Phase angle as an indicator of body composition and physical performance in handball players.

BACKGROUND: Phase angle (PhA), obtained from the bioimpedance analysis, is widely used in clinical situations and in sports. This study evaluated the association between PhA with body composition and physical performance of handball athletes. METHODS: 43 national-level players (22.19 ± 3.86 years) of both sexes were evaluated regarding anthropometry, body composition, squat (SJ) and countermovement (CMJ) jumps, handgrip strength, and cardiorespiratory fitness. RESULTS: We verified a correlation between PhA of the whole body and fat-free mass (r = 0.511), body mass index (r = 0.307), and body fat % (r = -0.303). There was a positive correlation between PhA of the whole body and SJ (r = 0.376), CMJ (r = 0.419), and handgrip for the dominant hand (r = 0.448). Moreover, PhA of the upper limbs was more strongly correlated with handgrip for the dominant (r = 0.630) and non-dominant hand (r = 0.575) compared to PhA of the whole body considering both sexes. Similarly, segmental PhA had a stronger significant correlation with SJ (r = 0.402) and handgrip for the dominant hand (r = 0.482) in males, as well as CMJ (r = 0.602) in females, compared to PhA of the whole body. CONCLUSION: PhA of the whole body was positively related to fat-free mass, body mass index, body fat %, and lower- and upper-limbs strength in handball athletes. Segmental PhA might be used as a tool for estimating lower and upper limbs performance considering the sex, in preference to the PhA of the whole body.

Glycerophospholipids in Red Blood Cells Are Associated with Aerobic Performance in Young Swimmers.

This study aimed to characterize the composition of lipids in the red blood cells (RBCs) of adolescent swimmers and correlate this lipidome with the aerobic performance of the athletes. Five experimental assessments were performed by 37 adolescent swimmers. During the first session, the athletes went to the laboratory facility for venous blood sampling. The critical velocity protocol was conducted over the 4 subsequent days to measure aerobic performance (CV), comprising maximal efforts over distances of 100, 200, 400, and 800 m in a swimming pool. RBCs were obtained and extracted for analysis using the liquid chromatography-high resolution mass spectrometry untargeted approach. A total of 2146 ions were detected in the RBCs, of which 119 were identified. The enrichment pathway analysis indicated intermediary lipids in the glycerophospholipid, glycerolipid, sphingolipid, linoleic acid, and alpha-linolenic metabolisms, as well as pentose and glucuronate interconversions. A significant impact of the intermediary lipids was observed for the glycerophospholipid metabolism, including phosphatidylethanolamine (PE), phosphatidylcholine (PC), 1-acyl-sn-glycero-3-phosphocholine, sn-glycerol 3-phosphate, and phosphatidic acid. Inverse and significant associations were observed for PE 18:2/18:3 (r = -0.39; p = 0.015), PC 18:3/20:0 (r = -0.33; p = 0.041), and phosphatidic acid 18:0/0:0 (r = -0.47; p = 0.003) with aerobic performance. Swimmers who exhibited higher levels of aerobic performance also had the lowest abundance of PE, PC, and phosphatidic acid.

Association between ACTN3 (R577X), ACE (I/D), BDKRB2 (-9/+9), and AGT (M268T) polymorphisms and performance phenotypes in Brazilian swimmers.

BACKGROUND: The influence of genetic polymorphisms on athletic performance has been widely explored. This study investigated the interactions between the polymorphisms ACTN3 (R577X), ACE (I/D), BDKRB2 (-9/+9), and AGT (M/T) and their association with endurance and strength phenotypes in Brazilian swimmers. METHODS: 123 athletes (aged 20-30 years) and 718 controls participated in the study. The athletes were divided into elite and sub-elite (N = 19 and 104, respectively) and strength and endurance experts (N = 98 and 25, respectively). Hardy-Weinberg equilibrium was observed in all groups. RESULTS: Considering the ACE polymorphism, it was observed a higher frequency of the DD genotype than expected in the strength experts of the elite group, whereas the strength experts sub-elite athletes had a higher frequency of the ID genotype (χ2 = 8.17; p = 0.01). Subjects with XX genotypes of ACTN3 are more likely to belong to the athlete group when compared to the control group (OR = 1.79, p = 0.04). The DD homozygotes of the ACE are more likely to belong to the elite group with strength phenotypes than the group of sub-elite (OR = 7.96, p = 0.01) and elite strength experts compared to elite endurance (OR = 18.0, p = 0.03). However, no significant differences were observed in the allelic distribution of the polymorphisms evaluated when comparing Elite, sub-elite athletes and controls. CONCLUSION: ACE and ACTN3 allele frequencies should be considered with regard to performance influencing factors in Brazilian swimmers.

Is melatonin as an ergogenic hormone a myth? a systematic review and meta-analysis.

PURPOSE: Melatonin supplementation has been disclosed as an ergogenic substance. However, the effectiveness of melatonin supplementation in healthy subjects has not been systematically investigated. The present study analyzed the effects of melatonin supplementation on physical performance and recovery. In addition, it was investigated whether exercise bout or training alter melatonin secretion in athletes and exercise practitioners. METHODS: This systematic review and meta-analysis were conducted and reported according to the guidelines outlined in the PRISMA statement. Based on the search and inclusion criteria, 21 studies were included in the systematic review, and 19 were included in the meta-analysis. RESULTS: Melatonin supplementation did not affect aerobic performance relative to time trial (-0.04; 95% CI: -0.51 to 0.44) and relative to VO2 (0.00; 95% CI: -0.57 to 0.57). Also, melatonin supplementation did not affect strength performance (0.19; 95% CI: -0.28 to 0.65). Only Glutathione Peroxidase (GPx) secretion increased after melatonin supplementation (1.40; 95% CI: 0.29 to 2.51). Post-exercise melatonin secretion was not changed immediately after an exercise session (0.56; 95% CI: -0.29 to 1.41) and 60 min after exercise (0.56; 95% CI: -0.29 to 1.41). CONCLUSION: The data indicate that melatonin is not an ergogenic hormone. In contrast, melatonin supplementation improves post-exercise recovery, even without altering its secretion.

Effect of brain endurance training on maximal oxygen uptake, time-to-exhaustion, and inhibitory control in runners.

We aimed to analyze the effect of brain endurance training on maximum oxygen consumption (VO2máx ), time-to-exhaustion, and inhibitory control in amateur trained runners. We employed a mixed experimental design, with the group as the between-participant factor and time as the within-participant factor. 45 participants attended 36 training sessions over 12 weeks. The cognitive training group (CT) performed the Stroop word-color task [trials of each type (congruent, incongruent, and neutral) were randomly presented during each training session], the endurance training group (ET) participated in a running training program (intensity was 60%Δ of maximal aerobic velocity and performed on a motor-driven treadmill), and the brain endurance training group (BET) make cognitive and endurance training simultaneously over 12 weeks. The total time of each session (i.e., 20-40 min) was identical in the experimental groups. VO2máx , time-to-exhaustion, and inhibitory control tests were measured before (baseline) and after (post-experiment) the 12-week intervention. A significant effect of interaction (group × time) for VO2máx (p < 0.05) was found. A post-hoc test showed an increase in VO2máx from baseline to post-experiment only for ET (Δ% = 2.98) and BET (Δ% = 3.78) groups (p < 0.05). Also, the analyses showed a significant interaction (group × time) for time-to-exhaustion (p < 0.05), and a post-hoc test revealed an improvement in time-to-exhaustion for ET (Δ% = 8.81) and BET (Δ% = 11.01) (p < 0.05). No group × time interaction was found for accuracy and response time in the inhibitory control task (p > 0.05). The results conclude that BET was not superior to ET for improving VO2máx and time-to-exhaustion. Also, the findings conclude that BET improved inhibitory control similar to CT.

Head-to-head opponent mitigates mental fatigue effects during a 20-km time trial in well-trained cyclists.

We aimed to analyze the effect of a head-to-head virtual race on 20-km time trial performance in well-trained mentally fatigued cyclists. A total of 24 male professional cyclists participated in the present study, which was conducted in a within-factors design [four experimental conditions × four times (throughout 20-km time trial cycling)]. An avatar representing the participant on the racecourse was visible during the time trials. Then, a second virtual avatar representing the opponent was projected onto the screen in the mental fatigue head-to-head and control head-to-head experimental conditions. Measurements [rating of perceived exertion, heart rate, and eye-tracking measures (i.e., pupil diameter)] were performed every 5-km throughout the 20-km time trial. As a result, impaired total time, power output, and cadence throughout the 20-km cycling time trial were found for mental fatigue compared to mental fatigue head-to-head, control head-to-head, and control conditions (p < 0.05). Also, impaired 20-km time trial performance (total time, power output, and cadence) was found for mental fatigue head-to-head compared to control head-to-head (p < 0.05). Moreover, lower RPE was found for the control and control head-to-head conditions than mental fatigue head-to-head and mental fatigue experimental conditions (p < 0.05). Higher pupil diameter was also found for mental fatigue head-to-head, control head-to-head, and control than the mental fatigue experimental condition (p < 0.05). In summary, the overall performance throughout the 20-km cycling time trial was improved by the presence of a virtual opponent for the mentally fatigued cyclists.

How much does sleep deprivation impair endurance performance? A systematic review and meta-analysis.

We conducted a systematic review and meta-analysis to investigate the effect of sleep deprivation on endurance performance, as well as possible effect-modifying factors. Searches were done in Pubmed, Web of Science, Embase, and Scopus on 12 July 2022. We additionally searched the bibliographic references and citations on Google Scholar of the papers whose full text was analyzed. Eligible studies were randomized and non-randomized controlled trials that compared sleep deprivation and habitual-sleep night effects on endurance performance in healthy humans. The studies' quality was examined by the Cochrane Collaboration's risk of bias tool. We calculated the pooled standardized mean differences (pooled SMD) and 95% confidence interval (95%CI) by a random-effects model. A mixed-effects model analyzed subgroups. Thirty-one studies were analyzed (n = 478), generating 38 effect sizes in full. The overall risk of bias was low in 8% of the studies, unclear in 74%, and high in 18%. Sleep deprivation in general had a moderate negative effect on endurance performance (polled SMD [95%CI] = -0.52 [-0.67; -0.38]). Training status, sleep deprivation magnitude, assessment time, exercise mode, and endpoint type did not influence the sleep deprivation effect, whereas longer exercises (>30 min) were more affected by sleep deprivation than shorter ones (P = 0.035). Therefore, the available evidence supports that sleep deprivation's deleterious effect on endurance performance is of moderate size and depends on exercise duration. This information can be useful to estimate the performance decrement of endurance exercise practitioners under sleep deprivation in training routines and competitions.PROSPERO registration number CRD42021229717.

Sleep deprivation causes a moderate deleterious effect on endurance performance.Sleep deprivation similarly impairs endurance performance in untrained, recreationally-trained, and trained people, but its effect on well-trained and professional endurance athletes is unknown.One or more nights of partial sleep deprivation or one night of total sleep deprivation similarly compromise endurance performance. Uncertainties about the effect of more than one night of total sleep deprivation warrant more studies.Sleep deprivation impairs walking, running, and cycling endurance performance regardless of the exercise endpoint being unknown (i.e. incremental or constant load tests) or known (i.e. time trial tests) and assessment time. However, sleep deprivation causes a more deleterious effect on endurance performance in exercises lasting more than 30 min.

Acute Neuromuscular, Physiological and Performance Responses After Strength Training in Runners: A Systematic Review and Meta-Analysis.

BACKGROUND: Strength training (ST) is commonly used to improve muscle strength, power, and neuromuscular adaptations and is recommended combined with runner training. It is possible that the acute effects of the strength training session lead to deleterious effects in the subsequent running. The aim of this systematic review and meta-analysis was to verify the acute effects of ST session on the neuromuscular, physiological and performance variables of runners. METHODS: Studies evaluating running performance after resistance exercise in runners in the PubMed and Scopus databases were selected. From 6532 initial references, 19 were selected for qualitative analysis and 13 for meta-analysis. The variables of peak torque (PT), creatine kinase (CK), delayed-onset muscle soreness (DOMS), rating of perceived exertion (RPE), countermovement jump (CMJ), ventilation (VE), oxygen consumption (VO2), lactate (La) and heart rate (HR) were evaluated. RESULTS: The methodological quality of the included studies was considered reasonable; the meta-analysis indicated that the variables PT (p = 0.003), DOMS (p < 0.0001), CK (p < 0.0001), RPE (p < 0.0001) had a deleterious effect for the experimental group; for CMJ, VE, VO2, La, FC there was no difference. By qualitative synthesis, running performance showed a reduction in speed for the experimental group in two studies and in all that assessed time to exhaustion. CONCLUSION: The evidence indicated that acute strength training was associated with a decrease in PT, increases in DOMS, CK, RPE and had a low impact on the acute responses of CMJ, VE, VO2, La, HR and submaximal running sessions.

Age and Maturity Effects on Morphological and Physical Performance Measures of Adolescent Judo Athletes.

Studies assessing age and maturation effects on morphological and physical performance measures of young judokas are scarce. This study aimed to assess the independent and combined effects of chronological age and biological maturation on anthropometry and physical performance of 67 judokas aged 11-14. Participants' anthropometric profiles were assessed, and physical performance tests were completed. Multivariate analyses of variance revealed an independent effect of age (anthropometry: F = 1.871; p < 0.05; Pillai's trace = 0.545; η2 p = 0.272; physical performance: F = 2.876; p < 0.01; Pillai's trace = 0.509; η2 p = 0.254) and maturity (anthropometry: F = 10.085; p < 0.01; Pillai's trace = 0.669; η2 p = 0.669; physical performance: F = 11.700; p < 0.01; Pillai's trace = 0.581; η2 p = 0.581). There was no significant combined effect of age and maturity. The maturation effect remained significant when controlled for age (anthropometry: F = 4.097; p < 0.01; Pillai's trace = 0.481; η2 p = 0.481; physical performance: F = 3.859; p < 0.01; Pillai's trace = 0.0.318; η2 p = 0.318). Inadolescent judokas, the maturation effect on growth and physical performance seems to be more relevant than the age effect, leading to the need to control this effect in training routines and competitive events. As in studies with youth soccer players and other youth athletes, bio-banding can be a strategy for controlling maturation in combat sports.

The MCT1 gene Glu490Asp polymorphism (rs1049434) is associated with endurance athlete status, lower blood lactate accumulation and higher maximum oxygen uptake.

The purpose of this study was to explore the association of the MCT1 gene Glu490Asp polymorphism (rs1049434) with athletic status and performance of endurance athletes. A total of 1,208 Brazilians (318 endurance athletes and 890 non-athletes) and 867 Europeans (315 endurance athletes and 552 non-athletes) were evaluated in a case-control approach. Brazilian participants were classified based on self-declared ethnicity to test whether the polymorphism was different between Caucasians and Afro-descendants. Moreover, 66 Hungarian athletes underwent an incremental test until exhaustion to assess blood lactate levels, while 46 Russian athletes had their maximum oxygen uptake ( V ⋅ O 2 max ) compared between genotypes. In the Brazilian cohort, the major T-allele was more frequent in Caucasian top-level competitors compared to their counterparts of lower competitive level (P = 0.039), and in Afro-descendant athletes compared to non-athletes (P = 0.015). Similarly, the T-allele was more frequent in European athletes (P = 0.029). Meta-analysis of the Brazilian and European cohorts confirmed that the T-allele is over-represented in endurance athletes (OR: 1.48, P = 0.03), especially when Afro-descendant athletes were included in the meta-analysis (OR: 1.58, P = 0.005). Furthermore, carriers of the T/T genotype accumulated less blood lactate in response to intense effort (P < 0.01) and exhibited higher V ⋅ O 2 max (P = 0.04). In conclusion, the Glu490Asp polymorphism was associated with endurance athletic status and performance. Our findings suggest that, although ethnic differences may exist, the presence of the major T-allele (i.e., the Glu-490 allele) favours endurance performance more than the mutant A-allele (i.e., the 490-Asp allele).

Evaluation of maximal lactate steady state in middle-aged hypertensive women

Abstract AIM The aim of this study was to investigate the lactate response in physically inactive hypertensive women submitted to the treadmill maximal lactate steady state (MLSS) protocol. METHODS Twenty-two hypertensive women (40 - 64 years) performed a familiarization period of walking on the treadmill following by one incremental test for estimating the initial workload for exercise testing. MLSS protocol was composed by walking in a treadmill during thirty minutes with fixed velocity in 5.5 km/h. Incline was used for determination of the intensity of each volunteer. Blood samples were collected from the ear lobe in the rest period, minute 10th and at the end of the test (minute 30th or at exhaustion time point) for lactate analysis. RESULTS Hypertensive women showed a lower lactate concentration at MLSS (3.25 ± 0.81 mmol/L) as compared with data obtained in the literature (4 mmol/L), approximately 18.8%. Neither inclines nor age affected MLSS parameters in the population. A positive and strong correlation was found between incline and MLSS, as well as incline and lactate level at minute 30th, even when adjusted by age factor. CONCLUSION Physically inactive hypertensive women show a lower MLSS than the average established in the literature but within the range of variations previously reported. Furthermore, a higher MLSS incline correlates positive and directly with higher lactate concentrations for the same aerobic capacity regardless of age.

Analysis of reliability of peak treadmill running in maximum progressive effort test: influence of training level / Análise de confiabilidade da velocidade pico em teste de esforço progressivo máximo: influência do nível de treinamento

OBJECTIVE: To determine the reliability (stability) of the peak velocity measurement (VPeak) derived from the incremental maximal effort test, as well as to establish the possible influence of the level of training on these responses. METHOD: Thirty-eight male volunteers made two visits (3 - 5 days apart) to the training center where the study was conducted and performed maximal progressive running tests. The protocol consisted of increments of 0.5 km.h-1/min, starting at a running speed comfortable for each participant (7-9 km.h-1). All subjects were encouraged to achieve the maximum possible performance in both tests, with final voluntary exhaustion being the criterion for interruption. RESULTS: The intra-class correlation coefficient presented excellent consistency of measurements (ICC = 0.975 - p = 0.001). The typical relative error of the measurement was 2.6% for the stability of the measurement of VPeak. Moreover, there were no significant differences between the individual coefficients of variation for measures 1 vs. 2 (p > 0.05). Graphical representation of Bland-Altman demonstrated a homogeneous distribution of the measurement error for all dependent variables. CONCLUSION: Determination of VPeak exhibited excellent levels of reliability with small measurement errors. There was no influence of the training level on the reliability responses.

OBJETIVO: Determinar a confiabilidade (estabilidade) da medida de velocidade de pico (VPico) derivada do teste incremental de esforço progressivo máximo, bem como estabelecer a possível influência do nível de treinamento sobre estas respostas. MÉTODO: Trinta e oito voluntários fizeram duas visitas ao centro de treinamento com intervalo de três a cinco dias. Na primeira visita os voluntários assinaram um termo de consentimento, tiveram suas medidas antropométricas registradas e realizaram a primeira sessão de corrida progressiva máxima. Na segunda visita o teste progressivo máximo foi novamente realizado. O protocolo consistiu em incrementos de 0,5 km.h-1 a cada min iniciando a uma velocidade individual de corrida classificada como confortável por cada participante (7 a 9 km.h-1). Todos os participantes foram encorajados a alcançar o máximo de desempenho possível em ambos os testes, tendo como critério de finalização, a exaustão voluntária máxima. RESULTADO: O coeficiente de correlação intra-classe (CCI) apresentou excelente consistência da medida (0,975) para VPico (p = 0,001). O erro típico relativo da medida foi de 2,6% para a estabilidade da medida de VPico. Não foram observadas diferenças significativas entre os coeficientes de variação individuais para as medidas G1 vs. G2 (p > 0,05). A representação gráfica de Bland-Altman demonstrou distribuição homogênea do erro da medida para todas as variáveis dependentes. CONCLUSÃO: A determinação da VPico exibiu excelentes níveis de confiabilidade, com pequenos erros de medida. Não houve influência do nível de treinamento sobre as respostas de confiabilidade.

Running economy in elite soccer and futsal players: differences among positions on the field / Economia de corrida em jogadores de futebol e futsal de elite: diferenças entre as posições em campo

OBJECTIVE: To determine running economy in a large sample of elite soccer and futsal players to obtain benchmarks in different positions. METHODS: Running Economy is the energy demand at a submaximal running velocity. Players were divided into 6 subgroups. Soccer: defenders, midfielders, and strikers; futsal: defenders, wingers, and pivots. Elite soccer players (n=129) and elite futsal players n=72 performed an incremental running test starting at 8.4 km.h-1 with increments of 1.2 km.h-1 every two minutes on a treadmill until exhaustion. Running Economy was determined by interpolation between ventilatory thresholds 1 and 2 (VT1 and VT2). RESULTS: Running Economy (measured as mL.kg-1.km-1) was compared between the playing positions in the two team sports. In soccer, running economy was 222.7 (defenders), 227.0 (midfielders), and 219.8 (strikers) mL.kg-1.km-1, respectively. In futsal, the corresponding values were 198.5 (defenders), 196.9 (wingers), and 190.5 (pivots) mL.kg-1.km-1, respectively. We no found significantly differences between the three positions in both sports. The Running Economy of futsal players was 12.5% better than that of soccer players. Running Economy correlated positively with oxygen uptake at VT2 in both sports and in all positions. CONCLUSION: Futsal players exhibited better Running Economy than soccer players; this should be considered as a factor in the athlete's training plan.

OBJETIVO: Determinar a Economia de Corrida numa grande amostra de jogadores de futebol e futsal de elite em diferentes posições do campo. METODOS: Os jogadores foram subdivididos em três subgrupos: futebol (jogadores de defesa, meio-campistas e atacantes) e futsal (jogadores de defesa, alas e pivôs). Foram 129 jogadores de futebol e 72 jogadores de futsal, que competem nas respectivas primeiras divisões do Brasil. Os jogadores foram submetidos a teste de esforço em esteira (8,4 km-1.h+1,2km-1.h a cada dois minutos) até a exaustão. Consumo máximo de oxigênio, limiares ventilatórios e Economia de Corrida foram registrados por análise de troca gasosa respiratória. A Economia de Corrida foi determinada por interpolação utilizando as velocidades dos limiares ventilatórios 1 e 2 e o consume de oxigênio nas duas velocidades. RESULTADOS: Os valores de Economia de Corrida entre as posições nos dois esportes foram os seguintes: Futebol, jogadores de defesa (222,7±16,7mL.kg-1.km-1), meio-campistas (227±19,9mL.kg-1.km-1), e atacantes (219,8±17,2mL.kg-1.km-1). Futsal, jogadores de defesa (198,5±10,8mL.kg-1.km-1), alas (196,9±16,2mL.kg-1.km-1), e pivôs (190,5±11,8mL.kg-1.km-1). Não foram encontradas diferenças significativas entre as três posições em ambos os esportes. A Economia de Corrida dos jogadores de futsal foi 12,5% melhor do que dos jogadores de futebol. Neste estudo, os jogadores da posição pivô no futsal tiveram os melhores valores de Economia de Corrida (custo de oxigênio mais baixo). Embora o consumo máximo de oxigênio (VO2max) e o limiar ventilatório 2 (LV2) fosse maior nos jogadores de futebol, a Economia de Consumo foi pior. Esta correlacionou-se positivamente com o VO2 no LV2 em ambos os esportes e em todas as posições CONCLUSÃO: Futsal tem melhor Economia de Consumo do que futebol. O presente estudo aponta a importância dos índices Economia de Consumo no plano de treinamento físico dos atletas.

Subchronic exposure to chlorpyrifos affects energy expenditure and detoxification capacity in juvenile Japanese quails.

Effects of pesticides on non-target organisms have been studied in several taxa at different levels of biological organization, from enzymatic to behavioral responses. Although the physiological responses may be associated with higher energy costs, little is known about metabolic costs of pesticide detoxification in birds. To fill this gap, we exposed orally (diet) 15-d old Coturnix coturnix japonica individuals to sublethal doses of chlorpyrifos (10 and 20 mg active ingredient/kg dry food) for four weeks. Carboxylesterase (CbE), butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) activities were periodically measured in multiple tissues along with measurements of resting (RMR) and maximum metabolic rates (M(sum)). Furthermore, glucuronic acid in bird excreta was also assessed at the end of the trial. While CbE and BChE activities were inhibited by chlorpyrifos in all tissues during the third and fourth weeks following pesticide treatment, AChE activity was unaffected. At this sampling times, both M(sum) and RMR expansibility decreased. These results suggest that the exposure to chlorpyrifos caused a negative effect on aerobic performance. Additionally, excretion rate of glucuronic acid was up to 2-fold higher in the 20-mg/kg group than in the control and 10-mg/kg chlorpyrifos groups. The inhibition of CbE and BChE activities corroborated that these enzymes are fulfilling their role as bioscavengers for organophosphate pesticides, decreasing its concentration and thus protecting AChE activity against inhibition by chlorpyrifos.

Physiological characteristics, evaluation and prescription of aerobic training in Futsal / Características fisiológicas, avaliação e prescrição do treinamento aeróbio no Futsal

Abstract Futsal has intermittent characteristics with different requirements of displacements and changes of direction, requiring simultaneously aerobic and anaerobic capacities of athletes. So, during counter-attacks and returns to defense or fast movements to get rid or perform marking, there is maximum mobilization of specific capabilities of the sport and the ability to perform high-intensity intermittent exercise is a key factor of performance. The aim of this study was to perform an expositive review on the physiological characteristics, high-intensity interval training and aerobic evaluation methods that have been used and suggested in scientific literature in original studies. A search in scientific portals Google Scholar, Scopus®, SciELO®, ScienceDirect® (Elsevier) and PubMed® was conducted to find articles with publication date since 2000 using the following terms in different combinations: “Futsal”, “performance”, “aerobic evaluation”, “high-intensity interval training”, “field tests” and their variations in English. Analysis of physiological indexes related to game performance can help in the knowledge about the aerobic fitness of Futsal players and improve training assessment, prescription and monitoring, also serving as a reference to assist professionals of this sport in the preparation of high intensity interval training programs to meet the particular needs of the sport. Field tests with specific features of the sport were created as a means of assessment and also training prescription and are recommended due to their specificity and ecological validity.

Resumo O futsal apresenta características intermitentes com diferentes exigências de deslocamentos e mudanças de direção, exigindo simultaneamente as capacidades aeróbias e anaeróbias dos atletas. Assim, durante os contra-ataques e retornos à defesa, ou movimentações rápidas para se desmarcar ou realizar marcação, há uma mobilização máxima das capacidades específicas da modalidade, sendo que a habilidade de realizar exercícios intermitentes de alta intensidade é um fator decisivo da performance. O objetivo do presente trabalho foi realizar uma revisão de literatura expositiva sobre as características fisiológicas, treinamento intervalado de alta intensidade e métodos de avaliação aeróbia que vêm sendo utilizados e sugeridos na literatura científica em estudos originais. Realizou-se uma pesquisa nos portais científicos da Google Scholar, Scopus®, SciELO®, ScienceDirect® (Elsevier) e PubMed® buscando artigos com data de publicação a partir do ano 2000 pelos seguintes termos em diferentes combinações: “futsal”, “performance”, “avaliação aeróbia”, “treinamento intervalado de alta intensidade”, “testes de campo” e suas variações em inglês. A análise dos índices fisiológicos relacionados à performance de jogo podem auxiliar no conhecimento a respeito da aptidão aeróbia de jogadores de futsal e aprimorar a avaliação, prescrição e acompanhamento do treinamento. Adicionalmente, servem de referência para auxiliar os profissionais da modalidade na elaboração de programas de treinamento intervalado de alta intensidade que atendam às necessidades específicas do esporte. Os testes de campo com características próprias da modalidade foram criados como forma de avaliação e também prescrição de treinamento e são recomendados pela especificidade e validade ecológica que possuem.

Comparison of body composition and aerobic and anaerobic performance between competitive cyclists and triathletes / Comparação da composição corporal, desempenho aeróbio e anaeróbio entre ciclistas e triatletas competitivos

The aim of this study was to compare anthropometric characteristics and aerobic and anaerobic fitness between competitive cyclists and triathletes. The sample consisted of 11 cyclists and 12 triathletes with experience in competitions. The tests were performed on two different days, with an interval of 48 h between sessions. On the first day, the athletes were submitted to anthropometric assessment (body mass, height, and skinfold thickness) and a maximal incremental test to determine maximal oxygen uptake, maximum power, maximum heart rate, maximum lactate, and the first (LL1) and second lactate threshold (LL2). The Wingate test was conducted on the second day to determine peak power, average power, and fatigue index. There were significant difference (p < 0.05), with medium effect size (0.80 - 1.5), in mid-thigh skinfold thickness (15.2 ± 6.3 and 10.5 ± 4.8 mm), power at LL1 (195.0 ± 30.9 and 162.7 ± 28.3 W), power at LL2 (247.6 ± 25.0 and 219.7 ± 37.9 W), and fatigue index (47.2 ± 13.0 and 60.1 ± 16.4%) between cyclists and triathletes, respectively. The other variables did not differ between groups. Anthropometric characteristics are similar in triathletes and cyclists. However, cyclists present higher power outputs at the lactate thresholds (LL1 and LL2) and lower fatigue indexes.

O objetivo do presente estudo foi comparar as características antropométricas e aptidão aeróbia e anaeróbia entre ciclistas e triatletas competitivos. Participaram do estudo 11 ciclistas e 12 triatletas com experiência em competições esportivas. As avaliações foram realizadas em dois dias distintos, com intervalo de 48 h entre as sessões. No primeiro dia, foram realizados a avaliação antropométrica (massa corporal, estatura e dobras cutâneas) e um teste incremental máximo para determinação do consumo máximo de oxigênio, potência máxima, frequência cardíaca máxima, lactato máximo, primeiro limiar de lactato (LL1) e segundo limiar de lactato (LL2). No segundo dia, foi realizado um teste de Wingate para obter a potência pico, potência média e índice de fadiga. Houve diferença significativa (p < 0,05) e com tamanho de efeito moderado (0,80 - 1,5) para a dobra cutânea da coxa média (15,2 ± 6,3 e 10,5 ± 4,8 mm), potência no LL1 (195,0 ± 30,9 e 162,7 ± 28,3 W), potência no LL2 (247,6 ± 25 e 219,7 ± 37,9 W) e índice de fadiga (47,2 ± 13,0 e 60,1 ± 16,4 %) entre ciclistas e triatletas, respectivamente. As demais variáveis analisadas não diferiram estatisticamente entre os grupos. Os triatletas e ciclistas são semelhantes em relação às características antropométricas. No entanto, ciclistas apresentam maiores valores de potência nos limiares (LL1 e LL2) e menores valores do índice de fadiga.

Rendimiento aeróbico en niños obesos de 6 a 10 años / Aerobic performance in obese children of 6 to 10 years old

Objective: To study the relationship between aerobic performance and nutritional state in children of 6-10 years old. Method: Observational and cross-sectional design. A sample of 98 children (78 girls) attending school in the Metropolitan Region was taken. Of these, 47 were diagnosed as obese, 51 were used as controls. Aerobic performance was determined by distance walked (DW) in 6 minutes walk test (6MWT). Continuous measures of reserve heart rate (RHR) and subjective sense of fatigue (SSF) were taken. / or Wilcoxon tests were used for comparison between groups, Pearson coefficient for correlations and multiple regression to evaluate control variables. Significance level was set at p < 0.05. Results: DW in 6MWT shows differences according to nutritional state (p < 0.0001), with a mean distance of 627.6 +/- 24.5 m in control children vs 560 +/- 26.8 m in obese children; but these differences are independent of the gender and age variables. Values for RHR and SSF were similar for both groups except for SSF on the first minute. WD and body mass index showed inverse correlation (r = -0,58; p < 0.0001). Conclusions: The performance in 6MWT was lower among obese children, showing an independent relationship with nutritional state and limited cardiorespiratory efficiency, restricting functional activities in daily life.

Objetivo: Estudiar la relación entre rendimiento aeróbico y estado nutricional (EN) en escolares de 6 a 10 a±os. Método: Diseño observacional, corte transversal. Muestra: 98 escolares (78 mujeres), 51 controles (C) y 47 obesos (OB), de colegios de la Región Metropolitana. El rendimiento aeróbico se evaluó con distancia recorrida (DR) en el test de marcha en 6 minutos (TM6). Se estimó continuamente frecuencia cardíaca de reserva (FCR) y sensación subjetiva de fatiga (SSF). Para comparar medias, se usó test / o Wilcoxon; como índice de correlación, Pearson y para variables de control, regresión lineal múltiple; nivel de significancia, p < 0,05. Resultados: La DR en el TM6 se relacionó con EN (p < 0,0001), con media de DR 627,6 +/- 24,5 vs 560 +/- 26,8 m, en niños C y OB, respectivamente, asociación que no fue modificada por edad y género. Los valores de por ciento FCR y SSF fueron similares en los grupos, excepto la SSF del minuto 1. DR e IMC mostraron asociación inversa moderada (r = -0,58; p < 0,0001). Conclusión: El rendimiento en el TM6 fue menor en OB, mostrando una relación independiente con EN y limitada eficiencia cardiorrespiratoria, lo cual puede restringir la capacidad funcional en actividades de la vida diaria.

Correlações entre protocolos de determinação do limiar anaeróbio e o desempenho aeróbio em nadadores adolescentes / Correlations between anaerobic threshold determination protocols and aerobic performance in adolescent swimmers

O objetivo do presente estudo foi correlacionar as velocidades de limiar anaeróbio (LAn) obtidas a partir de concentrações fixas de lactato (VLAn 4 e VLAn 3,5mM), velocidade de lactato mínimo (VLac min) e velocidade crítica (VC) determinada a partir de diferentes distâncias e número de coordenadas: VC1 (50/100/200m), VC2 (100/200/400m), VC3 (50/100/200/400m) e VC4 (200/400m) com o desempenho nos 400m(s) em nadadores adolescentes. Fizeram parte da amostra 15 nadadores (10 meninos e cinco meninas = 14,7 ± 0,7 anos; 61,9 ± 8,5kg; 171,1 ± 8,8cm) de nível nacional, com experiência entre cinco e sete anos na natação competitiva. Para análise das correlações entre os índices e o desempenho nos 400m(s) foi utilizado o coeficiente de correlação de Pearson. O nível de significância adotado foi de p < 0,01. As correlações entre a VLAn 4mM, VLAn 3,5mM, VLac min e o desempenho nos 400m(s) foram de r = -0,63, r = -0,90 e r = -0,91, respectivamente (p < 0,01). As correlações entre a VC1 (50/100/200m), VC2 (100/200/400m), VC3 (50/100/200/400m), VC4 (200/400m) e o desempenho nos 400m(s) foram: r = -0,62, r = -0,97, r = -0,98 e r = -0,94, respectivamente (p < 0,01). Sugere-se que o LAn determinado a partir da concentração fixa de lactato de 3,5mM, bem como a VLac min e a VC obtidas por meio de distâncias maiores parecem ser os mais adequados índices preditores do desempenho aeróbio nos nadadores adolescentes estudados. Além disso, o número de coordenadas parece não influenciar a relação entre a VC e desempenho aeróbio.

The purpose of this study was to correlate the anaerobic threshold speeds (ATS) obtained from fixed lactate blood concentration (ATS 4 e ATS 3.5 mM), lactate minimum speed (Lac minS) and the critical speed (CS) determined from different distances and number of coordinates: CS1 (50/100/200 m), CS2 (100/200/400 m), CS3 (50/100/200/400 m) and CS4 (200/400 m) with the performance in 400 meters (s) in adolescent swimmers. The sample was constituted by 15 swimmers (10 boys and five girls = 14.7 ± 0.7 years; 61.9 ± 8.5 kg; 171.1 ± 8.8 cm) of national level, with five to seven years of experience in competitive swimming. The correlation between the indexes and the performance in 400 m (s) was made using Pearson correlation coefficients. Significance was set at p < 0.01. The correlations between ATS 4 mM, ATS 3.5 mM, Lac minS and the performance in 400 m (s) were: r = -0.63, r = -0.90 e r = 0.91, respectively (p < 0.01). The correlations between CS1 (50/100/200 m), CS2 (100/200/400 m), CS3 (50/100/200/400 m), CS4 (200/400 m) and the performance in 400 m (s) were: r = -0.62, r = -0.97, r = -0.98 e r = -0.94, respectively (p < 0.01). We suggest that ATS obtained from fixed lactate blood concentration of 3.5 mM, as well as Lac minS and the CS obtained through larger distances seem to be the most fitted indexes of prediction of the aerobic performance in the studied adolescent swimmers. Additionally, the number of coordinates seems no influencing the relation between CS and aerobic performance.