PurposeThe present study aims at investigating the physiological response and technical-tactical parameters in Brazilian jiu-jitsu competition.MethodsThe study included 35 male Brazilian jiu-jitsu athletes (adult category, body mass: 80.2 ± 13.0 kg), graded from white to brown belt, during combats fought at regional level. Twenty-two fights were analyzed in terms of technique and time structure. Blood glucose, lactate and maximal isometric grip strength were determined before and after the fights. The rate of perceived exertion was also assessed after the fight, using the 6-20 Borg rating. The fights were recorded and the following variables were determined: the exertion/pause ratio and subjective intensity of actions, categorized between low and high intensity.ResultsThe results indicated that during Brazilian jiu-jitsu fights, the glycolytic pathway is only moderately activated (lactate before: 4.4 (4.0 – 4.6) mmol/L, after: 10.1 (8.0 – 11.3) mmol/L; glucose before: 112.4 ± 22.3 mg/dL, after: 130.5 ± 31.0 mg/dL). The exertion during the fight resulted in significant reductions in handgrip strength (right hand grip before: 45.9 ± 10.3 kgf, after: 40.1 ± 9.5 kgf; left hand grip before: 44.2 ± 11.1 kgf, after: 37.0 ± 10.2 kgf). The athletes rated the fight as hard: 15 (13 – 15). Effort/pause ratio was 6:1, while high-intensity actions lasted approximately 4 s, resulting in a low/high intensity? ratio of 8:1.ConclusionIt is recommended that coaches direct the training loads to simulate the energy demand imposed by the competitive matches, activating moderately the glycolytic pathway. Moreover, the time structure of combats can be used to prescribe both physical and technical-tactical training.

The aim of this study was to analyze the effects of HRV-guided training compared to a standardized prescription on i) time to complete 5-km running performance (t5km), ii) peak treadmill running speed (Vpeak) and its time limit (tlim at Vpeak), and iii) autonomic cardiac modulation (i.e., parasympathetic activity and recovery) in untrained women. Additionally, we correlated changes in t5km with changes in Vpeak, tlim at Vpeak and autonomic cardiac modulation. Thirty-six untrained women were divided into a HRV-guided training group (HRVG) and a control group (CG). The CG followed a pre-defined program, alternating moderate-intensity continuous training (MICT) and high-intensity interval training (HIIT). The determination of MICT or HIIT was based on the pre-training HRV for HRVG. MICT was performed if HRV was < mean - 1 SD of previous measures. Otherwise, HIIT was prescribed. The t5km, Vpeak, tlim at Vpeak, parasympathetic activity (i.e., rMSSD) and parasympathetic reactivation (i.e., HRR) were measured before and after the training period. The t5km decreased to a greater magnitude in the HRVG (-17.5±5.6% vs. -14±4.7%; Effect Size (ES) between-group difference=moderate). rMSSD and tlim at Vpeak only improved in HRVG (+23.3±27.8% and +23.6±31.9%, respectively). The HRVG experienced greater improvements in Vpeak and HRR (Vpeak: 10±7.3% vs. 8.2±4.7%; HRR: 19.1±28.1% vs. 12.6±12.9%; ES between-group difference=small). Although HRVG performed less MICT than CG, the volume of MICT was negatively related to changes in t5km. Vpeak changes were highly correlated with t5km changes. The greater improvements in HRVG for t5km and autonomic modulation reinforce the potential application of this tool.

The aim of this study was to investigate the association between cardiac parasympathetic activity and cardiorespiratory fitness, insulin, and hemodynamic profile in overweight and obese adolescent girls and boys (aged 12-16 years). Data were taken from the Multidisciplinary Obesity Treatment Program. Only post-intervention measurements are presented herein. Body composition, cardiorespiratory fitness, blood pressure, and metabolic profile (insulin and glucose profile) of adolescents were assessed. Cardiac parasympathetic activity was determined by resting heart rate variability, which was analyzed using a heart rate monitor. Greater parasympathetic cardiac activity was associated with higher levels of cardiorespiratory fitness in both girls and boys (0.375 ≤ r ≤ 0.900), while the sympathetic-vagal balance was negatively related to maximal oxygen uptake (VO2max) in girls (r = 0.478). An association between lower parasympathetic activity and insulin resistance was noted in girls (mean of R-R intervals [RRmean] and homeostasis model assessment insulin-resistance index [HOMA-IR]: r = -0.678), while greater systolic blood pressure (SBP) and lower parasympathetic activity were associated in both sexes (RRmean and SBP: r = -0.526; high frequency [HF (nu)] and SBP: r = -0.754). In conclusion, autonomic nervous system activity was associated with cardiorespiratory fitness, insulin resistance, and SBP in overweight and obese adolescents. The identification of these potential relationships assists with the establishment of future long-term exercise interventions that evaluate the improvements in parasympathetic nervous system activity, in addition to metabolic profile and cardiorespiratory fitness in overweight and obese adolescents.

This study aims to assess the effects of a 16-week multidisciplinary program of obesity treatment on the control of metabolic syndrome (MS) and dyslipidemia in obese adolescents. Eighty-six adolescents aged 10-18 years were allocated in either the intervention group (IG; n = 44) or control group (CG; n = 42). IG was submitted to a multidisciplinary intervention based on cognitive behavioral therapy that aimed to modify eating habits and exercise behavior. We analyzed, before and after the intervention period, anthropometric parameters, body composition, bone mineral density, cardiorespiratory fitness, blood pressure, glucose, insulin, and lipid profile of the subjects. MS was classified according to International Diabetes Federation (2007) and the presence of dyslipidemia according to Back et al. (Arq Bras Cardiol 85:4-36, 2005). In the beginning of the intervention, the median number (range) of risk factors for MS present was 2.0 (0.0-5.0) in the IG and 2.0 (0.0-4.0) in the CG. After the intervention, this parameter reduced significantly in the IG (1.0 (0.0-5.0); p = 0.004) while no change was observed in the CG (2.0 (0.0-4.0); p = 0.349). In addition, we observed improvements in body mass index, waist circumference, hip circumference, maximal oxygen uptake, absolute and relative body fat, systolic blood pressure, diastolic blood pressure, and total cholesterol in the IG which was not identified in the CG. Conclusio n: We suggest that a 16-week multidisciplinary intervention based on cognitive behavioral therapy was adequate to reduce risk factors for MS in obese adolescents.

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To determine the effects of preparatory phase training on aerobic parameters, resting heart rate variability (HRV) and 5-km performance of high-level endurance runners and the relationship between the percentage change (% change) of resting HRV with the % change of aerobic parameters and 5-km performance. Six runners were assessed before and after seven weeks of training. The aerobic parameters were determined in an incremental test. The HRV was assessed by a heart rate monitor. Athletes performed a 5-km running test in a track. The analysis revealed 'likely' and 'very likely' improvements for velocity associated with maximal oxygen uptake ([Formula: see text]O2max) (20.0±1.0 km·h(-1) to 21.2±0.6 km·h(-1)) and 5-km performance (18.0±0.4 km·h(-1) to 18.9±0.7 km·h(-1)), respectively, as well as 'likely' decrease in high frequency (41.4±18.5 nu to 30.4±14.3 nu), and increase in low frequency (58.5±18.5 nu to 69.6±14.3 nu) band densities. The variation in the velocity associated with [Formula: see text]O2max showed the highest correlation with 5-km performance (r=0.95). The % change in the square root of the mean sum of the squared differences between R-R intervals and standard deviation 1 were highly correlated with variation in 5-km performance (r=0.69 and 0.66). Changes in the velocity associated with [Formula: see text]O2max and vagally mediated HRV were highly associated with 5-km running performance within the investigated team. These results have important implications because these parameters can be assessed longitudinally to monitor adaptation to training.

O objetivo do estudo foi avaliar os efeitos de um programa multiprofissional de tratamento da obesidade (PMTO) e de sua cessação sobre a aptidão física e composição corporal de adolescentes. Foi conduzido um estudo quase-experimental com 19 adolescentes com excesso de peso de ambos os gêneros e idade entre dez e 18 anos. Os mesmos foram submetidos a 16 semanas de intervenção com foco na mudança do comportamento alimentar e de atividade física. Na sequência, os adolescentes retornaram para avaliação após oito semanas de cessação das atividades. Foram observadas mudanças na aptidão cardiorrespiratória (26,39±6,18 mL/kg/min para 30,99±7,84 mL/kg/min) e gordura corporal (40,67±6,61% para 36,73±7,77%), com o PMTO, porém essas melhoras não se mantiveram após o período de cessação (27,56±7,31 mL/kg/min e 38,09±7,84%, respectivamente). Os resultados demonstraram que 16 semanas são suficientes para promover mudanças na aptidão física e composição corporal, entretanto, estas parecem não ser incorporadas no novo estilo de vida dos adolescentes.

ObjectiveTo systematically review the literature and describe the discrepancies in achieving the 2009 Institute of Medicine (IOM) gestational weight gain (GWG) guidelines across cultures.MethodsTen databases were searched from inception to April 2018. Observational cohort studies were included that examined adult women; reported on a measure of culture; compared cultural groups, and reported on GWG. Articles were broken down into papers that used the current 2009 IOM GWG guidelines and those that used others. A meta-analysis was conducted for studies using the 2009 guidelines examining the prevalence of discordant GWG across cultural groups.ResultsThe review included 86 studies. Overall, 69% of women experienced discordant GWG irrespective of culture. White women experienced excessive GWG most often, and significantly more than Asian and Hispanic women; Black women had a higher prevalence of excessive GWG than Hispanic and Asian women; however, this difference was not significant.ConclusionsThe majority of women experience excessive GWG, with White women experiencing this most often. Culturally diverse GWG guidelines are needed to individualize antenatal care and promote optimal maternal-fetal health outcomes across cultural groups.