Verusca Najara de Carvalho Cunha

Acute resistance exercise is more effective than aerobic exercise for 24 h blood pressure control in type 2 diabetics

AIM The study aimed to analyze blood pressure (BP) responses in individuals with type 2 diabetes (T2D) over a 24h period following resistance (RES) and aerobic (AER) exercise. METHODS Ten adults with T2D (age: 55.8 ± 7.7 years; weight: 79.4 ± 14.0 kg; fasting glucose: 133.0 ± 36.7 mg.dL⁻¹) underwent: (1) AER: 20 min of cycling at 90% lactate threshold (90% LT); (2) RES: three laps of a circuit of six exercises with eight repetitions at 70% 1-RM and 40s of recovery; and (3) a control session of no exercise. Heart rate (HR), and systolic (SBP), diastolic (DBP), mean arterial (MAP) and pulse (PP) BP, as well as lactataemia (Lac), VO(2), respiratory exchange ratio (RER) and rate of perceived exertion (RPE) were measured at rest, during exercise and control (CON) periods, and 60min after interventions. After each session, BP was also monitored over a 24h period. RESULTS Peak Lac (RES: 6.4 ± 1.4mM; AER: 3.8 ± 1.2mM), RER (RES: 1.1 ± 0.1; AER: 0.9 ± 0.1) and RPE (RES: 14.0 ± 1.3; AER: 11.0 ± 2.3) were higher following the RES session (P < 0.05). Similar VO₂ (~70% VO(₂peak)) was reached during AER and RES sessions (14.0 ± 3.0 vs 14.3 ± 1.6 mL.kg.min⁻¹; P > 0.05). Compared with CON, only RES elicited post-exercise BP reduction that lasted 8h after exercise. Also, in comparison to pre-exercise rest, the BP dip during sleep was greater following RES (P < 0.05). CONCLUSION A single exercise bout decreases BP in T2D patients over a 24h period, with RES being more effective than AER exercise for BP control.

Assessment of aerobic capacity during swimming exercise in ob/ob mice

Obesity is a highly prevalent condition associated with several diseases. Physical exercise has been considered as a non‐pharmacological tool in the treatment of obesity. However, several aspects underlying exercise evaluation and prescription in obesity and associated pathologies are still under investigation. Although many research involving exercise have been performed in animal models, there is a lack of protocols for aerobic capacity assessment in obese animals, such as the ob/ob mice. This study aimed the following: (i) to verify the possibility of determining the lactate threshold (LT) on swimming exercise in ob/ob mice and in non‐obese heterozygote mice (ob/OB), through visual inspection (vLT) and polynomial adjustment (pLT); and (ii) to verify if the LT determined through these protocols corresponds to the maximal lactate steady state (MLSS). Eight ob/ob and ten ob/OB mice performed an incremental exercise test to determine vLT and pLT as well as constant‐load exercise bouts to determine MLSS. There were no within‐group differences between vLT, pLT and MLSS [ob/ob: ~5.3% body weight (BW); ob/OB: ~3·6%BW] with a high agreement among protocols. In conclusion, the identification of the LT and MLSS intensities was possible for both groups. These data suggest that the proposed protocols may be used in new research on the effects of different exercise intensities on some aspects of obesity. Copyright

Effects of acute exercise over heart proteome from monogenic obese (ob/ob) mice.

Exercise is recognized to prevent and attenuate several metabolic and cardiovascular disorders. Obesity is commonly related to cardiovascular diseases, frequently resulting in heart failure and death. To elucidate the effects of acute exercise in heart tissue from obese animals, 12‐week‐old C57BL6/J obese (ob/ob) and non‐obese (ob/OB) mice were submitted to a single bout of swimming and had their hearts analyzed by proteomic techniques. Mice were divided into three groups: control (ob/ob, n = 3; ob/OB, n = 3); a moderate intensity consisting of 20 min of swimming around 90% of Maximal Lactate Steady State (ob/ob, n = 3; ob/OB, n = 3), and a high intensity exercise performed as an incremental overload test (ob/ob, n = 3; ob/OB, n = 3). Obesity modulations were analyzed by comparing ob/ob and ob/OB control groups. Differential 2‐DE analysis revealed that single session of exercise was able to up‐regulate: myoglobin (ob/ob), aspartate aminotransferase (ob/OB) and zinc finger protein (ob/OB) and down‐regulate: nucleoside diphosphate kinase B (ob/OB), mitochondrial aconitase (ob/ob and ob/OB) and fatty acid binding protein (ob/ob). Zinc finger protein and α‐actin were up‐regulated by the effect of obesity on heart proteome. These data demonstrate the immediate response of metabolic and stress‐related proteins after exercise so as contractile protein by obesity modulation on heart proteome. J. Cell. Physiol. 228: 824–834, 2013.

Treinamento de natação na intensidade do limiar anaeróbio melhora a aptidão funcional de ratos idosos

Os efeitos do treinamento aerobio em intensidade relativa ao limiar de lactato (LL) foram analisados em 15 ratos idosos (~448 dias de vida). Os grupos de animais treinados (n=9) e controle (n=6) foram submetidos a um teste antes e apos quatro semanas de treinamento. O teste incremental consistiu de uma carga inicial de 1% do peso corporal e incrementos de 1% a cada tres minutos, com mensuracoes de lactato sanguineo para identificacao do LL por inspecao visual do ponto de inflexao da curva. O programa de treinamento consistiu de 30 minutos de natacao/dia, cinco dias/semana, com sobrecarga de 5% do peso corporal (PC), ou controle sem exercicio. Foi observado aumento significativo na intensidade do LL apos o treinamento (pre = 4,5 ± 1,1 vs. Pos = 5.4 ± 0.9% PC). A carga maxima atingida ao final do teste incremental aumentou significativamente de 39,7 ± 7,5g no pre para 48,4 ± 10,5g no pos treinamento, sem mudancas para o grupo controle (44,7 ± 8 vs. 45,3 ± 9,3g). O peso corporal do grupo treinado nao apresentou diferenca como resultado de quatro semanas de natacao em intensidade correspondente ao LL (641,0 ±62,0 para 636,0 ± 72.7g; p>0.05). Por outro lado, o grupo nao treinado aumentou significativamente o PC de 614,0 ± 8,0 para 643,0 ± 74,1g. A carga maxima atingida expressa tanto em valores absolutos como relativos (%PC) aumentou significativamente apos o treinamento. Conclui-se que quatro semanas de treinamento de natacao em intensidade correspondente ao limiar de lactato resultou em uma melhora da aptidao aerobia e na manutencao do peso corporal em ratos idosos.

Role of exercise intensity on GLUT4 content, aerobic fitness and fasting plasma glucose in type 2 diabetic mice

Type 2 diabetes mellitus (T2D) results in several metabolic and cardiovascular dysfunctions, clinically characterized by hyperglycaemia due to lower glucose uptake and oxidation. Physical exercise is an effective intervention for glycaemic control. However, the effects of exercising at different intensities have not yet been addressed. The present study analysed the effects of 8 weeks of training performed at different exercise intensities on type 4 glucose transporters (GLUT4) content and glycaemic control of T2D (ob/ob) and non‐diabetic mice (ob/OB). The animals were divided into six groups, with four groups being subjected either to low‐intensity (ob/obL and ob/OBL: 3% body weight, three times/week/40 min) or high‐intensity (ob/obH and ob/OBH: 6% body weight, three times per week per 20 min) swimming training. An incremental swimming test was performed to measure aerobic fitness. After the training intervention period, glycaemia and the content of GLUT4 were quantified. Although both training intensities were beneficial, the high‐intensity regimen induced a more significant improvement in GLUT4 levels and glycaemic profile compared with sedentary controls (p < 0·05). Only animals in the high‐intensity exercise group improved aerobic fitness. Thus, our study shows that high‐intensity training was more effective for increasing GLUT4 content and glycaemia reduction in insulin‐resistant mice, perhaps because of a higher metabolic demand imposed by this form of exercise. Copyright

Identificação do lactato mínimo de corredores adolescentes em teste de pista de três estágios incrementais

OBJECTIVE: To analyze the possibility of determining the lactate minimum (LM) velocity in prepubertal runners applying only three incremental stages. METHODS: Eleven teens (13.7 ± 1.0 years; 47.3 ± 12.1 kg; 160.0 ± 1.0 cm; 18.3 ± 1.8 kg/m2) performed three run tests on athletic track field on different days: 1) performance at 3000m (Vm3000) 2) LM test consisting of a 500m sprint for hyperlactatemia induction, followed by 10min of recovery and six sets of 800m at intensities of 83, 86, 89, 92, 95 and 98% of Vm3000, 3) LM test with threestage (LMp3) similarly to the previous protocol; however, with only three sets of 800m at intensities of 83, 89 and 98% of Vm3000. During the first recovery minute between the second and third test stages, blood samples were collected in order to measure blood lactate. The following criteria were used to determine LM: a) visual inspection (LM), b) polynomial function of second order to LM six stages (LMp) and to three stages (LMp3). RESULTS: ANOVA showed no differences between speeds (m.min-1) identified in the studied methods (LM = 221.7 ± 15.4 vs. LMp = 227.1 ± 10.8 vs. LMp3 = 224.1 ± 11.2). High correlations were observed between the studied protocols and between these protocols and the Vm3000 (p <0.01). CONCLUSION: It was possible to identify the velocity corresponding to the LM in youth runners even when applying only three incremental stages for identification of the LM intensity (LMp3).

Respostas cardiovasculares pós-exercício de natação

INTRODUCAO: A crescente procura da natacao como um tratamento nao-farmacologico da hipertensao arterial tem aumentado. Objetivo: Analisar as respostas da pressao arterial (PA) apos o exercicio de natacao e durante a rotina diaria de trabalho de individuos pre-hipertensos. METODOS: Oito individuos pre-hipertensos (128,2 ± 7,8 / 77,8 ± 6,0mmHg; 41,8 ± 3,2 anos; 84,7 ± 17,9kg; 180,4 ± 4,8cm; 27,3 ± 5,8kg.m2(-1)) foram submetidos a duas sessoes, sendo uma de natacao (SN) e a outra de controle (SC). A PA foi medida no repouso pre-exercicio e durante 12 horas de recuperacao pos-exercicio. Na SN, os pacientes nadaram por 45min em uma intensidade moderada a alta (PSE 14,5 ± 1,6), e, durante a SC, os sujeitos permaneceram em repouso na posicao sentada pelo mesmo periodo de tempo. RESULTADOS: ANOVA para medidas repetidas evidenciou diminuicao significativa (p < 0,05) na PAS por duas horas apos a SN em relacao ao repouso, e uma diferenca significativa entre os deltas do PAS (Δ - PAS variacao na recuperacao pos-exercicio em relacao ao repouso pre-exercicio) foi observada entre as sessoes na primeira e segunda horas apos a recuperacao, respectivamente (ΔSS = -10,4 e -9,3 vs. ΔCS = 0,8 e 4,4mmHg, p < 0,05). Nγo houve diferencas significativas da PAD, intra e entre as sessoes. CONCLUSAO: O exercicio de natacao em intensidade moderada a alta foi eficaz para promover reducao da PA pos-exercicio em individuos hipertensos durante a sua rotina de trabalho.

Mobilidade articular de idosos diabéticos e não diabéticos e influência da fisioterapia

INTRODUCTION: Type 2 diabetes (T2D) is a chronical disease with an important socioeconomic impact nowadays. Prevention, early detection and treatment are important to morbidity and mortality reduction. OBJECTIVES: To verify and compare the which have the greatest limitation of joint mobility (LJM), the LJM relation to age, the time of diagnosis of T2D, the presence of a prayer signal (PS), the risk neuropathic (RN) and the influence of exercises used in physiotherapy in elderly T2D and non T2D individuals. MATERIALS AND METHODS: The subjects were accomplished in three groups being control group (C; n = 15); T2D group (T2D; n=15) and T2D in physiotherapeutic treatment - stretching and light resistance exercises (T2DPhys; n = 15). Goniometry of the ankles and wrists, PS and RN were evaluated and the average of range of motion (ROM) was associated between groups accordingly to the age, time of diagnosis of T2D, PS and RN. RESULTS AND CONCLUSIONS: The average ROM in groups were C > T2DPhys > T2D, significantly (p T2D)in the wrist extension movement. The LJM were higher in older individual and in T2S with more time with disease but these relations were not significant. In this study, the RN and PS were not the only determinants of LJM. It was concluded that T2D interferes negatively and significantly in ROM and the physiotherapy treatment through stretching and resistance light exercises exerted beneficial influences on these parameters in the T2D.

Training Performed Above Lactate Threshold Decreases p53 and Shelterin Expression in Mice

Telomere shortening is associated to sarcopenia leading to functional impairment during aging. There are mechanisms associated with telomere attrition, as well to its protection and repair. Physical training is a factor that attenuates telomere shortening, but little is known about the effects of different exercise intensities on telomere biology. Thus, we evaluated the effects of exercise intensity (moderate vs. high-intensity domain) on gene expression of senescence markers Checkpoint kinase 2 and tumor suppressor (Chk2 and p53, respectively), shelterin telomere repeat binding 1 and 2 (Trf1/Trf2), DNA repair (Xrcc5), telomerase reverse transcriptase (mTERT) and telomere length in middle aged mice. Three groups were studied: a control group (CTL) and two groups submitted to swimming at intensities below the lactate threshold (LI group) and above the lactate threshold (HI group) for 40 and 20 min respectively, for 12 weeks. After training, the HI group showed reduction in p53 expression in the muscle, and decreased shelterin complex expression when compared to LI group. No differences were observed between groups for mTERT expression and telomere length. Thus, exercise training in high-intensity domain was more effective on reducing markers of senescence and apoptosis. The higher intensity exercise training also diminished shelterin expression, with no differences in telomere length and mTERT expression. Such results possibly indicate a more effective DNA protection for the higher-intensity exercise training.