Resistance Training in Spontaneously Hypertensive Rats with Severe Hypertension

Background: Resistance training (RT) has been recommended as a non-pharmacological treatment for moderate hypertension. In spite of the important role of exercise intensity on training prescription, there is still no data regarding the effects of RT intensity on severe hypertension (SH). Objective: This study examined the effects of two RT protocols (vertical ladder climbing), performed at different overloads of maximal weight carried (MWC), on blood pressure (BP) and muscle strength of spontaneously hypertensive rats (SHR) with SH. Methods: Fifteen male SHR [206 +/- 10 mmHg of systolic BP (SBP)] and five Wistar Kyoto rats (WKY; 119 +/- 10 mmHg of SBP) were divided into 4 groups: sedentary (SED-WKY) and SHR (SED-SHR); RT1-SHR training relative to body weight (similar to 40% of MWC); and RT2-SHR training relative to MWC test (similar to 70% of MWC). Systolic BP and heart rate (HR) were measured weekly using the tail-cuff method. The progression of muscle strength was determined once every fifteen days. The RT consisted of 3 weekly sessions on non-consecutive days for 12-weeks. Results: Both RT protocols prevented the increase in SBP (delta -5 and -7 mmHg, respectively; p > 0.05), whereas SBP of the SED-SHR group increased by 19 mmHg (p 0.05). Conclusions: Our data indicated that both RT protocols were effective in preventing chronic elevation of SBP in SH. Additionally, a higher RT overload induced a greater increase in muscle strength.Fundamentos: O treinamento de força (TF) tem sido recomendado como tratamento não farmacológico para hipertensão arterial moderada. Apesar do papel importante que a intensidade do exercício desempenha sobre a prescrição do treinamento, ainda não há nenhum dado avaliando os efeitos da intensidade do TF sobre a hipertensão arterial grave (HAG). Objetivo: Este estudo analisou os efeitos de dois protocolos do TF(subida em escada vertical), realizados com diferentes sobrecargas do peso máximo carregado (PMC), sobre a pressão arterial (PA) e a força muscular de ratos espontaneamente hipertensos (SHR) com HAG. Métodos: Quinze SHR machos (206 ± 10 mmHg de PA sistólica (PAS)) e cinco ratos Wistar Kyoto (WKY; 119 ± 10 mmHg de PAS) foram divididos em 4grupos:sedentários: (SED-WKY) e SHR (SED-SHR); treinados: TF1-SHR conforme o peso corporal (~40% do PMC); e TF2-SHR conforme o teste de PMC (~70% do PMC). Foram coletadas medidas de PAS e a frequência cardíaca (FC) semanalmente usando o método de pressão arterial caudal. A progressão da força muscular foi determinada a cada 15 dias. O TF consistiu de 3 sessões semanais em dias não consecutivos durante 12 semanas. Resultados: Os dois protocolos de TF preveniram o aumento da PAS(respectivamente, delta - 5 e -7 mmHg; p > 0, 05), enquanto que a PAS do grupo SED-SHR aumentou em 19 mmHg (p 0, 05). Conclusões: Nossos dados indicam que ambos os protocolos de TF foram efetivos na prevenção da elevação crônica da PAS na HAG. Além disso, sobrecargas maiores de TF induziram a um maior aumento de força muscular.CapesCNPqUniv Catolica Brasilia, Programa Posgrad Educ Fis, Brasilia, DF, BrazilUniv Fed Sao Paulo, Programa Posgrad Med Translac, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Div Nefrol, Lab Imunol Clin & Expt, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Med, Div Nefrol, Sao Paulo, SP, BrazilUniv Sao Paulo, Escola Artes Ciencias & Humanidades, Sao Paulo, SP, BrazilUniv Sao Paulo, Inst Ciencias Biomed, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Fisiol, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Programa Posgrad Med Translac, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Div Nefrol, Lab Imunol Clin & Expt, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Med, Div Nefrol, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Fisiol, Sao Paulo, SP, BrazilWeb of Scienc

Estimating the Perceived Exertion Threshold Using the OMNI Scale

Nakamura, FY, Pereira, G, Chimin, P, Siqueira-Pereira, TA, Simões, HG, and Bishop, DJ. Estimating the perceived exertion threshold using the OMNI scale. J Strength Cond Res 24(6): 1602-1608, 2010-This study aimed to determine if the OMNI scale with cycle ergometer pictorial format can be used to estimate perceived exertion threshold (PETOMNI) and nonexhaustive PET (PETOMNI5-8) and to compare and to correlate these PET estimates with PETBorg, PETBorg14-17, and critical power (CP). During different days, 13 men performed 4 different high-intensity constant-loads work bouts until exhaustion on a cycle ergometer using the Borg scale, whereas the OMNI scale was used during the other 4 work bouts using previous constant loads. The PET for both scales was determined by plotting the increasing rates of perceived exertion against power outputs, PET being the intersection point of the regression line. In addition, a hyperbolic relationship between power and time to exhaustion was used to determine CP. The PETOMNI (183 ± 36 W) was similar to PETBorg (178 ± 46 W), and they were also significantly correlated (r = 0.77). The PETOMNI5-8 (175 ± 36 W) was similar to PETBorg14-17 (181 ± 38 W); however, they were not significantly correlated (r = 0.36). All the PET estimates were similar to CPOMNI (167 ± 36 W) and CPBorg (169 ± 40 W) and also significantly correlated (r = 0.79-0.94), excepting PETOMNI5-8 (r = 0.46). In conclusion, OMNI cycling scale can be used to estimate PET and CP with high accuracy. However, the nonexhaustive PET derived from the 5-8 range in the OMNI scale did not provide a valid estimate of maximal sustainable power output because of the absence of correlation with PETBorg14-17 and with CP. Therefore, professionals and practitioners can assess the subjects' aerobic fitness through the PET estimation using the OMNI scale during exhaustive tests

A influência do genótipo da ECA sobre a aptidão cardiovascular de jovens do sexo masculino moderadamente ativos

FUNDAMENTO: O gene da enzima conversora de angiotensina (gene ECA) tem sido amplamente estudado em relação a fenótipos de aptidão cardiorrespiratória, contudo a associação do genótipo da ECA com corridas de meia-distância tem sido pouco investigada. OBJETIVO: O presente estudo investigou a possível influência da enzima conversora de angiotensina (ECA) (I/D) sobre a aptidão cardiovascular e o desempenho em corridas de meia-distância por parte de brasileiros jovens do sexo masculino. A validade da previsão de VO2max em relação ao genótipo da ECA também foi analisada. MÉTODOS: Um grupo homogêneo de homens jovens moderadamente ativos foi avaliado em um teste de corrida (V1600 m; m.min-1) e em um teste adicional em esteira ergométrica para a determinação de VO2max. Posteriormente, o [(0,177*V1600m) + 8.101] VO2max real e previsto foi comparado com os genótipos da ECA. RESULTADOS: O VO2max e V1600m registrados para os genótipos DD, ID e II foram 45,6 (1,8); 51,9 (0,8) e 54,4 (1,0) mL.kg-1.min-1 e 211,2 (8,3); 249,1 (4,3) e 258,6 (5,4 ) m.min-1, respectivamente e foram significativamente mais baixos para os genótipos DD (p < 0,05). O VO2max real e previsto não diferiram entre si, apesar do genótipo da ECA, mas o nível de concordância entre os métodos de VO2max real e estimado foi menor para o genótipo DD. CONCLUSÃO: Concluiu-se que existe uma possível associação entre o genótipo da ECA, a aptidão cardiovascular e o desempenho em corridas de média distância de jovens do sexo masculino moderadamente ativos e que a precisão da previsão do VO2max também pode ser dependente do genótipo da ECA dos participantes.Background: The angiotensin I-converting enzyme gene (ACE gene) has been broadly studied as for cardiorespiratory fitness phenotypes, but the association of the ACE genotype to middle-distance running has been poorly investigated.Objective: This study investigated the possible influence of Angiotensin-Converting Enzyme (ACE) genotype (I/D) on cardiovascular fitness and middle-distance running performance of Brazilian young males. The validity of VO2max prediction with regard to the ACE genotype was also analyzed.Methods: A homogeneous group of moderately active young males were evaluated in a 1,600 m running track test (V1600m; m.min(-1)) and in an incremental treadmill test for VO2max determination. Subsequently, the actual and the predicted [(0.177*V1600m) + 8.101] VO2max were compared to ACE genotypes.Results: The VO2max and V1600m recorded for DD, ID and II genotypes were 45.6 (1.8); 51.9 (0.8) and 54.4 (1.0) mL.kg(-1). min(-1) and 211.2 (8.3); 249.1 (4.3) and 258.6 (5.4) m.min(-1) respectively, and were significantly lower for DD carriers (p< 0.05). The actual and predicted VO2max did not differ from each other despite ACE genotype, but the agreement between actual and estimated VO2max methods was lower for the DD genotype.Conclusion: It was concluded that there is a possible association between ACE genotype, cardiovascular fitness and middle-distance running performance of moderately active young males and that the accuracy of VO2max prediction may also depend on the ACE genotype of the participants.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Determination of the lactate threshold and maximal blood lactate steady state intensity in aged rats

The reliability of the lactate threshold (LT) determined in aged rats and its, validity to identify an exercise intensity corresponding to the maximal blood lactate steady state (MLSS) were analyzed. Eighteen male aged Wistar rats (similar to 365 days) were submitted to two incremental swimming tests until exhaustion, consisting of an initial load corresponding to 1% of body mass (BM) and increments of 1% BM at each 3-min with blood lactate ([lac]) measurements. The LT was determined by visual inspection (LT(V)) as well by applying a polynomial function on the [lac]/workload ratio (LT(P)) by considering the vertices of the curve. For the MLSS, twelve animals were submitted, on different days, to 3-4 exercise sessions of 30-min with workload corresponding to 4, 5 or 6% BM. The MLSS was considered the highest exercise intensity at which the [lac] variation was not higher than 0.07 mM.min(-1) during the last 20-min. No differences were observed for the test-retest results (4.9 +/- 0.7 and 5.0 +/- 0.8 %BM for LTv; and 6.0 +/- 0.6 and 5.8 +/- 0.6 %BM for LTp) that did not differ from the MLSS (5.4 +/- 0.5 %BM). The LT identified for aged rats in swimming, both by visual inspection and polynomial function, was reliable and did not differ from the MLSS. Copyright (C) 2009 John Wiley & Sons, Ltd.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Effects of carbohydrate supplementation on competitive runners undergoing overload training followed by a session of intermittent exercise

This study evaluated the effects of a micro cycle of overload training (1st-8th day) on metabolic and hormonal responses in male runners with or without carbohydrate supplementation and investigated the cumulative effects of this period on a session of intermittent high-intensity running and maximum-performance-test (9th day). The participants were 24 male runners divided into two groups, receiving 61% of their energy intake as CHO (carbohydrate-group) and 54% in the control-group (CON). The testosterone was higher for the CHO than the CON group after the overload training (694.0 +/- A 54.6 vs. CON 610.8 +/- A 47.9 pmol/l). On the ninth day participants performed 10 x 800 m at mean 3 km velocity. An all-out 1000 m running was performed before and after the 10 x 800 m. Before, during, and after this protocol, the runners received solution containing CHO or the CON equivalent. The performance on 800 m series did not differ in either group between the first and last series of 800 m, but for the all-out 1000 m test the performance decrement was lower for CHO group (5.3 +/- A 1.0 vs. 10.6 +/- A 1.3%). The cortisol concentrations were lower in the CHO group in relation to CON group (22.4 +/- A 0.9 vs. 27.6 +/- A 1.4 pmol/l) and the IGF1/IGFBP3 ratio increased 12.7% in the CHO group. During recovery, blood glucose concentrations remained higher in the CHO group in comparison with the CON group. It was concluded that CHO supplementation possibly attenuated the suppression of the hypothalamic-pituitary-gonadal axis and resulted in less catabolic stress, and thus improved running performance.FAPES

Type 2 Diabetes Elicits Lower Nitric Oxide, Bradykinin Concentration and Kallikrein Activity Together with Higher DesArg(9)-BK and Reduced Post-Exercise Hypotension Compared to Non-Diabetic Condition

This study compared the plasma kallikrein activity (PKA), bradykinin concentration (BK), DesArg(9)-BK production, nitric oxide release (NO) and blood pressure (BP) response after moderate-intensity aerobic exercise performed by individuals with and without type 2 diabetes. Ten subjects with type 2 diabetes (T2D) and 10 without type 2 diabetes (ND) underwent three sessions: 1) maximal incremental test on cycle ergometer to determine lactate threshold (LT); 2) 20-min of constant-load exercise on cycle ergometer, at 90% LT and; 3) control session. BP and oxygen uptake were measured at rest and at 15, 30 and 45 min post-exercise. Venous blood samples were collected at 15 and 45 minutes of the recovery period for further analysis of PKA, BK and DesArg(9)-BK. Nitrite plus nitrate (NOx) was analyzed at 15 minutes post exercise. The ND group presented post-exercise hypotension (PEH) of systolic blood pressure and mean arterial pressure on the 90% LT session but T2D group did not. Plasma NOx increased similar to 24.4% for ND and similar to 13.8% for T2D group 15min after the exercise session. Additionally, only ND individuals showed increases in PKA and BK in response to exercise and only T2D group showed increased DesArg(9)-BK production. It was concluded that T2D individuals presented lower PKA, BK and NOx release as well as higher DesArg(9)-BK production and reduced PEH in relation to ND participants after a single exercise session.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Precision measurement of the structure of the CMS inner tracking system using nuclear interactions

The structure of the CMS inner tracking system has been studied using nuclear interactions of hadrons striking its material. Data from proton-proton collisions at a center-of-mass energy of 13 TeV recorded in 2015 at the LHC are used to reconstruct millions of secondary vertices from these nuclear interactions. Precise positions of the beam pipe and the inner tracking system elements, such as the pixel detector support tube, and barrel pixel detector inner shield and support rails, are determined using these vertices. These measurements are important for detector simulations, detector upgrades, and to identify any changes in the positions of inactive elements