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

Berendschot T, S.A.G. Schouten J, Kroon AA, van der Kallen CJ, Henry RM, van Dongen MC, J.P.M. Eussen S, H.C.M. Savelberg H, van der Berg JD, Schaper NC, Schram MT, Stehouwer CD. Higher levels of daily physical activity are associated with better skin microvascular function in type 2 diabetes-The Maastricht Study

OBJECTIVE

Physical activity may provide a means for the prevention of cardiovascular disease via improving microvascular function. Therefore, this study investigated whether physical activity is associated with skin and retinal microvascular function.

METHODS

In The Maastricht Study, a population-based cohort study enriched with type 2 diabetes (n = 1298, 47.3% women, aged 60.2 ± 8.1 years, 29.5% type 2 diabetes), we studied whether accelerometer-assessed physical activity and sedentary time associate with skin and retinal microvascular function. Associations were studied by linear regression and adjusted for major cardiovascular risk factors. In addition, we investigated whether associations were stronger in type 2 diabetes.

RESULTS

In individuals with type 2 diabetes, total physical activity and higher-intensity physical activity were independently associated with greater heat-induced skin hyperemia (regression coefficients per hour), respectively, 10 (95% CI: 1; 18) and 36 perfusion units (14; 58). In individuals without type 2 diabetes, total physical activity and higher-intensity physical activity were not associated with heat-induced skin hyperemia. No associations with retinal arteriolar %-dilation were identified.

CONCLUSION

Higher levels of total and higher-intensity physical activity were associated with greater skin microvascular vasodilation in individuals with, but not in those without, type 2 diabetes.

Impact of high-intensity interval training and sprint interval training on peripheral markers of glycemic control in metabolic syndrome and type 2 diabetes

Glycemic control is essential to reduce the risk of complications associated with metabolic syndrome (MetS) and type 2 diabetes (T2D). Aerobic and resistance exercise performed alone or in combination improve glycemic control in both conditions. However, perceived lack of time and commitment are considered principal barriers to performing exercise regularly. High intensity interval training (HIIT) and sprint interval training (SIT) can be performed in a fraction of the time required for continuous aerobic exercise. A substantial scientific evidence indicates that HIIT/SIT improve glycemic control to a similar or greater extent than aerobic exercise in populations without MetS or T2D. Likewise, growing evidence suggest that HIIT/SIT improve the glycemic control during MetS and T2D. The aim of this review is to discuss the effects of interval training protocols on peripheral markers of glucose metabolism in patients with MetS and T2D.

Effectiveness of High-Intensity Interval Training Versus Moderate-Intensity Continuous Training in Hypertensive Patients: a Systematic Review and Meta-Analysis

PURPOSE OF REVIEW

The purpose of this meta-analysis is to compare the effects of moderate-intensity continuous training (MICT) and high-intensity interval training (HIIT) on blood pressure of hypertensive individuals.

RECENT FINDINGS

Continuous aerobic training programs are successful in health promotion and are effective in systolic blood pressure (SBP) and diastolic blood pressure (DBP) modulation. However, HIIT seems to be superior to MICT to improvement of cardiorespiratory fitness. PubMed, ScienceDirect, and Google Scholar were searched for randomized clinical trials that compared chronic effects of HIIT and MICT on BP in hypertensive subjects. Pre- and post-intervention changes in maximal oxygen uptake (VO₂max) between MICT and HIIT were analyzed. Both interventions presented significant differences in SBP (MICT: mean difference (MD), 3.7 mmHg [95% CI = 2.57, 4.82], p < 0.00001; and HIIT: MD, 5.64 mmHg [95% CI = 1.69, 9.52], p = 0.005) and in DBP (MICT: MD, 2.41 mmHg [95% CI = 1.09, 3.72], p = 0.0003; and HIIT: MD, 4.8 mmHg [95% CI = 2.9, 6.7], p < 0.00001) compared with the control group. No differences were found in the SBP values (MD, 1.13 mmHg [95% CI = - 0.01, 2.27], p = 0.05); however, differences were found between groups in DBP (MD, 1.63 mmHg [95% CI = 0.83, 2.44], p = 0.0001). In the secondary outcome, both interventions increased VO₂max in comparison with control groups (MICT: MD, 1.30 ml/kg/min [95% CI = 0.92, 1.68], p < 0.00001; and HIIT: MD, 4.90 ml/kg/min [95% CI = 3.77, 6.04], p < 0.00001), and HIIT promoted greater improvement than MICT (MD, 2.52 ml/kg/min [95% CI = 1.90, 3.13], p < 0.0001). In conclusion, HIIT and MICT promote reduction in SBP in adults with hypertension, and HIIT showed a greater magnitude in DBP reduction. For hypertensive patients, HIIT may be associated with a greater improvement in VO₂max than MICT might.

Diabetic vasculopathy: macro and microvascular injury

PURPOSE OF REVIEW

Diabetes is a common and prevalent medical condition as it affects many lives around the globe. Specifically, type-2 Diabetes (T2D) is characterized by chronic systemic inflammation alongside hyperglycemia and insulin resistance in the body, which can result in atherosclerotic legion formation in the arteries and thus progression of related conditions called diabetic vasculopathies. T2D patients are especially at risk for vascular injury; adjunct in many of these patients heir cholesterol and triglyceride levels reach dangerously high levels and accumulate in the lumen of their vascular system.

RECENT FINDINGS

Microvascular and macrovascular vasculopathies as complications of diabetes can accentuate the onset of organ illnesses, thus it is imperative that research efforts help identify more effective methods for prevention and diagnosis of early vascular injuries. Current research into vasculopathy identification/treatment will aid in the amelioration of diabetes-related symptoms and thus reduce the large number of deaths that this disease accounts annually.

SUMMARY

This review aims to showcase the evolution and effects of diabetic vasculopathy from development to clinical disease as macrovascular and microvascular complications with a concerted reference to sex-specific disease progression as well.

Effects of Preconditioning Local Vibrations on Subsequent Plantar Skin Blood Flow Response to Walking

Weight-bearing exercise such as walking may increase risk of foot ulcers in people with diabetes mellitus (DM) because of plantar ischemia due to repetitive, high plantar pressure. Applications of local vibrations on plantar tissues as a preconditioning intervention before walking may reduce plantar tissue ischemia during walking. The objective of this study was to explore whether preconditioning local vibrations reduce reactive hyperemia after walking. A double-blind, repeated-measures, and crossover design was tested in 10 healthy participants without DM. The protocol included 10-minute baseline, 10-minute local vibrations (100 Hz or sham), 10-minute walking, and 10-minute recovery periods. The order of local vibrations was randomly assigned. Skin blood flow (SBF) was measured over the first metatarsal head during baseline and recovery periods. SBF responses were characterized as peak SBF, total SBF, and recovery time of reactive hyperemia. SBF was expressed as a ratio of recovery to baseline SBF to quantify the changes. Peak SBF in the vibration protocol (6.98 ± 0.87) was significantly lower than the sham control (9.26 ± 1.34, P < .01). Total SBF in the vibration protocol ([33.32 ± 7.98] × 103) was significantly lower than the sham control ([48.09 ± 8.9] × 103, P < .05). The recovery time in the vibration protocol (166.08 ± 32.71 seconds) was not significantly different from the sham control (223.53 ± 38.85 seconds, P = .1). Local vibrations at 100 Hz could reduce walking-induced hyperemic response on the first metatarsal head. Our finding indicates that preconditioning local vibrations could be a potential preventive intervention for people at risk for foot ulcers.

PHYSICAL TRAINING ON GLYCEMIA AND OXIDATIVE STRESS IN TYPE 2 DIABETES: A SYSTEMATIC REVIEW

ABSTRACT Introduction: Diabetes mellitus is accompanied by increased formation of reactive oxygen species (ROS) and decreased antioxidant capacity, leading to oxidative damage to cellular components. There is evidence to suggest that regular physical training positively changes oxidative homeostasis in the cells and tissues by lowering basal levels of oxidative damage, increasing resistance to oxidative stress. Objective: To verify the possible effects of aerobic physical training and resistance on glycemia and oxidative metabolism, and to determine whether there is any difference in outcomes resulting from different types of training in sedentary people with Type 2 Diabetes Mellitus (T2DM). Methods: A systematic review of controlled and randomized trials based on PRISMA. The databases LILACS, IBECS, Pubmed/MEDLINE, Cochrane Library, SciELO, PEDro, ScienceDirect and BIREME were searched, combining the descriptors type 2 diabetes mellitus, resistance training, aerobic exercise and oxidative stress in Portuguese, English and Spanish. The methodological quality of the papers was assessed by the PEDro scale. The data were read, analyzed, extracted and summarized. Results: Of the 1386 papers retrieved, only five met the inclusion criteria. The five selected papers, consisting of controlled and randomized clinical trials, were summarized. Conclusion: There have been many published studies reporting on exercises and diabetes. However, there is limitation when it comes to comparing their results. The variability of research methods and measurement instruments used makes it difficult to draw conclusions as to which physical training modality is most effective in reducing glycemic levels and oxidative stress in sedentary individuals with T2DM, considering that in each study analyzed in this review, the response to these variables is different. In future research, it would be important to standardize exercise modality, intensity, training time and evaluation parameters. Level of evidence I; Systematic review of RCTs (Randomized controlled trials).

Improved carotid intima-media thickness-induced high-intensity interval training associated with decreased serum levels of Dkk-1 and sclerostin in type 2 diabetes

AIMS

Carotid intima-media thickness (cIMT) is a validated surrogate marker of atherosclerosis. Dickkopf-1 (Dkk-1) and sclerostin modulate wingless signaling, which is involved in atherosclerosis. The purpose of this study was to investigate whether 12 weeks of high-intensity interval training (HIIT) would improve cIMT and serum Dkk-1 and sclerostin levels in patients with type 2 diabetes.

METHODS

Seventy-four sedentary patients with type 2 diabetes were randomly divided into HIIT and control groups. The HIIT group intervention was 6 intervals (4 min) at 85%-90% HR_max separated by 3 min at 45%-50% HR_max in 3 sessions/week for 12 weeks. Before and after the intervention, cIMT, artery diameter and wall/lm ratio were recorded with high-resolution ultrasound. Serum sclerostin and Dkk-1 were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

cIMT decreased significantly in the HIIT group (0.83 ± 0.17 baseline, 0.71 ± 0.14 follow-up) compared to the control group (0.84 ± 0.20 baseline, 0.85 ± 0.19 follow-up) (P < .05). Dkk-1 and sclerostin decreased significantly after 12 weeks of HIIT (P < .01). In addition, VO_2peak was increased in the HIIT group than the control group (by 6.2 mL/kg/min) (P < .05). There was a positive correlation between percent changes in cIMT and percent changes in Dkk-1 and sclerostin (both P < .01). Additionally, there were a negative correlation between percent changes VO2peak and cIMT (r = - 0.740, P = .003), Dkk-1 (r = - 0.844, P < .001) and sclerostin (r = - 0.575, P = .001) in HIIT group.

CONCLUSION

Our results indicate that HIIT decreases cIMT, serum levels of Dkk-1 and sclerostin and improves VO_2peak in patients with type 2 diabetes.

Comparing the Efficacy of Supervised and Unsupervised Exercise Training on Glycaemic Control in Type 2 Diabetes: A Systematic Review

BACKGROUND

Exercise training is vital for glycaemic control in patients with type 2 diabetes mellitus (T2D). While the positive effects of supervised exercise training are well established, unsupervised training may offer an alternative and more sustainable means of realising the benefits of exercise away from a resource-heavy supervised setting.

OBJECTIVE

To evaluate the available literature and compare the efficacy of supervised and unsupervised exercise training programs on glycemic control in patients with T2D.

METHODS

CINAHL, MEDLINE, PubMed, and EMBASE, searched from inception to 20 July 2018. Only studies that included both supervised and unsupervised training were included.

RESULTS

Four studies, involving 115 participants, were included. One compared supervised with unsupervised exercise training and three investigated the efficacy of unsupervised training following supervised training. While supervised training is effective for improving glycaemic control in patients with T2D, unsupervised training may not maintain these changes. Included studies lacked detail relating to the supervised and unsupervised training programs.

CONCLUSIONS

Given that exercise is a critical component for maintenance of glycaemic control in patients with T2D, and because unsupervised training has been shown to be effective in improving clinical outcomes in other disease populations, further research is warranted to compare supervised and unsupervised exercise training in patients with T2D. It is important that future studies report standardised and detailed descriptions of key elements that form the basis of supervised and unsupervised exercise training groups.

Anthropometric, Cardiopulmonary and Metabolic Benefits of the High-Intensity Interval Training Versus Moderate, Low-Intensity or Control for Type 2 Diabetes: Systematic Review and Meta-Analysis

Abstract: This study aims to evaluate the effectiveness of high-intensity interval training compared with no intervention and other types of training interventions for people with Type 2 Diabetes. A systematic review and meta-analysis of randomized controlled trials that used high-interval intensity training to improve anthropometric, cardiopulmonary and metabolic conditions were conducted. The search was performed during October-December 2017 using the databases PubMed, Web of Science and Physiotherapy Evidence Database (PEDro). The methodological quality of the studies was evaluated using the PEDro scale. A total of 10 articles were included in this meta-analysis. After statistical analysis, favorable results were obtained for high-Intensity Interval Training compared with control (non-intervention): [Weight: Standardized mean difference (SMD) = -2.09; confidence interval (CI) 95%: (-3.41; -0.78); body-mass index: SMD = -3.73; CI 95%: (-5.53; -1.93); systolic blood pressure: SMD = -4.55; CI 95%: (-8.44; -0.65); VO2max: SMD = 12.20; CI 95%: (0.26; 24.14); HbA1c: SMD = -3.72; CI 95%: (-7.34; -0.10)], moderate intensity continuous training: [body-mass index: SMD = -0.41; CI 95%: (-0.80; -0.03); VO2max: SMD = 1.91; CI 95%: (0.18; 3.64)], and low intensity training: [Weight: SMD = -2.06; CI 95%: (-2.80; -1.31); body-mass index: SMD = -3.04; CI 95%: (-5.16; -0.92); systolic blood pressure: SMD = -2.17; CI 95%: (-3.93; -0.41); HbA1c: SMD = -1.58; CI 95%: (-1.84; -1.33)]. The results show that high-intensity interval training can be a useful strategy in order to improve anthropometric, cardiopulmonary and metabolic parameters in people with Type 2 diabetes. Despite this, it could be essential to clarify and unify criteria in the intervention protocols, being necessary new lines of research.

Effect of Exercise on Risk Factors of Diabetic Foot Ulcers: A Systematic Review and Meta-Analysis

The objectives of this study were to examine the effectiveness of different types of exercise on risk factors of diabetic foot ulcers, including glycated hemoglobin, peripheral arterial disease, and diabetic peripheral neuropathy, in people with type 2 diabetes mellitus. PubMed, Web of Science, Cochrane Library, Scopus, and CINAHL were searched from inception to January 2018 for relevant articles. Eligible studies were randomized controlled trials that examined effects of exercise on the selected risk factors. Twenty randomized controlled trials with 1357 participants were included in the meta-analyses. The differences in postintervention values of glycated hemoglobin and ankle brachial index between exercise and control groups were synthesized, yielding mean differences of -0.45% (P < 0.00001) and 0.03 (P = 0.002), respectively; the differences in within-group changes in glycated hemoglobin were synthesized, yielding mean differences of -0.19% (P = 0.1), -0.25% (P = 0.0006), and -0.64% (P = 0.006) for aerobic versus resistance, combined versus aerobic, and combined versus resistance exercise, respectively. Exercise has a significant effect on reducing glycated hemoglobin, whereas combined exercise is more effective compared with aerobic or resistance exercise alone. Exercise also improves ankle brachial index. However, evidence regarding the association between exercise and peripheral neuropathy and risks of diabetic foot ulcers in people with type 2 diabetes mellitus remains insufficient.

Effects of Local Vibration With Different Intermittent Durations on Skin Blood Flow Responses in Diabetic People

Objective: Poor blood flow supply is an important pathological factor that leads to the development and deterioration of diabetic foot ulcers. This study aims to investigate the acute effects of local vibration with varying intermittent durations on the plantar skin blood flow (SBF) response in diabetic and healthy subjects.

Methods: Eleven diabetic patients (7 males, 4 females) and 15 healthy adults (6 males, 9 females) participated in this experiment and accepted three tests. Local continuous vibration (LCV) and two levels of local intermittent vibration (LIV1 and LIV2) were randomly applied to the middle metatarsal head of each subject's right foot in each test. The SBF was measured prior to intervention (Baseline), during Vibration and during the Recovery Stage for each test. The mean SBF in each stage, the change percentages and change rates of SBF in Vibration and Recovery stage among three tests were compared and analyzed for both diabetic and healthy subjects.

Results: For diabetic subjects, the SBF was significantly increased in both Vibration and Recovery Stage with local intermittent vibrations (LIV1 and LIV2), but not with LCV. However, there was no significant difference in change percentage and change rate of SBF in diabetic subjects across the three tests. For healthy subjects, all vibration interventions significantly increased the SBF in the Vibration Stage and in the first 1.5 min of the Recovery Stage. Also, the change rate of SBF during the Vibration stage in LIV1 test was significantly greater than that in LIV2 test for healthy subjects. Moreover, change percentage of SBF in Vibration stage of LIV1 test and in some periods of Recovery stages of LIV1 and LIV2 tests for diabetic subjects were lower than for healthy subjects; the absolute change rate of SBF in LIV1 test for diabetic subjects was also lower than for healthy subjects.

Conclusion: These findings suggest that both LIV1 and LIV2 may effectively improve SBF in the feet of diabetic people, but LCV may not achieve the same level of vasodilatation. The diabetic subjects were also found to have a lower SBF response to applied vibration than the healthy subjects.

High-Intensity Interval Training Versus Moderate-Intensity Continuous Training in Middle-Aged and Older Patients with Type 2 Diabetes: A Randomized Controlled Crossover Trial of the Acute Effects of Treadmill Walking on Glycemic Control

Background: This study aimed to compare the acute effects of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) on glycemic control in middle-aged and older patients with type 2 diabetes (T2D), using treadmill walking as aerobic exercise mode. Methods: Fifteen patients with T2D (60.25 ± 3.14 years; glycated hemoglobin 7.03 ± 0.33%; medicated with metformin and/or gliptins), participated in a randomized controlled crossover trial. They underwent three experimental conditions (treadmill walking HIIT session (5 × (3 min at 70% of heart rate reserve (HRR) + 3 min at 30% HRR)); treadmill walking MICT session (30 min at 50% HRR); and a control session of rest (CON)) in random order and in the postprandial state. Measurements of capillary blood glucose (BG) were taken immediately before, during, and until 50 min after the experimental conditions. Results: Both HIIT and MICT treadmill walking sessions reduced BG levels during exercise and laboratory 50 min recovery period compared to CON (time*condition interaction effect; p < 0.001). The effect of HIIT was greater compared with MICT (p = 0.017). Conclusions: Treadmill walking HIIT seems a safe and more effective exercise strategy on immediate acute glycemic control compared with MICT in middle-aged and older patients with T2D under therapy with metformin and/or gliptins. Trial Registration Number: ISRCTN09240628.

Aerobic exercise training at maximal fat oxidation intensity improves body composition, glycemic control, and physical capacity in older people with type 2 diabetes

Background

Aerobic training has been used as one of the common treatments for type 2 diabetes; however, further research on the individualized exercise program with the optimal intensity is still necessary. The purpose of this study was to investigate the effects of supervised exercise training at the maximal fat oxidation (FATmax) intensity on body composition, glycemic control, lipid profile, and physical capacity in older people with type 2 diabetes.

Methods

Twenty-four women and 25 men with type 2 diabetes, aged 60–69 years. The exercise groups trained at the individualized FATmax intensity for 1 h/day for 3 days/week over 16 weeks. No dietary intervention was introduced during the experimental period. Whole body fat, abdominal fat, oral glucose tolerance test, lipid profile, and physical capacity were measured before and after the interventions.

Results

FATmax intensity was at 41.3 ± 3.2% VO₂max for women and 46.1 ± 10.3% VO₂max for men. Exercise groups obtained significant improvements in body composition, with a special decrease in abdominal obesity; decreased resting blood glucose concentration and HbA1c; and increased VO₂max, walking ability, and lower body strength, compared to the non-exercising controls. Daily energy intake and medication remained unchanged for all participants during the experimental period.

Conclusion

Beside the improvements in the laboratory variables, the individualized FATmax training can also benefit daily physical capacity of older people with type 2 diabetes.

Exercise Intensities as Factors of Metabolic Outcomes in Type 2 Diabetes: A Systematic Review

Exercise is effective to prevent and treat type 2 diabetes, although currently underutilized. This review analyzes the metabolic response to exercise performance at various intensities in individuals with type 2 diabetes. These findings provide insight into the development of safe and efficacious exercise prescriptions and education. We conducted a systemic review of the literature to examine the association of various exercise protocols with metabolic outcomes in type 2 diabetes. Between 1984 and 2018, 29 studies were categorized per exercise mode and intensity levels according to the American College of Sports Medicine standards. The most consistent improvement was found in HbA1c following moderate- to high-intensity exercise—post-exercise fasting glucose improved to a lesser extent. Low-intensity exercise improved HOMA-IR (homeostasis model assessment for insulin resistance) levels. Glucose and HbA1c improved most following interval compared with continuous exercise, irrespective of intensity. A comparison of high-intensity exercise with moderate-intensity exercise demonstrated few differences in HbA1c, fasting glucose, fasting insulin, and HOMA-IR. Irrespective of exercise intensity, HbA1c improvements were observed, suggesting a delayed progression to diabetes-related complications. Initial low-intensity exercise, with increased quantities when feasible, will contribute to metabolic improvements. The variability in methodology and measurement contributed to inconsistent outcomes; additional research with larger samples sizes is warranted.

Aerobic exercise can modulate the underlying mechanisms involved in the development of diabetic complications

Diabetes mellitus is a highly prevalent metabolic disorder that affects many molecular pathways, causing a shift from a physiologic to a pathophysiologic state. Alterations in the molecular pathways promote diabetic complications and, thus, many medical and nonmedical therapies have been directed at preventing these complications. Despite the beneficial effects on moderating glycemic control, medical therapies may also have unfavorable side effects. This makes nonmedical therapeutic approaches more attractive due to lower pharmacological side effects of these strategies compared to medical agents. Aerobic exercise is now considered as a major nonmedical strategy that can promote beneficial and protective effects to counteract the development of diabetic complications via attenuation of the major molecular mechanisms involved in diabetes.

Acute Demands and Recovery From Common Interval Training Protocols

Elmer, DJ, Barron, EN, and Chavez, JL. Acute demands and recovery from common interval training protocols. J Strength Cond Res XX(X): 000-000, 2019-The definition of interval training is quite broad, with no accepted procedure for classifying protocols with different workloads and work and recovery interval times. In addition, little is known about the differences in training load and recovery from common interval protocols. The purpose of this study was to evaluate the differences in acute physiological demands and perceived difficulty between 3 common interval training protocols and a moderate, continuous exercise session. Eight subjects completed the training sessions on a cycle ergometer in a randomized order, with at least 1 week between sessions: 30-second/4-minute, 1-minute/1-minute, 4-minute/3-minute, and a 45-minute continuous session. Metabolic variables were measured throughout exercise and 30 minutes of recovery. Training impulse (TRIMP), session-RPE, and RPE-training load were also measured. There were significant differences between protocols, including between interval training protocols, for average V[Combining Dot Above]O2 (p < 0.001) and heart rate (HR) (p = 0.02), total O2 consumption (p < 0.001), peak lactate (p < 0.001), TRIMP (p = 0.02), session-RPE (p = 0.01), and RPE-training load (p < 0.001). There were no significant differences between interval training protocols for peak V[Combining Dot Above]O2 or peak HR attained during exercise. There were also no differences in V[Combining Dot Above]O2 or HR after 5 or 30 minutes of recovery. Blood lactate was only significantly higher after 30 minutes of recovery from the 30-second/4-minute compared with the 4-minute/3-minute protocol (p = 0.001) and the 45-minute session (p < 0.001). These findings show a range of differences in acute physiological demands and perceptions from interval training protocols, which should be accounted for when planning training sessions or research studies or when interpreting past research.

Cardiorespiratory burden of brass neck coils placed on Kayan Karen long-neck women of Thailand

There is only scarce information regarding the physiological and health impact of lifelong wearing of the neck brass coils in Karen Kayan women. The purpose of this study was to determine the influence of wearing brass neck coils on cardiorespiratory and cerebrovascular functions in long-neck Karen women. A total of 28 Karen women (aged 23-66 years) were studied. Fourteen Karen women who had been wearing neck brass coils were compared with 14 Karen women with no neck coils. We also studied 14 age-matched city-living controls. Radiographic examination of 2 older Karen women wearing neck coils showed low levels of the clavicles. There were no group differences in resting heart rate and brachial-ankle pulse wave velocity. Both systolic and diastolic blood pressure was greater and functional capacity was lower in both Karen women than city-living controls (all p < 0.05). Karen women wearing neck coils demonstrated lower flow-mediated dilation, lung functions, including forced vital capacity and forced expiratory volume during the first second, and cerebral blood flow velocity than Karen women without neck coils (all p < 0.05). Karen women wearing neck coils demonstrate reduced endothelial and pulmonary functions as well as cerebral perfusion compared with age-matched Karen women without neck coils living in the same villages. Brass neck coils worn by Karen women may elevate risks of developing cardiopulmonary and cerebrovascular diseases. Novelty Cerebral blood flow velocity and macrovascular and microvascular functions were lower in Karen wearing neck coils. There appears to be substantial burden of brass neck coils exerted on physiological systems in Karen women.

The Role of Aerobic Training Variables Progression on Glycemic Control of Patients with Type 2 Diabetes: a Systematic Review with Meta-analysis

BACKGROUND

Aerobic training (AT) improves glycemic control in patients with type 2 diabetes. However, the role of the progression of training variables remains unclear. The objective of this review was to analyze the effects of progressive AT (PAT) and non-progressive AT (NPAT) on glycated hemoglobin (HbA1c) in patients with type 2 diabetes.

METHODS

Data sources used were PubMed, Cochrane Central, Embase, SPORTDiscus, and LILACS. Studies that evaluated the effect of at least 12 weeks of PAT and NPAT compared to a control condition on HbA1c levels in type 2 diabetes patients were eligible for analysis. Two independent reviewers screened the search results, extracted the data, and assessed the risk of bias. Effect sizes (ESs) were calculated using the standardized mean difference in HbA1c levels between the intervention and control groups using a random-effect model.

RESULTS

Of 5848 articles retrieved, 24 randomized clinical trials (825 participants) were included. Among the included studies, 92% reported to have performed a randomization process, 8% presented allocation concealment, 21% reported blinding of outcome assessment, and 38% reported complete outcome data. AT reduced HbA1c levels by 0.65% (ES: - 1.037; 95% confidence interval [CI]: - 1.386, - 0.688; p < 0.001). The reduction in HbA1c induced by PAT was 0.84% (ES: - 1.478; 95% CI - 2.197, - 0.759; p < 0.001), and NPAT was 0.45% (ES: - 0.920; 95% CI - 1.329, - 0.512; p < 0.001). Subgroup analysis of the different forms of progression showed a reduction in HbA1c levels of 0.94% (ES: - 1.967; 95% CI - 3.783, - 0.151; p = 0.034) with progression in volume, 0.41% (ES: - 1.277; 95% CI - 2.499, - 0.056; p = 0.040) with progression in intensity, and 1.27% (ES: - 1.422; 95% CI - 2.544, - 0.300; p = 0.013) with progression in both volume and intensity. Subgroup analysis of the different modalities of AT showed a reduction of 0.69% (ES: - 1.078; 95% CI - 1.817, - 0.340; p = 0.004) with walking and/or running and of 1.12% (ES: - 2.614; 95% CI - 4.206, - 1.022; p = 0.001) with mixed protocols while progressive training was adopted. In non-progressive protocols, a significant HbA1c reduction was only found with walking and/or running (- 0.43%; ES: - 1.292; 95% CI - 1.856, - 0.72; p < 0.001).

CONCLUSION

The effect of PAT on glycemic control was greater than that of NPAT, especially when volume and intensity were progressively incremented throughout the interventions.

The combined effect of high-intensity intermittent training and vitamin D supplementation on glycemic control in overweight and obese adults

High-intensity intermittent training (HIIT) has been shown to reduce the risk of chronic conditions including the development of type 2 diabetes mellitus (T2DM). Independently, a low vitamin D status has also been linked to the prevalence of T2DM. The aim of this study was to investigate if there was a synergistic metabolic effect of HIIT and vitamin D supplementation on glycemic control. A total of 20 male and female participants (age, 34 ± 9 year; BMI, 31.4 ± 2.8 kg·m^-2 ) completed 6 weeks HIIT, and were randomized to ingest 100 μg·day^-1 of vitamin D₃ or placebo. Response to an oral glucose tolerance test (OGTT) was determined at baseline and at 72 h postintervention. Glucose tolerance was improved as a result of the HIIT intervention, shown through a reduction in glucose and insulin concentrations during the OGTT, accompanied by a decrease in glucose (829 ± 110 to 786 ± 139 mmol·h^-1 ·L^-1 ; P = 0.043) and insulin (8101 ± 4755-7024 ± 4489 mU·h^-1 ·L^-1 ; P = 0.049) area under the curve (AUC). Supplementation increased 25-hydroxyvitamin D₃ concentration by 120% to a sufficiency status (P < 0.001). However, the consumption of vitamin D₃ seemed to attenuate the glucose response during an OGTT. Triglyceride content was lowered following the intervention (P = 0.025). There was no effect of the intervention on insulin sensitivity (IS) indices: ISI_Matsuda and HOMA-IR. Our findings demonstrate that HIIT improves glucose tolerance in nondiabetic overweight and obese adults; however vitamin D₃ supplementation did not proffer any additional positive effects on the measured indices of metabolic health.

Prevalence and predictors of dropout from high-intensity interval training in sedentary individuals: A meta-analysis

Recent evidence suggests that high-intensity interval training (HIIT) is an effective method to improve fitness and various health markers. However, the tolerability and acceptability of HIIT among sedentary individuals is currently controversially discussed. Therefore, our objective was to investigate the prevalence and predictors of dropout among sedentary individuals in HIIT-based exercise interventions. MEDLINE/PubMed, SPORTDiscus, and Web of Science were searched systematically for relevant articles until 06/2018. Studies included were required to (a) be written in English, (b) include sedentary healthy adults, (c) use some form of HIIT without any complementary intervention, (d) last ≥4 weeks, (e) report detailed description of the applied HIIT protocol, and (f) report data that allow calculation of a dropout rate. Fifty-five studies reporting results from 67 HIIT interventions with 1318 participants met the eligibility criteria. The trim and fill adjusted pooled dropout rate across all interventions was 17.6% (95% confidence interval 14.2-21.5%). Dropout rates were significantly lower in cycling-based interventions compared with studies using running/walking as exercise modality (P < 0.001). Longer session time (β = 0.02, P < 0.05), higher time effort/week (β = 0.005, P < 0.05), and overall time effort/intervention (β = 0.0003, P < 0.05) predicted greater dropout. Exercise intensity was not related to dropout. Our data suggest that HIIT-based interventions are tolerable and acceptable for previously sedentary individuals, exhibiting generally lower dropout rates than commonly reported for traditional exercise programs. Given the association between HIIT volume and dropouts, future studies should further focus on identifying the minimally effective dose of practical HIIT for improving health status. Such efforts would be important to increase implementation and public health impact of HIIT.

Moderate-intensity continuous training: is it as good as high-intensity interval training for glycemic control in type 2 diabetes?

In Egypt, type 2 diabetes is higher in females than in males. Moderate-intensity continuous training (MICT) has been the most widely used exercise form in type 2 diabetes. This study aims to compare the classical MICT to the newly popular high intensity interval training (HIIT) with regard to changes in glycosylated hemoglobin (HbA1c) and estimated average glucose (eAG) in female type 2 diabetics. Twenty-six female patients with type 2 diabetes were assigned into three groups: a control group (n=9), a MICT group (n=9), and a HIIT group (n=8). Patients in both groups exercised on treadmill three days/week for 8 weeks. Patients in MICT exercised continuously for about 40 min at 65%–75% of peak heart rate (HRpeak). Patients in HIIT exercised for 4×4 min at 85%–90% of HRpeak with 3-min recovery in between at 65%–75% of HRpeak. Results showed that HbA1c was reduced significantly from 8.2% (7.45%–8.65%) to 6.9% (6.6%–7.15%) in MICT and from 8.23% (7.94%–8.85%) to 6.25% (6.1%–6.89%) in HIIT after interventions. Likewise, eAG was significantly reduced from 188.64 mg/dL (167.11–201.55 mg/dL) to 151.33 mg/dL (142.72–158.50 mg/dL) in MICT and from 189.64 mg/dL (181.18–207.29 mg/dL) to 136.69 mg/dL (128.37–151.04 mg/dL) in HIIT. No significant difference was found between HIIT and MICT in the measured variables. It is concluded that the less physically demanding MICT is as good as HIIT for normalizing hyperglycemia in type 2 diabetic females. Therefore, recent interests surrounding HIIT should not overemphasize it compared to the traditional MICT for improving glycemic outcomes.

Effectiveness of high-intensity interval training on glycemic control and cardiorespiratory fitness in patients with type 2 diabetes: a systematic review and meta-analysis

Aims

The aim of this systematic review and meta-analysis was to quantify the effect of high-intensity interval training (HIIT) on glycemic control and cardiorespiratory fitness compared with moderate-intensity training (MICT) and no training at all in patients with type 2 diabetes (T2D).

Methods

Relevant articles were sourced from PubMed, Embase, the Web of Science, EBSCO, and the Cochrane Library. Randomized-controlled trials were included based upon the following criteria: participants were clinically diagnosed with T2D, outcomes that included glycemic control (e.g., hemoglobin A1c); body composition (e.g., body weight); cardiorespiratory fitness (e.g., VO_2peak) are measured at baseline and post-intervention and compared with either a MICT or control group.

Results

Thirteen trials involving 345 patients were finally identified. HIIT elicited a significant reduction in BMI, body fat, HbA1c, fasting insulin, and VO_2peak in patients with type 2 diabetes. Regarding changes in the body composition of patients, HIIT showed a great improvement in body weight (mean difference: − 1.22 kg, 95% confidence interval [CI] − 2.23 to − 0.18, P = 0.02) and body mass index (mean difference: − 0.40 kg/m², 95% CI − 0.78 to − 0.02, P = 0.04) than MICT did. Similar results were also found with respect to HbA1c (mean difference: − 0.37, 95% CI − 0.55 to − 0.19, P < 0.0001); relative VO_2peak (mean difference: 3.37 ml/kg/min, 95% CI 1.88 to 4.87, P < 0.0001); absolute VO_2peak (mean difference: 0.37 L/min, 95% CI 0.28 to 0.45, P < 0.00001).

Conclusions

HIIT may induce more positive effects in cardiopulmonary fitness than MICT in T2D patients.

Superior Effects of High-Intensity Interval vs. Moderate-Intensity Continuous Training on Endothelial Function and Cardiorespiratory Fitness in Patients With Type 1 Diabetes: A Randomized Controlled Trial

This study aimed to compare the effect of high-intensity interval training (HIIT) with moderate-intensity continuous training (MCT) on endothelial function, oxidative stress and clinical fitness in patients with type 1 diabetes. Thirty-six type 1 diabetic patients (mean age 23.5 ± 6 years) were randomized into 3 groups: HIIT, MCT, and a non-exercising group (CON). Exercise was performed in a stationary cycle ergometers during 40 min, 3 times/week, for 8 weeks at 50–85% maximal heart rate (HR_max) in HIIT and 50% HR_max in MCT. Endothelial function was measured by flow-mediated dilation (FMD) [endothelium-dependent vasodilation (EDVD)], and smooth-muscle function by nitroglycerin-mediated dilation [endothelium-independent vasodilation (EIVD)]. Peak oxygen consumption (VO_2peak) and oxidative stress markers were determined before and after training. Endothelial dysfunction was defined as an increase < 8% in vascular diameter after cuff release. The trial is registered at ClinicalTrials.gov, identifier: NCT03451201. Twenty-seven patients completed the 8-week protocol, 9 in each group (3 random dropouts per group). Mean baseline EDVD was similar in all groups. After training, mean absolute EDVD response improved from baseline in HIIT: + 5.5 ± 5.4%, (P = 0.0059), but remained unchanged in MCT: 0.2 ± 4.1% (P = 0.8593) and in CON: −2.6 ± 6.4% (P = 0.2635). EDVD increase was greater in HIIT vs. MCT (P = 0.0074) and CON (P = 0.0042) (ANOVA with Bonferroni). Baseline VO_2peak was similar in all groups (P = 0.96). VO_2peak increased 17.6% from baseline after HIIT (P = 0.0001), but only 3% after MCT (P = 0.055); no change was detected in CON (P = 0.63). EIVD was unchanged in all groups (P = 0.18). Glycemic control was similar in all groups. In patients with type 1 diabetes without microvascular complications, 8-week HIIT produced greater improvement in endothelial function and physical fitness than MCT at a similar glycemic control.

Functional high-intensity exercise training ameliorates insulin resistance and cardiometabolic risk factors in type 2 diabetes

NEW FINDINGS

What is the central question of this study? Does short-duration, high-intensity exercise training that combines functional aerobic and resistance exercises into training sessions lasting 8-20 min benefit individuals with type 2 diabetes? What is the main finding and its importance? Functional high-intensity training improves insulin sensitivity and reduces cardiometabolic risk in individuals with type 2 diabetes. This type of exercise training may be an effective exercise mode for managing type 2 diabetes. The increase in insulin sensitivity addresses a key defect in type 2 diabetes.

ABSTRACT

Functional high-intensity training (F-HIT) is a novel fitness paradigm that integrates simultaneous aerobic and resistance training in sets of constantly varied movements, based on real-world situational exercises, performed at high-intensity in workouts that range from ∼8 to 20 min per session. We hypothesized that F-HIT would be an effective exercise mode for reducing insulin resistance in type 2 diabetes (T2D). We recruited 13 overweight/obese adults (5 males, 8 females; 53 ± 7 years; BMI 34.5 ± 3.6 kg m^-2 , means ± SD) with T2D to participate in a 6-week (3 days week^-1 ) supervised F-HIT programme. An oral glucose tolerance test was used to derive measures of insulin sensitivity. F-HIT significantly reduced fat mass (43.8 ± 83.8 vs. 41.6 ± 7.9 kg; P < 0.01), diastolic blood pressure (80.2 ± 7.1 vs. 74.5 ± 5.8; P < 0.01), blood lipids (triglyceride and VLDL, both P < 0.05) and metabolic syndrome z-score (6.4 ± 4.5 vs. -0.2 ± 5.2 AU; P < 0.001), and increased basal fat oxidation (0.08 ± 0.03 vs. 0.10 ± 0.04 g min^-1 ; P = 0.05), and high molecular mass adiponectin (214.4 ± 88.9 vs. 288.8 ± 127.4 ng mL^-1 ; P < 0.01). Importantly, F-HIT also increased insulin sensitivity (0.037 ± 0.010 vs. 0.042 ± 0.010 AU; P < 0.05). Increases in high molecular mass adiponectin and basal fat oxidation correlated with the change in insulin sensitivity (ρ, 0.75, P < 0.05 and ρ, 0.81, P < 0.01, respectively). Compliance with the training programme was >95% and no injuries or adverse events were reported. These data suggest that F-HIT may be an effective exercise mode for managing T2D. The increase in insulin sensitivity addresses a key defect in T2D and is consistent with improvements observed after more traditional aerobic exercise programmes in overweight/obese adults with T2D.

Effectiveness of high-intensity interval training combined with resistance training versus continuous moderate-intensity training combined with resistance training in patients with type 2 diabetes: A one-year randomized controlled trial

AIMS

To evaluate the impact of one-year high intensity interval training (HIIT) combined with resistance training (RT) vs continuous moderate intensity training (MCT) combined with RT on glycaemic control, body composition and cardiorespiratory fitness (CRF) in patients with type 2 diabetes.

MATERIALS AND METHODS

A randomized controlled trial included 96 participants with type 2 diabetes for a one-year supervised exercise intervention with three groups: Control, HIIT with RT and MCT with RT). The control group received standard counseling regarding general PA guidelines, with no structured exercise sessions. The main outcome variable was HbA1c (%). Secondary outcomes were other glycaemic variables, body composition, anthropometry measurements, CRF and enjoyment of exercise. Generalized estimating equations (GEE) were used to model outcomes.

RESULTS

Among the 96 participants enrolled in the intervention, 80 were randomized, with a mean (SD) age of 58.5 years (7.7) and a mean HbA1c of 7.2% (1.6). After adjusting the model for sex and total moderate-to-vigorous physical activity (MVPA), we found that both the MCT with RT (β, 0.003; P, 0.921) and the HIIT with RT (β, 0.025; P, 0.385) groups had no effect on HbA1c. A favourable effect was observed in the MCT with RT group, with a reduction in whole body fat index (β, -0.062; P, 0.022), android fat index (β, -0.010; P, 0.010) and gynoid fat index (β, -0.013; P, 0.014). Additionally, CRF increased during the intervention, but only in the MCT with RT group (β, 0.185; P, 0.019).

CONCLUSIONS

The results from this study suggest that there was no effect of either MCT with RT or HIIT with RT on glycaemic control in individuals with type 2 diabetes. However, the combination of MCT and RT improved body composition and CRF following a one-year intervention.

High-intensity exercise training ameliorates aberrant expression of markers of mitochondrial turnover but not oxidative damage in skeletal muscle of men with essential hypertension

AIM

To examine whether hypertensive individuals exhibit altered muscle mitochondrial turnover and redox homeostasis compared with healthy normotensive counterparts, and whether the antihypertensive effect of high-intensity exercise training is associated with improved mitochondrial quality and enhanced anti-oxidant defence.

METHODS

In a cross-sectional and longitudinal parallel design, 24 essential hypertensive (HYP) and 13 healthy normotensive (NORM) men completed 6 weeks of high-intensity interval training (HIIT). Twenty four-hour ambulatory blood pressure, body composition, cardiorespiratory fitness, exercise capacity and skeletal muscle characteristics were examined before and after HIIT. Expression of markers of mitochondrial turnover, anti-oxidant protection and oxidative damage was determined in vastus lateralis muscle biopsies. Muscle protein levels of eNOS and VEGF, and muscle capillarity were also evaluated.

RESULTS

At baseline, HYP exhibited lower expression of markers of mitochondrial volume/biogenesis, mitochondrial fusion/fission and autophagy along with depressed eNOS expression compared with NORM. Expression of markers of anti-oxidant protection was similar in HYP and NORM, whereas oxidative damage was higher in HYP than in NORM. In HYP, HIIT lowered blood pressure, improved body composition, cardiorespiratory fitness and exercise capacity, up-regulated markers of mitochondrial volume/biogenesis and autophagy and increased eNOS and VEGF protein content. Furthermore, in HYP, HIIT induced divergent responses in markers of mitochondrial fusion and anti-oxidant protection, did not affect markers of mitochondrial fission, and increased apoptotic susceptibility and oxidative damage.

CONCLUSION

The present results indicate aberrant muscle mitochondrial turnover and augmented oxidative damage in hypertensive individuals. High-intensity exercise training can partly reverse hypertension-related impairments in muscle mitochondrial turnover, but not redox imbalance.

High-Intensity Interval Training in Patients with Type 2 Diabetes Mellitus: a Systematic Review

PURPOSE OF REVIEW

High-intensity exercise may beneficially impact on insulin sensitivity. However, there is still uncertainty on the actual impact of high-intensity interval training (HIIT) on chronic physiologic adaptations among patients with type 2 diabetes mellitus (T2DM). We aimed to systematically search and appraise the evidence base on the effects of HIIT in comparison to mild- or moderate-intensity interval training (MMIIT) on glycemic control inT2DM.

RECENT FINDINGS

A total of 5 RCT met the inclusion criteria. Most studies presented significant differences for weight and BMI with HIIT, and with both interventions for total body fat. For the other health-related variables (systolic and diastolic BP, fasting cholesterol, LDL and HDL, triglycerides, fasting glucose, and HbAc1), only 1 study provided detailed results for HIIT, showing significant differences for systolic BP and HDL cholesterol in 2 studies, total cholesterol, LDL, and triglycerides, whereas for MIIT, only 1 study brought significant differences for LDL cholesterol. For glucose levels, significant differences were reported in 4 studies for both HIIT and MMIT, but only two studies used the percentage delta assessment tool, whereas 1 study only showed significant improvements for HIIT. The number of studies for the analysis is not precise as to the statements regarding the results of the intervention proposed for this public, since they do not allow identifying a consistency of the findings, not presenting diversity between the training methods and the different methods of volume control and intensity of training.

Effects of HIIT and MICT on cardiovascular risk factors in adults with overweight and/or obesity: A meta-analysis

Objective

The purpose of this study was to evaluate the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on cardiovascular disease (CVD) risk factors in adults with overweight and obesity.

Methods

Twenty-two articles were included by searching six databases, the total number of subjects was 620 in these articles. Outcomes were synthesised using a random-effects meta-analysis of the Standardized mean difference (SMD) in CVD risk factors.

Results

HIIT and MICT resulted in statistically significant reductions in Weight, BMI, fat%, total cholesterol(TC), and improvement in VO_2max. Compared with MICT, subgroup of durations of HIIT training interval ≥2 min can significantly increase VO_2max (SMD = 0.444, 95% CI:0.037~0.851,P = 0.032), subgroup of energy expenditure of HIIT equal to MICT can significantly increase VO_2max (SMD = 0.399, 95% CI:0.106~0.692,P = 0.008).

Conclusions

HIIT appears to provide similar benefits to MICT for improving body composition, VO_2maxand TC, but HIIT spent less time than MICT by 9.7 min on one session. HIIT is superior to MICT in improving cardiopulmonary fitness when durations of HIIT training interval ≥2 min or energy expenditure of HIIT same as MICT. PROSPERO ID: CRD42016045835.

Exercise training for patients with type 2 diabetes and cardiovascular disease: What to pursue and how to do it. A Position Paper of the European Association of Preventive Cardiology (EAPC)

Patients with type 2 diabetes mellitus suffer from dysregulation of a plethora of cardiovascular and metabolic functions, including dysglycaemia, dyslipidaemia, arterial hypertension, obesity and a reduced cardiorespiratory fitness. Exercise training has the potential to improve many of these functions, such as insulin sensitivity, lipid profile, vascular reactivity and cardiorespiratory fitness, particularly in type 2 diabetes mellitus patients with cardiovascular comorbidities, such as patients that suffered from an acute myocardial infarction, or after a coronary intervention such as percutaneous coronary intervention or coronary artery bypass grafting. The present position paper aims to provide recommendations for prescription of exercise training in patients with both type 2 diabetes mellitus and cardiovascular disease. The first part discusses the relevance and practical applicability of treatment targets that may be pursued, and failure to respond to these targets. The second part provides recommendations on the contents and methods to prescribe exercise training tailored to these treatment targets as well as to an optimal preparation and dealing with barriers and risks specific to type 2 diabetes mellitus and cardiac comorbidity.

Effect of all-extremity high-intensity interval training vs. moderate-intensity continuous training on aerobic fitness in middle-aged and older adults with type 2 diabetes: A randomized controlled trial

Aging and diabetes are associated with decreased aerobic fitness, an independent predictor of mortality. Aerobic exercise is prescribed to improve aerobic fitness; however, middle-aged/older diabetic patients often suffer from mobility limitations which restrict walking. Non-weight-bearing/low-impact exercise is recommended but the optimal exercise prescription is uncertain. The goal of this randomized controlled trial was twofold: 1) to test if high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT), implemented on a non-weight-bearing all-extremity ergometer, are feasible, well-tolerated and safe in middle-aged/older adults with type 2 diabetes; and 2) to test whether all-extremity HIIT is more effective in improving aerobic fitness than MICT. A total of 58 sedentary individuals with type 2 diabetes (46 to 78 years; 63 ± 1) were randomized to all-extremity HIIT (n = 23), MICT (n = 19) or non-exercise control (CONT; n = 16). All-extremity HIIT and MICT, performed 4×/week for 8 weeks under supervision, resulted in no adverse events requiring hospitalization or medical treatment. Aerobic fitness (VO_2peak) improved by 10% in HIIT and 8% in MICT and maximal exercise tolerance increased by 1.8 and 1.3 min, respectively (P ≤ 0.002 vs. baseline; P ≥ 0.9 for HIIT vs. MICT). In conclusion, all-extremity HIIT and MICT are feasible, well-tolerated and safe and result in similar improvements in aerobic fitness in middle-aged/older individuals with type 2 diabetes. These findings have important implications for exercise prescription for diabetic patients; they indicate that all-extremity exercise is a feasible alternative to weight-bearing exercise and those who are unable or unwilling to engage in HIIT may receive similar benefits from MICT.

Glycemic, inflammatory and oxidative stress responses to different high-intensity training protocols in type 1 diabetes: A randomized clinical trial

AIMS

To investigate the effects of high-intensity interval training (HIIT) and/or strength training (ST) on inflammatory, oxidative stress (OS) and glycemic parameters in type 1 diabetes (T1DM) patients.

METHODS

After a 4-week control period, volunteers were randomly assigned to 10-week HIIT, ST or ST + HIIT protocol, performed 3×/week. Blood biochemistry, anthropometric, strength and cardiopulmonary fitness variables were assessed. Outcomes were analyzed via generalized estimating equations (GEE), with Bonferroni post hoc analysis.

RESULTS

ST, HIIT and ST + HIIT improved glycemic (HbA_1c and fasting glucose) and antioxidant parameters (total antioxidant capacity, catalase and superoxide dismutase activities), but not plasma inflammatory (C-reactive protein, TNF-α and IL-10) or OS markers (thiobarbituric acid-reactive substances, 8-hydroxy-2-deoxyguanosine and oxLDL) levels. Noteworthy, interventions reduced soluble receptors for advanced glycation end products levels. However, intracellular heat shock protein 70 content increased only after HIIT. While daily insulin dosage decreased only in the ST + HIIT group, all training models induced anthropometric and functional benefits.

CONCLUSIONS

Similar benefits afforded by ST, HIIT or ST + HIIT in T1DM people are associated with enhanced antioxidant systems and glucose-related parameter, even in a few weeks. From a practical clinical perspective, the performance of ST + HIIT may be advised for additional benefits regarding insulin dosage reduction.

Prescribing high-intensity interval exercise by RPE in individuals with type 2 diabetes: metabolic and hemodynamic responses

We tested the hypothesis that rating of perceived exertion (RPE) is a tool as efficient as the heart rate (HR) response to the cardiopulmonary exercise test (CPX) for prescribing and self-regulating high-intensity interval exercise (HIIE), and that metabolic and hemodynamic response to HIIE is superior than to continuous moderate-intensity exercise (MICE) in individuals with type 2 diabetes mellitus (T2DM). Eleven participants (age = 52.3 ± 3 years) underwent HIIE prescribed and self-regulated by RPE (HIIE_RPE; 25 min), HIIE prescribed and regulated by an individual's HR response to CPX (HIIE_HR; 25 min), MICE prescribed and self-regulated by RPE (30 min) and control (30 min of seated resting) intervention in random order. HR, blood pressure (BP), capillary glucose, endothelial reactivity, and carotid-femoral pulse wave velocity were assessed before, immediately after, and 45 min after each intervention. Exercise HR, speed, and distance were measured during exercise sessions. Twenty-four-hour ambulatory BP was measured after each intervention. Exercise HR, speed, and distance were similar between HIIE_RPE and HIIE_HR. BP response was not different among HIIE_RPE, HIIE_HR, and MICE. Capillary glycaemia reduction was greater (P < 0.05) after HIIE_RPE (48.6 ± 9.6 mg/dL) and HIIE_HR (47.2 ± 9.5 mg/dL) than MICE (29.5 ± 11.5 mg/dL). Reduction (P < 0.05) in 24-h (6.7 ± 2.2 mm Hg) and tendency toward reduction (P = 0.06) in daytime systolic (7.0 ± 2.5 mm Hg) ambulatory BP were found only after HIIE_RPE. These results suggest that HIIE is superior to MICE for reducing glycaemia and ambulatory BP, and that the 6-20 RPE scale is a useful tool for prescribing and self-regulating HIIE in individuals with T2DM.

Effects of Polarized Training on Cardiometabolic Risk Factors in Young Overweight and Obese Women: A Randomized-Controlled Trial

Introduction: Volume and intensity are major variables governing exercise training-mediated beneficial effects in both athletes and patients. Although polarized endurance training optimizes and maximizes physiological gains in highly trained individuals, its cardiometabolic protective-effects have not been established. The purpose of the present single site, randomized-controlled trial was to compare the effects of 12-weeks of high-intensity interval training (HIIT), moderate-intensity continuous training (MICT), and polarized volume training (POL) programs on cardiometabolic risk factors in young overweight and obese women.

Materials and Methods: A total of 64 overweight/obese young women (age 23.3 ± 3.8 years, body mass index 33.8 ± 3.8 kg/m²) were randomly assigned to four groups: control group (CTRL), polarized volume training group, moderate-intensity endurance training group, and HIIT group. The cardiorespiratory capacity, glycemic and lipid profiles, whole-body substrate utilization, and body composition were assessed before and after the intervention.

Results: After the intervention, VO_2peak and power output at VO_2peak increased in all exercised-groups (time effect: p < 0.0001). Power output at VT1 was increased only in the POL group compared to the CTRL group (p = 0.019). Relative fold changes in fasting plasma glucose concentrations decreased only in POL group (p = 0.002). Training induced a significant increase in relative fat oxidation in all the groups (time effect: p < 0.001). Relative fat oxidation increased only in the POL group compared to the CTRL group (training effect: p = 0.032).

Conclusion: Twelve-weeks of polarized volume training showed overall superior effects on cardiorespiratory fitness, basal glycemic control, and substrate oxidation in comparison to MICT and HIIT training modalities. These data suggest that polarized volume training is an effective non-pharmacological treatment strategy for reducing cardiovascular disease risk factors in young overweight and obese women. The trial is registered at ISRCTN, number ISRCTN34421723.

The effects of upper and lower limb exercise on the microvascular reactivity in limited cutaneous systemic sclerosis patients

BACKGROUND

Aerobic exercise in general and high-intensity interval training (HIIT) specifically is known to improve vascular function in a range of clinical conditions. HIIT in particular has demonstrated improvements in clinical outcomes, in conditions that have a strong macroangiopathic component. Nevertheless, the effect of HIIT on microcirculation in systemic sclerosis (SSc) patients is yet to be investigated. Therefore, the purpose of the study was to compare the effects of two HIIT protocols (cycle and arm cranking) on the microcirculation of the digital area in SSc patients.

METHODS

Thirty-four limited cutaneous SSc patients (65.3 ± 11.6 years old) were randomly allocated in three groups (cycling, arm cranking and control group). The exercise groups underwent a 12- week exercise program twice per week. All patients performed the baseline and post-exercise intervention measurements where physical fitness, functional ability, transcutaneous oxygen tension (ΔTcpO2), body composition and quality of life were assessed. Endothelial-dependent as well as -independent vasodilation were assessed in the middle and index fingers using LDF and incremental doses of acetylcholine (ACh) and sodium nitroprusside (SNP). Cutaneous flux data were expressed as cutaneous vascular conductance (CVC).

RESULTS

Peak oxygen uptake increased in both exercise groups (p < 0.01, d = 1.36). ΔTcpO2 demonstrated an increase in the arm-cranking group only, with a large effect, but not found statistically significant,(p = 0.59, d = 0.93). Endothelial-dependent vasodilation improvement was greater in the arm-cranking (p < 0.05, d = 1.07) in comparison to other groups. Both exercise groups improved life satisfaction (p < 0.001) as well as reduced discomfort and pain due to Raynaud's phenomenon (p < 0.05). Arm cranking seems to be the preferred mode of exercise for study participants as compared to cycling (p < 0.05). No changes were observed in the body composition or the functional ability in both exercise groups.

CONCLUSIONS

Our results suggest that arm cranking has the potential to improve the microvascular endothelial function in SSc patients. Also notably, our recommended training dose (e.g., a 12-week HIIT program, twice per week), appeared to be sufficient and tolerable for this population. Future research should focus on exploring the feasibility of a combined exercise such as aerobic and resistance training by assessing individual's experience and the quality of life in SSc patients.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT number): NCT03058887 , February 23, 2017.

Exercise training and endothelial function in patients with type 2 diabetes: a meta-analysis

BACKGROUND AND AIMS

Exercise training is considered a cornerstone in the management of type 2 diabetes, which is associated with impaired endothelial function. However, the association of exercise training with endothelial function in type 2 diabetes patients has not been fully understood. This meta-analysis aimed to investigate their associations with focus on exercise types.

METHODS

Databases were searched up to January 2018 for studies evaluating the influences of exercise training with durations ≥ 8 weeks on endothelial function assessed by flow-mediated dilation (FMD) among type 2 diabetes patients or between type 2 diabetics and non-diabetics. Data were pooled using random-effects models to obtain the weighted mean differences (WMDs) and 95% confidence intervals (CIs).

RESULTS

Sixteen databases were included. Exercise training resulted in an overall improvement in FMD by 1.77% (95% CI 0.94-2.59%) in type 2 diabetes patients. Specifically, both aerobic and combined aerobic and resistance exercise increased FMD by 1.21% (95% CI 0.23-2.19%) and 2.49% (95% CI 1.17-3.81%), respectively; but resistance exercise only showed a trend. High-intensity interval aerobic exercise did not significantly improve FMD over moderate-intensity continuous exercise. Notably, the improvement in FMD among type 2 diabetes patients was smaller compared with non-diabetics in response to exercise training (WMD - 0.72%, 95% CI - 1.36 to - 0.08%) or specifically to aerobic exercise (WMD - 0.65%, 95% CI - 1.31 to 0.01%).

CONCLUSIONS

Exercise training, in particular aerobic and combined exercise, improves endothelial function in type 2 diabetes patients, but such an improvement appears to be weakened compared with non-diabetics. Trial registration PROSPERO CRD42018087376.

Achieving ADA/ISPAD clinical guideline goals is associated with higher insulin sensitivity and cardiopulmonary fitness in adolescents with type 1 diabetes: Results from RESistance to InSulin in Type 1 ANd Type 2 diabetes (RESISTANT) and Effects of MEtformin on CardiovasculaR Function in AdoLescents with Type 1 Diabetes (EMERALD) Studies

OBJECTIVE

Most youth with type 1 diabetes do not meet the American Diabetes Association (ADA) and International Society for Pediatric and Adolescent Diabetes (ISPAD) targets for hemoglobin A1c (HbA1c), blood pressure (BP), lipids, and body mass index (BMI). We hypothesized that ISPAD/ADA goal achievement would be associated with better insulin sensitivity (IS) and cardiopulmonary fitness.

METHODS

IS was quantified as glucose infusion rate (GIR) from a hyperinsulinemic-euglycemic clamp in youth with type 1 diabetes from the RESistance to InSulin in Type 1 ANd Type 2 diabetes (RESISTANT) (n = 86) and Effects of MEtformin on CardiovasculaR Function in AdoLescents with Type 1 Diabetes (EMERALD) (n = 41) cohorts (n = 127; age 15.7 ± 2.2 years, 52% girls). Cardiopulmonary fitness was measured as peak oxygen consumption (VO₂ peak/kg) during upright (RESISTANT) or supine (EMERALD) cycle ergometry and were stratified by cycle type. Goal achievement was defined as HbA1c < 7.5%, BP < 90th percentile, LDL-cholesterol < 100 mg/dL, HDL-cholesterol > 35 mg/dL, triglycerides < 150 mg/dL and BMI < 85th percentile. Participants were stratified into 3 groups: achieving 0-3 goals (n = 52), 4 goals (n = 48), and 5-6 goals (n = 27). Differences between groups were examined with generalized linear models.

RESULTS

IS was lower in youth who met 0-3 goals (5.2 ± 3.4 mg/kg/min) vs those who met 4 goals (7.4 ± 4.1 mg/kg/min, P = .04) and those who met 5-6 goals (8.5 ± 4.3 mg/kg/min, P = .003), and remained significant after adjustments for sex and diabetes duration. Upright VO₂ peak was lower in youth who met 0-3 goals (25.8 ± 4.6 mL/kg/min) vs those who met 4 goals (33.0 ± 7.8 mL/kg/min, P = .01) and those who met 5-6 goals (33.2 ± 4.4 mL/kg/min, P = .004). Similar and significant relationships were observed in EMERALD participants for supine VO₂ peak.

CONCLUSIONS

ADA/ISPAD goal achievement was associated with greater IS and cardiopulmonary fitness.

High-intensity interval training versus continuous training on physiological and metabolic variables in prediabetes and type 2 diabetes: A meta-analysis

AIMS

To compare the effects of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) on functional capacity and cardiometabolic markers in individuals prediabetes and type 2 diabetes (T2D).

METHODS

The search was performed in PubMed (MEDLINE), EMBASE, PEDro, CENTRAL, Scopus, LILACS database, and Clinical Trials from the inception to July 2017, included randomized clinical trials that compared the use of HIIT and MICT in prediabetes and T2D adults. The risk of bias was defined by Cochrane Handbook and quality of evidence by GRADE.

RESULTS

From 818 relevant records, seven studies were included in systematic review (64 prediabetes and 120 T2D patients) and five with T2D were meta-analyzed. HIIT promoted significantly increased of 3.02 mL/kg/min (CI95% 1.42-4.61) of VO₂max, measured for functional capacity, compared to MICT. No differences were found between two modalities of exercises considering the outcomes HbA1c, systolic and diastolic blood pressure, total cholesterol, HDL and LDL cholesterol, triglycerides, BMI, and waist-to-hip ratio. Most of the studies presented unclear risk of bias, and low and very low quality of evidence.

CONCLUSION

HIIT induces cardiometabolic adaptations similar to those of MICT in prediabetes and T2D, and provides greater benefits to functional capacity in patients with T2D.

PROSPERO

CRD42016047151.