Influence of Intensity on Post-Running Jump Potentiation in Recreational Runners vs. Physically Active Individuals.

The aim of this study was to verify post-activation performance enhancement (PAPE) in jumping and sprinting after two endurance volume-equated running protocols with different intensities, in runners vs. active individuals. Nine recreational runners (age: 34.5 ± 9.3 years, body mass: 73.1 ± 11.9 kg, body height: 1.76 ± 0.06 m, 17.4 ± 4.4 %body fat; maximum aerobic speed [MAS]: 16.4 ± 1.0 km•h-1), and 9 active individuals (age: 34.1 ± 9.4 years; body mass: 83.2 ± 7.7 kg; body height: 1.79 ± 0.06 m; 25.6 ± 5.4 %body fat; MAS: 13.3 ± 1.2 km•h-1) volunteered for participation. The evaluations were performed over three days as follows: 1) anthropometric measures, physical fitness tests, and the University of Montreal Track Test (UMTT) to determine MAS and the distance to be covered in the running protocols; 2 and 3) the countermovement jump (CMJ) and the flying 20-m sprint (SPRINT) were assessed pre- and post-running at 70% of MAS or a time trial race (TTR), equated by volume and completed in random order. A three-way ANOVA (time*group*running) was performed to analyze the PAPE effects. The results showed a time effect (F = 10 .716; p < 0.01) and a group*running interaction (F = 12.094; p < 0.01) for the CMJ, indicating that active individuals demonstrated PAPE after running at 70% of MAS, while for runners both running interventions (70% of MAS and TTR) induced PAPE in CMJ performances. For the SPRINT, a time*group interaction (F = 4.790; p = 0.044) and a group effect were observed, with runners showing greater SPRINT performances than active individuals. From the current results, it can be suggested that training background and intensity can modulate PAPE responses in jumping and sprinting after volume-equated running protocols at different intensities.

Effects of Photobiomodulation Therapy on Performance in Successive Time-to-Exhaustion Cycling Tests: A Randomized Double-Blinded Placebo-Controlled Trial.

The goal of this study was to investigate the effects of photobiomodulation therapy (PBMT) on performance, oxygen uptake (VO2) kinetics, and lower limb muscle oxygenation during three successive time-to-exhaustions (TTEs) in cyclists. This was a double-blind, randomized, crossover, placebo-controlled trial study. Sixteen cyclists (~23 years) with a cycling training volume of ~460 km/week volunteered for this study. In the first session, cyclists performed a maximal incremental test to determine maximal oxygen uptake and maximal power output (POMAX). In the following sessions, cyclists performed three consecutive TTEs at POMAX. Before each test, PBMT (135 J/thigh) or a placebo (PLA) was applied to both thighs. VO2 amplitude, O2 deficit, time delay, oxyhemoglobin (O2Hb), deoxyhemoglobin (HHb), and total hemoglobin (tHb) were measured during tests on the right vastus lateralis. The PBMT applied before three successive TTE increased performance of the first and second TTE (~10-12%) tests, speed of VO2 and HHb kinetics during the first test, and increased peripheral muscle oxygenation (increase in HHb and tHb) in the first and second exhaustion tests. However, the PBMT effects were attenuated in the third TTE, as performance and all the other outcomes were similar to the ones from the PLA intervention. In summary, PBMT application increased the first and second successive TTEs, speed of VO2, and muscle oxygenation.

Brazilian Jiu-Jitsu fighters present greatest rapid and maximal strength imbalances at extreme elbow angles.

BACKGROUND: The performance of Brazilian jiu-jitsu (BJJ) fighters is dependent on rapid and maximal elbow strength actions. Appropriate strength balance between elbow flexors (F) and extensors (E) across the full joint range of motion may be required to decrease risk of injuries. AIM: To compare rapid and maximal elbow F/E strength balance through full range of motion in BJJ fighters. MATERIALS AND METHODS: Twenty-three male BJJ fighters (27.9 ± 4.6 years, 82.9 ± 10.9 kg, 174.5 ± 6.8 cm, and 15.3 ± 6.8% body fat) with 8.2 ± 6.5 years of practice volunteered to participate. Participants were tested for rate of torque development (RTD) and peak torque (PT) of elbow F and E at six angles (45°, 60°, 75°, 90°, 105°, and 120°; 0° = full extension). Rapid (F RTD/E RTD) and maximal (F PT/E PT) angle-specific torque (AST) ratios were calculated. RESULTS: Rapid AST ratio at 45° (0.66 ± 0.18) and maximal AST ratio at 45° (0.91 ± 0.16) and 120° (0.88 ± 0.20) were significantly less than all other AST ratios at mid-point angles of elbow range of motion (p < 0.05). Individual data demonstrates that both beginners and advanced BJJ fighters present overall similar rapid and maximal F/E AST imbalances. CONCLUSION: BJJ fighters present greater rapid and maximal strength imbalances at extreme-compared to mid-point angles of range of motion. Results may benefit coaches to develop strength exercises focusing on these specific angles to potentially reduce the risk of elbow injury and improve performance of BJJ fighters.

Comportamento sedentário de adultos e idosos durante a pandemia de COVID-19 / Sedentary behavior of adults and elderly people during COVID-19 pandemic

Objetivo: avaliar a associação entre indicadores de comportamento sedentário e variáveis sociodemográficas em adultos e idosos de Campo Grande/MS, durante o período de vigência das medidas de distanciamento social para conter a pandemia de COVID-19 no ano de 2020. Métodos: a coleta de dados ocorreu com uso de formulário online distribuído via aplicativo de mensagem aos adultos e idosos, de ambos os sexos, cadastrados no programa de promoção de atividades físicas da Fundação Municipal de Esportes do Município de Campo Grande-MS. Utilizou-se amostragem não probabilística por julgamento, com distribuição e recebimento do formulário online entre os dias 7 e 14 de abril de 2020. Resultados: foram obtidos 1907 formulários com respostas válidas. A maioria dos participantes excedeu o valor considerado adequado à saúde para o tempo de tela (86,7%), mas, simultaneamente, a maioria do grupo se manteve com valores recomendados para o tempo sentado (61,4%). Os idosos diferiram dos adultos (p<0,01), com menor frequência de tempo de tela e maior proporção de tempo sentado. Conclusões: durante o período de distanciamento social, o tempo de tela foi o comportamento sedentário com frequência mais elevada na população geral, mas os idosos foram mais expostos ao excessivo tempo sentado.

Objective: to analyse the association between sedentary behaviour parameters and sociodemographic variables in adults and elderly of Campo Grande/MS, Brazil, during the social distancing period due to the COVID-19 pandemic in the year 2020. Methods: For data collection, an online form was applied through a messaging app for adults and elderly registered in the promotion of the physical activity program of the Municipal Sports Foundation of the City of Campo Grande/MS. A non-probabilistic sampling was used in the present study, in which the data collection was performed between April 7th and 14th, 2020. Results: 1907 forms were answered. The majority of participants presented excessive screen time (86.7%), however, a high proportion of participants had adequate values for sitting time (61.4%). The difference was observed between elderly and adults (p<0.01), in which low and high proportions of the screen and sitting time were observed for the elderly, respectively. Conclusion: During the social distancing period, the screen time was the sedentary behaviour more frequent, but for the elderly, the sitting time was the main sedentary behaviour.

Effect of Photobiomodulation Therapy in the 1500 m Run: An Analysis of Performance and Individual Responsiveness.

Objective: The aims of this study were to verify the effects of photobiomodulation therapy (PBMT) on time trial run performance over 1500 m, as well as on individual responsiveness of recreative runners. Materials and methods: Nineteen recreationally trained runners participated in a randomized, crossover, double-blind placebo-controlled trial. The study was divided in four sessions: (1) incremental maximal running test; (2) 1500 m run control (without placebo or PBMT); and (3, 4) PBMT or placebo before 1500 m run. PBMT or placebo was applied over 14 sites per lower limb immediately before time trial run using a mixed wavelength device (33 diodes: 5 LASERs of 850 nm, 12 LEDs of 670 nm, 8 LEDs of 880 nm, and 8 LEDs with 950 nm). PBMT delivered 30 J per site, with a total energy dose of 840 J. Physiological variables [maximal oxygen uptake (VO2MAX), velocity associated to VO2MAX (vVO2MAX), peak of velocity, and respiratory compensation point (RCP)] were assessed during incremental maximal test. During 1500 m races we accessed the following: time, heart rate, and lower limb rate perception exertion per lap, total time, and blood lactate concentration ([Lac]). Results: PBMT had no significant difference and likely trivial effect for performance in the total time trial run over 1500 m compared to placebo. In the responsiveness analyses, 10 participants positively responded to PBMT, whereas total time reduced for responders (-10.6 sec; -3.18%) and increased for nonresponders (+6.0 sec; +1.73%). Responders presented higher aerobic parameters (VO2MAX and RCP) than nonresponders. Moreover, responders had lower time per lap and [Lac] (1 and 3 min) when PBMT was applied. Conclusions: PBMT applied immediately before running in noncontrolled environment was not able to improve the 1500 m performance of recreationally trained runners. However, responders to PBMT presented higher aerobic capacity than nonresponders.

Dose-Response Effect of Photobiomodulation Therapy on Muscle Performance and Fatigue During a Multiple-Set Knee Extension Exercise: A Randomized, Crossover, Double-Blind Placebo-Controlled Trial.

Objective: The aim of this study was to identify the best energy dose of photobiomodulation therapy (PBMT) able to improve muscle performance and reduce fatigue during multiple-set knee extension exercise. Methods: Eighteen physically active men participated in this study. Each participant performed an isokinetic exercise protocol (5 sets of 10 knee extension repetitions, maximum contractions at 60°·s-1) in 6 sessions, 1 week apart. Control condition (no PBMT/placebo treatments) was applied at the first and sixth sessions. Placebo or PBMT with 135, 270, or 540 J/quadriceps was randomly applied from the second to fifth sessions. Placebo/PBMT treatments were always applied at two moments: 6 h before and immediately before exercise. The isometric and isokinetic concentric peak torques were assessed before and after the exercise protocol. Results: The knee extension exercise performance (total work performed during exercise) was not affected by PBMT (135, 270, and 540 J) compared with placebo treatment. However, all PBMT treatments (135, 270, and 540 J) led to lower percentage drop compared with placebo and control conditions on isometric peak torque (IPT), concentric peak torque (CPT), and concentric work (W). All PBMT doses led to possibly positive or likely positive effects on IPT, CPT, and W compared with placebo. Conclusions: Our findings demonstrate that PBMT with 135, 270, and 540 J applied at two moments (6 h before and immediately before exercise) was able to produce the same total work with lower fatigue, which may facilitate the performance of additional sets (i.e., higher training volume).

Head Trauma Exposure in Mixed Martial Arts Varies According to Sex and Weight Class.

BACKGROUND: Brain injury arising from head trauma is a major concern in mixed martial arts (MMA) because knockout (KO) and technical knockout (TKO) are frequent fight outcomes. Previous studies have shown a high incidence of matches ending due to strikes to the head but did not consider weight categories and female fights. This study aimed at analyzing match stoppages in MMA and the exposure to head trauma distinguished by sex and weight categories. HYPOTHESIS: The heavier the weight class, the greater the risk and incidence of head trauma will be, regardless of sex. STUDY DESIGN: Descriptive epidemiology study. LEVEL OF EVIDENCE: Level 3. METHODS: Publicly available data of 167 MMA events from 1903 fights between 2014 and 2017 were assessed, comprising 8 male and 2 female weight categories. RESULTS: The combined KO/TKO rates per 100 athlete-exposures in the middleweight (19.53), light heavyweight (20.8), and heavyweight (26.09) divisions were greater than previously reported for MMA. While stoppage via KO/TKO occurred in 7.9% of combats in the female strawweight division, it occurred in 52.1% of the male heavyweight fights. The male middleweight ( P = 0.001), light heavyweight ( P < 0.001), and heavyweight divisions ( P < 0.001) had an increased risk of KO/TKO due to strikes to the head by 80%, 100%, and 206%, respectively. The risk in the flyweight division decreased 62% ( P = 0.001). All categories were compared with the lightweight division. The female bantamweight category presented a 221% increased risk in matches ending due to KO/TKO compared with the strawweight division ( P = 0.012). Punches to the head were the major technique used to end a combat via KO/TKO, regardless of sex and weight class. CONCLUSION: Head injury risk and incidence varies considerably according to sex and weight category in MMA. CLINICAL RELEVANCE: The analysis of head trauma exposure in MMA athletes should be distinguished according to sex and weight category.

Injury prevalence in Brazilian jiu-jitsu athletes: comparison between different competitive levels / Prevalência de lesões em atletas de Brazilian jiu-jitsu: comparação entre diferentes níveis competitivos

Abstract This study aimed to identify types and sites of body injury, location of injury occurrence, and the mechanism and severity of injuries in novice and advanced Brazilian jiu-jitsu (BJJ) athletes. One hundred and eight BJJ athletes took part in this study separated in two groups: advanced (n = 53) and novice (n = 55). Athletes answered a questionnaire concerning regions of injury, locality of occurrence, injury severity and mechanism. Chi square test and a logistic regression analysis were used with the level of significance set at p < 0.05. The main results showed that shoulders and knees were the most injury location reported by novice and advanced athletes. Novice athletes demonstrated higher prevalence of injuries during training sessions (54.5%), whereas advanced athletes reported more injuries during competitions (66.1%). Significant associations between novice and advanced athletes were observed for major joints (p < 0.05). The odds ratio of having injury was 70-87% less for novice versus advanced athletes for the major joints cited. We concluded that BJJ athletes demonstrate high prevalence of injury mainly at knee and shoulder. While risk of injury appeared less in novice, the advanced demonstrated higher number of injuries during competitions as a consequence of injured joint keys. By contrast, novice athletes reported higher number of injuries associated with training sessions as a consequence of overuse.

Resumo O objetivo deste estudo foi verificar as regiões do corpo afetadas por lesões, o local de maior ocorrência de lesão, o mecanismo e a gravidade das lesões em atletas iniciantes e avançados de Brazilian jiu-jitsu (BJJ). Cento e oito atletas participaram deste estudo, separados em dois grupos: avançados (n = 53) e iniciantes (n = 55). Os atletas responderam um questionário sobre as regiões acometidas por lesões, local de ocorrência, grau de gravidade e mecanismos. O teste do Qui-Quadrado e análise de regressão logística foram utilizados com o nível de significância de p < 0,05. Os principais resultados mostraram que o ombro e o joelho foram os locais de lesão mais citados pelos atletas iniciantes e avançados; os atletas iniciantes apresentaram maior prevalência de lesões durante a sessão de treino (54,5%), enquanto os atletas avançados apresentaram mais lesões durante as competições (66,1%). Foram observadas associações significativas entre atletas iniciantes e avançados para as principais articulações (p < 0,05). A chance de ter lesão foi de 70-87% menor para iniciantes do que avançados nas principais articulações citadas. Concluímos que os atletas do BJJ apresentaram alta prevalência de lesões principalmente no joelho e no ombro. A razão de chance de ter lesão foi menor para atletas iniciantes do que avançados. Atletas avançados apresentaram maior número de lesões durante as competições e o mecanismo principal foram chaves articulares. Os atletas iniciantes apresentaram maior número de lesões durante as sessões de treino e o mecanismo principal foi o uso excessivo.

Dose-response effect of photobiomodulation therapy on neuromuscular economy during submaximal running.

The purpose of this study was to verify the photobiomodulation therapy (PBMT) effects with different doses on neuromuscular economy during submaximal running tests. Eighteen male recreational runners participate in a randomized, double-blind, and placebo-controlled trial, which each participant was submitted to the same testing protocol in five conditions: control, placebo, and PBMT with doses of 15, 30, and 60 J per site (14 sites in each lower limb). The submaximal running was performed at 8 and 9 km h-1 during 5 min for each velocity. Muscle activation of the vastus lateralis (VL), vastus medialis (VM), rectus femoris (RF), biceps femoris (BF), and gastrocnemius lateralis (GL) was collected during the last minute of each running test. The root mean square (RMS) was normalized by maximal isometric voluntary contraction (MIVC) performed a priori in an isokinetic dynamometer. The RMS sum of all muscles (RMSLEG) was considered as main neuromuscular economy parameter. PBMT with doses of 15, 30, and 60 J per site [33 diodes = 5 lasers (850 nm), 12 LEDs (670 nm), 8 LEDs (880 nm), and 8 LEDs (950 nm)] or placebo applications occurred before running tests. For the statistical analysis, the effect size was calculated. Moreover, a qualitative inference was used to determine the magnitude of differences between groups. Peak torque and RMS during MIVCs showed small effect sizes. According to magnitude-based inference, PBMT with dose of 15 J per site showed possibly and likely beneficial effects on neuromuscular economy during running at 8 and 9 km h-1, respectively. On other hand, PBMT with doses of 30 and 60 J per site showed possible beneficial effects only during running at 9 km h-1. We concluded that PBMT improve neuromuscular economy and the best PBMT dose was 15 J per site (total dose of 420 J).

The Accuracy of Anthropometric Equations to Assess Body Fat in Adults with Down Syndrome.

BACKGROUND: The aim of this study was to verify the accuracy of anthropometric equations to estimate the body density (BD) of adults with Down syndrome (DS), and propose new regression equations. MATERIALS AND METHODS: Twenty-one males (30.5 ± 9.4 years) and 17 females (27.3 ± 7.7 years) with DS participated in this study. The reference method for BD was air displacement plethysmography (ADP). Also, the BD was estimated by anthropometric equations. The body fat percentage (BF %) was estimated by the Siri equation. RESULTS: For females, the Durnin and Womersley equation showed no difference from the ADP, but a trend of underestimation was observed. For males, all equations were significantly different for the BF % from ADP. The equations developed in this study showed a high correlation and acceptable agreement with BF % from ADP in both genders. CONCLUSION: All equations are not valid for DS adults. The new equations developed here were accurate in estimating the BF %.

Rebound boots change lower limb muscle activation and kinematics during different fitness exercises.

The purpose of this study was to evaluate electromyography and kinematic parameters of the lower limbs using rebound boots (RB) and barefoot during a gym workout. This information can be helpful to practitioners to schedule rehabilitation and training programs. Ten women (25 ± 9 years) volunteered for the study; inclusion criteria were as follows: subjects must have experienced the use of RB and the analyzed exercises for at least 6 months, and have no previous injuries in the lower limbs. Seven exercises were performed for 30 s with the RB and subsequently barefoot. Data from muscle activation of vastus lateralis (VL), biceps femoris (BF), lateral gastrocnemius (LG) and 2D kinematics were collected. The use of RB triggered postural changes, characterized by greater hip extension (in 4 of the exercises) and knee extension (in 6 of the exercises) for the landing. RB reduced activation mainly in LG (in 6 of the exercise) while no changes were observed for VL (except in exercise 1) and BF. RB change kinematics and muscle activation suggesting changes in the way the legs absorb and transmit force during jumps. LG was the main muscle affected by the use of RB.

Is respiratory exchange ratio an alternative to estimate anaerobic threshold in trained runners? / A razão de troca respiratória é uma alternativa para estimar o limiar anaeróbio em corredores treinados?

Abstract Several studies showed that respiratory exchange ratio (RER) have been used as an alternative to evaluate the aerobic capacity in a single incremental test. However, few studies have investigated trained runners. The aim of this study was to verify if the respiratory exchange ratio (RER) could be used as an alternative criterion for estimating anaerobic threshold (AT) in long-distance runners. Nineteen male long-distance runners volunteered to participate in the study. An incremental treadmill test was performed with initial speed of 10 km∙h-1 with increments of 1 km∙h-1 every 1 min until voluntary exhaustion. The variables measured were oxygen uptake (VO2), first and second ventilatory thresholds (VT1 and VT2, respectively), intensity corresponding to RER level of 1.0 (iRER1.0), peak velocity (PV), heart rate (HR), and rate of perceived exertion (RPE). One-way repeated measure analysis variance was used, following Bonferroni post hoc test. Agreement between parameters was evaluated by Pearson correlation and dispersion error. There were no significant differences between iRER1.0 and VT2 parameters. The correlations were significant between iRER1.0 and VT2 parameters for absolute and relative VO2, speed, and HR (r=0.95; r=0.60; r=0.72; r=0.81, respectively). A small mean error (-0.2 km∙h-1) was observed between iRER1.0 and VT2. However, it was also observed an overestimation trend for high speeds. In conclusion, iRER1.0 can be used as an alternative method to detect AT in long distance runners. However, its use is limited in runners with high aerobic capacity.

Resumo Diversos estudos demonstram que a razão de troca respiratória (RER) tem sido utilizada como uma alternativa para estimar a capacidade aeróbia em único teste incremental. No entanto, poucos estudos foram realizados com corredores treinados. Sendo assim, o objetivo do estudo foi avaliar a utilização do RER como uma alternativa para estimar o limiar anaeróbio (AT) em corredores de longa distância. Dezenove corredores de longa distância do sexo masculino participaram do estudo. Foi realizado um teste incremental com velocidade inicial de 10 km∙h-1 com incrementos de 1 km∙h-1 a cada minuto até a exaustão voluntária. As variáveis mensuradas foram consumo de oxigênio (VO2), limiares ventilatórios (VT1 e VT2), intensidade correspondente ao RER no valor igual a 1,0 (iRER1.0), pico de velocidade (PV), frequência cardíaca (HR) e percepção subjetiva de esforço (RPE). Foi realizada a análise de variância de medidas repetidas do tipo one-way, seguido do teste post hoc de Bonferroni. A relação entre as variáveis foi verificada pela correlação de Pearson e a concordância por meio da medida de dispersão dos erros. Não houve diferença significativa entre as variáveis iRER1.0 e VT2. Foram encontradas correlações significativas entre as variáveis iRER1.0 e VT2 para os valores absolutos e relativos de VO2, velocidade e HR (r=0,95; r=0,60; r=0,72; r=0,81, respectivamente). Um pequeno erro médio (-0,2 km∙h-1) foi observado entre iRER1.0 e VT2, bem como uma tendência de superestimação em altas velocidade. Em conclusão, iRER1.0 pode ser utilizado como um método alternativo para detectar o AT em corredores de longa distância, entretanto, seu uso é limitado em corredores com alta capacidade aeróbia.

Analysis of elbow muscle strength parameters in Brazilian jiu-jitsu practitioners.

Upper-body dynamic and isometric maximum strength are essential components for success in Brazilian jiu-jitsu (BJJ). This study was aimed at analysing strength parameters in the elbow flexor and extensor muscles of BJJ practitioners. Participants (n = 28) performed maximum isometric contractions of elbow flexors and extensors to determine peak torque (PT), rate of force development (RFD), and the torque-angle (T-A) relationship at elbow angles of 45°, 60°, 75°, 90°, 105°, and 120°. Additionally, concentric and eccentric PTs were measured at 1.04 rad·s-1. Student t-test and ANOVA were performed using α = 0.05. Elbow flexors were stronger isometrically (P < 0.001, ES = 1.23) but weaker concentrically (P < 0.05, ES = 0.54) than extensor muscles, possibly because of the extensive grip disputes and pushing of opponents in BJJ. The T-A relationship had an inverted "U"-shape. Torque differences across elbow angles were moderate (ES = 0.62) for the extensor and large (ES = 0.92) for the flexor muscles. Isometric torque was greatest for elbow angles of 105° and 75° and smallest for 45° and 120° for extensor and flexor muscles, respectively. Elbow flexors had a greater RFD than extensors, regardless of elbow angle. The present study provides comprehensive results for elbow muscle strength in BJJ practitioners.

Effect of a Brazilian Jiu-jitsu-simulated tournament on strength parameters and perceptual responses.

This study aimed to analyse the effects of a simulated Brazilian jiu-jitsu (BJJ) tournament on vertical jump performance, grip strength test and perceived effort responses. 22 male BJJ athletes participated in a simulated tournament consisting of three 7 min matches separated by 14 min of rest. Kimono grip strength test (KGST), counter movement jump (CMJ) and rate of perceived exertion (RPE) were measured before and after each match, while RPE of specific areas was assessed after three matches. ANOVA for repeated measures was used to compare strength parameters after each match with the level of significance set at 5%. The key results showed a significant decrease of jump height (p = 0.001) and net vertical impulse in the CMJ (p = 0.031), as well as a reduction of the number of reps in the KGST (p < 0.001). A significant increase of RPE was found throughout the matches (p < 0.001). Considering the RPE in specific areas, no differences were observed between the upper and lower body (p = 0.743). We conclude that the BJJ simulated tournament generated a decrease of performance in both upper and lower limbs and provoked a progressive increase in the effort perception over the matches.

Relationship of kimono grip strength tests with isokinetic parameters in jiu-jitsu athletes / Relação entre testes de resistência de força com o kimono com parâmetros isocinéticos em atletas de jiu jitsu

Abstract The aim of the present study was to correlate two specific kimono grip strength tests (KGST) with elbow flexors and extensors isokinetic parameters in Jiu Jitsu (JJ) athletes. Fifteen male JJ athletes, from blue to black belt, participated in the study. The two KGST were: maximum static lift (MSL), and maximum number of repetitions (MNR), both gripping a kimono wrapped around a bar. Isokinetic tests consisted of three sets of 5 s elbow flexion-extension maximum voluntary isometric contraction (MVIC) in three different elbow angles (45, 90 and 120°), and two sets of five concentric-eccentric elbow flexion-extension maximum dynamic contractions at 60°∙s-1, to determine peak torque (PT). Absolute values of MSL and MNR were 41.4 ± 16.2 s and 10 ± 5 reps, respectively, and tests presented a nearly perfect correlation among them (r=0.91; p<0.001). Significant correlations were reported between MNR and PT during MVIC for elbow flexors at 45° and 90°, elbow extensors at 120°, and during concentric and eccentric dynamic contractions for both flexors and extensors. Therefore, KGST were highly correlated with isokinetic parameters, and were nearly perfect correlated among them, supporting that one of the tests could be chosen to evaluate strength in JJ athletes. The MNR test presented apparently higher levels of relation than MSL, and provided significant information about muscle strength endurance in JJ athletes.

Resumo O objetivo do presente estudo foi correlacionar dois testes de força (Kimono Grip Strength Tests - KGST) com parâmetros isocinéticos de flexores e extensores do cotovelo em atletas de Jiu Jitsu (JJ). Quinze praticantes do sexo masculino, faixa azul à preta, participaram do estudo. Os dois KGST foram: máximo tempo de sustentação (MTS), e o máximo número de repetições (MNR), ambos com a pegada no kimono enrolado em uma barra fixa. O protocolo isocinético consistiu em três séries de 5 s de contração voluntária isométrica máxima (CVIM) para flexores e extensores do cotovelo, em três ângulos articulares (45, 90 e 120°), e duas séries de cinco contrações dinâmicas no modo concêntrico-excêntrico a 60°∙s-1, para determinação do pico de torque (PT). Os valores absolutos do MTS e MNR foram 41,4 ± 16,2 s e 10 ± 5 repetições, respectivamente, e apresentaram uma correlação quase perfeita (r=0.91; p<0.001). Correlações significativas foram encontradas entre MNR e PT durante a CVIM de flexores a 45° e 90°, extensores a 120° e em contrações concêntricas e excêntricas para flexores e extensores. Portanto, os KGST foram altamente correlacionados com parâmetros isocinéticos, e com correlação quase perfeita entre si, concluindo que apenas um dos testes pode ser utilizado para avaliar força em atletas de JJ. O teste MNR parece apresentar maiores correlações quando comparado ao MTS e fornecer informações significantes sobre força muscular em atletas de JJ.

[High blood pressure in adolescents: prevalence and associated factors]. / Pressão arterial elevada em adolescentes: prevalência e fatores associados.

The aim of this study was to assess the prevalence and associated factors of high Blood Pressure (BP) among adolescents in a Brazilian city. A cross-sectional study was conducted with 653 adolescents (57.9% female) of high school level between 14 and 19 years of age. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) of all subjects were measured. Social and demographic variables and lifestyle factors and body mass index were obtained. Binary logistic regression, crude and adjusted, was employed with a significance level of 5%. The mean SBP and DBP were 111.9 mmHg and 69.9 mmHg, respectively. The prevalence of high BP levels was 12.4%. The multivariable analysis revealed that males (OR: 2.37, 95% CI: 1.45, 3.90), adolescents with maternal education < 8 years (OR: 1.84, 95% CI: 1.03, 3.30) and overweight (OR: 3.79, 95% CI: 2.23, 6.43) had greater indices of high BP. The interaction term between males and overweight represented the subgroup with greater indices of high BP (OR: 6.41, 95% CI: 3.00, 13.16). High BP affects adolescents from Ponta Grossa, State of Paraná, and the groups with greater indices of high BP were males, with low maternal educational level and overweight.

Pressão arterial elevada em adolescentes: prevalência e fatores associados / High blood pressure in adolescents: prevalence and associated factors

Objetivou-se verificar a prevalência e os fatores associados à pressão arterial (PA) elevada em adolescentes de um município Brasileiro. Estudo transversal, conduzido em 653 adolescentes (57,9% do sexo feminino) de 14 a 19 anos de idade, estudantes do ensino médio. A Pressão arterial sistólica (PAS) e a diastólica (PAD) foram mensuradas em todos os sujeitos. Variáveis sociodemográficas, do estilo de vida e índice de massa corporal foram obtidas. Regressão logística binária, bruta e ajustada, foi empregada com nível de significância de 5%. A média da PAS e PAD foi de 111,9 mmHg e 69,9 mmHg, respectivamente. A prevalência de PA elevada foi de 12,4%. Na análise multivariável foi identificado que jovens do sexo masculino (OR: 2,37; IC95%: 1,45-3,90), com escolaridade materna de até oito anos (OR: 1,84; IC95%: 1,03-3,30) e com excesso de peso (OR: 3,79; IC95%: 2,23-6,43), apresentaram maiores chances de PA elevada. O termo de interação entre sexo masculino e excesso de peso representou o subgrupo com maiores chances de PA elevada (OR: 6,41; IC95%: 3,00-13,16). Níveis pressóricos elevados acometem adolescentes da cidade de Ponta Grossa, Paraná, e os grupos com maiores chances de PA elevada foram os do sexo masculino, com escolaridade materna baixa e com excesso de peso.

The aim of this study was to assess the prevalence and associated factors of high Blood Pressure (BP) among adolescents in a Brazilian city. A cross-sectional study was conducted with 653 adolescents (57.9% female) of high school level between 14 and 19 years of age. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) of all subjects were measured. Social and demographic variables and lifestyle factors and body mass index were obtained. Binary logistic regression, crude and adjusted, was employed with a significance level of 5%. The mean SBP and DBP were 111.9 mmHg and 69.9 mmHg, respectively. The prevalence of high BP levels was 12.4%. The multivariable analysis revealed that males (OR: 2.37, 95% CI: 1.45, 3.90), adolescents with maternal education < 8 years (OR: 1.84, 95% CI: 1.03, 3.30) and overweight (OR: 3.79, 95% CI: 2.23, 6.43) had greater indices of high BP. The interaction term between males and overweight represented the subgroup with greater indices of high BP (OR: 6.41, 95% CI: 3.00, 13.16). High BP affects adolescents from Ponta Grossa, State of Paraná, and the groups with greater indices of high BP were males, with low maternal educational level and overweight.

Overweight as hypertension risk prediction in bus drivers / O excesso de peso como preditor de risco para hipertensão em motoristas de ônibus

Blood pressure (BP) has been currently associated with several risk markers in cardiovascular diseases and excess body weight although there is only slight evidence on the association of Body Mass Index (BMI) with BP in bus drivers. Current analysis verified the association of BMI with BP in bus drivers and the risk of individuals with excess weight within the context of high blood pressure. The sample consisted of 75 bus drivers who had their BMI and BP evaluated. Statistical analysis was descriptive and Pearson correlation and odds -ratio were p < 0.05. A significant relationship between BMI and blood pressure, namely, r = 0.438 (p < 0.05) was evident. Individuals with weight excess weight were 4.04 times more likely to have high blood pressure (p < 0.05). Results showed individuals with excess weight were more likely to develop high blood pressure conditions.

O excesso de peso (EP) vem sendo associado atualmente com diversos marcadores de riscos a doenças cardiovasculares, dentre eles a pressão arterial (PA), porém ainda há poucas evidências sobre a associação do índice de massa corporal (IMC) com a PA. Neste sentido, o objetivo do presente estudo foi verificar qual a associação do IMC com a PA em motoristas de ônibus, e em um segundo momento verificar qual o risco de indivíduos com excesso de peso apresentar quadros de hipertensão. A amostra foi constituída de 75 motoristas de ônibus, foram avaliados o IMC e a pressão arterial. A análise estatística empregada foi a descritiva, correlação de Pearson e Odds-ratio com um p < 0,05. Foi encontrada uma relação significativa entre o IMC e a pressão arterial r = 0,438 (p < 0,05). Além disso, foi constatado que indivíduos com excesso de peso apresentam 4,04 vezes mais chances de apresentarem pressão arterial elevada (p < 0,05). Pelos resultados apresentados concluiu- se que indivíduos que apresentam excesso de peso possuem maiores chances de desenvolverem quadros de pressão arterial elevada.

Validade de equações antropométricas para estimar a massa muscular em idosos / Validity of anthropometric equations for the estimation of muscle mass in the elderly

O presente estudo objetivou validar equações preditivas para estimar a quantidade de massa muscular esquelética (MME) em idosos. A absorciometria radiológica de dupla energia (DXA) foi adotada como referência, e utilizada para estimar a MME apendicular, cujos valores foram comparados àqueles, obtidos por equações preditivas, que utilizam dados antropométricos, idade, etnia e sexo. A concordância entre os métodos foi verificada pelo teste t pareado, pelo coeficiente de correlação de Pearson e pela medida de dispersão dos erros, enquanto a comparação da prevalência de sarcopenia foi analisada pelo coeficiente de Kappa, pela sensibilidade e especificidade. Foram mensurados 180 idosos (120 mulheres e 60 homens), com idade entre 60 e 81 anos. A quantidade de MME, estimada pela equação preditiva de Lee et al., não diferiu daquela obtida pela DXA (p>0,05), e apresentou elevada correlação, tanto em homens (r=0,90; p<0,001), quanto em mulheres (r=0,86; p<0,001), com significância estatística. A prevalência de sarcopenia, também, não diferiu entre os métodos (DXA=33,3 por cento e equação=36,1 por cento) e apresentou elevados valores de concordância (k=0,74; p<0,001), bem como de especificidade (89 por cento) e de sensibilidade (86 por cento). Conclui-se que a equações preditivas, em particular a de Lee et al., são válidas para estimar a quantidade de MME e a prevalência de sarcopenia, em idosos.

The objective of this study was to compare skeletal muscle mass (SMM) in older adults as estimated by dual-energy X-ray absorptiometry (DXA) and three predictive equations. A total of 180 older adults (120 women and 60 men) aged 60 to 81 years were studied. Appendicular SMM was measured by DXA and estimated using predictive equations based on anthropometric measures, age, race, and gender. Agreement between methods was evaluated by the paired t-test, Pearson's correlation coefficient, and dispersion error. The prevalence of sarcopenia estimated with the different methods was compared using the kappa coefficient, sensitivity, and specificity. No difference was observed in mean SMM estimated by the predictive equation of Lee et al. and DXA (p>0.05), with a high correlation between methods in men (r=0.90; p<0.001) and women (r=0.86; p<0.001). The prevalence of sarcopenia did not differ between methods (DXA = 33.3 percent vs. equation = 36.1 percent), with high agreement between methods (kappa = 0.74; p<0.001) and high specificity (89 percent) and sensitivity (86 percent). The results indicate agreement between DXA and the predictive equation of Lee et al. for estimation of SMM and prevalence of sarcopenia in older adults.

Composição corporal, maturação sexual e desempenho motor de jovens praticantes de handebol / Body composition, sexual maturation and motor performance the young practitioners handball

O presente estudo teve como objetivo investigar a associação entre composição corporal e maturação sexual com o desempenho motor de jovens praticantes de handebol de ambos os sexos. Foram avaliados 47 adolescentes com idades entre 12 e 17 anos. A avaliação da maturação sexual foi realizada através do teste de auto-avaliação. As variáveis antropométricas de massa corporal e estatura foram mensuradas, além das dobras cutâneas do tríceps e da panturrilha, para a estimativa do percentual de gordura (%G). Para a análise do desempenho motor foi realizada uma bateria de testes motores: impulsão horizontal (IH), flexão de braços, abdominal, sentar e alcançar e corrida de vai e vem – shuttle run (agilidade). Observou-se uma relação inversa entre %G e IH (r=-0,42), e a agilidade (Ag) obteve relação positiva com o %G (r=0,61). A correlação entre maturação e IH foi positiva (r=0,32), e com a Ag negativa (r=-0,27). O sexo explicou 32,8% da variabilidade da IH e em conjunto com o %G e maturação o valor foi de 36,5%. Para a Ag a variabilidade foi explicada em 39,4% pelo sexo, juntamente com o %G e a maturação este valor foi elevado à 55%. Apesar da contribuição preditora do sexo em conjunto com o %G e a maturação para as variáveis de IH e Ag, os valores foram baixos, podendo não atribuir as alterações destas variáveis motoras apenas às variáveis independentes analisadas.

This study aimed to investigate the association between body composition and sexual maturity with the motor performance of male and female youngsters playing handball. 47 adolescents between 12 and 17 years old were evaluated. The assessment of sexual maturation was performed using self-assessment. The anthropometric variables of body mass and height were measured, and skinfolds of triceps and calf, to estimate the percentage of body fat (% BF). For the analysis of motor performance was performed a battery of motor tests: horizontal jump (HJ), arm flexion, abdominal, sit and reach and shuttle run (agility). There was an inverse relationship between %BF and IH (r=-0,42), and agility (Ag) obtained positive relationship with %BF (r=0,61). The correlation between maturation and IH (0,32) was positive, and the Ag negative (-0,27). Sex explained 32.8% of the variability of IH and in conjunction with the %BF and maturation the value was 36.5%. For Ag the variability was explained in 37.6% by the sex, along with the %BF and maturation of this value was raised to 55%. Despite the predictive contribution of the sex together with the %BF and maturation of the variables of IH and Ag, the values were low. It can not be attributed the variation of the motor variables only to independent variables.