High-Intensity Interval Training Versus Research Articles

A Comparative Study: Cardioprotective Effects of High-Intensity Interval Training Versus Ischaemic Preconditioning in Rat Myocardial Ischaemia-Reperfusion.

(1) Background: Years of research have identified ischemic preconditioning (IPC) as a crucial endogenous protective mechanism against myocardial ischemia-reperfusion injury, enhancing the myocardial cell's tolerance to subsequent ischemic damage. High-intensity interval training (HIIT) is promoted by athletes because it reduces exercise duration and improves metabolic response and cardiopulmonary function. Our objective was to evaluate and compare whether HIIT and IPC could reduce myocardial ischemia and reperfusion injury in rats. (2) Methods: Male Sprague-Dawley rats were divided into four groups: sham surgery, coronary artery occlusion (CAO), high-intensity interval training (HIIT), and ischemic preconditioning (IPC). The CAO, HIIT, and IPC groups experienced 40 min of coronary artery occlusion followed by 3 h of reperfusion to induce myocardial ischemia-reperfusion injury. Subsequently, the rats were sacrificed, and blood samples along with cardiac tissues were examined. The HIIT group received 4 weeks of training before surgery, and the IPC group underwent preconditioning before the ischemia-reperfusion procedure. (3) Results: The HIIT and IPC interventions significantly reduced the extent of the myocardial infarction size and the levels of serum troponin I and lactate dehydrogenase. Through these two interventions, serum pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6, were significantly decreased, while the anti-inflammatory cytokine IL-10 was increased. Furthermore, the expression of pro-apoptotic proteins PTEN, caspase-3, TNF-α, and Bax in the myocardium was reduced, and the expression of anti-apoptotic B-cell lymphoma 2 (Bcl-2) was increased, ultimately reducing cellular apoptosis in the myocardium. In conclusion, both HIIT and IPC demonstrated effective strategies with potential for mitigating myocardial ischemia-reperfusion injury for the heart.

High-intensity Interval Training Versus Moderate-intensity Interval Training: Anthropometrics, Inflammation, Stress Markers And Exercise Enjoyment

High-intensity Interval Training Versus Moderate-intensity Interval Training: Anthropometrics, Inflammation, Stress Markers And Exercise Enjoyment

High-Intensity Interval Training Versus Moderate-Intensity Continuous Training for Improving Physical Health in Elderly Women.

In elderly women, a lack of regular physical exercise may result in faster decreases in general health and functional performance. Although high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) have been effectively applied in young and clinical groups, there is no evidence to support their use in elderly women to achieve health benefits. Thus, the major goal of this study was to investigate how HIIT affected health-related outcomes in elderly women. Twenty-four inactive elderly women agreed to participate in the 16-week HIIT and MICT intervention. Body composition, insulin resistance, blood lipids, functional capacity, cardiorespiratory fitness, and quality of life were all measured before and after the intervention. The number of differences between groups was determined using Cohen's effect sizes, and the pre-post intra-group changes were compared using paired t-tests. Using 2 × 2 ANOVA, the time × group interaction effects between HIIT and MICT were evaluated. Body fat percentage, sagittal abdominal diameter, waist circumference, and hip circumference all were improved significantly in the 2 groups. HIIT substantially improved fasting plasma glucose and cardiorespiratory fitness as compared to the MICT. HIIT improved the lipid profile and functional ability more significantly compared to the MICT group. These findings show that HIIT is a useful exercise for improving elderly women's physical health.

The Comparison of High-Intensity Interval Training Versus Moderate-Intensity Continuous Training after Coronary Artery Bypass Graft: A Systematic Review of Recent Studies.

Currently, no international consensus on cardiac rehabilitation exists, leading to great variability in the intensity recommendations for training programs for cardiac patients, including those undergoing coronary artery bypass graft surgery (CABG). While some countries prefer the high-intensity interval training (HIIT) method to improve cardiorespiratory fitness, other countries opt for moderate-intensity continuous training (MICT). The aim of this systematic review was to compare the effects of HIIT and MICT on aerobic fitness and quality of life (QoL) in patients undergoing CABG with the intention of providing support for a consensus on exercise therapy. Methods: A systematic review of randomized controlled trials (RCTs) was conducted using the online publication databases PubMed, the Cochrane Library and the Bibliothèque nationale du Luxembourg (BnL) covering the last ten years to July 2022. Relevant identified studies respecting the inclusion/exclusion criteria were selected, screened and extracted by four reviewers. Furthermore, the methodological quality of the clinical trials was assessed using the PEDro scale, which was reinforced using the Cochrane Risk of Bias Tool for Randomized Trials (RoB2) for the evaluation of the risk of bias to provide more detail in the evaluation. The certainty of the evidence analysis was established using different levels of evidence in accordance with the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework. Results: A total of 379 patients from five RCTs diagnosed with coronary artery disease, including patients undergoing CABG, performed aerobic exercise over different time periods and were assessed based on peakVO2, VO2max and QoL. Overall, both training methods provided improvements in cardiorespiratory fitness and quality of life, with greater changes in HIIT groups. Conclusion: Both trainings methods provide improvements in cardiorespiratory fitness and QoL, with greater increases from HIIT. The moderate quality of evidence supports the use of HIIT and MICT to improve cardiorespiratory fitness and QoL.

High Intensity Interval Training Versus Circuit Weight Training on Glycated Hemoglobin in Type 2 Diabetic Patients

High Intensity Interval Training Versus Circuit Weight Training on Glycated Hemoglobin in Type 2 Diabetic Patients

Effect of High-Intensity Interval Training Versus Small-Sided Games Training on Sleep and Salivary Cortisol Level.

The authors compared sleep quality and salivary cortisol concentration after high-intensity interval training (HIIT) and small-sided games (SSGs) performed at the habitual training time in nonprofessional male soccer players. A total of 32 players (age = 24 [6]y, height = 1.77 [0.06]m, and body mass = 75 [12]kg) were randomized into an HIIT group or an SSG group. Actual sleep time, sleep efficiency (SE), sleep latency, immobility time (IT), moving time (MT), and fragmentation index were monitored using actigraphy before (PRE) and 2 nights after (POST 1 and POST 2) the training session. Salivary cortisol levels were measured before (PRE) and after (POST) training. Cortisol awakening response was evaluated. Significant intragroup differences in the HIIT group were noted for actual sleep time (P < .0001), SE (P < .0001), sleep latency (P = .047), IT (P < .0001), MT (P < .0001), and fragmentation index (P < .0001) between PRE and POST 1 and for SE (P = .035), IT (P = .004), MT (P = .006), and fragmentation index (P = .048) between PRE and POST 2. Intergroup differences for actual sleep time (P = .014), SE (P = .048), IT (P < .0001), and MT (P = .046) were observed between the HIIT and the SSGs group at POST 1 were detected. Significant intragroup variations were observed in PRE and POST salivary cortisol levels (P < .0001 for HIIT; P = .0003 for SSGs) and cortisol awakening response (P < .0001 for HIIT; P < .0001 for SSGs). Significant intergroup differences between the HIIT and the SSGs group were found at POST (P < .0001) and in cortisol awakening response (P = .017). Changes in actigraphy-based sleep parameters and salivary cortisol levels were greater after an acute session of HIIT than SSGs in this sample of nonprofessional male soccer players.

Effect of High-Intensity Interval Training Versus Moderate-Intensity Aerobic Continuous Training on Galectin-3 Gene Expression in Postmenopausal Women: A Randomized Controlled Trial.

Galectin-3 is a pro-inflammatory biomarker associated with the pathogenesis of heart failure (HF). Physical-activity reduces the risk of heart-failure by modification of inflammation and fibrosis. The purpose of this study was to compare the effects of 8 weeks of high-intensity interval training (HIIT) versus moderate-intensity aerobic continuous training on a predictive factor of HF in postmenopausal women. Thirty sedentary postmenopausal women were randomly assigned to three groups. The first group performed the HIIT program at 60%-90%, and the second group performed an exercise program at 50%-65% of HR reserve. The control group maintained their normal daily regular physical activity level. The gene expressions of galectin-3 and lipid profiles were measured at the baseline and the end of Week 8. The HIIT and moderate-intensity aerobic continuous training attenuated the gene expression of galectin-3, serum low-density lipoprotein, cholesterol, and triglyceride concentrations and enhanced high-density lipoprotein concentrations. These changes were considerably higher in the HIIT group. Our results show that HIIT is superior to moderate-intensity aerobic continuous training in improving the decrease in HF risk in postmenopausal women.

The Effects Of High Intensity Interval Training Versus Moderate Intensity Continuous Training On Energy Compensation

To determine the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on energy compensation in response to 12-weeks of supervised aerobic exercise. After a 4 wk lead in period of 3x/wk of MICT, subjects (N = 24) were randomly assigned into: HIIT or MICT, for an additional 8 wks. HIIT included a 10x1 min protocol 3x/wk and MICT included 30 min of exercise 5x/wk. Subjects completed both stationary cycling and inclined treadmill exercise. 13 participants (1 M, 12 F) were randomized into the HIIT group (28.0 ± 9.7 yr; BMI = 23.9 ± 3.9 kg/m2; VO2max = 29.0 ± 6.0 ml/kg/min). 11 participants (2 M, 9 F) were randomized into the MICT group (26.0 ± 6.9 yr; BMI = 27.4 ± 8.7 kg/m2; VO2max = 26.2 ± 7.3 ml/kg/min). Resting metabolic rate (RMR), body composition, and maximal oxygen uptake (VO2max) were measured at baseline and after 4 and 12 wks. Physical activity and dietary intake were measured for 7-day periods pre-intervention and during wks 5 and 12. Compensation was calculated through caloric equivalents of fat and lean mass compared to cumulative total exercise energy expenditure. 5 of 11 in MICT and 6 of 13 in HIIT were categorized as compensators. Change in fat mass (kg) (MICT: -0.59 ± 1.89, HIIT: -0.03 ± 1.72, p=0.45), change in weight (kg) (MICT: +0.66 ± 2.11, HIIT: -0.54 ± 1.45, p=0.12), and overall compensation (kcal) (MICT: 3111 ± 17220, HIIT: 3870 ± 15911, p=0.91) were similar between exercise groups. The difference between actual and predicted weight loss was greater for MICT (-1.61 ± 2.15 kg) than HIIT (-0.07 ± 1.45 kg, p=0.049). Potential compensatory variables including changes in RMR, VO2max, daily steps, and sedentary time were not different between the compensator and non-compensator groups (P > 0.05). Mean energy and macronutrient intake did not differ among all participants, by exercise intervention group, or by compensation status (P > 0.05). Both HIIT and MICT led to a similar percentage (~45%) of participants compensating for the exercise intervention. Despite the large difference in cumulative exercise training time (480 vs 1200 min, HIIT vs MICT), body fat and weight changes were similar between groups. Finally, our data suggests that HIIT may elicit weight loss that is closer to that predicted by exercise energy expenditure when compared to MICT.

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

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. 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), 3.7mmHg [95% CI = 2.57, 4.82], p < 0.00001; and HIIT: MD, 5.64mmHg [95% CI = 1.69, 9.52], p = 0.005) and in DBP (MICT: MD, 2.41mmHg [95% CI = 1.09, 3.72], p = 0.0003; and HIIT: MD, 4.8mmHg [95% CI = 2.9, 6.7], p < 0.00001) compared with the control group. No differences were found in the SBP values (MD, 1.13mmHg [95% CI = - 0.01, 2.27], p = 0.05); however, differences were found between groups in DBP (MD, 1.63mmHg [95% CI = 0.83, 2.44], p = 0.0001). In the secondary outcome, both interventions increased VO2max in comparison with control groups (MICT: MD, 1.30ml/kg/min [95% CI = 0.92, 1.68], p < 0.00001; and HIIT: MD, 4.90ml/kg/min [95% CI = 3.77, 6.04], p < 0.00001), and HIIT promoted greater improvement than MICT (MD, 2.52ml/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.

Effect of High-Intensity Interval Training Versus Sprint Interval Training on Time-Trial Performance: A Systematic Review and Meta-analysis.

Two forms of interval training commonly discussed in the literature are high-intensity interval training (HIIT) and sprint interval training (SIT). HIIT consists of repeated bouts of exercise that occur at a power output or velocity between the second ventilatory threshold and maximal oxygen consumption (VO2max). SIT is performed at a power output or velocity above those associated with VO2max. The primary objective of this study is to systematically review published randomized and pair-matched trials to determine which mode of interval training, HIIT versus SIT, leads to a greater improvement in TT performance in active and trained individuals. The second objective of this review is to perform a subgroup analysis to determine if there is a distinction between HIIT programs that differ in work-bout duration. SPORTDiscus (1800-present) and Medline with Full Text (1946-present) were used to conduct a systematic literature search. Studies were selected for the review if they met the following criteria: (1) individuals (males and females) who were considered at least moderately trained (~ 3-h per week of activity) as specified by the authors of the included studies; (2) between the ages of 18 and 45years; (3) randomized or pair-matched trials that included a HIIT and a SIT group; (4) provided detailed information about the interval training program; (5) were at least 2weeks in duration; (6) included a TT test that required participants to complete a set distance. A total of 6 articles met the inclusion criteria for the subjective and objective analysis. The pooled analysis was based on a random-effects model. There was no difference in the change in TT performance when comparing all HIIT versus SIT (0.9%; 90% CI -1.2-1.9%, p = 0.18). However, subgroup analysis based on duration of work interval indicated a 2% greater improvement in TT performance following long-HIIT (≥4min) when compared to SIT. There was no difference in change in VO2max/peak oxygen consumption (VO2peak) between groups. There was a moderate effect (ES = 0.70) in favor of HIIT over SIT in maximal aerobic power (MAP) or maximal aerobic velocity (MAV). The results of the meta-analysis indicate that long-HIIT may be the optimal form of interval training to augment TT performance. Additional research that directly compares HIIT exercise differing in work-bout duration would strengthen these results and provide further insight into the mechanisms behind the observed benefits of long-HIIT.

Effects of High-Intensity Interval Training Versus Moderate-Intensity Continuous Training on Epicardial Fat Thickness and Endothelial Function in Hypertensive Metabolic Syndrome.

Background: Hypertension is common in patients with metabolic syndrome (MS), and it is an important risk factor for cardiovascular-related morbidity and mortality. Compared to moderate-intensity continuous training (MICT), high-intensity interval training (HIIT) is considered a time-efficient exercise strategy for cardiometabolic health. We compared the effects of HIIT and MICT on epicardial fat thickness (EFT) and endothelial function in patients with hypertensive MS. Methods: In total, 34 participants with hypertensive MS (mean age: 50.9 ± 7.9 years) were randomized to either the HIIT (n = 17) or MICT (n = 17) group. In the HIIT group, participants performed for 3 min at 40% heart-rate reserve (HRR), which was alternated with 3 min at 80% HRR, whereas participants in the MICT group performed at 60% of HRR thrice a week for 8 weeks. EFT was measured with echocardiography, and endothelial function was determined by quantifying endothelial progenitor cells (EPCs), nitric oxide (NO), and flow-mediated dilation (FMD). Results: After exercise training, patients in both the groups showed significantly decreased EFT (P < 0.001 and P < 0.01) and improved FMD (P < 0.001 and P < 0.01). NO (P < 0.05) and EPCs (CD34/KDR, P < 0.01; CD34/CD117, P < 0.05; CD34/CD133, P < 0.05) were significantly improved in the HIIT group, but not in the MICT group. In addition, HIIT had a greater effect than MICT on FMD (group difference, P < 0.05) and EFT (group difference, P < 0.05). Conclusions: Compared to MICT, HIIT seems to better improve FMD and EFT. This finding suggests that HIIT could be more effective than MICT in improving endothelial function in patients with hypertensive MS.

The Impact of High-Intensity Interval Training Versus Moderate-Intensity Continuous Training on Carotid Intima-Media Thickness and Ankle-Brachial Index in Middle-Aged Women.

Objective:Obesity has been linked to cardiovascular risk factors characterized by endothelial dysfunction and arterial wall thickening. Regular exercise training is recognized as a powerful tool to improve endothelial function and cardiovascular risk profile, but it is unknown which of high-intensity interval training or moderate-intensity continuous training is the best exercise.Materials and Methods:A total of 33 inactive and overweight women aged 40–50 years old and body mass index >27 kg/m2 were randomized to high-intensity interval training, moderate-intensity continuous training, or control. The exercise intervention consisted of 12 weeks of training and three supervised sessions per week. The moderate-intensity group was trained continuously for 47 min at 60–70% of maximal heart rate. High-intensity interval training consisted of four interval bouts of 4 min at 85%–95% of maximal heart rate with 3 min breaks at 50%–60% of maximal heart rate between the intervals. For all analyses, statistical significance was assigned at P < 0.05.Results:According to our findings, while carotid intima-media thickness decreased in both training groups, this reduction was not statistically significant. In the high-intensity training group, the right ankle-brachial index increased significantly (P = 0.007).Conclusion:Twelve weeks of exercise training, especially in high-intensity interval training, have led to improving lipid profiles and endothelial function, it can be said that regular and prolonged exercise can probably be a preventive factor in cardiovascular disease in overweight women.

Low-Volume High-Intensity Interval Training (HIIT) versus Moderate-Intensity Continuous Training on Body Composition, Cardiometabolic Profile and Physical Capacity in Older Women.

To compare the effect of low-volume HIIT to moderate-intensity aerobic training (MICT) on fat mass, cardiometabolic profile and physical capacity and confirm its feasibility in older women. Inactive older women (60-75 years) were randomly assigned to 8 weeks of either HIIT (75 min/week; n=9) or MICT (150 min/week; n=9). Body composition, fasting metabolic profile, cardiovascular risk (Framingham score), and physical capacity (senior fitness test, VO2peak) were assessed before and after the intervention. Feasibility was evaluated with completion rate (training compliance; dropout rate) and affective response (Feeling scale; pre- and post-exercise). Total cholesterol, non-HDL-C levels and the Framingham risk score decreased in both groups (all p≤0.03). Although VO2peak remained unchanged, the 6MWT distance increased (p<0.0001), irrespective of the group. Completion rate and affective responses were not different between groups (all p≥0.38). A short-term HIIT program is feasible and provides as much benefits as MICT in older women.

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.

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.

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.

The Effect of High Intensity Interval Training Versus Steady State Aerobic Training on Skin Microvascular Reactivity in Moderately Active Young Adults: A Pilot Study

A sedentary lifestyle is associated with endothelial dysfunction, leading to vascular pathology and impaired microvascular reactivity (MVR). Enhanced endothelial functioning has been seen in aerobically trained individuals. The purpose of this study was to determine if there was a differential training response of skin MVR in response to high intensity aerobic interval training (HIAIT) as compared to steady state aerobic training (SSAT). The study involved 16 moderately active male students (age: 20.93 &amp;plusmn; 5.05 yrs). They were randomly assigned to one of three groups; HIAIT, SSAT, and control group (CG). Baseline testing was performed to determine the VO2max, lactate threshold, blood pressure, body composition and a post-occlusive reactive hyperemia response (PORH) test was used to assess microvascular reactivity on the right palmer forearm using a moorVMS-Laser Doppler Flowmetry (LDF) These parameters were reassessed after three weeks (mid-point) and six-weeks (post intervention) weeks. Statistical significance was set at p&amp;le;0.05. There were no significant interactions between the variables measured in the three groups over time. There was a positive linear relationship in the SSAT group for PORHmax/time to peak (Tp) at baseline (r = 0.998, p = 0.039), midpoint (r = 0.992, p = 0.083), and the post intervention (r = 0.987, p = 0.103). Training in the SSAT group had improved PORHpeak at midpoint and post intervention time points (r = 0.999, p = 0.22; r = 1, p = 0.006; r = 1, p = 0.011). Training in either the HIAIT or the SSAT group had no significant effect on skin MVR in moderately active young adults. SSAT did display a positive linear relationship with PORHmax/Tp, and PORHpeak, which are variables influencing skin MVR.

The Effectiveness Of High-intensity Interval Training Versus Moderate-intensity Continuous Training On Cardiometabolic Risk Factors In Childhood Obesity: A Meta-analysis

Exercise training is mainly prescribed for obese children to decreased cardiometabolic risks, however, studies examining the difference between high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) are limited. PURPOSE: The purpose of this study was to determine if HIIT differentially impacted on cardiovascular risk factors compared with MICT in obese children. METHODS: The relevant literature was searched from the databases of PubMed, Web of Science, Embase, the Cochrane library, and CNKI, which was completed in September 2018. Only randomized controlled trials involving both HIIT and MICT on obese children were included, and studies involving only one intervention would be excluded. Two researchers independently performed literature screening, literature quality evaluation, and data extraction according to inclusion and exclusion criteria. RESULTS: A total of 9 study with 309 obese children were included. Compared with baseline, both HIIT and MICT can significantly reduce body weight (BW), body mass index, systolic blood pressure, diastolic blood pressure, and increase VO2peak. Similar results were also found with respect to fasting glucose (FG) and fasting insulin in HIIT, while MICT is not significant. HIIT showed a small but significant effect on BW (mean difference (MD): -0.797 kg, 95%CI -1.018 to -0.575, p = 0.0001), total cholesterol (standardized mean difference (SMD) = -0.877, 95%CI -1.733 to -0.022, 0.044), HOMA-IR (MD = -0.620 mmol/L, 95%CI -1.234 to -0.006, 0.048), FG (MD = -0.391 mmol/L, 95%CI -0.608 to -0.173, 0.001) compared than MICT did. The main difference between HIIT and MICT is that HIIT is more effective for VO2peak (MD: 3.364 ml/kg/min, 95% CI 1.902 to 4.826, p = 0.0001). CONCLUSIONS: Our meta-analysis of randomized controlled trails indicates that both HIIT and MICT can significantly reduce cardiovascular risk factors in obese children, while HIIT with greater improvement observed in cardiorespiratory fitness.

Effects of High-Intensity Interval Training Versus Moderate-Intensity Training on Cardiometabolic Health Markers in Individuals With Spinal Cord Injury: A Pilot Study.

Background: Recent studies in nondisabled individuals have demonstrated that low-volume high-intensity interval training (HIIT) can improve cardiometabolic health similar to moderate-intensity training (MIT) despite requiring 20% of the overall time commitment. To date, there have been no studies assessing the effects of HIIT for improving cardiometabolic health in individuals with SCI. Objectives: The primary purpose of this pilot study was to compare the effects of 6 weeks of low-volume HIIT vs MIT using arm crank ergometer exercise to improve body composition, cardiovascular fitness, glucose tolerance, blood lipids, and blood pressure in a cohort of individuals with longstanding SCI. Methods: Participants were randomized to 6 weeks of HIIT or MIT arm crank exercise training. Aerobic capacity, muscular strength, blood lipids, glucose tolerance, blood pressure, and body composition were assessed at baseline and 6 weeks post training. Results: Seven individuals (6 male, 1 female; n = 3 in MIT and n = 4 in HIIT; mean age 51.3 ± 10.5 years) with longstanding SCI completed the study. The preliminary findings from this pilot study demonstrated that individuals with SCI randomized to either 6 weeks of HIIT or MIT displayed improvements in (a) insulin sensitivity, (b) cardiovascular fitness, and (c) muscular strength (p < .05). However, MIT led to greater improvements in arm fat percent and chest press strength compared to HIIT (p < .05). Conclusion: No differences between MIT and HIIT were observed. Both conditions led to improvements in insulin sensitivity, aerobic capacity, muscle strength, and blood lipids in individuals with SCI. Future larger cohort studies are needed to determine if the shorter amount of time required from HIIT is preferable to current MIT exercise recommendations.

High-Intensity Interval Training Versus Moderate Intensity Combined Training (Resistance and Aerobic) for Improving Insulin-Related Adipokines in Type 2 Diabetic Women

Background: The impaired adipocytes secrete factors observed in diabetes contribute to insulin resistance. The purpose of the present study was to compare the effects of high-intensity interval versus moderate intensity combined resistance and aerobic training on some adipokines related to insulin resistance (interleukin-6 [IL-6], apelin, and monocyte chemoattractant protein 1 (MCP-1)) in women with type 2 diabetes. Methods: Fifty two females with type 2 diabetes (aged 45 - 60 years, the HbA1C value of 6.5% or above, and fasting blood glucose ≥ 126 mg/dL (7.0 mmol/L)) were assessed for eligibility. The participants were assigned to a HIIT group (n = 17), a combined resistance and aerobic training group (n = 17), and a control group (n = 18) randomly. The exercises included 10 weeks of combined training and HIIT. Results: TNF-α concentrations changed significantly in the HIIT (P = 0.001) and combined training (P = 0.015) groups. The same test revealed that the differences were significant for the IL-6 in the HIIT (P 0.05). The ANCOVA test showed no significant differences in apelin (F = 0.511, P = 0.12). Conclusions: The results highlight that exercise training, independent of the mode of training, is an effective strategy to improve some adipokines related to insulin resistance in women with type 2 diabetes.

Effects of High-Intensity Interval Training Versus Moderate-Intensity Continuous Training On Blood Pressure in Adults with Pre- to Established Hypertension: A Systematic Review and Meta-Analysis of Randomized Trials.

Aerobic exercise reduces blood pressure (BP), but it is unknown whether a high-intensity training approach can elicit a greater BP reduction in populations with elevated BP. This systematic review compared the efficacy of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) for reducing BP in adults with pre- to established hypertension. Five electronic databases (MEDLINE, EMBASE, CENTRAL, PEDro, and SPORTDiscus) were searched for randomized trials comparing the chronic effects of HIIT versus MICT on BP in individuals with resting systolic BP ≥ 130mmHg and/or diastolic BP ≥ 85mmHg and/or under antihypertensive medication. Random-effects modelling was used to compare changes from pre- to post-intervention in resting and ambulatory BP between HIIT and MICT. Changes from pre- to post-intervention in maximal oxygen uptake ([Formula: see text]O2max) between HIIT and MICT were also meta-analyzed. Data were reported as weighted mean difference (MD) and 95% confidence interval (CI). Ambulatory BP was excluded from the meta-analysis due to the limited number of studies (two studies). Comparing changes from pre- to post-intervention, no differences in resting systolic BP (MD - 0.22mmHg [CI 95%, - 5.36 to 4.92], p = 0.93, I2 = 53%) and diastolic BP (MD - 0.38mmHg [CI 95%, - 3.31 to 2.54], p = 0.74, I2 = 0%) were found between HIIT and MICT (seven studies; 164 participants). HIIT improved [Formula: see text]O2max to a greater magnitude than MICT (MD 2.13ml/kg/min [CI 95%, 1.00 to 3.27], p < 0.01, I2 = 41%) with similar completion rates of the intervention and attendance at the exercise training sessions (nine studies; 245 participants). Limited data were available to compare the incidence of adverse events between HIIT and MICT. HIIT and MICT provided comparable reductions in resting BP in adults with pre- to established hypertension. HIIT was associated with greater improvements in [Formula: see text]O2max when compared to MICT. Future randomized trials should investigate the efficacy of HIIT versus MICT for reducing ambulatory BP in adults with pre- to established hypertension. PROSPERO registration (2016: CRD42016041885).