas no primeiro trimestre do ano, não influenciou a condição de titular, a distribuição nas equipes, ou qualquer vantagem no perfil antropométrico. Nível de evidência III, Estudo Caso-Controle.

RESUMEN Introducción: Evidencias sugieren mayor distribución de atletas de élite con fecha de nacimiento en los primeros meses del año. Entretanto, las ventajas que el mes de nacimiento ejerce sobre el desempeño relacionado a la titularidad, estructura y composición corporal en el futsal femenino son desconocidas. Objetivo: Determinar el efecto de la edad relativa (EER) en atletas de futsal femenino competitivo y su influencia en el perfil antropométrico y en la titularidad. Métodos: Ciento quince atletas, participantes de la XX Copa Brasil de Clubes de Futsal Femenino Adulto, división especial, fueron sometidas a medición de masa corporal, estatura, espesores de los pliegues cutáneos, perímetros corporales y diámetros óseos, a fin de caracterizar el perfil antropométrico y determinar el somatotipo corporal. Las atletas fueron distribuidas en semestres y cuartiles de los meses del año, de acuerdo con sus fechas de nacimiento. Las diferencias en la distribución de las fechas de nacimiento esperadas y observadas fueron probadas usando el test de chi cuadrado (χ2). Las comparaciones entre los semestres y los cuartiles de nacimiento realizadas usando tests paramétricos y no paramétricos. Resultados: No hubo EER en la distribución (p = 0,248), en el perfil antropométrico (p = 0,872 a 0,912) o en la titularidad entre atletas nacidas de enero a junio (p = 0,352) y las nacidas entre julio a diciembre (p = 0,744). Por otro lado, las atletas nacidas en los primeros meses del año demostraron mayor tiempo de práctica que las nacidas en los últimos meses del año. Conclusión: Aunque el EER en este estudio revela un tiempo de práctica más prolongado que favorece a las atletas de futsal femenino nacidas en el primer trimestre del año, no influyó en la posición inicial, la distribución en los equipos ni ninguna ventaja en el perfil antropométrico. Nivel de evidencia III, Estudio Caso-Control.

Internal mechanical work and maximum subtalar joint pronation in different gradients / Trabalho mecânico interno e máxima pronação subtalar em diferentes gradientes de inclinação / Trabajo mecánico interno y máxima pronación subtalar en diferentes gradientes de inclinación

Abstract Introduction: Some authors have described the importance of physiological intensity in the behavior of the biomechanical aspects of running (for example, subtalar pronation), but the complex relationships between these variables are not yet well understood. Objective: This study investigated the influence of positive gradients on internal mechanical work (Wint) and maximum subtalar pronation at a submaximal running speed. Method: Sixteen male, trained long-distance runners (age: 29 ± 7 yr; stature: 1.72 ± 0.07 m; body mass: 72.1 ± 10.6 kg), performed four running economy tests (gradients: +1%, +5%, +10% and +15%, respectively) for four minutes at a same submaximal running speed to quantify the maximum values of subtalar pronation and predict the Wint values. Data were analyzed using descriptive statistics, Student's T-test, and one-way repeated-measures (ANOVA) along with the Statistical Package for the Social Sciences (SPSS) version 20.0. Results: Wint increased according to the gradient (p < 0.05). However, no significant differences were observed in the maximum values of maximum subtalar pronation corresponding to each gradient. Conclusion: Results show the maximum subtalar pronation during submaximal running depends on the speed rather than intensity of effort.

Resumo Introdução: Autores têm descrito a importância da intensidade fisiológica no comportamento dos aspectos biomecânicos da corrida (por exemplo, a pronação subtalar), mas as complexas relações entre essas variáveis todavia não estão bem compreendidas. Objetivo: O presente estudo investigou a influência de gradientes de inclinação positivos, a uma mesma velocidade de corrida, no trabalho mecânico interno (Wint) e na máxima pronação subtalar. Método: Dezesseis corredores masculinos, especialistas em longas-distâncias (idade: 29 ± 7 anos; estatura: 1,72 ± 0,07 m; massa corporal: 72,1 ± 10,6 kg) realizaram quatro testes de economia de corrida (gradientes: +1%, +5%, +10% e +15%, respectivamente), de quatro minutos cada, em uma mesma velocidade submáxima de corrida, objetivando quantificar os valores de máxima pronação subtalar e predizer os Wint. Foi realizada a análise descritiva e aplicados os testes T de Students e ANOVA de Medidas Repetidas, todos através do software Statistical Package for the Social Sciences (SPSS), versão 20.0. Resultados: O Wint aumentou com o gradiente (p < 0,05). Entretanto, diferenças estatisticamente significativas não foram observadas nos valores de máxima pronação subtalar correspondentes a cada gradiente. Conclusão: Os resultados do presente estudo revelam que a máxima pronação subtalar durante a corrida submáxima é dependente da velocidade em comparação a intensidade de esforço.

Resumen Introducción: Autores tienen descrito la importancia de la intensidad fisiológica en el comportamiento de los aspectos biomecánicos de la carrera (por ejemplo, la pronación subtalar), mas las complejas relaciones entre esas variables todavía no están bien comprendidas. Objetivo: El presente estudio investigó la influencia de gradientes de inclinación positivos, a una misma velocidad de carrera, en el trabajo mecánico interno (Wint) y en la máxima pronación subtalar. Método: Dieciséis corredores masculinos, especialistas en largas-distancias (edad: 29 ± 7 años; estatura: 1,72 ± 0,07 m; masa corporal: 72,1 ± 10,6 kg) realizaron cuatro testes de economía de carrera (gradientes: +1%, +5%, +10% e +15%, respectivamente), de cuatro minutos cada, en una misma velocidad submáxima de carrera, objetivando cuantificar los valores de máxima pronación subtalar y predecir los Wint. Fue realizada la análisis descriptiva y aplicados los testes T de Students y ANOVA de Medidas Repetidas, todos realizados en el software Statistical Package for the Social Sciences (SPSS), versión 20.0. Resultados: EL Wint aumentó con el gradiente (p < 0,05). Entretanto, diferencias estadísticamente significativas no fueran observadas en los valores de máxima pronación subtalar correspondientes a cada gradiente. Conclusión: Los resultados del presente estudio revelan que la máxima pronación subtalar durante la carrera submáxima es dependiente de la velocidad en comparación a la intensidad del esfuerzo.

Relationship of simple reaction time and aerobic and anaerobic capacities with performance of recreational adult orienteers / Relação do tempo de reação simples e das capacidades aeróbica e anaeróbica com o desempenho de adultos recreacionais em Orientação

Abstract This study aimed to examine the effects of Simple Reaction Time (SRT), MaximalOxygen Uptake ( V ? V ? O2max) and Maximal Anaerobic Power (Pmax) on the performance of category A recreational adult orienteers of both sexes. Sixteen subjects (8 men and 8 women; age: 30 ± 4 and 27 ± 5 years; body mass 78.8 ± 5.9 and 69.2 ± 10.4 kg; SRT: 1.391 ± 0.19 and 1.317 ± 0.25 ms; V ? V ? O2max: 67.4 ± 3.22 and 48.5 ± 8.28 ml.kg-1.min-1; Pmax: 675.0 ± 149.6 and 458.4 ± 88.62 W), were submitted to three evaluation sessions: sample characterization (1st session); SRT - Reaction Time Task v.2.0, V ? V ? O2max, and Pmax - Running Anaerobic Sprint Test (2nd session); official Orienteering test (3rd session). Results of comparison (Student's T-test) and relation (Pearson Product-Moment Correlation and Multiple Linear Regression) tests showed significant relationships between independent variables and performance. Pmax presented strong predictive power in the male group (41%), followed by SRT (32%) and V ? V ? O2max (27%). In the female group, SRT was the most predictive variable (54%), followed by V ? V ? O2max (32%) and Pmax (12%). These findings indicated that SRT, V ? V ? O2max, and Pmax are variables predictive of performance in recreational category A orienteers. Specifically in recreational orienteers with high cardiorespiratory capacities, Pmax seems to be the mainpredictor variable. Conversely, SRT becomes the variable with the greatest predictive power.

Resumo Objetivou-se investigar as relações do Tempo de Reação Simples (TRS), do Consumo Máximo de Oxigênio ( V ? V ? O2max) e da Potência Máxima Anaeróbica (Pmáx) no desempenho de homens e mulheres, adultos da categoria A, praticantes recreacionais de Orientação. Dezesseis sujeitos (8 homens e 8 mulheres; idade: 30 ± 4 e 27 ± 5 anos; massa corporal 78,8 ± 5,9 e 69,2 ± 10,4 kg; TRS: 1,391 ± 0,19 e 1,317 ± 0,25 ms; V ? V ? O2max: 67,4 ± 3,22 e 48,5 ± 8,28 ml.kg-1.min-1; Pmáx: 675,0± 149,6 e 458,4 ± 88,62 W), foram submetidos a três sessões de avaliação: caracterização amostral (1a sessão); mensurações do TRS - Reaction Time Task v.2.0, do V ? V ? O2max e da Pmáx - Running Anaerobic Sprint Test (2a sessão); prova de Orientação (3a sessão). Os resultados de comparação (teste T de Students) e de relação (Correlação Linear Produto-Momento de Pearson e Regressão Linear Múltipla) demonstraram relações estatisticamente significativas entre as variáveis independentes e o desempenho. A Pmáx apresentou forte poder de predição no grupo masculino (41%), seguida do TRS (32%) e do V ? V ? O2max (27%). No grupo feminino, o TRS foi a variável mais preditora (54%), seguida do V ? V ? O2max (32%) e da Pmáx (12%). Pode-se concluir que o TRS, o V ? V ? O2max e a Pmáx são variáveis preditoras do desempenho em adultos praticantes recreacionais de Orientação da categoria A. Especificamente, em sujeitos com maiores capacidades cardiorrespiratórias, a Pmáxparece ser a principal variável preditora. Em contrapartida, o TRS passa a ser a variável com maiorpoder de predição

Comparison between two generations to verify the morphological changes in female futsal athletes in a period of 10 years / Comparação entre duas gerações para verificar as alterações morfológicas em atletas de futsal feminino em um período de 10 anos

Abstract The aim was to compare two generations to verify the morphological changes in female futsal athletes. Age, years of playing, anthropometry measurements, percentage body fat and somatotype were compared between professional athletes in 2001 (n=112) and 2011 (n=115). The 2011 group revealed a significant longer practice time (9.0±4.3 vs. 5.7±3.5 years; p<0.001), higher thigh skinfold (26.1±8.5 vs. 22.5±6.7 mm; p<0.001), circumference of tensed forearm (27.4±2.1 vs. 26.7±2.1 cm; p=0.007), mesomorphy (4.1 vs. 3.3; p=0.001) and lower supraspinale skinfold (14.0±5.0 vs. 19.1±7.4 mm; p<0.001), trunk/extremity relationship (0.8±0.3 vs. 1.1±0.1; p<0.001) and endomorphy (4.5 vs. 5.0; p=0.009) than those of the 2001 athletes. Comparison in playing positions revealed that the 2011 goalkeepers (9.5±5.0 vs. 6.3±3.4 years; p=0.027), wings (9.0±4.3 vs. 5.4±3.2 years; p=0.001) and fixed (8.4±4.3 vs. 6.9±4.5 years; p=0.001) practiced more time than the 2001 athletes, whereas the somatotype profile of goalkeepers (4.6±1.0 vs. 3.4±1.1; p=0.001), wings (3.9±0.8 vs. 3.0±0.9; p=0.001), pivots (3.8±1.0 vs. 3.4±1.0; p=0.028) and fixed (4.3±0.9 vs. 3.7±1.0; p=0.036) registered a higher mesomorphy rate than that of the 2001 athletes, respectively. We may conclude that the 2011 group showed a significant increase in practicing time, coupled to higher mesomorphy and lower endomorphy rates than those experienced by the 2001 athletes.

Resumo O objetivo foi comparar duas gerações para verificar as alterações morfológicas em atletas de futsal feminino. Idade, tempo de treino, medidas antropométricas, percentual de gordura e somatotipo foram comparadas entre atletas profissionais de 2001 (n=112) e 2011 (n=115). A geração de 2011 demonstrou significativamente maior tempo de prática (9,0±4,3 vs 5,7±3,5 anos; p<0,001), espessura da dobra cutânea da coxa (26,1±8,5 vs 22,5±6,7 mm; p<0,001), circunferência de braço contraído (27,4±2,1 vs 26,7±2,1 cm; p=0,007), mesomorfia (4,1 vs 3,3; p=0,001) e menor espessura da dobra cutânea supraespinhal (14,0±5,0 vs 19,1± 7,4mm; p<0,001), relação tronco/extremidade (0,8±0,3 vs 1,1±0,1; p<0,001) e endomorfia (4,5 vs 5,0; p=0,009) do que as atletas de 2001. A comparação de acordo com a posição em quadra revelou que as goleiras (9,5±5,0 vs 6,3±3,4 anos; p=0,027) alas (9,0±4,3 vs 5,4±3,2 anos; p=0,001) e fixos (8,4±4,3 vs 6,9±4,5 anos; p=0,001) de 2011, apresentaram maior tempo de prática do que as atletas de 2001, enquanto o perfil somatotipológico das goleiras (4,6±1,0 vs 3,4±1,1; p=0,001), alas (3,9±0,8 vs 3,0±0,9; p=0,001), pivôs (3,8±1,0 vs 3,4±1,0; p=0,028) e fixos (4,3±0,9 vs 3,7±1,0; p=0,036) apresentou maior mesomorfia do que as atletas de 2001, respectivamente. Conclui-se que o grupo de 2011 demonstrou maior tempo de prática e taxas de mesomorfia, além de menor endomorfia comparado às atletas de 2001.

Influence of slope on subtalar pronation in submaximal running performance.

OBJECTIVE: : To investigate the slope influence on the maximal subtalar pronation in submaximal running speeds. METHODS: : Sixteen endurance runners participated of a running economy (RE) test in a treadmill with different slopes (+1%, +5%, +10%, +15%). For each slope a 4-minute run was performed with no rest break for the purpose of measuring the magnitude of kinematic variables by means of a high frequency video camera positioned in a frontal-posterior plane of the individual. RESULTS: : No significant differences were verified in maximal subtalar pronation between legs and between the slopes adopted, showing that changes of running technique due to modifications of slope aren't enough to modify the behavior of maximum subtalar pronation. CONCLUSION: : The subtalar pronation is independent of slope, which may be influenced by other intervening variables. Level of Evidence II, Diagnostic Study.

Mechanical work and long-distance performance prediction: the influence of allometric scaling.

The purpose of this study was to examine the effect of allometric scaling on the relationship between mechanical work and long-distance running performance in recreational runners. Fourteen recreational long-distance runners (male, mean ± SD - age: 29 ± 7 years; body mass: 70.0 ± 10.2 kg; body height: 1.71 ± 0.07 m; maximal oxygen uptake: VO2max 52.0 ± 4.9 ml·kg(-1)·min(-1)) performed two tests: a continuous incremental test to volitional exhaustion in order to determine VO2max, and a 6-minute running submaximal test at 3.1 m·s(-1), during which segments in the sagittal plane were recorded using a digital camera and the internal (Wint), external (Wext) and total (Wtot) mechanic work, in J·kg(-1)·m(-1), was subsequently calculated. The results indicated a significant correlation between mechanical work and performance, however, the strongest correlations were observed when allometric exponents were used (respectively for Wint, Wext and Wtot; non allometric vs. allometric scaling defined by literature (0.75) or determined mathematically (0.49): r = 0.38 vs. r = 0.44 and r = 0.50; r = 0.80 vs. r = 0.83 and r = 0.82; r = 0.70 vs. r = 0.77 and r = 0.78). These results indicate that mechanical work could be used as a predictor of recreational long-distance performance and an allometric model may improve this prediction.