Effects of prior exercise on glycemic responses following carbohydrate inges on in individuals with type 2 diabetes.

BACKGROUND: Exercise is effective in reducing glycemia, especially when it is performed in the postprandial period. However, no consensus exists in the literature about the effect of exercise on postprandial glucose control when it is performed before carbohydrate consumption. AIMS: The main aim was to determine whether 20 min of exercise performed prior to carbohydrate consumption reduces postprandial glycemic and insulinemic responses. A secondary aim was to analyze the effectiveness of short-term (10 min) exercise bout with respect to postprandial glycemia reduction. METHODS: Nine individuals with type 2 diabetes (54.9 ± 1.7 years; 30.7 ± 1.8 kg/m2; glycemia level of 167.0 ±10.6 mg/dL) participated in the study and underwent the following procedures: (a) an incremental test to determine the lactate threshold; (b) an exercise session for 20 minutes at moderate intensity (90% of the lactate threshold); and c) a control session. The last two sessions were randomized, and the participants were monitored during 135 minutes of post-exercise recovery. A standard meal was consumed two hours before the experimental procedures started. A dextrose solution was administered at 45 minutes of post-exercise recovery while monitoring glucose and insulin concentrations. At 135 min of post-exercise recovery, eight of the participants performed an additional 10-min exercise bout following induced hyperglycemia. RESULTS: Exercise reduced glycemia (-46.6 ± 7.9 mg/dL) and the insulin/glucose ratio (from 1.73 ± 0.59 to 0.93 ± 0.22 µU/mL/mmol/L) during the first 45 minutes of post-exercise recovery. Glycemia was significantly increased after carbohydrate consumption, reaching its peak value at 105 minutes of post-exercise recovery (261.8 ± 15.8 mg/dL) or control (281.3 ± 13.4 mg/dL). There was no effect of the previous exercise in attenuating glycemia or reducing the area under the curve for glucose and insulin after carbohydrate consumption. However, the effectiveness of exercise in reducing glycemia was shown again when it was performed at the end of the experimental session, even in case of only a 10-min exercise (reduction of -44.5 ± 4.9 mg/dL). CONCLUSIONS: Twenty minutes of moderate exercise does not alter the kinetics or the area under the curve in terms of glycemia and insulinemia after subsequent carbohydrate consumption. However, moderate exercise, even if performed for only 10-20 minutes, is effective in reducing postprandial glycemia in individuals with type 2 diabetes. RELEVANCE FOR PATIENTS: Moderate-intensity exercise, even of short duration, may benefit individuals with type 2 diabetes on blood glucose control. A fast reduction in postprandial glycemia can be obtained with only ten minutes of exercise that, in turn, may ameliorate some of complications associated with the disease.

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 ~24.4% for ND and ~13.8% for T2D group 15 min 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.

Efeito da intensidade do exercício sobre a oxidação de carboidratos e gorduras durante a recuperação pós-exercício em diabéticos tipo 2 / Effects of exercise intensity in fat and carbohydrate oxidation during post-exercise recovery in type 2 diabetes

Indivíduos com diabetes tipo 2 apresentam alterações na utilização de substratos energéticos em repouso e durante o exercício, como capacidade reduzida de utilização de carboidratos e síntese de glicogênio muscular, acentuando a hiperglicemia e a resistência à insulina. Estudos têm demonstrado que o exercício pode ser efetivo no controle e tratamento do diabetes tipo 2, porém o efeito de diferentes intensidades de exercício sobre a contribuição de carboidratos e gorduras durante a recuperação ainda não foi elucidado. Participaram do estudo 20 indivíduos sedentários, divididos em 2 grupos, sendo 9 diabéticos tipo 2 (DB) (2 mulheres) e 11 não diabéticos (ND) (2 mulheres), os quais foram submetidos a 3 sessões experimentais: Teste incremental máximo (TI), seguido de sessão de exercício submáximo realizado a 90% da carga do limiar de lactato (90%LL) e sessão controle (C) sem a realização de exercício, estas duas últimas em ordem randomizada. Em todas as sessões experimentais, os participantes permaneceram em repouso durante 20 min antes do inicio das sessões, bem como por 135 minutos durante o período de recuperação pós-exercício ou controle para a mensuração das variáveis ventilatórias, sendo que aos 45 minutos de recuperação uma solução de carboidrato (CHO) foi administrada. Ambos os grupos apresentaram elevada oxidação de carboidratos durante as sessões de exercício máximo (TI) e submáximo (90%LL) quando comparado aos valores de repouso (p<0,05). A oxidação de gorduras ficou elevada durante o período de recuperação do TI em ambos os grupos (p<0,05), contudo, no grupo DB, essa alteração se prolongou por um maior período de recuperação. Por outro lado, durante a recuperação do exercício submáximo, somente o grupo ND apresentou oxidação de gordura elevada após 60 min de recuperação...

Individuals with type 2 diabetes (DB) have changes in energy substrate utilization at rest and during exercise, with less use of carbohydrate and muscle glycogen synthesis, emphasizing the hyperglycemia and insulin resistance. Exercise can help control and treatment of type 2 diabetes, but effect of different exercise intensities on the carbohydrates and fats contribution during recovery has not yet been elucidated. Participated in the study 20 sedentary individuals, 9 individuals (2 women) with type 2 diabetes (DB) and 11 (2 women) without diabetes (ND), underwent three experimental sessions (SE): maximal incremental test (IT); submaximal exercise, 90% of the load of the lactate threshold (90% LL) and control (Cont) or without exercise (the latter two session in randomized order). In all the SE, the participants were at rest (pre-exercise) for 20 minutes and 135 minutes during the post-exercise for measurement of ventilatory variables, and the 45-minute of recovery the volunteers were given a carbohydrate solution was given. The results showed that both groups had high carbohydrate oxidation during exercise of high and moderate intensity compared with rest (p <0.05). The fat oxidation was higher during the recovery of IT in both groups (p <0.05), and longer in the DB. On the other hand, during recovery from moderate exercise, only ND had higher fat oxidation after 60 min of recovery...

Respostas cardiovasculares pós-exercício de natação / Swimming post-exercise cardiovascular responses

INTRODUÇÃO: A crescente procura da natação como um tratamento não-farmacológico da hipertensão arterial tem aumentado. Objetivo: Analisar as respostas da pressão arterial (PA) após o exercício de natação e durante a rotina diária de trabalho de indivíduos pré-hipertensos. MÉTODOS: Oito indivíduos pré-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 sessões, sendo uma de natação (SN) e a outra de controle (SC). A PA foi medida no repouso pré-exercício e durante 12 horas de recuperação pós-exercício. 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 posição sentada pelo mesmo período de tempo. RESULTADOS: ANOVA para medidas repetidas evidenciou diminuição significativa (p < 0,05) na PAS por duas horas após a SN em relação ao repouso, e uma diferença significativa entre os deltas do PAS (Δ - PAS variação na recuperação pós-exercício em relação ao repouso pré-exercício) foi observada entre as sessões na primeira e segunda horas após a recuperação, respectivamente (ΔSS = -10,4 e -9,3 vs. ΔCS = 0,8 e 4,4mmHg, p < 0,05). Nγo houve diferenças significativas da PAD, intra e entre as sessões. CONCLUSÃO: O exercício de natação em intensidade moderada a alta foi eficaz para promover redução da PA pós-exercício em indivíduos hipertensos durante a sua rotina de trabalho.

INTRODUCTION: The increasing demand for swimming as a non-pharmacological treatment of hypertension has increased. PURPOSE: To analyze the blood pressure (BP) responses after swimming and during the daily work routine of pre-hypertensive individuals. METHODS: Eight male borderline hypertensive individuals (128.2 ± 7.8 / 77.8 ± 6.0 mmHg; 41.8 ± 3.2 years; 84.7 ± 17.9 kg; 180.4 ± 4.8 cm; 27.3 ± 5.8 kg.m2 (-1)) were submitted to a swimming exercise (SS) and control (CS) sessions. BP was measured at pre-exercise rest and during 12 hours of the post-exercise recovery. In SS, patients swan for 45 minutes in a moderate-high intensity (PSE 14.5 ± 1.6), and during CS the subjects remained at seated rest for 45 min. RESULTS: ANOVA for repeated measures evidenced significant decrease (P < 0.05) in SBP in the for 2 hours after SS in comparison to rest, and a significant difference between the SBP deltas (Δ - SBP variation in the post-exercise recovery compared to pre-exercise rest) was observed when comparing sessions at 1 and 2 hours after recovery, respectively (ΔSS = -10.4 and -9.3 vs. ΔCS = 0.8 and 4.4 mmHg, p <0.05). There were not significant differences in DBP within and between sessions. CONCLUSION: Swimming exercise at moderate-high intensity was effective in promoting post-exercise BP reduction for borderline hypertensive individuals during their daily work routine.

Recomendação de procedimentos da Sociedade Americana de Fisiologia do Exercício (ASEP) I: avaliação precisa da força e potência muscular / Procedures recommendation I: accurate assessment of muscular strength and power

Este manuscrito visa a ajudar o leitor a coletar dados válidos e confiáveis para quantificar a força e a potência muscular. Vários inconvenientes e desvantagens de testes específicos, assim como recomendações para praticantes também são apresentadas. O conteúdo é dividido em seções, abrangendo modos de exercício isométrico, isotônico, testes de campo e isocinéticos. Inerentes a esses modos estão ambas as ações musculares concêntricas e excêntricas, assim como as atividades de cadeia cinética aberta e fechada. Para o teste isométrico, as contrações devem ocorrer com uma duração de quatro a cinco segundos com um período de transição de um segundo no início da contração. Ao menos um minuto de descanso deve ser oferecido entre as contrações. Para cada músculo testado, em cada posição, no mínimo três contrações devem ser executadas, embora outras possam ser executadas se julgadas necessárias pelo examinador. Para o teste isotônico, o teste de 1-RM deve ser executado. Após o aquecimento geral, o indivíduo deve executar uma série de aquecimento específico de 8 repetições a aproximadamente 50% da 1-RM estimada, seguida por outra série de três repetições a 70% da 1-RM estimada. Os levantamentos subseqüentes são repetições simples com cargas progressivamente mais pesadas até a fadiga. Repete-se até que a 1-RM seja determinada com o nível desejado de precisão. O intervalo de descanso entre as séries não deve ser menor que um e maior que cinco minutos. O número ótimo de repetições simples varia de três a cinco. Os dados e diretrizes dos seguintes testes de campo também são fornecidos: salto vertical, supino, Teste ciclístico anaeróbico de Wingate (WAT), e o Teste Margaria de corrida em escada (Teste de potência de Margaria). Para o teste isocinético, são fornecidos detalhes sobre o pico de torque, trabalho, potência, endurance e estimativa dos percentuais dos tipos de fibra.

The content of this manuscript is intended to assist the reader in collecting valid and reliable data for quantifying muscular strength and power. Various drawbacks and pitfalls of specific tests, as well as recommendations for the practitioner are also provided. The content is divided into sections covering isometric, isotonic, field tests, and isokinetic modes of exercise. Inherent in these modes are both concentric and eccentric muscle actions as well as both open and closed kinetic chain activities. For Isometric testing, contractions should occur over a four to five seconds duration with a one second transition period at the start of the contraction. At least one minute of rest should be provided between contractions. For each muscle tested at each position, at least three contractions should be performed although more may be performed if deemed necessary by the tester. For isotonic testing, the 1-RM test should be performed. After the general warm-up, the subject should perform a specific warm-up set of 8 repetitions at approximately 50% of the estimated 1-RM followed by another set of 3 repetitions at 70% of the estimated 1-RM. Subsequent lifts are single repetitions of progressively heavier weights until failure. Repeat until the 1-RM is determined to the desired level of precision. The rest interval between sets should be not less than one and not more than five minutes. The optimal number of single repetitions ranges fADM three to five. Data and guidelines of the following field tests are also provided; vertical jump, bench press, Wingate anaerobic cycle test (WAT), and the Margaria stair-run test. For isokinetic testing, details are provided for testing peak torque, work, power, endurance, and estimation of fiber type percentages.