[Show abstract][Hide abstract] ABSTRACT: Obesity is epidemic in the western world and central adipose tissue deposition points to increased cardiovascular morbidity and mortality, independently of any association between obesity and other cardiovascular risk factors. Physical exercise has been used as non-pharmacological treatment to significantly reverse/attenuate obesity comorbidities. In this study we have investigated effects of exercise and/or dietary modification on microcirculatory function, body composition, serum glucose, iNOS and eNOS expression on 120 male hamsters treated for 12 weeks with high fat chow (HF, n = 30) starting on the 21 st day of birth. From week 12 to 20, animals were randomly separated in HF (no treatment change), return to standard chow (HFSC, n = 30), high fat chow associated to an aerobic exercise training program (AET) (HFEX, n = 30) and return to standard chow+AET (HFSCEX, n = 30). Microvascular reactivity in response to acetylcholine and sodium nitroprusside and macromolecular permeability increase induced by 30 minutes ischemia followed by reperfusion were assessed on the cheek pouch preparation. Total body fat and aorta eNOS and iNOS expression by immunoblotting assay were evaluated on the experimental day. Compared to HFSC and HFSCEX groups, HF and HFEX ones presented increased visceral fat [(mean6SEM) (HF)4.961.5 g and (HFEX)4.760.9 g vs. (HFSC)*3.060.7 g and (HFSCEX)*1.960.4 g/100 g BW]; impaired endothelial-dependent vasodilatation [Ach 10 28 M, macromolecular permeability increase after ischemia/reperfusion [(HF)40.564.2; (HFSC)*19.061.6; (HFEX)*18.662.1 and (HFSCEX)* 21.563.7 leaks/cm 2), decreased eNOS expression, increased leptin and glycaemic levels. Endothelial-independent microvascular reactivity was similar between groups, suggesting that only endothelial damage had occurred. Our results indicate that an aerobic routine and/or dietary modification may cause significant improvements to high fat fed animals, diminishing visceral depots, increasing eNOS expression and reducing microcirculatory dysfunction. Citation: Boa BCS, Souza MdGC, Leite RD, da Silva SV, Barja-Fidalgo TC, et al. (2014) Chronic Aerobic Exercise Associated to Dietary Modification Improve Endothelial Function and eNOS Expression in High Fat Fed Hamsters. PLoS ONE 9(7): e102554. doi:10.1371/journal.pone.0102554 Editor: Erik Svensjo, Universidade Federal do Rio de Janeiro (UFRJ), Brazil Copyright: ß 2014 Boa et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability: The authors confirm that all data underlying the findings are fully available without restriction. All relevant data are within the paper. Funding: This study was supported by grants from the National Research Council (CNPq -474116/2008-5) and the Research Supporting Agency of Rio de Janeiro State (FAPERJ -E-26/111.732/2011). Further information concerning those agencies are founded on the following URLs: CNPq:. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist.
[Show abstract][Hide abstract] ABSTRACT: 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.
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.
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).
In conclusion, altered body composition and muscle matrix metalloproteinase 2 activity promoted by excessive weight gain were positively modified by resistance training.
Clinics (São Paulo, Brazil) 04/2014; 69(4):265-70. · 1.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to assess the effects of resistance training on oxidative stress markers in the livers of ovariectomized rats.
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.
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.
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.
Clinics (São Paulo, Brazil) 09/2013; 68(9):1247-54. · 1.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to compare the effect of a cycling training programme performed at intensity corresponding to the lowest value of the respiratory quotient (RQ) versus at intensity corresponding to the ventilatory threshold (VT), on body composition and health-related parameters in overweight women. Thirty-two sedentary obese women (27-42 years old) were studied in a randomized trial of either RQ (n = 17) or VT (n = 15). RQ and VT training sessions were equalized by time (60 min) and performed in a cycloergometer. Anthropometry, body composition, lipid profile, glucose, basal metabolic rate (BMR) and fitness (maximal oxygen uptake) were evaluated before and after 12 weeks of intervention. Body weight, body mass index, fatness and fitness were improved in both groups (P<0·001). Triglycerides (TG) levels decreased only in response to RQ (P<0·001) and fat-free mass (FFM) to VT (P = 0·002). No differences were observed between groups. Both exercise intensities seem to be effective for improving health in overweight women. However, low-intensity compared with the high-intensity exercise training appears to have additional benefits on TG levels and to maintenance of FFM.
Clinical Physiology and Functional Imaging 07/2013; · 1.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to evaluate the effect of resistance training (RT) on body composition, systolic and diastolic blood pressures (BP), and activity of muscle MMP-2 in the left ventricle of high-fat fed rats.
We have evaluated 32 male Wistar rats divided into four experimental groups (n=8/each) according to diet and exercise status: sedentary (SED; standard diet), sedentary obese (SED-OB; diet: 30% of fat), RT (RT; standard diet) and RT obese (RT-OB; diet: 30% of fat). After weaning (day 21), animals were subjected to the experimental diet according to their groups during 24weeks. A 12-week strength-training period was used, during which the rats climbed a 1.1-m vertical ladder with weights attached to their tails. Sessions were performed three times/week (Mondays, Wednesdays and Fridays), with 4-9 climbs/session and 8-12 dynamic movements/climb.
RT induced higher muscle MMP-2 activity in the left ventricle in RT and RT-OB groups. Moreover, this study demonstrated that RT promoted lower body and fat masses, fat percentage, systolic and diastolic BPs and higher fat free mass in both trained groups.
RT increased muscle MMP-2 activity in the left ventricle, induced positive changes on body composition and lowered BPs in high-fat diet fed rats, suggesting that it may be a useful tool to prevent alterations induced by high-fat diet consumption.
Metabolism: clinical and experimental 06/2013; · 3.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to examine acute hormonal responses after different sequences of an upper-body resistance-exercise session. Twenty men completed 2 sessions (3 sets; 70% 1-repetition maximum; 2 min passive rest between sets) of the same exercises in opposite sequences (larger to smaller vs. smaller to larger muscle-group exercises). Total testosterone (TT), free testosterone (FT), testosterone/cortisol (T/C) ratio, sex-hormone-binding globulin (SHBG), growth hormone (GH), and cortisol (C) concentrations were measured before and immediately after each sequence. The results indicate that the GH concentration increased after both sessions, but the increase was significantly greater (p < 0.05) after the sequence in which larger muscle-group exercises were performed prior to the smaller muscle-group exercises. No differences were observed between sessions for TT, FT, SHBG, C, or the T/C ratio at baseline or immediately after resistance exercise. These results indicate that performing larger muscle-group exercises first in an upper-body resistance-exercise session leads to a significantly greater GH response. This may have been due to the significantly greater exercise volume accomplished. In summary, the findings of this investigation support the common prescriptive recommendation to perform larger-muscle group exercises first during a resistance-exercise session.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to examine acute hormonal responses after different sequences of an upper-body resistance-exercise session. Twenty men completed 2 sessions (3 sets; 70% 1-repetition maximum; 2 min passive rest between sets) of the same exercises in opposite sequences (larger to smaller vs. smaller to larger muscle-group exercises). Total testosterone (TT), free testosterone (FT), testosterone/cortisol (T/C) ratio, sex-hormone-binding globulin (SHBG), growth hormone (GH), and cortisol (C) concentrations were measured before and immediately after each sequence. The results indicate that the GH concentration increased after both sessions, but the increase was significantly greater (p < 0.05) after the sequence in which larger muscle-group exercises were performed prior to the smaller muscle-group exercises. No differences were observed between sessions for TT, FT, SHBG, C, or the T/C ratio at baseline or immediately after resistance exercise. These results indicate that performing larger muscle-group exercises first in an upper-body resistance-exercise session leads to a significantly greater GH response. This may have been due to the significantly greater exercise volume accomplished. In summary, the findings of this investigation support the common prescriptive recommendation to perform larger-muscle group exercises first during a resistance-exercise session. Résumé : Cette étude se propose d'analyser les réponses immédiates des hormones suscitées par diverses séquences d'exercices contre résistance du haut du corps. Vingt hommes participent à deux séances comprenant trois séries d'exercices réalisés à 70% 1-RM; chaque séance, intercalée de 2 min de repos passif, est constituée des mêmes exercices réalisés, mais selon des séquences inversées (exercices des grosses masses musculaires suivis des exercices des petites masses musculaires vs exercices des petites masses musculaires suivis des exercices des grosses masses musculaires). Avant et immédiatement après chacune des séances, on évalue la concentration des variables suivantes : testostérone totale (TT), testostérone libre (FT), ratio testostérone/ cortisol (T/C), globuline spécifique (SHBG), hormone de croissance (GH) et cortisol (C). D'après les observations, la concentration de GH augmente à la suite de chacune des séances, mais l'augmentation est significativement plus grande (p ≤ 0,05) à la suite de la séance commençant par les exercices des grosses masses musculaires suivis des exercices des petites masses musculaires. On n'observe aucune différence en ce qui concerne TT, FT, SHBG, C et T/C avant et après chacune des séances d'exercices contre résistance. D'après ces observations, la réalisation des exercices contre résistance du haut du corps sollicitant des grosses masses musculaires suscite notamment une plus grande réponse significative de la GH. Cette plus grande réponse significative de la GH suscitée par des exercices des grosses masses musculaires est probablement due au plus important volume d'exercices réalisés. Ces observations appuient la recommandation courante d'effectuer en premier lieu les exercices des grosses masses musculaires au cours d'une séance d'exercices contre résistance. [Traduit par la Rédaction] Mots-clés : entraînement contre résistance, réponses endocrines, testostérone, cortisol, hormone de croissance, haut du corps.
[Show abstract][Hide abstract] ABSTRACT: The aim of the present study was to evaluate the effect of both swimming and resistance training on tumor necrosis factor-alpha and interleukin-10 expression, adipocyte area and lipid profiles in rats fed a high-fat diet.
The study was conducted over an eight-week period on Wistar adult rats, who were divided into six groups as follows (n = 10 per group): sedentary chow diet, sedentary high-fat diet, swimming plus chow diet, swimming plus high-fat diet, resistance training plus chow diet, and resistance training plus high-fat diet. Rats in the resistance training groups climbed a vertical ladder with weights on their tails once every three days. The swimming groups swam for 60 minutes/day, five days/week.
The high-fat diet groups had higher body weights, a greater amount of adipose tissue, and higher tumor necrosis factor-alpha expression in the visceral adipose tissue. Furthermore, the high-fat diet promoted a negative change in the lipid profile. In the resistance training high-fat group, the tumor necrosis factor-alpha expression was lower than that in the swimming high-fat and sedentary high-fat groups. Moreover, smaller visceral and retroperitoneal adipocyte areas were found in the resistance training high-fat group than in the sedentary high-fat group. In the swimming high-fat group, the tumor necrosis factor-alpha expression was lower and the epididymal and retroperitoneal adipocyte areas were smaller compared with the sedentary high-fat group.
The results showed that both exercise modalities improved the lipid profile, adiposity and obesity-associated inflammation in rats, suggesting their use as an alternative to control the deleterious effects of a high-fat diet in humans.
Clinics (São Paulo, Brazil) 12/2012; 67(12):1469-77. · 1.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to compare repetition maximum performance and ratings of perceived exertion during resistance exercise sessions conducted at a low intensity (i.e., 20 RM) and in different exercise orders. Twenty-one recreationally trained men performed two total body resistance exercise sessions in opposite orders; each exercise was performed for three sets with 2 minutes passive rest between sets and exercises. The results indicated significantly greater total repetitions for each exercise when performed near the beginning of a sequence and for the first set of each exercise, irrespective of the sequence. The ratings of perceived exertion, however, were not significantly different between sequences. In conclusion, repetition maximum performance for resistance exercise sessions conducted at a low intensity is significantly different based on exercise order. Therefore, when performing high repetitions with relatively low intensity loads, exercises should be prioritized based on individual needs and sports-specific movement patterns for greater volume and potential for the desired neuromuscular adaptations.
Research in Sports Medicine An International Journal 07/2012; 20(3-4):263-73.
[Show abstract][Hide abstract] ABSTRACT: The aim of this randomized controlled study was to verify the impact of a 12-weeks muscular endurance (ME) training of high repetitions (i. e., 15-30) with 2 different periodization models on body composition, maximal strength, muscular endurance and cardiorespiratory fitness. Twenty eight sedentary women aged 20-35 years were randomly assigned to: control (CON) (n=8), linear periodization (LP) (n=10) and daily undulating periodization (DUP) (n=10). LP and DUP models significantly improved body composition, maximal strength and ME. However, no significant changes were detected for cardiorespiratory fitness. LP showed a higher body fat loss (- 12.73%) compared to DUP (- 9.93%) (p=0.049), and systematically higher effect sizes (ES) when compared with DUP for maximal strength and cardiorespiratory fitness parameters (e. g. ES=0.53 for ventilatory threshold). In contrast, DUP exhibited a significantly (p=0.002) greater ME gain (129.43%) compared to LP (70.72%) in bench press, and greater ES in all exercises. It may be suggested that LP performed with a high number of repetitions may be considered an appropriate periodization model for untrained young women that would likely lead to the improvement of body composition and maximum strength performance, whereas DUP is more effective for the development of ME.
International Journal of Sports Medicine 05/2012; 33(9):723-7. · 2.27 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of the present study was to investigate the effects of resistance training on glycogen content and muscle cross-sectional area (CSA) in ovariectomized rats. Wistar rats were divided into: sedentary; ovariectomized sedentary; resistance trained; and ovariectomized resistance trained. In the 12-week resistance training, the animals climbed a 1.1 m vertical ladder, 3 days per week, with 4-8 climbs. Cardiac, liver and muscle glycogen content was determined. After the 12-week resistance training period there was a higher hepatic and muscle glycogen content in the resistance training group compared with the other groups (p<0.01). CSA was higher in soleus for the resistance trained, ovariectomized resistance trained and sedentary compared with ovariectomized sedentary (p<0.05). Ovariectomy attenuated the increase in liver and muscle glycogen content, while soleus muscle cross-sectional area increased with resistance training, even in ovariectomized rats. Resistance training could be an important exercise to increase muscle function in situations of reduced estrogen and progesterone.
International Journal of Sports Medicine 04/2012; 33(7):550-4. · 2.27 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aims of our study were to investigate effects of postnatal overnutrition, obtained by restricting the number of pups per litter, on microcirculatory reactivity, fat depots, its total percentage and lipid profile. Microvascular reactivity was evaluated in the cremaster muscle of 24 hamsters divided into four groups, with 6 animals in each one: normal (NL) and restricted (RL) litter groups, both at 6th and 21st weeks of age. The NL group had 8-9 pups and the RL 3 pups per litter and to avoid the litter effect, only one animal was used per litter. The results have shown that the RL group had higher velocity of weight, body mass and fat gain compared to the NL one at weeks 6 and 21. Significant differences were also observed on urogenital fat depot, total cholesterol and low density lipoprotein between groups. At the lowest concentration of Ach, the RL group showed smaller arteriolar dilatation at the 21st than at the 6th week [5(3-13) vs 19(8-40)%, p<0.01] while the NL one did not show any difference within the group. The highest concentration of Ach at the 21th week pointed to endothelial-dependent microvascular dysfunction in RL compared to NL [3(8-26) vs. 13(8-26)%, p<0.05]. Endothelial-independent microvascular reactivity was similar between groups. Our data suggest that postnatal overnutrition is associated to muscle endothelial-dependent microvascular dysfunction, greater body mass and total percentage of fat and impaired the lipid profile. In conclusion, the imprinting promoted by this experimental model of obesity was able to influence microvascular reactivity later in life.
Microvascular Research 03/2012; 84(1):94-8. · 2.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The indiscriminate use of anabolic-androgenic steroids has been shown to induce left ventricular dysfunctions. The main objective of the present study was to investigate the effects of nandrolone decanoate on matrix metalloprotease (MMP-2) activity and protein level in the left ventricle (LV) of rats after 7 weeks of mechanical load exercise. Wistar rats were grouped into: sedentary (S); nandrolone decanoate-treated sedentary (AAS); trained without AAS (T) and trained and treated with AAS (AAST). Exercised groups performed a 7-weeks water-jumping program. Training significantly increased the MMP-2 activity by zymography and the protein level by Western blotting analysis. However, the AAS treatment abolished both the increase in MMP activity and protein level induced by exercise. These results suggest that AAS may impair cardiac tissue remodeling which may lead to the heart malfunction.
International Journal of Sports Medicine 03/2012; 33(3):181-5. · 2.27 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: versão eletrônica P e r i ó d i c o do I n s t i t u t o B r a s i l e i r o d e P e sq u i s a e E n si n o e m F i s i o l o gi a do E x e r c í c i o w w w . i b p e f e x . c o m . b r / w w w . r b p f e x . c o m . b r RESUMO O presente estudo revisou os mecanismos fisiológicos e as maneiras de aplicar atividades de força máxima dinâmica, de forma que esta potencialize de forma aguda as ações musculares subseqüentes realizadas rapidamente, como os saltos ou corridas curtas em velocidade máxima. Após a aplicação do movimento de força máxima, mudanças moleculares e alterações no recrutamento motor pelo sistema nervoso, fazem com que a atividade de força rápida seja potencializada, fenômeno conhecido como potencialização pós-ativação. Ao realizar este método de treinamento, a força máxima e a força rápida podem ser treinadas em uma mesma sessão de treino (microciclo), com ambas sendo otimizadas. Após revisar as publicações mais relevantes sobre o assunto, este artigo propõe como adotar esta metodologia na prática. A aplicação deste método é importante para atletas que utilizam à força rápida em suas modalidades, tais como: futebol, basquete, vôlei, entre outras, ou para aqueles que desejam incluir este treino dentro de alguma etapa na montagem do seu programa de treinamento (periodização). Palavras-chave: Periodização, Microciclo, Força máxima, Força rápida, Métodos de treino.
Revista Brasileira de Prescrição e Fisiologia do Exercício. 01/2012; 6(34):349-359.
[Show abstract][Hide abstract] ABSTRACT: The plyometric training is an essential tool for improving the explosive force. The objective of the present study was to analyze the responses of a plyometric training program on fatigue index in young women athletes. 14 young female basketball players aged 13.28±0.63 years; body mass 51.71±9.11 kg; height 1.61±6.77 m; and body fat percentage 22.71±4.93 % were selected. The training was developed with the preparatory phase of periodization, during 8 weeks with 3 sessions/week, divided into 3 separate programs: jump training (swedish bench height of 30 cm; barriers with height of 40 cm and stands of timber); depth jumps (with wooden boxes of 40 and 70 cm) and jumps with additional loads on the shoulders (bags of sand with 5 kg and 40 cm wood boxes). The jump training sessions were performed in a circuit fashion. An anaerobic endurance test was done by the forward-backward protocol, before and after the plyometric training. Student's t-test was applied (p≤0.05). The percentage of fatigue index (%FI) declined by 2% (from 7.4% to 5.4%), showing a significant improvement (p = 0.022) in the forward-backward protocol test. The structure of the proposed plyometric program proved to be effective in improving the rate of fatigue in basketball athletes in an anaerobic test, which may directly affect specific sport performance.
International Journal of Exercise Science. 01/2012;
[Show abstract][Hide abstract] ABSTRACT: Resistance training (RT) has been recommended to prevent muscle force and power decrease induced by aging. Neuromuscular tests are important tools to analyze muscle force function. The objective of the present study was to analyze the behavior of lower limb muscle power of elderly women submitted to 12 weeks of periodized RT. 16 women aged 65.5±3.6 years with a minimum of one year of previous experience in strength training were selected, they performed 24 sessions of RT divided in 3 mesocycles (MA, MB and MC), of 8 sessions each, with a session frequency of twice a week. The MA with light intensity, MB moderate and MC with high intensity. Lower limb muscle power was measured by vertical jump test. For statistical analysis a p<0.05 was assumed. There was a significant increase in vertical jump after four (T2), eight (T3) and 12 weeks (T4) as compared with baseline (T1). Periodized RT induced positive effects on lower limb muscle power in elderly women. These results are very important for aging, since higher loses in muscle force are observed in lower limb. Periodization is an important tool to prolong the results of muscle power increase induced by RT.
International Journal of Exercise Science. 01/2012;
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to evaluate the correlation between strength gain in bench press and spirometric parameters of sedentary women submitted to a circuit resistance training (CRT). 14 healthy and non-trained women 39.8 ± 3.9 years, 60.6 ± 6.6 kg and 163.6 ± 6.6 cm were submitted to a CRT. The training consisted of 3 sessions/week of a circuit training of 9 stations with alternating muscle groups. In each session, the subjects performed the circuit 2 times with one set of 8-12 maximal repetitions (RM) in each station, during 10 weeks. The spirometric maneuvers, slow vital capacity (SVC), forced expiratory volume (FEV1) and forced vital capacity (FVC) were analyzed by spirometric test, while the strength in bench press was measured by 1-RM test. These tests were performed before and after the CRT. Paired Wilcoxon’s test was applied for comparison between the pre versus post CRT values of the spirometric parameters and of the 1-RM test; and the Spearman’s test for correlation between strength gain in bench press and spirometric parameters in the pre and post CRT (α=0.05 for all statistical tests). In post CRT the strength in bench press test increased, but there was not modification in spirometric parameters; and there was not correlation between the strength gain in bench press and the spirometric parameters analyzed. Therefore, our findings suggest that the gain of strength in bench press induced by CRT do not change spirometric parameters in healthy women.
International Journal of Exercise Science. 01/2012;
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to evaluate the acute effects of short-term and high intensity exercise on serum cytokines concentrations, oxygen consumption and power of sedentary women pre and post 10 weeks of circuit resistance training (CRT). 14 women, 40.23 ± 3.9 years old, 164 ± 6.6 cm and 57.84 ± 7.7 kg were evaluated. Ventilatory threshold (WVT) and VO2peak (IVO2peak) were determined by ergoespirometric incremental test in a cycloergometer. In pre and post CRT, the women performed a test of cycling exercise with two stages: pedaling 30 minutes on WVT and 5 minutes on IVO2peak. The VO2peak was measured by gas analyzer and the cytokines by flow cytometry. The blood samples were taken at rest and immediately after the two stages to measure the plasmatic concentrations of cytokines (IL-1β; IL-6; IL-8; IL-10, IL-12p70 and TNF). Paired Wilcoxon’s test was used to compare the pre and post values of all variables; The cytokines concentrations at rest, and after the two exercise stages were compared by Friedman´s with Tukey post hoc test CRT (α=0.05). The IVO2peak post CRT increased (p=0.01) without alteration of the VO2peak. The IL-6 concentrations were higher after 5 minutes in IVO2peak compared with the rest, both in pre and in post CRT (p<0.05). The alterations in IL-6 plasmatic levels were protocol-dependent; and the proposed CRT increased the power in watts of VO2peak in cycling exercise, but was not sufficient to trigger an inflammatory reaction indicated by serum cytokines levels in women.
International Journal of Exercise Science. 01/2012;
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was analyze the effect of the resistance training on muscle soleus lipid content in ovariectomized rats. Wistar adult female rats were grouped into: sedentary (S); ovariectomized sedentary (Sovx); resistance trained (T) and ovariectomized resistance trained (Tovx). A 12-week strength training that consisted to climb a 1.1-m vertical ladder with weights secured to rats in tail was used. The session was performed once every 3 days with a 4-9 climbs and 8-12 dynamic movements per climb. The muscle soleus lipid content (mg/100mg tissue) was determined by sulfo-vanilin reaction. For statistical analyzes ANOVA was used with p ≤ 0.05. The muscle soleus lipid content was significantly higher in S (2.61±0.31), Sovx (4.28±0.44) and Tovx (3.54±0.36) groups when compared with the T group (0.75±0.15). The S group showed lower values compared with Sovx and Tovx groups. Resistance training decreased lipid content in ovariectomized rats (Tovx) as compared with Sovx group. Ovariectomy increase soleus muscle lipid content, which is decreased by resistance training. Resistance training alone decrease muscle lipid content, indicating an important clinical effect.
International Journal of Exercise Science. 01/2012;
[Show abstract][Hide abstract] ABSTRACT: The aim of the present study was to analyze the effects of different rest intervals on the number of repetitions performed in the bench press exercise. Methods: 6 resistance-trained men (age 24.27±1.61 years, body fat 14.72±5.32 %, body mass 76.60±11.00 kg, 1-RM bench press 98.42±19.78kg) volunteered for the study. Subjects performed a bench press 1-RM test and in two subsequent sessions they performed five maximal sets of the bench press exercise with 70%, 75%, 75%, 80% and 85% of 1-RM and a 1- or 2-minute rest interval between sets. Sessions occurred at least 48h apart, with the last two in a random fashion. Statistical analyzes was made by the student t-test to compare the differences between rest intervals. The number of repetitions performed with the 2-minute rest interval (33.16 ± 6.14) was significantly higher than with 1-minute rest interval (26.67 ± 3.44), (p=0.009) and in sets 2 (p=0.016), 3 (p=0.004) and 4 (p=0.018). The 2-minute rest interval yielded a larger number of repetitions performed throughout the five sets of bench press. Furthermore, the subjects were unable to maintain a large number of repetitions even when a 2-minute rest interval was taken. This indicates that larger rest intervals may be necessary when training with this intensity, especially if the maintenance of exercise volume is desired.
International Journal of Exercise Science. 01/2012;