OBJECTIVE: The purpose of this study was to investigate the effects of resistance training on angiogenesis markers of visceral adipose tissue in ovariectomized rats. METHOD: Adult Sprague-Dawley female rats were divided into four groups (n=6 per group): sham-sedentary, ovariectomized sedentary, sham-resistance training and ovariectomized resistance training. The rats were allowed to climb a 1.1-m vertical ladder with weights attached to their tails and the weights were progressively increased. Sessions were performed three times per week for 10 weeks. Visceral adipose tissue angiogenesis and morphology were analyzed by histology. VEGF-A mRNA and protein levels were analyzed by real-time PCR and ELISA, respectively. RESULTS: Ovariectomy resulted in higher body mass (p=0.0003), adipocyte hypertrophy (p=0.0003), decreased VEGF-A mRNA (p=0.0004) and protein levels (p=0.0009), and decreased micro-vascular density (p=0.0181) in the visceral adipose tissue of the rats. Resistance training for 10 weeks was not able to attenuate the reduced angiogenesis in the visceral adipose tissue of the ovariectomized rats. CONCLUSION: Our findings indicate that the resistance training program used in this study could not ameliorate low angiogenesis in the visceral adipose tissue of ovariectomized rats.

OBJECTIVE: We investigated the influence of resistance training on body composition and matrix metalloproteinase 2 activity in skeletal muscles of rats fed a high-fat diet. METHODS: Thirty-two Wistar rats were divided into four experimental groups (n = 8/each) according to diet and exercise status: Control (standard diet), Obese Control (high-fat diet), Resistance Training (standard diet) and Obese Resistance Training (high-fat diet) groups. Animals were fed a high-fat diet for 12 weeks to promote excessive weight gain. Resistance Training groups performed 12 weeks of training periods after this period in a vertical ladder three times/week. Fat percentage, fat-free mass and fat mass were assessed using dual-energy X-ray absorptiometry, and matrix metalloproteinase 2 activity in biceps and gastrocnemius muscles was analyzed using zymography. RESULTS: Resistance training significantly reduced body and fat masses and fat percentages in both trained groups (p<0.05). The maximal carrying load between trained groups was not different, but relative force was higher in the Resistance Training group (p<0.05). Of note, increased matrix metalloproteinase 2 activity was noted in the tested muscles of both trained groups (p<0.05). CONCLUSION: In conclusion, altered body composition and muscle matrix metalloproteinase 2 activity promoted by excessive weight gain were positively modified by resistance training.

OBJECTIVE: The objective of this study was to assess the effects of resistance training on oxidative stress markers in the livers of ovariectomized rats. METHOD: Adult Sprague-Dawley rats were divided into the following four groups (n = 8 per group): sham-operated sedentary, ovariectomized sedentary, sham-operated resistance training, and ovariectomized resistance training. During the resistance training period, the animals climbed a 1.1-m vertical ladder with weights attached to their tails; the sessions were conducted 3 times per week, with 4-9 climbs and 8-12 dynamic movements per climb. The oxidative stress was assessed by measuring the levels of reduced glutathione and oxidized glutathione, the enzymatic activity of catalase and superoxide dismutase, lipid peroxidation, vitamin E concentrations, and the gene expression of glutathione peroxidase. RESULTS: The results showed significant reductions in the reduced glutathione/oxidized glutathione ratio (4.11±0.65 nmol/g tec), vitamin E concentration (55.36±11.11 nmol/g), and gene expression of glutathione peroxidase (0.49±0.16 arbitrary units) in the livers of ovariectomized rats compared with the livers of unovariectomized animals (5.71±0.71 nmol/g tec, 100.14±10.99 nmol/g, and 1.09±0.54 arbitrary units, respectively). Moreover, resistance training for 10 weeks was not able to reduce the oxidative stress in the livers of ovariectomized rats and induced negative changes in the hepatic anti-oxidative/oxidative balance. CONCLUSION: Our findings indicate that the resistance training program used in this study was not able to attenuate the hepatic oxidative damage caused by ovariectomy and increased the hepatic oxidative stress.

O agachamento afundo possui um posicionamento dos membros inferiores diferencial em relação ao agachamento padrão, necessitando de maiores esclarecimentos acerca das participações dos músculos envolvidos. O objetivo foi analisar a atividade eletromiográfica dos músculos vastus lateralis (VL), vastus medialis (VM), bíceps femoris (BF) e semitendinosus (ST) durante a execução do agachamento afundo até à exaustão com o membro inferior posicionado frontalmente e posteriormente. Participaram do estudo nove mulheres ativas com média (DP) de idade de 22 (3,4) anos e massa corporal 60,3 (4,1) kg. O agachamento afundo foi dividido em duas etapas, diferindo apenas o posicionamento do membro inferior dominante (randomizado). Os sinais eletromiográficos foram captados utilizando um eletromiógrafo e analisados os valores "root mean square" (RMS) na fase concêntrica. Os resultados indicaram um aumento significativo do RMS em função do tempo para o membro inferior posicionado frontalmente e posteriormente (p< 0,001). No membro posicionado frontalmente, o aumento do RMS correspondeu a 50% para o VL, 54% para o VM e 48% para o BF. O membro posicionado posteriormente apresentou um aumento de 75% para o VL, 113% para o VM, 62% para o BF e 48% para o ST. O RMS também foi significativamente maior no músculo VM em relação ao ST no membro inferior posicionado anteriormente (p = 0,03) e em relação ao ST e BF no membro inferior posicionado posteriormente (p = 0,02). Não ocorreu interação significativa entre o efeito do tempo e músculo na atividade eletromiográfica. O RMS normalizado não apresentou diferenças estatisticamente significativas no que se refere ao posicionamento do membro inferior dominante. A atividade muscular foi semelhante em ambos os posicionamentos do membro inferior, apresentando maior aumento de ativação dos músculos VL e VM em relação ao BF e ST.

The position of lower limbs during lunge is different from squat without clear understanding on differences in muscle activation. The objective was to compare the electromyographic activity of the vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF) and semitendinosus (ST) during the execution of the lunge to exhaustion of the lower limb, changing position of the legs frontally and posteriorly. Nine active women participated of this study with a mean (SD) age of 22 (3.4) years and body mass 60.3 (4.1) kg. The lunge was divided in two phases, changing the forward leg (random order). The electromyographic signals were captured by an eletromyograph, and the root mean square (RMS) values were analyzed during the concentric phase. There was a significant increase of the RMS in time for the LL positioned frontally and posterior (p< 0,001). For the forward position, the increase of RMS was 50% for VL, 54% for VM and 48% for BF. The backward position had an increase of 75% for VL, 113% for VM, 62% for BF and 48% for ST. The RMS was significantly higher for VM than for ST the forward position (p = 0,03) and ST and BF for the backward position (p = 0,02). No interaction was observed between time and muscle in the electromyigraphic activity. The normalized RMS was not statistically different comparing the forward and backward position of the dominant leg. Muscle activity was similar in both positions of the LL, showing increased activation of the VM and VL muscles in relation to the BF and ST.

Foi investigada a influência do gênero no tempo limite (Tlim) e na cinética do VO2 durante corrida na velocidade associada ao VO2max (vVO2max) em nove homens e nove mulheres, todos adultos, jovens e sedentários, com idades entre 20 e 30 anos. Homens e mulheres realizaram dois testes em esteira rolante, sendo um teste incremental para determinar VO2max (42,66 ± 4,50 vs. 32,92 ± 6,03mL.kg-1.min-1) e vVO2max (13.2 ± 1.5 vs. 10,3 ± 2,0km.h-1), respectivamente. Um segundo teste com carga constante na vVO2max até a exaustão. O Tlim e a cinética do VO2 foram determinados. Não houve diferença significante entre homens e mulheres para constante de tempo (τ) (35,76 ± 21,03 vs. 36,5 ± 6,21s, respectivamente; P = 0,29); Tlim (308 ± 84,3 vs. 282,11 ± 57,19s, respectivamente; P = 0,68), tempo para atingir o VO2max (TAVO2max) (164,48 ± 96,73 vs. 167,88 ± 28,59s, respectivamente; P = 0,29), tempo para atingir o VO2max em percentual do Tlim (%Tlim) (50,24 ± 16,93 vs. 62,63 ± 16,60%, respectivamente; P = 0,19), tempo mantido no VO2max (TMVO2max) (144,08 ± 42,55 vs. 114,23 ± 76,96s, respectivamente; P = 0,13). Estes resultados sugerem que a cinética do VO2 e o Tlim são similares entre homens e mulheres sedentários na vVO2max.

The aim of this study was to investigate the influence of gender on Tthre and VO2 response during running exercise performed at vVO2max. Therefore, eighteen untrained individuals (9 male and 9 female) with normal weight and aged between 20 - 30 years (VO2max = 42.66 ± 4.50 vs 32.92 ± 6.03 mL.kg-1.min-1 and vVO2max = 13.2 ± 1.5 vs 10.3 ± 2.0 km.h-1, for male and female, respectively) were assessed. Subjects performed two exercise tests on treadmill. First one was an incremental test to determine VO2max, velocity at VO2max (vVO2max) and second test was performed at steady velocity - vVO2max - until exhaustion. The threshold time (Tthre) and VO2 kinetics response was determined. No significant differences were observed between men and women for time constant (τ) (35.76 ± 21.03 vs 36.5 ± 6.21s, respectively; P = 0.29); Tthre (308 ± 84.3 vs 282.11 ± 57.19s, respectively; P = 0.68), time to achieve VO2max (TAVO2max) (164.48 ± 96.73 vs 167.88 ± 28.59s, respectively; P = 0.29), time to achieve VO2max in Tthre percentage (%Tthre) (50.24 ± 16.93 vs 62.63 ± 16.60%, respectively; P = 0.19); time maintained at VO2max (TMVO2max) (144.08 ± 42.55 vs 114.23 ± 76.96s, respectively; P = 0.13). These results suggest that the VO2 kinetics response and Tthre is similar between untrained men and women at the vVO2max.

Com o objetivo de analisar a possibilidade de identificar o limiar glicêmico (LG), bem como comparar e correlacionar as intensidades dos limiares glicêmico e de lactato (LL) em exercícios resistidos incrementais, 12 voluntários do sexo masculino (24,4 ± 1,2 anos) adaptados ao exercício resistido foram submetidos a testes incrementais realizados nos exercícios leg press 45º (LP) e supino reto (SR). As intensidades aplicadas nos estágios incrementais de 1 min foram de 10%, 20%, 25%, 30%, 35%, 40%, 50%, 60%, 70%, 80% e 90% da carga máxima (1RM) determinada anteriormente, ou até a exaustão voluntária. As coletas sanguíneas para as dosagens das concentrações de lactato e glicose sanguínea foram realizadas durante os 2 min de pausa entre os estágios (YSI 2300 S). O comportamento da glicemia e lactatemia foram similares em ambos os exercícios estudados. Não foram encontradas diferenças significativas (p > 0,05) entre as percentuais de 1RM nos limiares lactatêmicos e glicêmicos observados, respectivamente, no LP (36,6 ± 1,4% e 32,9 ± 1,5%) e SR (31,2 ± 1,2% e 31,2 ± 1,8%). Alta correlação foi observada entre os limiares glicêmico e lactatêmico identificados tanto no LP (r = 0,80; p < 0,001) quanto no SR (r = 0,73; p < 0,006). Concluiu-se que foi possível identificar os limiares de lactato e glicêmico em exercícios resistidos incrementais. No entanto, o significado desses limiares bem como sua validade para avaliação funcional e prescrição de exercícios devem ser melhor investigados.

The purpose of this study was to verify the possibility of identifying the blood glucose threshold (GT) as well as to compare and correlate the GT with the lactate threshold (LT) during resistance exercises. Twelve healthy male volunteers aged 24.4 ± 1.2 years and adapted to resistance training were submitted to an incremental resistance exercise with graded intensities according to their maximal workload (kg) performed for 1 repetition (1RM) on both leg press (LP) and bench press (BP). The intensities applied for each 1 min stage were of 10%, 20%, 25%, 30%, 35%, 40%, 50%, 60%, 70%, 80% and 90% of 1RM, respectively, or until volitional exhaustion. Blood lactate and glucose measurements were done each 2 min rest between each stage (YSI 2300 S). The blood lactate and glucose responses were similar for both exercises. No differences were verified for the relative intensity (% 1RM) at which the inflection point of blood lactate and glucose curves were observed respectively for LP (36.6 ± 1.4% and 32.9 ± 1.5%) and BP (31.2 ± 1.2% and 31.2 ± 1.8%) (p > 0.05). Additionally, a high correlation was verified between LT and GT identified both on LP (r = 0.80) and SR (r = 0.73) (p < 0,05). It was concluded that it is possible to identify the LT and GT on resistance exercises. However, additional studies should investigate the meaning of these thresholds and their validity for exercise evaluation and training prescription.

Con el objetivo de analizar la posibilidad de identificar el límite glicémico (LG), bien como comparar y correlacionar las intensidades de los límites glicémico y de lactato (LL) en ejercicios continuos incrementales, doce voluntarios del sexo masculino (24,4 ± 1,2 años) adaptados al ejercicio continuo fueron sometidos a tests incrementales realizados en los ejercicios leg press 45º (LP) y supino recto (SR). Las intensidades aplicadas en las etapas incrementales de 1 min fueron 10%, 20%, 25%, 30%, 35%, 40%, 50%, 60%, 70%, 80% y 90% de la carga máxima (1RM) determinada anteriormente, o hasta la extenuación voluntaria. Las colectas sanguíneas para los dosajes de las concentraciones de lactato y glicosis sanguínea fueron realizadas durante los 2 min de pausa entre las etapas (YSI 2300 S). El comportamiento de glicemia y lactatemia fueron similares en ambos ejercicios estudiados. No se encontraron diferencias significativas (p > 0,05) entre los percentiles de 1RM en los límites lactatémicos y glicémicos observados respectivamente en LP (36,6 ± 1,4% y 32,9 ± 1,5%) y SR (31,2 ± 1,2% y 31,2 ± 1,8%). Se observó alta correlación entre los límites glicémico y lactacidémico identificados tanto en LP (r = 0,80; p < 0,001) como en SR (r = 0,73; p < 0,006). Concluimos que fue posible identificar los límites de lactato y glicemia en ejercicios continuos incrementales. Sin embargo, el significado de estos límites así como su validez para la evaluación funcional y prescripción de ejercicios deben ser mejor investigados.