Effect of Combined Exercise Training on Physical and Cognitive Function in Women With Type 2 Diabetes.

OBJECTIVES: One of the consequences of old age is cognitive and physical decline, which can cause a wide range of problems. These complications are more pronounced in those with type 2 diabetes (T2D). The aim of this pilot study was to investigate the effect of combined exercise training on blood biomarkers, physical fitness, and cognitive function in elderly women with T2D. METHODS: Twenty-one elderly women with T2D were randomly allocated to training (n=12) and control (n=9) groups. The exercise training program was a combination of aerobic, resistance, and balance exercises performed 3 times per week over 12 weeks. In the same period, the control group received no training intervention. Blood markers, including brain-derived neurotrophic factor (BDNF), irisin, glycated hemoglobin (A1C), fasting blood sugar (FBS), cardiorespiratory fitness (CRF), lower and upper body strength, and cognitive function, were measured in all participants at baseline and after 12 weeks. RESULTS: Serum BDNF levels were not significantly different between the exercise and control groups at 12 weeks (p>0.05). FBS and A1C levels in the exercise group decreased significantly compared with the control group (p<0.05). CRF, dynamic balance, and both upper and lower body strength in the exercise group improved significantly compared with the control group (p<0.05). Irisin levels decreased significantly in the control group, but levels did not change significantly in the exercise group. Greater improvements from exercise were observed on the Montreal Cognitive Assessment index compared with the control group (p=0.05), but no other group differences in cognitive function were noted. CONCLUSIONS: Combined exercise improved some physical fitness and diabetes-related surrogate factors, as well as select cognitive functions, but had no significant effect on cognition-related biochemical factors (i.e. BDNF) in women with T2D.

Effects of Power and Ballistic Training on Table Tennis Players' Electromyography Changes.

The aim of the present study was to analyze the effects of ballistic and power training on table tennis players' electromyography (EMG) changes. Thirty male table tennis players, who were able to perform top spin strikes properly, were randomly assigned to three groups: power training (PT; n = 10); ballistic training (BT; n = 10); and no training (CON = control group; n = 10). PT and BT were performed 3 times weekly for 8 weeks. Before and after training programs, a one-repetition maximum test (1RM) and the EMG activity of all the subjects' upper/lower body muscles while performing top spin strokes were analyzed. After training, significant interactions (group × time) were observed in increasing 1RM strength in upper/lower muscles (p < 0.05). However, neither training type had any significant effect on muscle EMG activity. These findings suggest that there should not necessarily be any significant change in the EMG signal after BT and PT despite the increase in muscle strength.

Combined mental task and metaboreflex impair cerebral oxygenation in patients with type 2 diabetes mellitus.

Cardiovascular regulation is altered by type 2 diabetes mellitus (DM2), producing an abnormal response to muscle metaboreflex. During physical exercise, cerebral blood flow is impaired in patients with DM2, and this phenomenon may reduce cerebral oxygenation (COX). We hypothesized that the simultaneous execution of a mental task (MT) and metaboreflex activation would reduce COX in patients with DM2. Thirteen individuals suffering from DM2 (6 women) and 13 normal age-matched controls (CTL, 6 women) participated in this study. They underwent five different tests, each lasting 12 min: postexercise muscle ischemia (PEMI) to activate the metaboreflex, control exercise recovery (CER), PEMI + MT, CER + MT, and MT alone. COX was evaluated using near-infrared spectroscopy with sensors applied to the forehead. Central hemodynamics was assessed using impedance cardiography. We found that when MT was superimposed on the PEMI-induced metaboreflex, patients with DM2 could not increase COX to the same extent reached by the CTL group (101.13% ± 1.08% vs. 104.23% ± 2.51%, P < 0.05). Moreover, patients with DM2 had higher mean blood pressure and systemic vascular resistance as well as lower stroke volume and cardiac output levels compared with the CTL group, throughout our experiments. It was concluded that patients with DM2 had reduced capacity to enhance COX when undertaking an MT during metaboreflex. Results also confirm that patients with DM2 had dysregulated hemodynamics during metaboreflex, with exaggerated blood pressure response and vasoconstriction. This may have implications for these patients' lack of inclination to exercise.

A brief bout of exercise in hypoxia reduces ventricular filling rate and stroke volume response during muscle metaboreflex activation.

PURPOSE: The hemodynamic consequences of exercise in hypoxia have not been completely investigated. The present investigation aimed at studying the hemodynamic effects of contemporary normobaric hypoxia and metaboreflex activation. METHODS: Eleven physically active, healthy males (age 32.7 ± 7.2 years) completed a cardiopulmonary test on an electromagnetically braked cycle-ergometer to determine their maximum workload (Wmax). On separate days, participants performed two randomly assigned exercise sessions (3 minutes pedalling at 30% of Wmax): (1) one in normoxia (NORMO), and (2) one in normobaric hypoxia with FiO2 set to 13.5% (HYPO). After each session, the following protocol was randomly assigned: either (1) post-exercise muscle ischemia (PEMI) to study the metaboreflex, or (2) a control exercise recovery session, i.e., without metaboreflex activation. Hemodynamics were assessed with impedance cardiography. RESULTS: The main result was that the HYPO session impaired the ventricular filling rate (measured as stroke volume/diastolic time) response during PEMI versus control condition in comparison to the NORMO test (31.33 ± 68.03 vs. 81.52 ± 49.23 ml·s-1,respectively, p = 0.003). This caused a reduction in the stroke volume response (1.45 ± 9.49 vs. 10.68 ± 8.21 ml, p = 0.020). As a consequence, cardiac output response was impaired during the HYPO test. CONCLUSIONS: The present investigation suggests that a brief exercise bout in hypoxia is capable of impairing cardiac filling rate as well as stroke volume during the metaboreflex. These results are in good accordance with recent findings showing that among hemodynamic modulators, ventricular filling is the most sensible variable to hypoxic stimuli.

Hemodynamic abnormalities during muscle metaboreflex activation in patients with type 2 diabetes mellitus.

Metaboreflex is a reflex triggered during exercise or postexercise muscle ischemia (PEMI) by metaboreceptor stimulation. Typical features of metaboreflex are increased cardiac output (CO) and blood pressure. Patients suffering from metabolic syndrome display hemodynamic abnormalities, with an exaggerated systemic vascular resistance (SVR) and reduced CO response during PEMI-induced metaboreflex. Whether patients with type 2 diabetes mellitus (DM2) have similar hemodynamic abnormalities is unknown. Here we contrast the hemodynamic response to PEMI in 14 patients suffering from DM2 (age 62.7 ± 8.3 yr) and in 15 age-matched controls (CTLs). All participants underwent a control exercise recovery reference test and a PEMI test to obtain the metaboreflex response. Central hemodynamics were evaluated by unbiased operator-independent impedance cardiography. Although the blood pressure response to PEMI was not significantly different between the groups, we found that the SVR and CO responses were reversed in patients with DM2 as compared with the CTLs (SVR: 392.5 ± 549.6 and -14.8 ± 258.9 dyn·s-1·cm-5; CO: -0.25 ± 0.63 and 0.46 ± 0.50 l/m, respectively, in DM2 and in CTL groups, respectively; P < 0.05 for both). Of note, stroke volume (SV) increased during PEMI in the CTL group only. Failure to increase SV and CO was the consequence of reduced venous return, impaired cardiac performance, and augmented afterload in patients with DM2. We conclude that patients with DM2 have an exaggerated vasoconstriction in response to metaboreflex activation not accompanied by a concomitant increase in heart performance. Therefore, in these patients, blood pressure response to the metaboreflex relies more on SVR increases rather than on increases in SV and CO. NEW & NOTEWORTHY The main new finding of the present investigation is that subjects with type 2 diabetes mellitus have an exaggerated vasoconstriction in response to metaboreflex activation. In these patients, blood pressure response to the metaboreflex relies more on systemic vascular resistance than on cardiac output increments.