Continuous vs interval training on glycemic control and macro- and microvascular reactivity in type 2 diabetic patients

Aerobic exercise-induced circulating extracellular vesicle combined decellularized dermal matrix hydrogel facilitates diabetic wound healing by promoting angiogenesis

Background: Insufficient blood supply results in unsatisfactory wound healing, especially for challenging wound repair such as diabetic wound defects. Regular exercise training brings a lot of benefits to cardiovascular fitness and metabolic health including attenuation of T2DM progression. Circulating extracellular vesicles (EVs) are postulated to carry a variety of signals involved in tissue crosstalk by their modified cargoes, representing novel mechanisms for the effects of exercise. Prominently, both acute and chronic aerobic exercise training can promote the release of exercise-induced cytokines and enhance the angiogenic function of circulating angiogenic cell–derived EVs.

Methods: We investigated the possible angiogenesis potential of aerobic exercise-induced circulating EVs (EXE-EVs) on diabetic wound healing. Circulating EVs were isolated from the plasma of rats subjected to 4 weeks of moderate aerobic exercise or sedentariness 24 h after the last training session. The therapeutic effect of circulating EVs was evaluated in vitro by proliferation, migration, and tube formation assays of human umbilical vein endothelial cells (HUVECs), as well as in vivo by quantification of angiogenesis and cutaneous wound healing in diabetic rats.

Results: The number of circulating EVs did not change significantly in exercised rats 24 h post-exercise in comparison with the sedentary rats. Nevertheless, EXE-EVs showed remarkable pro-angiogenic effect by augmenting proliferation, migration, and tube formation of HUVECs. Furthermore, the findings of animal experiments revealed that the EXE-EVs delivered by decellularized dermal matrix hydrogel (DDMH) could significantly promote the repair of skin defects through stimulating the regeneration of vascularized skin.

Discussion: The present study is the first attempt to demonstrate that aerobic exercise-induced circulating EVs could be utilized as a cell-free therapy to activate angiogenesis and promote diabetic wound healing. Our findings suggest that EXE-EVs may stand for a potential strategy for diabetic soft tissue wound repair.

The effect of a 6-month walking program on biochemical parameters in sedentary adults with type 2 diabetes mellitus

This study assessed the effect of a 6-month walking program on biochemical parameters in patients with type-2 diabetes mellitus. A group of 40 sedentary patients with type-2 diabetes volunteered to participate in this study. Plasma glucose, triglyceride, total cholesterol, low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase, urea, creatinine, uric acid, C-reactive protein (CRP), and erythrocyte sedimentation rate were measured. Differences in outcome measures between pre- and post-intervention were assessed using paired t-test or Wilcoxon signed-rank test, with effect sizes interpreted separately for normally (µ2: small 0.01-0.06, moderate 0.061-0.14, and large >0.14) and non-normally distributed data (r: small = 0.1-0.3, moderate = 0.3-0.5, and large >0.5). Significant (p < 0.001) large decrease between the initial and final measurements was observed for glucose (r = 0.62), total cholesterol (µ2 = 0.88), triglycerides (r = 0.62), LDL (r = 0.61), AST (µ2 = 0.82), ALT (µ2 = 0.79), gamma-glutamyl transferase (µ2 = 0.79), urea (µ2 = 0.92), creatinine (r = 0.62), uric acid (r = 0.62), CRP (µ2 = 0.80), and erythrocyte sedimentation rate (µ2 = 0.58). On the other hand, significant (p < 0.001) large increase between the initial and final measurements was observed for HDL (r = 0.62). Supervised 6-month aerobic walking program is an effective strategy in (1) reducing hyperglycemia; (2) increasing HDL and reducing LDL, and triglycerides; (3) reducing plasma biomarkers of liver dysfunction, kidney dysfunction, and inflammation in type-2 diabetic patients.

Dose-Dependent Effect of Supervised Aerobic Exercise on HbA1c in Patients with Type 2 Diabetes: A Meta-analysis of Randomized Controlled Trials

BACKGROUND

Previous meta-analyses indicated that aerobic exercise can improve glycemic control. However, the optimum dose of exercise is still being discussed.

OBJECTIVE

The aim of this study was to examine the dose-dependent effect of supervised aerobic training (SAT) on glycated hemoglobin (HbA1c).

METHODS

We searched PubMed, Scopus, and Web of Science to May 2021 for randomized trials with an intervention period of 12 weeks or longer evaluating the effect of SAT on HbA1c in adults with type 2 diabetes mellitus. Secondary outcomes included quality of life, change in hypoglycemic medications, and adverse events. A random-effects dose-response meta-analysis was conducted.

RESULTS

The analysis of 26 trials with 1253 participants indicated that each 30-min/week SAT reduced HbA1c by - 0.22 percentage point (95% CI - 0.29 to - 0.15; GRADE = strong). Levels of HbA1c decreased proportionally with the increase in the duration of moderate to vigorous-intensity SAT to 100 min/week (mean difference100 min/week: - 0.96 percentage point, 95% CI - 1.25 to - 0.67), with flattening of the curve at higher duration. Aerobic exercise decreased antidiabetic medications by 13 per 100 patients (risk difference 0.13, 95% CI 0.02-0.23; 7 trials, n = 375; GRADE = moderate), and increased hypoglycemic reactions by 10 per 100 patients (risk difference: 0.10, 95% CI 0.03-0.17; 4 trials, n = 263; GRADE = low) and adverse events by 4 per 100 patients (risk difference: 0.04, 95% CI - 0.02 to 0.11; 2 trials, n = 236; GRADE = low). Limited evidence is available for quality of life.

CONCLUSIONS

Every 30 min/week of moderate to vigorous aerobic exercise can exert a significant effect on HbA1c, with the highest effect observed from 100 min/week and above. However, exercise durations above 100 min/week seem ineffective for further reductions.

PROTOCOL REGISTRATION

PROSPERO (CRD42021257251).

The effects of high-intensity interval training on glucose metabolism, cardiorespiratory fitness and weight control in subjects with diabetes: Systematic review a meta-analysis

AIM

The objective of this meta-analysis was to explore the effects of high-intensity interval training (HIIT) compared with control conditions (CON) or moderate intensity continuous training (MICT) on glycemic parameters in diabetes subjects.

METHODS

Pubmed, Embase and Google Scholar databases were searched for HIIT interventions that were carried out in diabetic subjects and exploring fasting glucose, glycated haemoglobin (HbA1c), fasting insulin and/or HOMA-IR.

RESULTS

This systematic review retrieved a total of 1741 studies of which 32 articles fulfilled the eligibility criteria. Nineteen trials were included in the meta-analysis since they compared HIIT intervention with CON or MICT group. There was a significantly reduction of fasting glucose of 13.3 mg/dL (p < 0.001), Hb1Ac -0.34% (p < 0.001), insulin -2.27 UI/L (p = 0.003), HOMA-IR -0.88 (p = 0.005) in the HIIT-group compared with CON-group. Nevertheless, this reduction was not significantly different when comparing HIIT with MICT (p = 0.140, p = 0.315, p = 0.520 and p = 0.389). Besides, there was a significant increase of absolute VO2max of 0.21 L/min (p < 0.001) and relative VO2max of 2.94 ml/kg/min (p < 0.001) in the HIIT-group compared with the CON-group and the MICT-group (0.22 L/min, p = 0.025) and (0.97 ml/kg/min, p = 0.045).

CONCLUSIONS

These findings revealed that HIIT intervention led to significant improvement in glycemic control and insulin resistance in subjects with diabetes compared with CON-group.

Cardioprotective Effects of Physical Activity: Focus on Ischemia and Reperfusion

This review aimed to revisit the old and introduce some of the new various cardioprotective effects of physical exercise, focusing on ischemia-reperfusion injury. A wealth of data shows that regular physical exercise is necessary to prevent cardiovascular diseases. In the last few years, a number of new training regimes, usually modified variations of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) protocols, have been rising in popularity among people of all ages. Since exercising is not limited to only healthy people, our study emphasized the benefits of HIIT and MICT in preventing or mitigating cardiac ischemia-reperfusion injury. Different kinds of research are being performed, studying the various positive and side effects of these training regimes, all in hopes of finding the most optimal ones. So far, all of them have shown that exercising to any extent, even for a short period of time, is beneficial in one way or another, and outweighs the possible risks it might have. We also revisited some of the known molecular mechanisms responsible for many of the effects of physical exercise and introduced some new findings related to them. Lastly, we summarized and compared the benefits of different HIIT and MICT protocols to narrow down the search for the most efficient training method.

High-Intensity Interval Training Improves Cardiac Function by miR-206 Dependent HSP60 Induction in Diabetic Rats

Objective

A role for microRNAs is implicated in several biological and pathological processes. We investigated the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on molecular markers of diabetic cardiomyopathy in rats.

Methods

Eighteen male Wistar rats (260 ± 10 g; aged 8 weeks) with streptozotocin (STZ)-induced type 1 diabetes mellitus (55 mg/kg, IP) were randomly allocated to three groups: control, MICT, and HIIT. The two different training protocols were performed 5 days each week for 5 weeks. Cardiac performance (end-systolic and end-diastolic dimensions, ejection fraction), the expression of miR-206, HSP60, and markers of apoptosis (cleaved PARP and cytochrome C) were determined at the end of the exercise interventions.

Results

Both exercise interventions (HIIT and MICT) decreased blood glucose levels and improved cardiac performance, with greater changes in the HIIT group (p < 0.001, η²: 0.909). While the expressions of miR-206 and apoptotic markers decreased in both training protocols (p < 0.001, η²: 0.967), HIIT caused greater reductions in apoptotic markers and produced a 20% greater reduction in miR-206 compared with the MICT protocol (p < 0.001). Furthermore, both training protocols enhanced the expression of HSP60 (p < 0.001, η²: 0.976), with a nearly 50% greater increase in the HIIT group compared with MICT.

Conclusions

Our results indicate that both exercise protocols, HIIT and MICT, have the potential to reduce diabetic cardiomyopathy by modifying the expression of miR-206 and its downstream targets of apoptosis. It seems however that HIIT is even more effective than MICT to modulate these molecular markers.

Global Trends and Research Hotspots of Exercise for Intervening Diabetes: A Bibliometric Analysis

Background

Diabetes is a chronic metabolic disease characterized by hyperglycemia that often occurs in adults. Many studies have indicated that exercise is beneficial to the medical management of diabetes. Bibliometric analysis can help investigators to identify the current research concerns to guide future research directions. Nevertheless, the overview bibliometric analysis of this global research topic related to exercise and diabetes is lacking. The present bibliometric study aimed to investigate development trends and research hotspots of exercise and diabetes research and provide researchers with new perspectives in further studies.

Materials and Methods

The articles and reviews regarding exercise and diabetes between 2000 and 2020 were retrieved from the Web of Science Core Collection. The scientometrics analytical tool CiteSpace software was used to analyze the cooperation among countries/institutions/journals/authors, analysis of co-occurrence keywords, keywords bursts, and references.

Results

In all, 3,029 peer-reviewed papers were found with a persistently increased tendency over time. The most prolific country and institution were the USA (965) and Univ Alberta (76), respectively. Diabetes Care published most papers (178) and was the most co-cited journal (2,630). Riddell MC had the most publications (53), and Sigal RJ was the most influential author (503 cited times). Colberg et al.'s paper (co-citation counts: 183) showed the strongest citation bursts by the end of 2020, which was the most representative reference. The four research focuses were mellitus, exercise, physical activity, and glycemic control. The two frontiers trends were sedentary behavior and stress. The combination of aerobic and resistance training can effectively improve glycemic control, decrease HbA1c levels, enhance cardiorespiratory fitness, improve lipid levels, and decrease the demand for non-insulin antihyperglycemic agents.

Conclusions

This study offers a scientific perspective on exercise and diabetes research and provides investigators with valuable information to detect the current research condition, hotspots, and emerging trends for further study.

MicroRNAs as biomarkers for monitoring cardiovascular changes in Type II Diabetes Mellitus (T2DM) and exercise

Introduction

MicroRNAs (miRNAs) have been shown to be altered in both CVD and T2DM and can have an application as diagnostic and prognostic biomarkers. miRNAs are released into circulation when the cardiomyocyte is subjected to injury and damage.

Objectives

Measuring circulating miRNA levels in human plasma may be of great potential use for measuring the extent of damage to cardiomyocytes and response to exercise. This review is aimed to highlight the potential application of miRNAs as biomarkers of CVD progression in T2DM, and the impact of exercise on recovery.

Methods

The review aims to examine whether the health improvements following exercise in T2DM patients are reflective of changes in expression of plasma miRNAs. For this purpose, studies were identified from the literature that have established a correlation between diabetes, disease progression and plasma miRNA levels. We also reviewed studies which looked at the effect of exercise on plasma miRNA levels.

Results

The review identified miRNA signatures that are affected by T2DM and DHD and a subset of these miRNAs that are also affected by different types of exercise. This approach helped us to identify those miRNAs whose expression and function can be altered by regular bouts of exercise.

Conclusions

miRNAs identified as part of this review can serve as tools to monitor the cardio-protective, anti-inflammatory and metabolic effects of exercise in people suffering from T2DM. Future research should focus on regulation of these miRNAs in T2DM and how they can be altered by appropriate exercise interventions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-01066-4.

Exercise mode influences post-exercise glucose sensitivity and insulin clearance in young, healthy males and females in a sex-dependent manner: A randomized control trial

Type 2 diabetes (T2D) risk is lower in females than males. It has been reported that females have greater pancreatic 𝛽-cell function than males, which may at least in part contribute to the T2D risk in females. 𝛽-cell function is influenced by exercise training; however, previous trials comparing 𝛽-cell function between the sexes have not included participants matched for training status. Furthermore, the acute effects of different modes of exercise on 𝛽-cell function, and whether sex inherently influences these effects, are largely unexamined. Males and females (12/sex) completed a 120-min oral glucose tolerance test (OGTT) at rest (CON) and following acute bouts of high-intensity interval exercise (HIIE), moderate intensity continuous (MIC) exercise, and low-load high-repetition (LLHR) resistance exercise to assess whether sex inherently influences baseline and/or post-exercise pancreatic function in the absence of pathology. We found no sex differences in basal pancreatic 𝛽-cell function. Females had greater basal insulin clearance following MIC exercise compared to males (p = 0.01) and males tended to have a higher potentiation ratio following HIIE (p = 0.07). Females also had lower glucose sensitivity following MIC exercise compared to HIIE (p = 0.007) and LLHR (p = 0.003). Insulin clearance during the OGTT was greater following HIIE as compared with CON and MIC exercise (p = 0.02). 2-H oral glucose insulin sensitivity was greater following LLHR compared to CON (p = 0.01). Acute bouts of different modes of exercise do not differentially influence 𝛽-cell function but do influence insulin clearance and insulin sensitivity. Therefore, sex and exercise mode interact to differentially influence insulin clearance and glucose sensitivity.

Improved blood pressure and flow-mediated dilation via increased plasma adropin and NOx induced by high-intensity interval training in patients with type 2 diabetes

NEW FINDINGS

What is the central question of this study? Exercise training increases adropin and NOx plasma levels in middle-aged and older healthy people. We hypothesized that high-intensity interval training may improve blood pressure and flow-mediated dilation through the effects of adropin and NOx in patients of this age with type 2 diabetes. What is the main finding and its importance? High-intensity interval training may be more effective than moderate-intensity continuous training in improving endothelial function, blood pressure and flow-mediated dilation through its effects on adropin and NOx in patients with type 2 diabetes.

ABSTRACT

Adropin is a newly identified bioactive protein that is important in energy hemostasis and vascular endothelial function. Lower levels of adropin in patients with type 2 diabetes are related to coronary atherosclerosis, characterized by impaired flow-mediated dilation (FMD). The purpose of the present study was to investigate FMD, and plasma levels of adropin and nitrite/nitrate (NOx), in patients with type 2 diabetes at baseline and follow-up after 12 weeks of high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT). Sixty-six persons with type 2 diabetes were divided into HIIT, MICT and control groups. The HIIT group intervention was 12 intervals (1.5 min) at 85% to 90% maximal heart rate (HR_max ) separated by 2 min at 55% to 60% HR_max in 3 session per week for 12 weeks. MICT training consisted of 42 min of cycling at 70% HR_max . Before and after the intervention, FMD was recorded with high-resolution Doppler ultrasound. Plasma levels of adropin and NOx were measured by enzyme-linked immunosorbent assay. After training FMD was significantly higher in the MICT and HIIT groups compared to the control group (P<0.05). Plasma levels of adropin and NOx were higher in both exercise groups, but the increase was greater in the HIIT group (P<0.01). Peak oxygen consumption was increased after exercise training in both groups compared to the control group (P<0.01). Percent FMD showed a positive correlation with plasma levels of adropin and NOx (both P<0.01), and a negative correlation with DBP (r = -0.530, P = 0.035) and SBP (r = -0.606, P = 0.013) in the HIIT group. The results indicate that HIIT improved FMD whilst increasing adropin, NOx and peak oxygen consumption. Increased plasma levels of adropin may contribute, in part, to blood pressure reduction by increasing nitric oxide production. This article is protected by copyright. All rights reserved.

Exercise and Nutrition Strategies for Combating Sarcopenia and Type 2 Diabetes Mellitus in Older Adults

Medical and technology development have drastically the improved quality of life and, consequently, life expectancy. Nevertheless, the more people who enter the third-age, the more geriatric syndromes expand in the elderly. Sarcopenia and Type 2 diabetes mellitus (T2DM) are common diseases among the elderly and the literature has extensively studied these two diseases separately. Recent evidence, however, revealed that there is a bidirectional relationship between sarcopenia and T2DM. The aims of the present review were: (1) to present diet and exercise interventions for the management of sarcopenia and T2DM and (2) identify which diet and exercise interventions can be used simultaneously in order to effectively deal with these two disorders. Exercise and a balanced diet are used as effective countermeasures for combating sarcopenia and T2DM in older adults based on their bidirectional relationship. Lifestyle changes such as exercise and a balanced diet seem to play an important role in the remission of the diseases. Results showed that chronic exercise can help towards glycemic regulation as well as decrease the incidence rate of muscle degradation, while diet interventions which focus on protein or amino acids seem to successfully treat both disorders. Despite the fact that there are limited studies that deal with both disorders, it seems that a combined exercise regime (aerobic and resistance) along with protein intake > 1gr/kg/d is the safest strategy to follow in order to manage sarcopenia and T2DM concurrently.

Physiological Adaptations to High-Intensity Interval Training Combined with Blood Flow Restriction in Masters Road Cyclists

PURPOSE

High-intensity interval training (HIIT) and blood flow restriction (BFR) training have been used to enhance athletic performance and cardiovascular health. Combining these training modalities might be an effective training modality for masters athletes who seek to enhance athletic performance and to reduce cardiovascular risks.

METHODS

Fifty masters road cyclists age 35-49 yr were randomly assigned to the continuous exercise training (n = 16), continuous plus HIIT (n = 17), and continuous plus BFR training combined with HIIT (BFRIT; n = 17) for 12 wk. Both HIIT and BFRIT were performed on a cycle ergometer twice a week.

RESULTS

Maximal oxygen consumption (V̇O2max) increased in the HIIT and BFRIT groups (P < 0.05). This was accompanied by significant improvements in maximal cardiac output and stroke volume (P < 0.05). Forty-kilometer time trial performance improved in all three groups (P < 0.05). Peak power output increased in both HIIT and BFRIT groups (P < 0.05). Flow-mediated dilation in both brachial and popliteal arteries increased in all three groups (all P < 0.05). There were no significant changes in carotid intima-media thickness and arterial stiffness in any of the groups. Total lean mass, muscle cross-sectional area and thickness in rectus femoris and vastus lateralis, and peak torque of isokinetic knee extension increased only in the BFRIT group (all P < 0.05). Tissue saturation index decreased only in the BFRIT group (P < 0.05). Changes in 40-km time trial performance were associated with corresponding changes in V̇O2max (r = -0.312, P = 0.029) and peak isokinetic extensor torque (r = -0.432, P = 0.002).

CONCLUSIONS

Including HIIT particularly with BFR in the routine continuous training may be more effective in enhancing performance and physiological functions in masters road cyclists.

Effects of high intensity interval training on sustained reduction in cardiometabolic risk associated with overweight/obesity. A randomized trial

Background

Considering the potential greater cardiocirculatory effects of high intensity interval training (HIIT), we hypothesized that a 2-month supervised high volume short interval HIIT would induce greater improvements in CRF and cardiometabolic risk and increase long-term maintenance to physical activity compared to isocaloric moderate intensity continuous training (MICT) in overweight/obesity.

Methods

Sixty (19 females) subjects with overweight/obesity were randomized to three training programs (3 times/week for 2 months): MICT (45 min, 50% peak power output-PPO), HIIT (22 × 1-min cycling at 100% PPO/1-min passive recovery) and HIIT-RM (RM: recovery modulation, i.e. subjects adjusted passive recovery duration between 30s and 2 min). After the intervention, participants no longer benefited from supervised physical activity and were instructed to maintain the same exercise modalities on their own. We assessed anthropometrics, body composition, CRF, fat oxidation, lipid profile, glycemic balance, low-grade inflammation, vascular function, spontaneous physical activity and motivation for eating at three time points: baseline (T0), 4 days after the end of the 2-month supervised training program (T2) and 4 months after the end of the training program (T6).

Results

HIIT/HIIT-RM induced greater improvement in VO_2peak (between +14% and +17%), power output at ventilatory thresholds and at maximal fat oxidation rate (+25%) and waist circumference (−1.53 cm) compared to MICT and tended to decrease insulin resistance. During the four-month follow-up period during which exercise in autonomy was prescribed, HIIT induced a greater preservation of CRF, decreases in total and abdominal fat masses and total cholesterol/HDL.

Conclusion

We have shown greater short-term benefits induced by a high volume short interval (1 min) HIIT on cardiorespiratory fitness and cardiometabolic risk over an isocaloric moderate intensity continuous exercise in persons with overweight/obesity. We also showed greater long-term effects (i.e. after 4 months) of this exercise modality on the maintenance of CRF, decreases in total and abdominal fat masses and total cholesterol/HDL.

Changes in Appetite-Dependent Hormones and Body Composition After 8 Weeks of High-Intensity Interval Training and Vitamin D Supplementation in Sedentary Overweight Men

Exercise and diet are important factors for energy balance and appetite regulation. The aim of this study was to investigate the effect of 8 weeks High Intensity Interval Training (HIIT) and vitamin D₃ supplementation in sedentary overweight men. Forty-eight participants were randomly assigned to one of the following four groups (n = 12): HIIT + VitD, HIIT + placebo (3 sessions per week, 10 × 1 min interval cycling at 90-100% VO_2peak separated by 1 min active recovery at 15% VO_2peakfor 8 weeks), Vit D and control groups. Participants received 2,000 IU/day 25 (OH) D₃ or placebo. Measurements were taken pre and post training after 10 h overnight fasting. Insulin, weight, BMI and body fat percentage were significantly decreased, but PYY was significantly increased in the HIIT + Vit D and HIIT + placebo groups (p = 0.001 and p = 0.001, respectively) after 8 weeks of HIIT. Insulin (p = 0.009, p = 0.001), weight, BMI and body fat percentage (p = 0.001, p = 0.001) were significantly lower in the HIIT + Vit D and HIIT + placebo groups compared to the Vit D and control groups. However, PYY was significantly higher in the HIIT + Vit D group compared to the Vit D (p = 0.025) and control groups (p = 0.007) and also in the HIIT + placebo group compared to the Vit D (p = 0.037) and control groups (p = 0.032) after 8 weeks of HIIT. The combination of regular HIIT with vitamin D supplementation has a effect on appetite control and body composition.

Exercise/Physical Activity in Individuals with Type 2 Diabetes: A Consensus Statement from the American College of Sports Medicine

ABSTRACT

This consensus statement is an update of the 2010 American College of Sports Medicine position stand on exercise and type 2 diabetes. Since then, a substantial amount of research on select topics in exercise in individuals of various ages with type 2 diabetes has been published while diabetes prevalence has continued to expand worldwide. This consensus statement provides a brief summary of the current evidence and extends and updates the prior recommendations. The document has been expanded to include physical activity, a broader, more comprehensive definition of human movement than planned exercise, and reducing sedentary time. Various types of physical activity enhance health and glycemic management in people with type 2 diabetes, including flexibility and balance exercise, and the importance of each recommended type or mode are discussed. In general, the 2018 Physical Activity Guidelines for Americans apply to all individuals with type 2 diabetes, with a few exceptions and modifications. People with type 2 diabetes should engage in physical activity regularly and be encouraged to reduce sedentary time and break up sitting time with frequent activity breaks. Any activities undertaken with acute and chronic health complications related to diabetes may require accommodations to ensure safe and effective participation. Other topics addressed are exercise timing to maximize its glucose-lowering effects and barriers to and inequities in physical activity adoption and maintenance.

The Effect of Various Training on the Expression of the 5’amp-Activated Protein Kinase Α2 and Glucose Transporter - 4 in Type-2 Diabetes Mellitus Rat

BACKGROUND: Exercise is the main pillar in Type 2 Diabetes Mellitus (T2DM) management. The mechanism of glucose uptake mediated by exercise is different from insulin, and this mechanism is not disturbed in T2DM. One of the mechanisms is through the activation of 5’AMP-activated protein kinase (AMPK). AMPK also regulates the glucose transporter 4 (GLUT4) expression. Effect various types of exercise to AMPK α2 and GLUT-4 of the skeletal muscle still limited. AIM: This study aims to determine the effect of various physical training on the expression of Ampk α2 and Glut 4 in skeletal muscle of T2DM rats. METHODS: This study used stored skeletal muscles of 25 T2DM Wistar rats. Previously, the rats were divided into groups of K1 (control, not given exercise), K2 (moderate continuous training), K3 (severe continuous training), K4 (slow interval training), and K5 (fast interval training). Running on a treadmill frequency 3 times a week for 8 weeks. The relative expression of Ampk α2 and Glut 4 were assessed using Real Time-PCR and were compared among the groups using the Livak formula. RESULTS: Moderate intensity continuous training increased Ampk α2 and Glut 4 expression by 1.45 and 2.39 times, respectively. Severe intensity continuous training increased the expression of Ampk α2 and Glut 4 by 1.55 and 2.56 times, respectively. Slow interval training increased the expression of Ampk α2 and Glut 4 by 4.41 and 3.76 times, respectively. The expression of Ampk α2 and Glut4 in fast interval training was 4.56 and 4.79 times more than control. CONCLUSION: Continuous and interval training increase Ampk α2 and Glut 4 expression. The fast interval training showed the highest expression of Ampk α2 and Glut 4.

Impact of continuous vs. interval training on oxygen extraction and cardiac function during exercise in type 2 diabetes mellitus

PURPOSE

Exercise training improves exercise capacity in type 2 diabetes mellitus (T2DM). It remains to be elucidated whether such improvements result from cardiac or peripheral muscular adaptations, and whether these are intensity dependent.

METHODS

27 patients with T2DM [without known cardiovascular disease (CVD)] were randomized to high-intensity interval training (HIIT, n = 15) or moderate-intensity endurance training (MIT, n = 12) for 24 weeks (3 sessions/week). Exercise echocardiography was applied to investigate cardiac output (CO) and oxygen (O₂) extraction during exercise, while exercise capacity [([Formula: see text] (mL/kg/min)] was examined via cardiopulmonary exercise testing at baseline and after 12 and 24 weeks of exercise training, respectively. Changes in glycaemic control (HbA1c and glucose tolerance), lipid profile and body composition were also evaluated.

RESULTS

19 patients completed 24 weeks of HIIT (n = 10, 66 ± 11 years) or MIT (n = 9, 61 ± 5 years). HIIT and MIT similarly improved glucose tolerance (p_Time = 0.001, p_Interaction > 0.05), [Formula: see text] (mL/kg/min) (p_Time = 0.001, p_Interaction > 0.05), and exercise performance (W_peak) (p_Time < 0.001, p_Interaction > 0.05). O₂ extraction increased to a greater extent after 24 weeks of MIT (56.5%, p₁ = 0.009, p_Time = 0.001, p_Interaction = 0.007). CO and left ventricular longitudinal strain (LS) during exercise remained unchanged (p_Time > 0.05). A reduction in HbA1c was correlated with absolute changes in LS after 12 weeks of MIT (r = - 0.792, p = 0.019, LS at rest) or HIIT (r = - 0.782, p = 0.038, LS at peak exercise).

CONCLUSION

In patients with well-controlled T2DM, MIT and HIIT improved exercise capacity, mainly resulting from increments in O₂ extraction capacity, rather than changes in cardiac output. In particular, MIT seemed highly effective to generate these peripheral adaptations.

TRIAL REGISTRATION

NCT03299790, initially released 09/12/2017.

High-intensity interval training combining rowing and cycling efficiently improves insulin sensitivity, body composition and VO2max in men with obesity and type 2 diabetes

AIMS

Non-weight-bearing high-intensity interval training (HIIT) involving several muscle groups may efficiently improve metabolic health without compromising adherence in obesity and type 2 diabetes. In a non-randomized intervention study, we examined the effect of a novel HIIT-protocol, recruiting both lower and upper body muscles, on insulin sensitivity, measures of metabolic health and adherence in obesity and type 2 diabetes.

METHODS

In 15 obese men with type 2 diabetes and age-matched obese (n=15) and lean (n=18) glucose-tolerant men, the effects of 8-weeks supervised HIIT combining rowing and cycling on ergometers (3 sessions/week) were examined by DXA-scan, incremental exercise test and hyperinsulinemic-euglycemic clamp combined with indirect calorimetry.

RESULTS

At baseline, insulin-stimulated glucose disposal rate (GDR) was ~40% reduced in the diabetic vs the non-diabetic groups (all p<0.01). In response to HIIT, insulin-stimulated GDR increased ~30-40% in all groups (all p<0.01) entirely explained by increased glucose storage. These changes were accompanied by ~8-15% increases in VO₂max, (all p<0.01), decreased total fat mass and increased lean body mass in all groups (all p<0.05). There were no correlations between these training adaptations and no group-differences in these responses. HbA1c showed a clinically relevant decrease in men with type 2 diabetes (4±2 mmol/mol; p<0.05). Importantly, adherence was high (>95%) in all groups and no injuries were reported.

CONCLUSIONS

A novel HIIT-protocol recruiting lower and upper body muscles efficiently improves insulin sensitivity, VO₂max and body composition with intact responses in obesity and type 2 diabetes. The high adherence and lack of injuries show that non-weight-bearing HIIT involving several muscle groups is a promising mode of exercise training in obesity and type 2 diabetes.

Effect of high-intensity interval training protocols on VO2max and HbA1c level in people with type 2 diabetes: A systematic review and meta-analysis

BACKGROUND

The effect of high-intensity interval training (HIIT) protocols according to different work intervals, session volumes and training periods has not been evaluated in patients with type 2 diabetes mellitus (T2DM).

OBJECTIVE

This was a systematic review and meta-analysis of the effect of HIIT and its different protocols compared to moderate-intensity continuous training (MICT) and the control group on VO₂max and glycated hemoglobin (HbA1c) level in patients with T2DM.

METHODS

The search strategy considered studies published up to September 2020 in the databases MEDLINE (PubMed), EMBASE, Cochrane CENTRAL, Web of Science and SPORTDiscus. Two authors independently searched the selected databases for randomized clinical trials that compared HIIT to MICT or the control in adults with T2DM. A random-effects meta-analysis was performed and the data are presented as the mean difference (95% confidence intervals [95% CIs]) between HIIT, MICT and control groups.

RESULTS

A total of 20 studies (738 participants) were included. Overall, HIIT increased VO₂max by 5.09 mL/kg/min (95% CI 2.99; 7.19, I² = 80.89) versus the control and by 1.9 mL/kg/min (95% CI 0.81; 2.98, I² = 25.62) versus MICT. HIIT promoted a significant reduction in HbA1c level of -0.8% (95% CI -1.06; -0.49, I² = 77.31) versus the control but with no difference versus MICT. Moderate-interval, high-volume and long-term training promoted a greater increase in VO₂max. A long interval and moderate volume and period conferred a greater increase in VO₂max versus MICT. A short interval and moderate volume and period conferred a greater reduction in HbA1c level versus the control. No publication bias was detected, as evaluated by a funnel chart and Egger's test (p > 0.05).

CONCLUSIONS

As compared with MICT, HIIT had better effect on VO₂max and a similar effect on HbA1C level. Interval protocols, moderate to long training period and moderate to high volume may maximize the HIIT effect in patients with T2DM.

The Therapeutic Effects of Mild to Moderate Intensity Aerobic Exercise on Glycemic Control in Patients with Type 2 Diabetes Mellitus: A Meta-Analysis of Randomized Trials

INTRODUCTION

It has been recommended that physical activity be a part of treatment and management regimens of type 2 diabetes mellitus (T2DM), and research has shown that regular physical exercise facilitates glycemic control in these patients. In this analysis, our aim was to systematically show the therapeutic effects of mild to moderate intensity aerobic exercise on glycemic control in patients with T2DM.

METHODS

From February to April 2021, we searched the https://www.clinicaltrials.gov , EMBASE, MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science and Google Scholar databases for trials that showed the effects of aerobic exercise on glycemic control in patients with T2DM. Glycated hemoglobin (HbA1c) was the endpoint in the analysis. The RevMan version 5.4 statistical program was used for statistical analysis, and the mean difference (MD) and 95% confidence intervals (CI) used to represent the data following analysis.

RESULTS

Eighteen trials involving 972 participants with T2DM were included in this meta-analysis, of whom 523 were assigned to an exercise group and 449 were assigned to a control group. A comparison pre- versus post-aerobic exercise showed that aerobic exercise significantly improved glycemic control (HbA1c) (MD 0.35, 95% CI 0.23-0.48; P = 0.00001) in these patients with T2DM. A second comparison, T2DM participants in the experimental group post-exercise versus T2DM participants from the control group at the end of the follow-up, also showed that aerobic exercise significantly improved glycemic control (MD - 0.46, 95% CI - 0.69 to - 0.22; P = 0.0001). However, a comparison of HbA1c of T2DM participants in the control group at the beginning of the study compared to those at the end of follow-up did not show any significant improvement in glycemic control (MD 0.08, 95% CI - 0.05 to 0.21; P = 0.21).

CONCLUSION

The current analysis showed that mild to moderate intensity aerobic exercise significantly improved glycemic control in patients with T2DM. Patients with T2DM who regularly participated in aerobic exercise activities had a better control of their disease than those who were not on a regular aerobic exercise regimen. These results lead to the recommendation that at least mild to moderate intensity aerobic exercise should be included in the treatment and management regimens of patients with T2DM.

Effect of High-intensity Interval Training on Endothelial Function in Type 2 Diabetic Females

Background: Flow-mediated dilation (FMD) is a noninvasive approach to examine endothelial function. Objectives: The purpose of this study was to investigate the effect of 12 weeks of high-intensity interval training (HIIT) on FMD and circulating levels of adropin and nitric oxide (NO) in females with type 2 diabetes. Methods: Thirty females with type 2 diabetes were randomly assigned into two equal groups of HIIT and control. The exercise program consisted of three sessions a week for 12 weeks. Each training session included 4 × 4-minute running intervals at 85 - 95% of maximal heart rate (HRmax) with 3-minute active recoveries at 50 - 60% of HRmax. Circulating levels of adropin, NO, glucose, HbA1c, insulin, HOMA-IR, as well as lipid profile, and body composition parameters were measured before and after the intervention. Results: A significant increase of FMD% was observed after the intervention in the HIIT group (P = 0.001). In addition, the circulation levels of adropin and NO enhanced as a result of HIIT (P = 0.012 and P < 0.001, respectively). There were also significant positive effects on the levels of lipid profile (except for HDL), FBS, and HbA1c; as well as on the insulin resistance and the body composition variables. There were no significant changes in the control group except an increase in the total cholesterol levels (P < 0.01). Conclusions: The results showed that 12 weeks of the HIIT program could improve the endothelial function, glucose-related indices, lipid profile, and body composition variables in females with type 2 diabetes.

Responders and non-responders to aerobic exercise training: beyond the evaluation of V˙O2max

The evaluation of the maximal oxygen uptake ( V ˙ O 2 max ) following exercise training is the classical assessment of training effectiveness. Research has lacked in investigating whether individuals that do not respond to the training intervention ( V ˙ O 2 max ), also do not improve in other health-related parameters. We aimed to investigate the cardiovascular and metabolic adaptations (i.e., performance, body composition, blood pressure, vascular function, fasting blood markers, and resting cardiac function and morphology) to exercise training among participants who showed different levels of V ˙ O 2 max responsiveness. Healthy sedentary participants engaged in a 6-week exercise training program, three times a week. Our results showed that responders had a greater increase in peak power output, second lactate threshold, and microvascular responsiveness, whereas non-responders had a greater increase in cycling efficiency. No statistical differences were observed in body composition, blood pressure, fasting blood parameters, and resting cardiac adaptations. In conclusion, our study showed, for the first time, that in addition to the differences in the V ˙ O 2 max , a greater increase in microvascular responsiveness in responders compared to non-responders was observed. Additionally, responders and non-responders did not show differences in the adaptations on metabolic parameters. There is an increasing need for personalized training prescription, depending on the target clinical outcome.

Reactive oxygen species in exercise and insulin resistance: Working towards personalized antioxidant treatment

Reactive oxygen species (ROS) are well known for their role in insulin resistance and the development of cardiometabolic disease including type 2 diabetes mellitus (T2D). Conversely, evidence supports the notion that ROS are a necessary component for glucose cell transport and adaptation to physiological stress including exercise and muscle contraction. Although genetic rodent models and cell culture studies indicate antioxidant treatment to be an effective strategy for targeting ROS to promote health, human findings are largely inconsistent. In this review we discuss human research that has investigated antioxidant treatment and glycemic control in the context of health (healthy individuals and during exercise) and disease (insulin resistance and T2D). We have identified key factors that are likely to influence the effectiveness of antioxidant treatment: 1) the context of treatment including whether oxidative distress or eustress is present (e.g., hyperglycemia/lipidaemia or during exercise and muscle contraction); 2) whether specific endogenous antioxidant deficiencies are identified (redox screening); 3) whether antioxidant treatment is specifically designed to target and restore identified deficiencies (antioxidant specificity); 4) and the bioavailability and bioactivity of the antioxidant which are influenced by treatment dose, duration, and method of administration. The majority of human research has failed to account for these factors, limiting their ability to robustly test the effectiveness of antioxidants for health promotion and disease prevention. We propose that a modern "redox screening" and "personalized antioxidant treatment" approach is required to robustly explore redox regulation of human physiology and to elicit more effective antioxidant treatment in humans.

Effects of different intensities of continuous training on vascular inflammation and oxidative stress in spontaneously hypertensive rats

We aimed to study the effects and underlying mechanism of different intensities of continuous training (CT) on vascular inflammation and oxidative stress in spontaneously hypertensive rats (SHR). Rats were divided into five groups (n = 12): Wistar‐Kyoto rats sedentary group (WKY‐S), sedentary group (SHR‐S), low‐intensity CT group (SHR‐L), medium‐intensity CT group (SHR‐M) and high‐intensity CT group (SHR‐H). Changes in body mass, heart rate and blood pressure were recorded. The rats were euthanized after 14 weeks, and blood and vascular tissue samples were collected. Haematoxylin and Eosin staining was used to observe the aortic morphology, and Western blot was used to detect the expression of mesenteric artery proteins. After CT, the mean arterial pressures improved in SHR‐L and SHR‐M and increased in SHR‐H compared with those in SHR‐S. Vascular inflammation and oxidative stress levels significantly subsided in SHR‐L and SHR‐M (p < 0.05), whereas in SHR‐H, only vascular inflammation significantly subsided (p < 0.05), and oxidative stress remained unchanged (p > 0.05). AMPK and SIRT1/3 expressions in SHR‐L and SHR‐M were significantly up‐regulated than those in SHR‐S (p < 0.05). These results indicated that low‐ and medium‐intensity CT can effectively reduce the inflammatory response and oxidative stress of SHR vascular tissue, and high‐intensity CT can improve vascular tissue inflammation but not oxidative stress.

Inflammatory, antioxidant and glycemic status to different mode of high-intensity training in type 2 diabetes mellitus

BACKGROUND

Exercise has traditionally been used and prescribed as an effective and suitable way to treat type 2 diabetics Mellitus (T2DM). In this regard, we compared inflammatory, antioxidant, and glycemic status to different kinds of high-intensity interval training (strength training, HIIT, and HIIT + ST) in patients with T2DM.

METHODS AND RESULTS

Fifty-nine T2DM patients (age = 45-60 yrs) were randomly divided to strength training (ST) (n = 15), high intensity interval training (HIIT) (n = 16), HIIT + ST (n = 15) or served as control (CON) (n = 13) groups. Experimental groups performed three training sessions/week for 12 weeks. Inflammatory, antioxidant, glycemic factors, and anthropometric parameters were evaluated at baseline and after the 12 weeks of interventions. Training HIIT groups significantly improved antioxidant factors, lipid profile, and glycemic parameters (P ≤ 0.05). Interleukin 6 (IL-6), C-reactive protein (CRP), and tumor necrosis factor-α (TNF-α) significantly decreased in the three training groups. As a result of training, the overall inflammatory and antioxidant status were improved considerably in all three training groups compared to the CON group (P ≤ 0.05). In addition, there were significant differences in CRP at the follow-up values between ST and CON groups (P ≤ 0.05). Exercise time and TC were significantly improved in HIIT than in the CON group (P ≤ 0.05). The results showed a significant difference between the HIIT + ST group and the CON group in VO2_peak (P ≤ 0.05).

CONCLUSIONS

Our results showed improvement in inflammatory factors, antioxidants, and glycemic parameters in all training groups regardless of their type. However, for more benefits in T2DM patients, combination exercises can be suggested.

Iranian National Clinical Practice Guideline for Exercise in Patients with Diabetes

CONTEXT

Growing evidence highlights the importance of physical activity as a critical element for the prevention and control of diabetes. However, there is no clinical practice guideline focusing on the different aspects of exercise in patients with diabetes, especially for the Iranian population.

OBJECTIVE

We aimed to prepare and adopt a clinical practice guideline to provide well-defined, simple, and concise responses to certain questions related to physical activity and exercise in all patients with diabetes, including type 1, 2, and gestational diabetes mellitus (GDM).

EVIDENCE ACQUISITION

A multidisciplinary team of experts in various fields (sports medicine specialists, endocrinologists, and cardiologists) developed the guideline. This group did the task in four stages: (1) identifying and refining the subject area using 17 clinical questions; (2) appraising evidence through a systematic review of the literature; (3) extracting recommendations from evidence and grading them as A, B, C, or D based on the quality, quantity, and consistency of existing evidence; and (4) subjecting the guideline to external review and finally selecting the recommendations with high scores of appropriateness and agreement. The final version was evaluated and approved by the National Deputy for Curative Affairs - Ministry of Health and Medical Education and has also been endorsed by the Iran Endocrine Society (IES) and Iranian Association of Sports and Exercise Medicine (IASEM).

RESULTS

The guideline consists of 52 recommendations addressing 17 important questions concerning different aspects of exercise prescription in Iranian patients with diabetes.

CONCLUSIONS

The guideline provides evidence-based information that may help physicians to prescribe exercise for Iranian patients with diabetes safely and effectively.

Acute and Chronic Effects of Low-Volume High-Intensity Interval Training Compared to Moderate-Intensity Continuous Training on Glycemic Control and Body Composition in Older Women with Type 2 Diabetes

Objective: To compare the acute and chronic effects of low-volume high-intensity interval training (HIIT) to moderate-intensity continuous training (MICT) on glycemic control, body composition and continuous glucose monitoring (CGM) in older women with type 2 diabetes (T2D). Methods: Thirty older women (68 ± 5 years) with T2D were randomized in two groups—HIIT (75 min/week) or MICT (150 min/week). Glucose homeostasis (A1c, glucose, insulin, HOMA-IR2) and body composition (iDXA) were measured before and after the 12-week exercise intervention. During the first and last week of training (24-h before and 48-h after exercise), the following CGM-derived data were measured: 24-h and peak glucose levels, glucose variability and time spent in hypoglycemia as well as severe and mild hyperglycemia. Results: While lean body mass increased (p = 0.035), total and trunk fat mass decreased (p ≤ 0.007), without any difference between groups (p ≥ 0.81). Fasting glucose levels (p = 0.001) and A1c (p = 0.014) significantly improved in MICT only, with a significant difference between groups for fasting glucose (p = 0.02). Neither HIIT nor MICT impacted CGM-derived data at week 1 (p ≥ 0.25). However, 24-h and peak glucose levels, as well as time spent in mild hyperglycemia, decreased in HIIT at week 12 (p ≤ 0.03). Conclusion: These results suggest that 12 weeks of low-volume HIIT is enough to provide similar benefit to MICT for body composition and improve the acute effect of exercise when measured with CGM.

Endurance and Sprint Training Improve Glycemia and V˙O2peak but only Frequent Endurance Benefits Blood Pressure and Lipidemia

PURPOSE

Sprint interval training (SIT) has gained popularity as a time-effective alternative to moderate-intensity endurance training (END). However, whether SIT is equally effective for decreasing cardiometabolic risk factors remains debatable, as many beneficial effects of exercise are thought to be transient, and unlike END, SIT is not recommended daily. Therefore, in line with current exercise recommendations, we examined the ability of SIT and END to improve cardiometabolic health in overweight/obese males.

METHODS

Twenty-three participants were randomized to perform 6 wk of constant workload SIT (3 d·wk-1, 4-6 × 30 s ~170% Wpeak, 2 min recovery, n = 12) or END (5 d·wk-1, 30-40 min, ~60% Wpeak, n = 11) on cycle ergometers. Aerobic capacity (V˙O2peak), body composition, blood pressure (BP), arterial stiffness, endothelial function, glucose and lipid tolerance, and free-living glycemic regulation were assessed pre- and posttraining.

RESULTS

Both END and SIT increased V˙O2peak (END ~15%, SIT ~5%) and glucose tolerance (~20%). However, only END decreased diastolic BP, abdominal fat, and improved postprandial lipid tolerance, representing improvements in cardiovascular risk factors that did not occur after SIT. Although SIT, but not END, increased endothelial function, arterial stiffness was not altered in either group. Indices of free-living glycemic regulation were improved after END and trended toward an improvement after SIT (P = 0.06-0.09). However, glycemic control was better on exercise compared with rest days, highlighting the importance of exercise frequency. Furthermore, in an exploratory nature, favorable individual responses (V˙O2peak, BP, glucose tolerance, lipidemia, and body fat) were more prevalent after END than low-frequency SIT.

CONCLUSION

As only high-frequency END improved BP and lipid tolerance, free-living glycemic regulation was better on days that participants exercised, and favorable individual responses were consistent after END, high-frequency END may favorably improve cardiometabolic health.

Time course of changes in V̇o2peak and O2 extraction during ramp cycle exercise following HIIT versus moderate-intensity continuous training in type 2 diabetes

In the present study, we assessed the time course of adaptations in peak oxygen uptake (V̇o2peak) and muscle fractional oxygen (O2) extraction (using near-infrared spectroscopy) following 12 wk of low-volume high-intensity interval training (HIIT) versus moderate-intensity continuous endurance training (MICT) in adults with uncomplicated type 2 diabetes (T2D). Participants with T2D were randomly assigned to MICT ( n = 12, 50 min of moderate-intensity cycling) or HIIT ( n = 9, 10 × 1 min at ∼90% maximal heart rate) or to a nonexercising control group ( n = 9). Exercising groups trained three times per week and measurements were taken every 3 wk. The rate of muscle deoxygenation (i.e., deoxygenated hemoglobin and myoglobin concentration, Δ[HHb + Mb]) profiles of the vastus lateralis muscle were normalized to 100% of the response, plotted against % power output (PO), and fitted with a double linear regression model. V̇o2peak increased ( P < 0.05) by week 3 of MICT (+17%) and HIIT (+8%), with no further significant changes thereafter. Total increases in V̇o2peak posttraining ( P < 0.05) were 27% and 14%, respectively. The %Δ[HHb + Mb] versus %PO slope of the first linear segment ( slope1) was reduced ( P < 0.05) beyond 3 wk of HIIT and MICT, with no further significant changes thereafter. No changes in V̇o2peak or slope1 were observed in the control group. Low-volume HIIT and MICT induced improvements in V̇o2peak following a similar time course, and these improvements were likely, at least in part, due to an improved microvascular O2 delivery.

High-Intensity Interval vs. Continuous Endurance Training: Preventive Effects on Hormonal Changes and Physiological Adaptations in Prediabetes Patients

ABSTRACT

Safarimosavi, S, Mohebbi, H, and Rohani, H. High-intensity interval vs. continuous endurance training: Preventive effects on hormonal changes and physiological adaptations in prediabetes patients. J Strength Cond Res 35(3): 731-738, 2021-The aim of this study was to examine the effects of a 12-week high-intensity interval training (HIIT) intervention, or an isocaloric continuous endurance training (CET) intervention on insulin resistance indices and change in irisin and preptin in patients with prediabetes. Thirty-two prediabetic male patients (age = 38.7 ± 4; body mass index = 26.9 ± 1.4 kg·m-2; and V̇o2peak = 2.49 ± 0.22 L·min-1) were randomly assigned into 3 training groups (N = 8). These groups were matched based on the required energy expenditure (EE) for completing each protocol: (a) HIIT (10 × 60 seconds at 90% peak oxygen uptake [V̇o2peak], 1: 1 work to recovery at 50 W), (b) CET at an intensity equivalent to maximal fat oxidation (Fatmax) (CETFAT) (pedaling for a duration that expends an equivalent EE to an HIIT session [E ≈ HIIT]), (c) CET at an intensity equivalent to anaerobic threshold (CETAT) (E ≈ HIIT), and (d) the control group (CON): continued to perform their daily activities. After intervention, blood glucose levels were significantly (p < 0.05) lower in the HIIT group compared with CETAT group. Exercise training improved the insulin resistance index by 35, 28, and 37% in CETFAT, CETAT, and HIIT groups, respectively. Irisin concentrations in the HIIT and CETAT groups was significantly (p < 0.05) decreased compared with the pre-training values. Also, HIIT and CETFAT resulted in significant (p < 0.05) changes in preptin concentration compared with baseline. This study demonstrated that both HIIT and CETFAT protocols had similar effects on the insulin resistance index of prediabetic patients. Also, the intensity and type of exercise were effective factors in changing irisin and preptin concentrations.

Individual cardiovascular responsiveness to work-matched exercise within the moderate- and severe-intensity domains

Purpose

We investigated the cardiovascular individual response to 6 weeks (3×/week) of work-matched within the severe-intensity domain (high-intensity interval training, HIIT) or moderate-intensity domain (moderate-intensity continuous training, MICT). In addition, we analyzed the cardiovascular factors at baseline underlying the response variability.

Methods

42 healthy sedentary participants were randomly assigned to HIIT or MICT. We applied the region of practical equivalence-method for identifying the levels of responders to the maximal oxygen uptake (V̇O_2max) response. For investigating the influence of cardiovascular markers, we trained a Bayesian machine learning model on cardiovascular markers.

Results

Despite that HIIT and MICT induced significant increases in V̇O_2max, HIIT had greater improvements than MICT (p < 0.001). Greater variability was observed in MICT, with approximately 50% classified as “non-responder” and “undecided”. 20 “responders”, one “undecided” and no “non-responders” were observed in HIIT. The variability in the ∆V̇O_2max was associated with initial cardiorespiratory fitness, arterial stiffness, and left-ventricular (LV) mass and LV end-diastolic diameter in HIIT; whereas, microvascular responsiveness and right-ventricular (RV) excursion velocity showed a significant association in MICT.

Conclusion

Our findings highlight the critical influence of exercise-intensity domains and biological variability on the individual V̇O_2max response. The incidence of “non-responders” in MICT was one third of the group; whereas, no “non-responders” were observed in HIIT. The incidence of “responders” was 11 out of 21 participants in MICT, and 20 out of 21 participants in HIIT. The response in HIIT showed associations with baseline fitness, arterial stiffness, and LV-morphology; whereas, it was associated with RV systolic function in MICT.

Time-course of V̇o2 kinetics responses during moderate-intensity exercise subsequent to HIIT versus moderate-intensity continuous training in type 2 diabetes

We assessed the time-course of changes in oxygen uptake (V̇o₂) and muscle deoxygenation (i.e., deoxygenated hemoglobin and myoglobin, [HHb + Mb]) kinetics during transitions to moderate-intensity cycling following 12 wk of low-volume high-intensity interval training (HIIT) vs. moderate-intensity continuous training (MICT) in adults with type 2 diabetes (T2D). Participants were randomly assigned to MICT (n = 10, 50 min of moderate-intensity cycling), HIIT (n = 9, 10 × 1 min at ∼90% maximal heart rate), or nonexercising control (n = 9) groups. Exercising groups trained three times per week, and measurements were taken every 3 wk. [HHb + Mb] kinetics were measured by near-infrared spectroscopy at the vastus lateralis muscle. The local matching of O₂ delivery to O₂ utilization was assessed by the Δ[HHb + Mb]/ΔV̇o₂ ratio. The pretraining time constant of the primary phase of V̇o₂ (τV̇o_2p) decreased (P < 0.05) at wk 3 of training in both MICT (from 44 ± 12 to 32 ± 5 s) and HIIT (from 42 ± 8 to 32 ± 4 s) with no further changes thereafter, whereas no changes were reported in controls. The pretraining overall dynamic response of muscle deoxygenation (τ'[HHb + Mb]) was faster than τV̇o_2p in all groups, resulting in Δ[HHb + Mb]/V̇o_2p showing a transient "overshoot" relative to the subsequent steady-state level. After 3 wk, the Δ[HHb + Mb]/V̇o_2p overshoot was eliminated only in the training groups, so that τ'[HHb + Mb] was not different to τV̇o_2p in MICT and HIIT. The enhanced V̇o₂ kinetics response consequent to both MICT and HIIT in T2D was likely attributed to a training-induced improvement in matching of O₂ delivery to utilization.NEW & NOTEWORTHY High-intensity interval training and moderate-intensity continuous training elicited faster pulmonary oxygen uptake (V̇o₂) kinetics during moderate-intensity cycling within 3 wk of training with no further changes thereafter in individuals with type 2 diabetes. These adaptations were accompanied by unaltered near-infrared spectroscopy-derived muscle deoxygenation (i.e. deoxygenated hemoglobin and myoglobin concentration, [HHb+Mb]) kinetics and transiently reduced Δ[HHb+Mb]-to-ΔV̇o₂ ratio, suggesting an enhanced blood flow distribution within the active muscles subsequent to both training interventions.

Exercise Training and Cardiac Rehabilitation in COVID-19 Patients with Cardiovascular Complications: State of Art

Recent scientific literature has investigated the cardiovascular implications of COVID-19. The mechanisms of cardiovascular damage seem to involve the protein angiotensin-converting enzyme 2 (ACE2), to which severe acute respiratory syndrome (SARS) coronavirus-2 (CoV-2) binds to penetrate cells and other mechanisms, most of which are still under study. Cardiovascular sequelae of COVID-19 include heart failure, cardiomyopathy, acute coronary syndrome, arrhythmias, and venous thromboembolism. This article aims to collect scientific evidence by exploiting PubMed, Scopus, and Pedro databases to highlight the cardiovascular complications of COVID-19 and to define the physiotherapy treatment recommended for these patients. Exercise training (ET), an important part of cardiac rehabilitation, is a powerful tool in physiotherapy, capable of inducing significant changes in the cardiovascular system and functional in the recovery of endothelial dysfunction and for the containment of thromboembolic complications. In conclusion, due to the wide variety of possible exercise programs that can be obtained by combining intensity, duration, and speed in various ways, and by adjusting the program based on continuous patient monitoring, exercise training is well suited to the treatment of post-COVID patients with an impaired cardiovascular system of various degrees.

Comparison of prevalence of diabetes complications in Brazilian and Mexican adults: a cross-sectional study

BACKGROUND

Type 2 diabetes is more frequent in Latin American people than in non-Hispanic whites due to a combination of genetic and lifestyle risk factors. Brazil and Mexico are the most populous countries in Latin America. The present study aimed to compare the results of the National Health Survey "PNS" in Brazil and the National Survey Health and Nutrition "ENSANUT" in Mexico regarding the prevalence, complications and healthcare issues of diabetes in both countries.

METHODS

A cross-sectional study was conducted with data from the National Health Survey (PNS) of 2013 in Brazil and the National Survey of Health and Nutrition (ENSANUT) of 2018 in Mexico. The prevalence of diabetes, complications and risk factors related to developing diabetes were considered.

RESULTS

The respondents included 3636 individuals in Brazil and 4555 individuals in Mexico. There were significant differences in age and time living with diabetes between the two countries. Mexican people had twice as likely as Brazilian people to have a complication (p < 0.0001). The principal risk factor (OR 2.47; p ≤ 0.0001) for developing any diabetic complication was living with diabetes for more than 15 years. Visual impairment was the most frequent complication in both countries, but it was more prevalent in Mexico (p ≤ 0.001).

CONCLUSIONS

Diabetes complications are important health problems in Brazil and Mexico. Visual impairment was the principal complication in both countries. Several factors, such as access to and type of health system, living in a rural area, treatment, BMI and performing preventive actions, affected the risk of developing a complication. However, living with diabetes for more than 15 years was the principal risk factor. National health surveys have added significant information on the impact of diabetes in these Latin American populations. This comparison of data could provide valuable information to guide national policies and program decisions in both countries.

Effectiveness of HIIE versus MICT in Improving Cardiometabolic Risk Factors in Health and Disease: A Meta-analysis

PURPOSE

We aimed to investigate differences between high-intensity interval exercise (HIIE, including high-intensity interval training and sprint interval training) and moderate-intensity continuous training (MICT) on physical fitness, body composition, blood pressure, blood lipids, insulin and glucose metabolism, inflammation, and endothelial function.

METHODS

Differences between HIIE and MICT were summarized using a random-effects meta-analysis on the effect size (Cohen's d). A meta-regression was conducted using the following subgroups: population, age, training duration, men ratio, exercise type, baseline values (clinical relevant ranges), and type of HIIE. Studies were included if at least one of the following outcomes were reported: maximal oxygen uptake (V˙O2max), flow-mediated dilation (FMD), body mass index (BMI), body mass, percent body fat, systolic and diastolic blood pressure, high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides, total cholesterol, C-reactive protein (CRP), fasting glucose and insulin, glycated hemoglobin (HbA1c), and insulin resistance (HOMA-IR). A total of 55 studies were included.

RESULTS

Overall, HIIE was superior to MICT in improving V˙O2max (d = 0.40, P < 0.001) and FMD (d = 0.54, P < 0.05). Oppositely, MICT was superior to HIIE in improving HbA1c (d = -0.27, P < 0.05). No differences were observed in BMI (d = -0.02), body mass (d = -0.05), percent body fat (d = 0.04), systolic blood pressure (d = -0.04), diastolic blood pressure (d = 0.03), HDL (d = -0.05), LDL (d = 0.08), triglycerides (d = 0.03), total cholesterol (d = 0.14), CRP (d = -0.11), fasting insulin (d = 0.02), fasting glucose (d = 0.02), and HOMA-IR (d = -0.04). Moderator analyses indicated that the difference between HIIE and MICT was affected by different subgroups.

CONCLUSION

Overall, HIIE showed to be more effective in improving cardiovascular health and cardiorespiratory fitness, whereas MICT was superior in improving long-term glucose metabolism. In the process of personalized training counseling, health-enhancing effects of exercise training may be improved by considering the individual risk profiles.

Walking for subjects with type 2 diabetes: a systematic review and joint AMD/SID/SISMES evidence-based practical guideline

Aims

Regular exercise is considered a cornerstone in the management of type 2 diabetes mellitus (T2DM). It improves glucose control and cardiovascular risk factors, contributes to weight loss, and also improves general well-being, likely playing a role in the prevention of chronic complications of diabetes. However, compliance to exercise recommendations is generally inadequate in subjects with T2DM. Walking is the most ancestral form of physical activity in humans, easily applicable in daily life. It may represent, in many patients, a first simple step towards lifestyle changes. Nevertheless, while most diabetic patients do not engage in any weekly walking, exercise guidelines do not generally detail how to improve its use. The aims of this document are to conduct a systematic review of available literature on walking as a therapeutic tool for people with T2DM, and to provide practical, evidence-based clinical recommendations regarding its utilization in these subjects.

Data synthesis

Analysis of available RCTs proved that regular walking training, especially when supervised, improves glucose control in subjects with T2DM, with favorable effects also on cardiorespiratory fitness, body weight, and blood pressure. Moreover, some recent studies have shown that even short bouts of walking, used for breaking prolonged sitting, can ameliorate glucose profiles in diabetic patients with sedentary behavior.

Conclusions

There is sufficient evidence to recognize that walking is a useful therapeutic tool for people with T2DM. This document discusses theoretical and practical issues for improving its use.

Influences of Recreational Tennis-Playing Exercise Time on Cardiometabolic Health Parameters in Healthy Elderly: The ExAMIN AGE Study

BACKGROUND

Aging and chronic degeneration are the primary threats to cardiometabolic health in elderly populations. Regular appropriate exercise would benefit the advanced aging population.

PURPOSE

This study investigates whether the degree of weekly tennis participation exhibits differences in primary cardiometabolic parameters, including arterial stiffness, inflammation, and metabolic biomarkers in elderly tennis players.

METHODS

One hundred thirty-five long-term participants in elder tennis (>50 years old) were initially screened. Twenty-six eligible and voluntary subjects were divided into high tennis time group (HT) (14 ± 1.3 h/week) and low tennis time group (LT) (4.5 ± 0.7 h/week) by stratification analysis based on the amount of tennis playing activity time. The brachial-ankle pulse wave velocity (baPWV), blood pressure, ankle-brachial index (ABI), blood metabolic biomarkers, and insulin resistance were measured to compare the difference between HT and LT groups.

RESULTS

The baPWV was significantly lower in the HT group than that in the LT group (1283.92 ± 37.01 vs. 1403.69 ± 53.71 cm/s, p < 0.05). We also found that the HT insulin-resistant homeostasis model assessment (HOMA-IR) was significantly lower than that of LT (1.41 ± 0.11 vs. 2.27 ± 0.48 μIU/mL, p < 0.05). However, the blood lipid biomarkers (glucose, cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride) were not statistical different between HT and LT groups (p > 0.05).

CONCLUSION

We demonstrated that under the condition of similar daily physical activity level, elderly with a higher time of tennis-playing (HT group) exhibited relatively lower arterial stiffness (lower PWV) and lower insulin resistance compared to those with lower time tennis-playing (LT).

Exercise as a complementary medicine intervention in type 2 diabetes mellitus: A systematic review with narrative and qualitative synthesis of evidence

BACKGROUND AND AIMS

Type 2 diabetes mellitus (T2DM) is a rapidly growing public health issue. This systematic review aimed to narrate and qualitatively synthesize evidence and recommendations of physical activity/exercise for patients with T2DM.

METHODS

The databases Medline through Pubmed, Cochrane, and Scopus were systematically searched from inception to February 08, 2020 using MeSH terms related to "diabetes mellitus" and "physical activity/exercise". Studies were included if they reported on the roles of physical activity/exercise in managing patients with T2DM or effects of physical activity/exercise on glycemic control. Documents identified through the search were analyzed and evidence and recommendations were synthesized qualitatively.

RESULTS

Data were extracted from 16 original articles and 11 systematic reviews with meta-analyses. A qualitative summary of evidence included general items (n = 6) and recommendations for physical activity/exercise (n = 12). Physical activity/exercise can reduce incidence of T2DM, hyperinsulinemia, fasting plasma/blood glucose, HbA1c, body fats, cholesterol, blood pressure, heart rate, cardiovascular risk, and dosage of antidiabetic medications. Physical activity/exercise can improve sensitivity to insulin, muscle strength, oxygen consumption, aerobic capacity, and mental health of patients with T2DM.

CONCLUSION

Despite the increasing interest in incorporating physical activity/exercise in the management of T2DM and improving healthcare delivery, there are still limited clear instructions and guidelines for both the patient and the healthcare provider.

Greater increase in internal carotid artery shear rate during aerobic interval compared to continuous exercise in healthy adult men

Interval exercise has been determined to be more effective than continuous exercise for achieving improvement in the cardiovascular function of individuals suffering from cardiovascular disease. However, whether interval exercise improves the cerebrovascular function remains unclear. As per our hypothesis, interval exercise induces a higher cerebrovascular shear rate (SR) than continuous exercise. In this study, 11 adult men randomly performed continuous exercise for 12 min or work-equivalent (57.6 kJ/exercise session) interval exercise of semi-recumbent cycling. The SR in the internal carotid artery (ICA) represents an index of the cerebrovascular SR, which was measured during both the exercises using Doppler ultrasonography. Both the aerobic exercise modes increased the ICA SR. Moreover, the average ICA SR of the interval exercise for the final 4 min of exercise or 2 min of recovery was significantly higher than that for continuous exercise (exercise, 351 ± 75 vs. 330 ± 61/s, p = .038; recovery, 327 ± 86 vs. 290 ± 56/s, p = .014). To our knowledge, this is the first study to show that aerobic interval exercise increased the ICA SR more than equivalent work volume of aerobic continuous exercise. Thus, aerobic interval exercise may be more effective at stimulating the cerebrovasculature, resulting in greater improvements in cerebrovascular function as compared to continuous aerobic exercise in healthy adult men. These findings provide some important information that would help enhance exercise therapy programs for patients with arteriosclerosis, especially in the cerebral circulation.

Walking for subjects with type 2 diabetes: A systematic review and joint AMD/SID/SISMES evidence-based practical guideline

AIMS

Regular exercise is considered a cornerstone in the management of type 2 diabetes mellitus (T2DM). It improves glucose control and cardiovascular risk factors, contributes to weight loss, and also improves general well-being, likely playing a role in the prevention of chronic complications of diabetes. However, compliance to exercise recommendations is generally inadequate in subjects with T2DM. Walking is the most ancestral form of physical activity in humans, easily applicable in daily life. It may represent, in many patients, a first simple step towards lifestyle changes. Nevertheless, while most diabetic patients do not engage in any weekly walking, exercise guidelines do not generally detail how to improve its use. The aims of this document are to conduct a systematic review of available literature on walking as a therapeutic tool for people with T2DM, and to provide practical, evidence-based clinical recommendations regarding its utilization in these subjects.

DATA SYNTHESIS

Analysis of available RCTs proved that regular walking training, especially when supervised, improves glucose control in subjects with T2DM, with favorable effects also on cardiorespiratory fitness, body weight and blood pressure. Moreover, some recent studies have shown that even short bouts of walking, used for breaking prolonged sitting, can ameliorate glucose profiles in diabetic patients with sedentary behavior.

CONCLUSIONS

There is sufficient evidence to recognize that walking is a useful therapeutic tool for people with T2DM. This document discusses theoretical and practical issues for improving its use. This article is co-published in the journals Sport Sciences for Health and Nutrition, Metabolism and Cardiovascular Diseases.

Impact of combined training with different exercise intensities on inflammatory and lipid markers in type 2 diabetes: a secondary analysis from a 1-year randomized controlled trial

Background

Exercise is a well-accepted strategy to improve lipid and inflammatory profile in individuals with type 2 diabetes (T2DM). However, the exercise intensity having the most benefits on lipids and inflammatory markers in patients with T2DM remains unclear. We aimed to analyse the impact of a 1-year combined high-intensity interval training (HIIT) with resistance training (RT), and a moderate continuous training (MCT) with RT on inflammatory and lipid profile in individuals with T2DM.

Methods

Individuals with T2DM (n = 80, aged 59 years) performed a 1-year randomized controlled trial and were randomized into three groups (control, n = 27; HIIT with RT, n = 25; MCT with RT, n = 28). Exercise sessions were supervised with a frequency of 3 days per week. Inflammatory and lipid profiles were measured at baseline and at 1-year follow-up. Changes in inflammatory and lipid markers were assessed using generalized estimating equations.

Results

After adjusting for sex, age and baseline moderate-to-vigorous physical activity (MVPA), we observed a time-by-group interaction for Interleukin-6 (IL-6) in both the MCT with RT (β = − 0.70, p = 0.034) and HIIT with RT (β = − 0.62, p = 0.049) groups, whereas, only the HIIT with RT group improved total cholesterol (β = − 0.03, p = 0.045) and LDL-C (β = − 0.03, p = 0.034), when compared to control. No effect was observed for C-reactive protein (CRP), cortisol, tumour necrosis factor-α (TNF-α), soluble form of the haptoglobin-hemoglobin receptor CD163 (sCD163), triglycerides and HDL-C in both groups (p > 0.05).

Conclusions

Favorable adaptations on IL-6 were observed in both the HIIT and MCT combined with RT groups following a long-term 1-year exercise intervention in individuals with T2DM. However, only the HIIT with RT prevented further derangement of total cholesterol and LDL-C, when compared to the control group. Therefore, in order to encourage exercise participation and improve inflammatory profile, either exercise protocols may be prescribed, however, HIIT with RT may have further benefits on the lipid profile.

Trial registration Clinicaltrials.gov ID: NCT03144505

Comparison of High-Intensity Interval Training to Moderate-Intensity Continuous Training in Older Adults: A Systematic Review

High-intensity interval training (HIIT) is emerging as a safe and effective means to combat chronic diseases. The objective of this work was to perform a systematic review of the effect of HIIT interventions in an aging population. Three electronic databases were searched for randomized trials comparing the effect of HIIT and moderate-intensity continuous training in older adults. After a thorough screening process, 15 articles were identified as meeting the inclusion criteria. All studies expressed a comparable or superior effect of HIIT in cardiorespiratory fitness measures. No studies reported a lessened effect of HIIT in comparison with moderate-intensity continuous training. This systematic review demonstrates that HIIT is a useful exercise regimen, which can be used in older adults to increase cardiorespiratory fitness. More research is needed to determine the effects of HIIT in an aging, predominately female population.

Influence of sprint exercise on aortic pulse wave velocity and femoral artery shear patterns

PURPOSE

Aortic stiffness may affect shear patterns in the peripheral vasculature. This study examined if sprint exercise, which typically increases aortic stiffness is associated with increased peripheral retrograde blood flow and impaired microvascular function.

METHODS

Twenty participants (10 women; age: 27 ± 5 years) underwent arterial stiffness, shear rate, and microvascular function assessment at three time points: baseline; following time control; ~ 2 min post a 30-s cycle ergometer sprint against 7.0% body mass. Aortic stiffness was assessed using carotid-femoral pulse wave velocity (cfPWV). Superficial femoral artery (SFA) diameter and blood velocity were assessed using Doppler-ultrasound and were used to calculate shear rates and resistance index (RI). SFA wave reflections were obtained via wave intensity analysis. Vastus medialis microvascular function was measured as tissue saturation index reactivity pre-post exercise via near-infrared spectroscopy.

RESULTS

cfPWV increased by + 0.8 ± 0.7 m·s^-1 following exercise (p < 0.001). Retrograde shear was reduced following exercise compared with time control (- 4.9 ± 3.8 s^-1; p < 0.001), while tissue saturation index was increased post-exercise from baseline (+ 2.3 ± 4.6%; p = 0.04). Reductions in SFA wave reflections (- 1.70 ± 1.96 aU) and RI (- 0.17 ± 0.13 aU) were also noted following exercise (p < 0.001).

CONCLUSION

These data suggest sprint exercise-mediated changes in peripheral shear patterns and microvascular function in the exercised vasculature occur independent from increases in aortic stiffness. Exercise-induced reductions in SFA retrograde shear may be related to decreased wave reflections and peripheral vascular resistance.

The Importance of Redox Status in the Frame of Lifestyle Approaches and the Genetics of the Lung Innate Immune Molecules, SP-A1 and SP-A2, on Differential Outcomes of COVID-19 Infection

The pandemic of COVID-19 is of great concern to the scientific community. This mainly affects the elderly and people with underlying diseases. People with obesity are more likely to experience unpleasant disease symptoms and increased mortality. The severe oxidative environment that occurs in obesity due to chronic inflammation permits viral activation of further inflammation leading to severe lung disease. Lifestyle affects the levels of inflammation and oxidative stress. It has been shown that a careful diet rich in antioxidants, regular exercise, and fasting regimens, each and/or together, can reduce the levels of inflammation and oxidative stress and strengthen the immune system as they lead to weight loss and activate cellular antioxidant mechanisms and reduce oxidative damage. Thus, a lifestyle change based on the three pillars: antioxidants, exercise, and fasting could act as a proactive preventative measure against the adverse effects of COVID-19 by maintaining redox balance and well-functioning immunity. Moreover, because of the observed diversity in the expression of COVID-19 inflammation, the role of genetics of innate immune molecules, surfactant protein A (SP-A)1 and SP-A2, and their differential impact on the local lung microenvironment and host defense is reviewed as genetics may play a major role in the diverse expression of the disease.

Impact of interval walking training managed through smart mobile devices on albuminuria and leptin/adiponectin ratio in patients with type 2 diabetes

Background

Interval walking training has demonstrated more pronounced positive effects on physical fitness and metabolism in type 2 diabetes (T2D), compared to continuous walking. One of the pathogenic mechanisms of T2D is associated with derangements in leptin/adiponectin axis, which might predispose affected individuals to vascular inflammation and albuminuria. The aim of this study was to investigate the effects of interval walking training delivered through smart mobile devices upon albuminuria and leptin/adiponectin ratio in patients with T2D.

Methods

Patients with T2D aged 35–75 were randomized into control (n = 26) and interval training (IT, n = 14) groups. Patients in IT group had to perform three 60‐min interval walking sessions (3 min intervals of slow and fast walking with the intensity of 40% and 70% of the peak energy expenditure) per week delivered by smartphone application for four months. The adherence to training was monitored remotely. Outcome measures were albuminuria, leptin/adiponectin ratio, obesity indicators, and glycaemic control. Leptin and adiponectin concentration was measured in serum samples by Luminex technology.

Results

In the IT group compared to control group, we observed a statistically significant decrease in albuminuria (p = .002) and leptin/adiponectin ratio (p = .01), as well as a decrease in HbA1c close to statistical significance (p = .09). In IT group, changes in leptin/adiponectin ratio correlated significantly with changes in hip circumference (p = .024).

Conclusion

Interval walking training is beneficial for vascular health in T2D via impact on albuminuria and leptin/adiponectin ratio.

Efficacy of a Six-Week Dispersed Wingate-Cycle Training Protocol on Peak Aerobic Power, Leg Strength, Insulin Sensitivity, Blood Lipids and Quality of Life in Healthy Adults

The aim of this study was to evaluate the efficacy of a six-week dispersed Wingate Anaerobic test (WAnT) cycle exercise training protocol on peak aerobic power (VO_2peak), isokinetic leg strength, insulin sensitivity, lipid profile and quality of life, in healthy adults. Methods: We conducted a match-controlled cohort trial and participants were assigned to either the training (intervention, INT, N = 16) or non-training (control, CON, N = 17) group. INT performed 30-s WAnT bouts three times a day in the morning, afternoon and evening with each bout separated by ~4 h of rest, performed for 3 days a week for 6 weeks. Criterion measures of peak oxygen uptake (VO_2peak), leg strength, insulin markers such as homeostatic model assessment (HOMA) and quantitative insulin-sensitivity check index (QUICKI), blood lipids profile and health-related quality of life (HRQL) survey were assessed before and after 6 weeks in both groups. Results: Absolute VO_2peak increased by 8.3 ± 7.0% (p < 0.001) after INT vs. 0.9 ± 6.1% in CON (p = 0.41) group. Maximal voluntary contraction at 30°·s^-1 of the dominant lower-limb flexors in INT increased significantly post-training (p = 0.03). There were no changes in the INT individuals' other cardiorespiratory markers, HOMA, QUICKI, blood lipids, and HRQL measures (all p > 0.05) between pre- and post-training; but importantly, no differences were observed between INT and CON groups (all p > 0.05). Conclusions: The results indicate that 6 weeks of dispersed sprint cycle training increased cardiorespiratory fitness and dynamic leg strength but had minimal impact on insulin sensitivity, blood lipids and quality of life in the exercising individuals.

Hemodynamics in young athletes following high-intensity interval or moderate-intensity continuous training

BACKGROUND

The present study aimed to investigate the effects of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) on blood pressure (BP) and parameters of arterial stiffness in young athletes.

METHODS

Seventeen rowers (aged 15±1.3 years) were randomized into an intervention group (IG, N.=10) and the control group (CG, N.=7). During an 8-week intervention period, the IG completed a HIIT on the rowing ergometer twice-weekly (2×4×2 min at ≈95% of maximum heart rate [HR<inf>max</inf>], 60 s rest) in addition to the regular rowing training (3×/week MICT 70-90 min, ≈70% HR<inf>max</inf>). The CG completed the regular normal rowing training and, instead of the HIIT units, two additional MICT units (70-90 min, ≈70% HR<inf>max</inf>). Before and after the intervention period, hemodynamic parameters were recorded non-invasively in both groups.

RESULTS

After the intervention period, there was a significant decrease in peripheral systolic (P=0.01) and diastolic (P=0.05) BP, as well as in central systolic (P=0.05) and diastolic BP (P=0.03) in the IG. Furthermore, pulse wave velocity (PWV) (P=0.05) was significantly reduced. Analysis of intervention effects revealed significant between-group differences in central diastolic BP (P=0.05), in augmentation pressure (P=0.02), and in augmentation index (P=0.006) favoring IG. The CG showed no significant changes in the respected parameters throughout the intervention.

CONCLUSIONS

Already in adolescent athletes, a HIIT intervention has beneficial effects on peripheral and central BP as well as on PWV, augmentation pressure, and augmentation index.

HIITing the brain with exercise: mechanisms, consequences and practical recommendations

The increasing number of older adults has seen a corresponding growth in those affected by neurovascular diseases, including stroke and dementia. Since cures are currently unavailable, major efforts in improving brain health need to focus on prevention, with emphasis on modifiable risk factors such as promoting physical activity. Moderate-intensity continuous training (MICT) paradigms have been shown to confer vascular benefits translating into improved musculoskeletal, cardiopulmonary and cerebrovascular function. However, the time commitment associated with MICT is a potential barrier to participation, and high-intensity interval training (HIIT) has since emerged as a more time-efficient mode of exercise that can promote similar if not indeed superior improvements in cardiorespiratory fitness for a given training volume and further promote vascular adaptation. However, randomised controlled trials (RCTs) investigating the impact of HIIT on the brain are surprisingly limited. The present review outlines how the HIIT paradigm has evolved from a historical perspective and describes the established physiological changes including its mechanistic bases. Given the dearth of RCTs, the vascular benefits of MICT are discussed with a focus on the translational neuroprotective benefits including their mechanistic bases that could be further potentiated through HIIT. Safety implications are highlighted and components of an optimal HIIT intervention are discussed including practical recommendations. Finally, statistical effect sizes have been calculated to allow prospective research to be appropriately powered and optimise the potential for detecting treatment effects. Future RCTs that focus on the potential clinical benefits of HIIT are encouraged given the prevalence of cognitive decline in an ever-ageing population.