ABSTRACT Different competitive environments appears to affect the physical demands during the sports competitions. Thus, the aim of this study was to report the mechanical demand and pacing behaviour of twelve male elite mountain bikers on cross-country short track (XCC) and cross-country Olympic (XCO). During both competition, total race time, speed, power output (PO) and cadence (CA) were recorded. As the race time in the XCC is shorter (21.0 ± 0.5 vs 84.0 ± 3.0 min; p<0.01), the average speed (26.6 ± 0.6 vs 17.8 ± 0.6 km/h; p<0.01), PO (365.0 ± 26.7 vs 301.0 ± 26.2 watts; p<0.01) and CA (81.2 ± 4.7 vs 77.4 ± 4.3 rev∙min−1; p=0.01) were higher than the XCO. While a variable pacing was adopted during XCC, a positive profile was adopted in XCO. In addition, athletes adopted a more conservative starting pace during XCC (below average race speed) but a faster start during XCO (above average race speed). These findings demonstrated that mechanical parameters and pacing profile adopted by cyclists are different between XCC and XCO. Therefore, mountain bikers and coaches must develop specific strategy and training methods in order to obtain success in each competition.

RESUMO Diferentes ambientes competitivos parecem afetar as demandas físicas durante as competições esportivas. Assim, o objetivo deste estudo foi reportar as demandas mecânicas e o comportamento do pacing de doze homens ciclistas de montanha da categoria elite durante o cross-country de pista curta (XCC) e o cross-country Olímpico (XCO). Durante ambas as competições, o tempo total de corrida, velocidade, potência (PO) e cadência (CA) foram gravados. Como o tempo de prova do XCC é menor (21,0±0,5 vs 84,0±3,0 min; p<0,01), a velocidade média (26,6±0,6 vs 17,8±0,6 km/h; p<0,01), PO (365,0±26,7 vs 301,0±26,2 watts; p<0,01) e CA (81,2±4,7 vs 77,4±4,3 rev∙min−1; p=0,01) foram maiores que no XCO. Enquanto um ritmo variável foi adotado no XCC, um perfil positivo foi adotado no XCO. Além disso, os atletas adotaram um ritmo inicial mais conservador durante o XCC (abaixo da velocidade média da prova), mas um início mais rápido durante o XCO (velocidade acima da média da prova). Esses achados demonstraram que os parâmetros mecânicos e o ritmo adotados pelos ciclistas são diferentes entre o XCC e XCO. Portanto, ciclistas e treinadores devem desenvolver estratégias e métodos de treinamento específicos para obter sucesso em cada competição.

Abstract Aim: To verify the response of tissue saturation index (TSI) during ischemia-reperfusion (IR) interventions with different cuff-pressures. Methods: Twenty-nine healthy men experienced in resistance training were recruited. Each one has undergone a control condition (no cuff) and one of the three IR interventions: 1) 190 mmHg (CP-190, 22.7 ± 3.0 years; 176.6 ± 3.9 cm; 77.3 ± 9.5 kg; 2) 100 mmHg (CP-100, 22.9 ± 6.3 years; 180.5 ± 4.0 cm; 85.2 ± 14.1 kg) and 3) 20 mmHg (CP-20, 20.3 ± 2.4 years; 171.8 ± 5.2 cm; 72.4 ± 6.0 kg). Cuffs were placed on the proximal region of the thighs. IR interventions consisted of three cycles of 2-min occlusion-reperfusion. TSI was measured using near-infrared spectroscopy (NIRS), positioned on the middle portion of the vastus lateralis of the dominant leg. The oxygenation was measured at the control conditions (no cuff) and during cuff interventions. Results: While TSI values of CP-20 did not change compared to control (p > 0.05), the TSI in CP-190 was lower in the ischemia (p < 0.05), and CP-100 was lower in the second and third ischemia (p < 0.05). However, the TSI value increased during reperfusion but did not return to control levels (p < 0.05). Conclusion: TSI of the CP-190 significantly decreased during ischemia. However, these values increased by about 16% in the reperfusion period. Thus, our results show that the RI intervention may have caused an increase in metabolic demand, as even with the release of blood flow, the TSI values were below those of the other interventions.

RESUMO Introdução O jiu jitsu brasileiro (JJB) é um esporte individual, caracterizado por movimentos corporais intermitentes, cujo objetivo é a submissão (derrota) do oponente. Nessa modalidade, há dois perfis táticos dos lutadores, o guardeiro (GG) e o passador (GP), os quais apresentam potenciais diferenças em relação aos padrões antropométricos e à modulação autonômica cardíaca. Objetivos Avaliar os efeitos dos diferentes estilos de luta do JJB sobre a modulação autonômica cardíaca. Métodos Participaram do estudo 12 atletas com estilo de luta GP e 12 atletas com estilo de luta GG, ambos do sexo masculino e com idades médias de 30,4 ± 1,9 e 30,6 ± 1,3 anos, respectivamente. Foram avaliados, em repouso, o perfil antropométrico, a composição corporal e os parâmetros hemodinâmicos (pressão arterial [PA], frequência cardíaca [FC] basal e a variabilidade da frequência cardíaca [VFC], esta última através de análises lineares e não lineares). Resultados Os lutadores do GP apresentaram maiores diâmetros da circunferência da cintura e do quadril em comparação ao GG (p<0,05). Não houve diferenças em relação aos parâmetros hemodinâmicos basais da FC e da PA. A variabilidade total da FC, assim como os índices da modulação parassimpática tanto no domínio do tempo como no domínio da frequência, foram significativamente menores nos lutadores do GG quando comparados aos lutadores do GP (p<0,05). Em contrapartida, os marcadores da modulação simpática no domínio da frequência e o índice simpatovagal foram maiores no GG em relação ao GP (p<0,05). O índice SD1 da análise não linear foi menor nos lutadores do GG quando confrontados ao GP (p<0,05). Conclusão Lutadores com estilo predominantemente guardeiro apresentam menor modulação vagal e hiperatividade simpática cardíaca de repouso em comparação aos lutadores passadores. Nível de Evidência IV; Série de casos.

ABSTRACT Introduction Brazilian Jiu Jitsu (BJJ) is an individual sport, characterized by intermittent body movements aimed at the submission (defeat) of the opponent. The sport involves two tactical profiles of fighters: the guard (GG) and the passer (PG), which present potential differences in relation to anthropometric patterns and cardiac autonomic modulation. Objectives To evaluate the effects of different BJJ fighting styles on cardiac autonomic modulation. Methods Twelve PG-style athletes and 12 GG-style athletes, both male, with mean ages of 30.4 ± 1.9 and 30.6 ± 1.3 years, respectively, participated in the study. The following measurements were taken at rest: anthropometric profile, body composition and hemodynamic parameters (blood pressure [BP], basal heart rate [HR] and heart rate variability [HRV], the latter through linear and nonlinear analysis). Results The PG fighters had higher waist and hip circumference diameters compared to the GG fighters (p <0.05). There were no differences regarding baseline hemodynamic parameters of HR and BP. Total HRV as well as parasympathetic modulation indices in both the time and frequency domains were significantly lower in the GG fighters than in the PG fighters (p <0.05). In contrast, the sympathovagal modulation markers in the frequency domain, and the sympathovagal index, were higher in GG than in PG (p <0.05). The SD1 index of nonlinear analysis was lower in the GG fighters than in the PG (p <0.05). Conclusion In general, guardian style fighters have lower vagal modulation and cardiac sympathetic hyperactivity at rest, compared to passing fighters. Level of evidence IV; Case series.

RESUMEN Introducción El Jiu Jitsu brasileño (JJB) es un deporte individual, caracterizado por movimientos corporales intermitentes, cuyo objetivo es la sumisión (derrota) del oponente. En esta modalidad, hay dos perfiles tácticos de luchadores, el guardiero (GG) y el pasador (GP), que presentan diferencias potenciales con relación a los patrones antropométricos y a la modulación autónoma cardíaca. Objetivos Evaluar los efectos de diferentes estilos de lucha de JJB sobre la modulación autónoma cardíaca. Métodos Participaron en el estudio 12 atletas con estilo de lucha GP y 12 atletas con estilo de lucha GG, ambos del sexo masculino y con edades promedio de 30,4 ± 1,9 y 30,6 ± 1,3 años, respectivamente. Fueron evaluados, en reposo, el perfil antropométrico, la composición corporal y los parámetros hemodinámicos (presión arterial [PA], frecuencia cardíaca [FC] basal y la variabilidad de la frecuencia cardíaca [VFC], ésta última a través de análisis lineales y no lineales). Resultados Los luchadores del GP presentaron mayores diámetros de circunferencia de cintura y cadera en comparación al GG (p <0,05). No hubo diferencias con relación a los parámetros hemodinámicos basales de FC y de la PA. La variabilidad total de la FC, así como los índices de modulación parasimpática tanto en el dominio del tiempo como en el dominio de la frecuencia, fueron significativamente menores en los luchadores del GG cuando comparados a los luchadores del GP (p <0,05). En contrapartida, los marcadores de la modulación simpática en el dominio de frecuencia y el índice simpatovagal fueron mayores en el GG con relación al GP (p <0,05). El índice SD1 de análisis no lineal fue menor en los luchadores del GG cuando comparados al GP (p <0,05). Conclusión Los luchadores con estilo predominantemente guardiero presentan menos modulación vagal e hiperactividad simpática cardíaca de reposo en comparación a los luchadores pasadores. Nivel de evidencia IV; Serie de casos .

Abstract Aims: To evaluate whether body mass (BM) and body composition may influence mountain bike cycling performance. Methods: Forty male amateur mountain bikers attended the laboratory on two non-consecutive days. At the first visit, anthropometric measures (height, BM, body fat [BF], fat-free mass [FFM] and body mass index [BMI]) and familiarization to incremental cycling test were performed. On the second visit, cyclists performed again the incremental cycling test to measure peak power output (PPO), peak power output relative to BM (PPO-BM), and time to exhaustion (TE), which were posteriorly correlated with BM and anthropometric measures. Results: A low and moderate significant correlation were observed between TE and BM (p<0.01; r=0.40) and FFM (p<0.01; r=0.56). Moderate significant correlation was found between PPO and BM (p<0.01; r=0.45), BMI (p=0.03; r=0.35) and strong with FFM (p<0.01; r=0.59). Also, PPO-BM significantly correlated with BM (p=0.04; r=-0.31), BMI (p=0.02; r=-0.35) and BF (p<0.01; r=-0.55). No other significant correlations were observed. Conclusion: Considering PPO-BM as mainly performance variable, BM and BF can be a determining factor in mountain biking performance but FFM did not.

ABSTRACT Objective: To assess the relationships between serum dehydroepiandrosterone sulfate (DHEA-S) levels and heart rate variability (HRV) among different age groups. Subjects and methods: Forty-five healthy men were divided into 3 groups: young age (YA; 20-39 yrs; n = 15), middle age (MA; 40-59 yrs; n = 15) and old age (OA; ≥ 60 yrs; n = 15). Hemodynamic parameters, linear analyses of HRV and concentrations of cortisol and DHEA-S were measured at rest. Results: The OA group presented a higher resting heart rate (84.3 ± 4.6 bpm) than the YA group (72.0 ± 4.4 bpm; p < 0.05). The YA group showed an attenuated variance of HRV (2235.1 ± 417.9 ms2) compared to the MA (1014.3 ± 265.2 ms2; p < 0.05) and OA (896.3 ± 274.1 ms2; p < 0.05) groups, respectively. The parasympathetic modulation of HRV was lower in both the MA (244.2 ± 58.0 ms2) and OA (172.8 ± 37.9 ms2) groups in comparison with the YA group (996.0 ± 255.4 ms2; p < 0.05), while serum DHEA-S levels were significantly lower in both the MA (91.2 ± 19.6 mg/dL) and OA (54.2 ± 17.7 mg/dL) groups compared to the YA group (240.0 ± 50.8 mg/dL; p < 0.05). A positive correlation between lower serum concentrations of DHEA-S and attenuated variance of HRV (r = 0.47, p = 0.031), as well as lower serum concentrations of DHEA-S and decreased parasympathetic modulation of HRV (r = 0.54, p = 0.010), were found. Conclusion: The present study demonstrated that the decline of plasma DHEA-S is associated with reduced cardiac autonomic modulation during the aging process.

Abstract Aims: To investigate the early and late ischemic preconditioning (IPC) effect on the trained cyclists’ performance during incremental cycling test until exhaustion. Methods: Twenty-one male cyclists allocated to an IPC (2 x 5-min of blood flow occlusion at 50 mm Hg above systolic pressure followed + 5-min of deflation), SHAM (2 x 5-min at 20 mm Hg) or control (CON; no occlusion) interventions, performed three incremental cycling test (ICT) until exhaustion on separate days. The ICT were conducted pre interventions (baseline), 5-min and 24-h after interventions. The heart rate (HR) and power output (PO) were recorded during all ICT. Results: The IPC group increased ICT performance (4.4 ± 4.0 %; effect size (ES) = 0.27) 5-min post intervention, accompanied by HR mean reduction, compared to baseline (p < 0.05). However, there were no changes in SHAM (2.2 ± 4.2%; ES = 0.07) and CON (2.9 ± 5.0%; ES = 0.06) groups. In 24-h post intervention, SHAM (0.2 ± 4.7%; ES = 0.02) and CON (-1.0 ±1.6; ES = 0.03) maintained (p > 0.05) and IPC group decreased the performance (-4.6 ± 3.6 %; ES = 0.16) compared to 5-min post intervention (p < 0.05), but all groups were similar to baseline (p > 0.05). There were no difference (p > 0.05) among groups for PO peak, HR and ICT performance in all moments (baseline, 5-min and 24-h post intervention). Conclusion: The IPC increases early but not late incremental cycling test performance.

Resumo Fundamento: Alterações na estrutura dos vasos de resistência contribuem para elevar a resistência vascular sistêmica na hipertensão, estando ligadas à hiperatividade simpática e lesões em órgãos-alvo. Objetivo: Avaliar os efeitos do treinamento físico nos parâmetros hemodinâmicos e autônomos, assim como as lesões arteriolares esplênica em ratos machos Wistar Kyoto (WKY) e espontaneamente hipertensos (SHR). Métodos: Ratos normotensos sedentários (WKYS) e treinados (WKYT), e ratos hipertensos sedentários (SHRS) e treinados (SHRT) foram incluídos neste estudo. Após nove semanas de aplicação do protocolo experimental (treinamento de natação ou controle sedentário), registraram-se a pressão arterial (PA) e a frequência cardíaca (FC) dos ratos em movimento livre. Avaliamos o controle autônomo do coração através de bloqueio autônomo simpático e vagal. Análises morfométricas das arteríolas esplênicas foram realizadas. Adotou-se o nível de significado estatístico de p < 0,05. Resultados: Observou-se bradicardia de repouso nos dois grupos treinados (WKYT: 328,0 ± 7,3 bpm; SHRT: 337,0 ± 5,2 bpm) em comparação aos seus respectivos grupos sedentários (WKYS: 353,2 ± 8,5 bpm; SHRS: 412,1 ± 10,4 bpm; p < 0,001). O treinamento físico atenuou a PA média apenas no grupo SHRT (125,9 ± 6,2 mmHg vs. 182,5 ± 4,2 mmHg no SHRS; p < 0,001). O grupo WKYT mostrou maior efeito vagal (∆FC: 79,0 ± 2,3 bpm) em comparação ao grupo WKYS (∆FC: 67,4 ± 1,7 bpm; p < 0,05). Exercício crônico diminuiu os efeitos simpáticos em SHRT (∆FC: -62.8 ± 2.8 bpm) em comparação a SHRS (∆FC: -99,8 ± 9,2 bpm; p = 0,005). A espessura da parede das arteríolas esplênicas nos SHR foi reduzida pelo treinamento (332,1 ± 16,0 µm2 nos SHRT vs. 502,7 ± 36,3 µm2 nos SHRS; p < 0,05). Conclusões: O treinamento físico atenua a atividade simpática e a PA em SHR, o que pode contribuir para melhorar a morfologia das arteríolas esplênicas.

Abstract Background: Alterations in the structure of resistance vessels contribute to elevated systemic vascular resistance in hypertension and are linked to sympathetic hyperactivity and related lesions in target organs. Objective: To assess the effects of exercise training on hemodynamic and autonomic parameters, as well as splenic arteriolar damages in male Wistar Kyoto (WKY) and Spontaneously Hypertensive Rats (SHR). Methods: Normotensive sedentary (WKYS) and trained (WKYT) rats, and hypertensive sedentary (SHRS) and trained (SHRT) rats were included in this study. After 9 weeks of experimental protocol (swimming training or sedentary control), arterial pressure (AP) and heart rate (HR) were recorded in freely moving rats. We assessed the autonomic control of the heart by sympathetic and vagal autonomic blockade. Morphometric analyses of arterioles were performed in spleen tissues. The statistical significance level was set at p < 0.05. Results: Resting bradycardia was observed in both trained groups (WKYT: 328.0 ± 7.3 bpm; SHRT: 337.0 ± 5.2 bpm) compared with their respective sedentary groups (WKYS: 353.2 ± 8.5 bpm; SHRS: 412.1 ± 10.4 bpm; p < 0.001). Exercise training attenuated mean AP only in SHRT (125.9 ± 6.2 mmHg) vs. SHRS (182.5 ± 4.2 mmHg, p < 0.001). The WKYT showed a higher vagal effect (∆HR: 79.0 ± 2.3 bpm) compared with WKYS (∆HR: 67.4 ± 1.7 bpm; p < 0.05). Chronic exercise decreased sympathetic effects on SHRT (∆HR: -62.8 ± 2.8 bpm) in comparison with SHRS (∆HR: -99.8 ± 9.2 bpm; p = 0.005). The wall thickness of splenic arterioles in SHR was reduced by training (332.1 ± 16.0 µm2 in SHRT vs. 502.7 ± 36.3 µm2 in SHRS; p < 0.05). Conclusions: Exercise training attenuates sympathetic activity and AP in SHR, which may be contributing to the morphological improvement of the splenic arterioles.

Abstract Aims The aim of this study was to establish thermographic profiles of lower limbs and to correlate them with creatine kinase level in professional players. Method Thirty healthy male professional soccer players (25.4 ± 4.7 years; 179.5 ± 6.7 cm; 78.3kg ± 7.5 kg; body fat 10.2 ± 4.2 %) from a club of Brazilian first division soccer league volunteered. Thermal images sequences of lower limbs (thighs and legs) were acquired in an anteroposterior manner (i.e., frontal and dorsal views) by a digital infrared thermo-camera. Blood creatine kinase (CK) concentration was assessed by reflectance photometry. All thermographic images and CK were performed between 8:00 and 9:00 am. Results No significant difference (p>0.05) was found between left and right sides from both anterior and posterior measurements of thighs and legs for mean or maximal skin temperature. Low values of correlation (range r=0.14 to r=0.38) was found between skin temperature and CK levels while contralateral thermal symmetry in the lower limbs (regions of interest < 0.2°C) was found. Conclusion It was observed contralateral thermal symmetry in the lower limbs and low correlation between CK and temperature values in elite soccer players.

Abstract AIMS We evaluated whether exercise training ameliorates cardiovascular autonomic dysfunction in obesity-induced by high-fat diet (HFD) in rats. METHODS Wistar male rats were assigned in normal diet, sedentary (ND-S) and trained (ND-T) and HFD, sedentary (HFD-S) and trained (HFD-T). Blood pressure (BP), heart rate (HR), HR variability (HRV), BP variability (BPV), cardiac baroreflex and cardiac autonomic tonus were assessed. RESULTS HFD-S showed higher bodyweight increase (19.4%) compared to all other groups (HFD-T: 13.2%, ND-S: 14% and ND-T: 12.4%). Relative epididymal, retroperitoneal and visceral fat was also greater in HFD-S compared to all other groups. Resting bradycardia in ND-T (339.5±10.6 bpm) and HFD-T (341.0 ± 9.4 bpm) was more pronounced than ND-S (438.4 ± 6.3 bpm; p<0.05) and HFD-S (448.5 ± 18.7 bpm; p<0.05). The HFD-T group showed lower systolic (125.3 ( 1.9 mmHg), diastolic (88.5 ( 2.0 mmHg) and mean BP (100.3 ± 2.5 mmHg) in comparison with HFD-S (153.8 ( 3.7; 103.5 ( 2.6 and 120.5 ± 3.7 mmHg; p<0.05, respectively). Lower variance of HRV and higher variance of diastolic BPV was observed in HFD-S compared to other groups while sympathetic modulation of HRV and BPV was higher in HFD-S, as well as the LF/HF ratio. HFD-T showed a decrease in sympathetic tonus compared to HFD-S. ND-T and HFD-T showed higher cardiac vagal tonus than respective sedentary groups. Analysis showed an association between visceral fat, sympathetic activity and BP. CONCLUSIONS HFD induces hypertension and is associated with autonomic imbalance in rats, while exercise training may reverse these harmful changes.

Abstract We evaluated the effect of performing various distinct warm-up exercises on vertical countermovement jump (VCMJ) performance. Eight volleyball players (age 15.4 ± 0.5 yrs) performed five different warm-up activities (in a counterbalanced, randomized crossover study) over five days, at 24-h intervals: stretching (4 × 30 s, 30 s between sets), cycloergometer (5 min at 50 W + 5 min at 100 W), resistance exercise (leg press 45°, 3 × 5 repetitions maximum, 3-min pause between sets), specific vertical jumping (4 × 10 VCMJ, 2-min pause between sets), and no warm-up at all (control condition). Beginning 3 min after their warm-up, the players performed 3 attempts (at intervals of 3 min) of VCMJ (on a contact carpet), and each player's best jump was considered in the analysis. All warm-up activities presented higher VCMJ performance (p< 0.05) than the control condition, with the exception of stretching. Vertical jumping revealed a large effect size(0.8) than other interventions. We conclude that in practical terms, vertical jumps are the best warm-up exercise (when applied by itself) to acutely improve VCMJ performance in volleyball players, but that other exercises can make a complementary contribution.

O futebol de amputados é uma variação do futebol convencional, onde participam atletas amputados de membros inferiores e membros superiores (goleiro). O objetivo do estudo foi investigar as características físicas e antropométricas de atletas de futebol para amputados e verificar se existem diferenças entre a frequência cardíaca de pico (FCpico) e equações de predição da frequência cardíaca máxima (FCmax). Doze jogadores de futebol para amputados da seleção brasileira participaram do estudo. Foi mensurada a massa corporal, estatura e composição corporal. Os testes físicos utilizados foram: corrida de 20 m, teste do quadrado e o Yo Yo intermitent recovery test - level 1 (YYIRT1). O percentual de gordura foi significativamente diferente entre os meio-campistas e defensores. Não foram encontradas diferenças significativas entre as posições nos testes físicos. A FCpico foi significativamente menor do que todas as equações de predição da FCmax testadas. Conclui-se que os indicadores de desempenho físico não diferenciaram significativamente entre as diferentes funções táticas dos jogadores, e que a resposta cardíaca após esforço máximo intermitente é menor quando comparada com as equações de predição da FCmax investigadas.

Amputee football is a variation of conventional soccer in which athletes with lower limb amputation and one athelete with upper limb amputation (the goalkeeper) participate. The objective of this study was to investigate the anthropometric and physical characteristics of amputee football athletes and to verify differences between heart rate peak (HRpeak) and equations for predicting maximum heart rate (HRmax). Twelve amputee soccer players from the Brazilian team participated in this study. The body mass, height and body composition were measured. The physical tests used were: the 20 m running test, the T-square test and the Yo Yo intermitent recovery test - level 1 (YYIRT1). The percentage of fat was significantly different between midfielders and defenders. No significant differences were found between positions in the physical tests. The HRpeak was significantly lower than all of HRmax prediction equations tested. We conclude that the indicators of physical performance did not differ significantly between the different tactics roles of players, and that, after intermittent maximum effort, the cardiac response was lower when compared with the investigated HRmax prediction equations.

El fútbol de amputados es una variante del fútbol convencional, en el cual participan atletas amputados de miembros inferiores y miembros superiores (portero). El objetivo del estudio fue investigar las características físicas y antropométricas de atletas de fútbol para amputados y verificar si hay diferencias entre frecuencia cardíaca pico (FCpico) y ecuaciones de predicción de frecuencia cardíaca máxima (FCmax). Doce jugadores de fútbol para amputados del equipo oficial brasileño participaron del estudio. Fue mensurada la masa corporal, estatura y composición corporal. Los testes físicos utilizados fueron: carrera de 20 m, test del cuadrado y Yo Yo intermitent recovery test - level 1 (YYIRT1). El porcentual de grasa fue significativamente diferente entre los mediocampistas y defensores. No fueron identificadas diferencias significativas entre las posiciones en los testes físicos. FCpico fue significativamente menor que todas las ecuaciones de predicción de FCmax evaluadas. Concluí-se que los indicadores de desempeño físico no diferenciaron significativamente entre las diferentes funciones tácticas de los jugadores y que la respuesta cardíaca tras el esfuerzo máximo intermitente es menor si comparadas con las ecuaciones de predicción de FCmax investigados.

A força muscular é um componente importante para a atividade física e para o desempenho das tarefas da vida diária. Um fenômeno observado geralmente é que a capacidade de geração de força máxima está comprometida quando os membros homólogos se contraem bilateralmente. Esse fenômeno é chamado de déficit bilateral. Assim, objetivou-se comparar a atividade elétrica do músculo deltoide, porção medial durante contrações unilaterais e bilaterais em um aparelho multiarticular de desenvolvimento articulado convergente, com 90% da carga voluntária máxima (CVM), em nove homens com idades entre 20 e 30 anos, estatura 174 ± 5cm e massa corporal 78 ± 15kg. Os sinais mioelétricos foram captados através da colocação de eletrodos ativos de superfície diferenciais da EMG System do Brasil, um eletrodo de referência (terra) e um módulo condicionador de sinais (eletromiógrafo), que forneceu dados numéricos em RMS (raiz quadrada da média) para análise dos resultados. Cada sinal coletado captou apenas a fase concêntrica do movimento e o mesmo teve duração de três segundos. Os resultados evidenciaram que durante exercício bilateral e unilateral com 90% da CVM, a atividade elétrica do membro não dominante predominou significativamente sobre o dominante (p = 0,018). Quando somados os valores obtidos no trabalho do membro dominante com aqueles obtidos com o membro não dominante no exercício bilateral (2.231 ± 504µv) e comparados com os valores obtidos no trabalho unilateral (2.663 ± 701µv), o déficit bilateral foi encontrado (p = 0,018). De acordo com nosso estudo, verificamos que o fenômeno do déficit bilateral se faz presente para o músculo deltoide médio no exercício multiarticular de desenvolvimento articulado convergente em indivíduos familiarizados em exercícios resistidos.

Muscular strength is an important component for physical activity and performance of activities of daily living. A phenomenon usually observed is that the capacity of generating maximum strength is compromised when the homologous extremities bilaterally contract. This phenomenon is called bilateral deficit. Thus, the aim of this work was to compare the electrical activity of the deltoid muscle, medial portion, during unilateral and bilateral contractions in a multiarticular machine of convergent articulated development, with 90% of maximum voluntary load (mvl), in nine men aged between 20 and 30 years, stature of 174 ± 5cm and body mass of 78 ± 15 kg. The myoelectrical signals were obtained through placement of differential active surface electrodes by EMG System of Brazil, a reference electrode (ground) and a signal conditioner module (electromyograph), which provided numerical data in RMS (root median square) for results analysis. Each signal collected picked only the concentric phase of the movement and it had duration of three seconds. The results evidenced that during bilateral and unilateral exercise with 90% of MVL, the electric activity of the non-dominant extremity was significantly higher than in the dominant one (p = 0.018). When the values obtained in the work of dominant extremity are summed with the work of non-dominant extremity in the bilateral exercise (2.231 ± 504µv) and compared with the values obtained in the unilateral work (2.663 ± 701µv), bilateral deficit was found (p = 0.018). According to our study, it was verified that the bilateral defict phenomenon is present in the medium deltoid muscle in the multiarticular exercise of convergent articulated development in individuals familiarized with resistance exercises.

INTRODUÇÃO: A importância da mensuração do consumo máximo de oxigênio (<img border=0 id="_x0000_i1026" src="/img/revistas/rbme/v18n3/v.jpg" align=absmiddle>O2máx)é justificada por sua aceitação internacional como o melhor parâmetro fisiológico para avaliar a capacidade funcional do sistema cardiorrespiratório tanto em atletas como em não atletas que treinam fisicamente com objetivo de obter melhor saúde. OBJETIVO: Verificar a concordância entre os protocolos Polar Fitness Test® para a estimativa do <img border=0 id="_x0000_i1027" src="/img/revistas/rbme/v18n3/v.jpg" align=absmiddle>O2máx e o teste de esforço máximo com medida direta de gases. MÉTODOS: Dezessete homens ativos (22,5 ± dois anos) participaram. Em repouso, aplicou-se o protocolo Polar Fitness Test® e, em seguida, a coleta direta de gases sob o esforço máximo, em esteira, seguindo o protocolo de Bruce. RESULTADOS: Houve diferença significativa entre os valores médios dos métodos para estimativa do <img border=0 id="_x0000_i1028" src="/img/revistas/rbme/v18n3/v.jpg" align=absmiddle>O2máx. O protocolo Polar Fitness Test® subestimou o <img border=0 id="_x0000_i1029" src="/img/revistas/rbme/v18n3/v.jpg" align=absmiddle>O2máx, em média 15% (IC95%: 24; -53%) comparado com a medida direta de gases. Os valores obtidos pelo Polar Fitness Test® não tiveram boa correlação com a medida direta em ergoespirômetro (r = 0,1). CONCLUSÃO: O protocolo Polar Fitness Test® não é válido para a estimativa do <img border=0 id="_x0000_i1030" src="/img/revistas/rbme/v18n3/v.jpg" align=absmiddle>O2máx em homens jovens ativos fisicamente.

INTRODUCTION: The importance of maximal oxygen consumption (<img border=0 id="_x0000_i1032" src="/img/revistas/rbme/v18n3/v.jpg" align=absmiddle>O2máx) measurement is justified by its international acceptance as the best physiological parameter to assess the functional capacity of the cardiorespiratory system in both athletes and non-athletes who physically train in order to achieve better health. OBJECTIVE: To determine the agreement between the Polar Fitness Test® protocols to estimate of <img border=0 id="_x0000_i1033" src="/img/revistas/rbme/v18n3/v.jpg" align=absmiddle>O2máx and the maximal exercise test with direct gas measurement. METHODS: Seventeen active males (22.5 ± 2 years) participated in the study. At rest, the Polar Fitness Test® protocol by direct gas collection under maximum effort on treadmill and the Bruce protocol were applied. RESULTS: Significant difference in the <img border=0 id="_x0000_i1034" src="/img/revistas/rbme/v18n3/v.jpg" align=absmiddle>O2máx estimation was observed between methods. The Polar Fitness Test® protocol underestimated <img border=0 id="_x0000_i1035" src="/img/revistas/rbme/v18n3/v.jpg" align=absmiddle>O2máx a mean of 15% (CI95%: 24;-53%) when compared to the direct protocol. The values obtained by the Polar Fitness Test® did not correlate well with direct measurement in ergospirometer (r = 0.1). CONCLUSION: The Polar Fitness Test® protocol is not valid to estimate <img border=0 id="_x0000_i1036" src="/img/revistas/rbme/v18n3/v.jpg" align=absmiddle>O2máx in physically active young men.

O objetivo deste trabalho foi comparar a atividade elétrica do músculo deltoide (porção média), peitoral maior (porção clavicular) e tríceps braquial (cabeça longa) durante contração bilateral realizada num aparelho multiarticular de desenvolvimento articulado convergente, com 40% e 80% da carga voluntária máxima (CVM), em 11 nadadores do gênero masculino (idades entre 15 e 23 anos, peso 70 ± 4kg, estatura 183 ± 6cm e tempo de prática do esporte de 10 ± 4 anos) treinados em exercícios resistidos. Os sinais eletromiográficos (EMG) foram captados através da colocação de eletrodos ativos de superfície diferenciais de ganho de 20 vezes, composto por duas barras retangulares paralelas da EMG System do Brasil, um eletrodo de referência (terra), e um módulo condicionador de sinais (eletromiógrafo), com aquisição simultânea de até oito canais diferenciais, filtro com faixa de passagem de 20Hz a 5Hz, estágio amplificador ajustável, possibilitando ganhos entre 100 e 4.960 vezes, impedância de entrada de canais de 10GΩ em módulos diferencial e CMRR de 93db a 60Hz, e um sistema de aquisição de dados (Alc-EMG) que forneceu dados numéricos em RMS (raiz quadrada da média) para análise dos resultados. Cada sinal coletado captou apenas a fase concêntrica do movimento e o mesmo teve duração de três segundos. Diante dos resultados (teste U de Mann-Whitney, Friedman e Wilcoxon) conclui-se que, em termos práticos de prescrição e periodização do treinamento neuromuscular, as contrações bilaterais realizadas no aparelho desenvolvimento articulado convergente são eficientes visando recrutamento (80% > 40%) dos músculos deltoide médio, peitoral maior (porção clavicular) e tríceps braquial (cabeça longa), sendo evidenciadas diferenças entre o membro dominante e o não dominante apenas para o tríceps braquial dominante com a carga de 80% da CVM nestes atletas nadadores com histórico de treinamento com pesos.

The objective of this study was to compare the electrical activity of the deltoid (middle portion), pectoralis major (clavicular portion) and triceps (long head) muscles during bilateral contraction performed in a multi-articulated joint shoulder-press convergent machine with 40% and 80% maximum voluntary load (MVL) in 11 male swimmers (15 to 23 years, 70 ± 4 kg, 183 ± 6 cm and 10 ± 4 years time practice in sport), trained in resistance exercise. Electromyographic signals (EMG) were obtained by placing surface active differential electrodes (20x gain), composed of two parallel rectangular bars (EMG System, Brazil®). A data acquisition system (EMG-Alc) which provided numerical data in RMS (Root Mean Square) to analyze the signals composed by a reference electrode (ground) and a signal conditioning module (EMG) with simultaneous acquisition of up to 8 differential channels (band-pass filter 5-20 Hz), adjustable amplifier stage, allowing gains between 100 and 4960 times, channel input impedance 10GΩ in differential modules and CMRR of 93 dB/60 Hz was used. Only the concentric phase (3 seconds duration) in each EMG signal collected was recorded. After the tests (Mann-Whitney U test, Friedman and Wilcoxon) were applied, it was concluded that for prescription and periodization of the neuromuscular training, bilateral contractions performed in the shoulder-press apparatus are efficient at aiming muscular recruitment (80%> 40% ) of middle portion of the deltoid, pectoralis major (clavicular portion), and triceps brachii (long head) muscles, evidencing differences between dominant and non-dominant limbs only for the dominant brachial triceps in 80% of MVL in swimmers trained in resistance exercises.