High-intensity interval and moderate-intensity continuous training elicit similar enjoyment and adherence levels in overweight and obese adults

High-intensity interval training and medium-intensity continuous training may affect cognitive function through regulation of intestinal microbial composition and its metabolite LPS by the gut-brain axis

AIMS

The gut-brain axis is the communication mechanism between the gut and the central nervous system, and the intestinal flora and lipopolysaccharide (LPS) play a crucial role in this mechanism. Exercise regulates the gut microbiota composition and metabolite production (i.e., LPS). We aimed to investigate the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on cognitive function in C57BL/6 J mice through gut-brain axis regulation of gut microbiota composition and LPS displacement.

MAIN METHODS

C57BL/6 J male mice were randomly divided into sedentary, HIIT, and MICT groups. After 12 weeks of exercise intervention, the cognitive function of the brain and mRNA levels of related inflammatory factors were measured. RNA sequencing, Golgi staining, intestinal microbial 16 s rDNA sequencing, and ELISA were performed.

KEY FINDINGS

HIIT and MICT affect brain cognitive function by regulating the gut microbiota composition and its metabolite, LPS, through the gut microbiota-gut-brain axis. HIIT is suspected to have a risk: it can induce "intestinal leakage" by regulating intestinal permeability-related microbiota, resulting in excessive LPS in the blood and brain and activating M1 microglia in the brain, leading to reduced dendritic spine density and affecting cognitive function.

SIGNIFICANCE

This study revealed a potential link between changes in the gut microbiota and cognitive function. It highlighted the possible risk of HIIT in reducing dendritic spine density and affecting cognitive function.

Efficacy of Interval Training in Improving Body Composition and Adiposity in Apparently Healthy Adults: An Umbrella Review with Meta-Analysis

BACKGROUND

Although the efficacy of interval training for improving body composition has been summarized in an increasing number of systematic reviews in recent years, discrepancies in review findings and conclusions have been observed.

OBJECTIVE

This study aims to synthesize the available evidence on the efficacy of interval training compared with moderate-intensity continuous training (MICT) and nonexercise control (CON) in reducing body adiposity in apparently healthy adults.

METHODS

An umbrella review with meta-analysis was performed. A systematic search was conducted in seven databases (MEDLINE, EMBASE, Cochrane Database, CINAHL, Scopus, SPORTDiscus, and Web of Science) up to October 2023. Systematic reviews with meta-analyses of randomized controlled trials (RCTs) comparing interval training and MICT/CON were included. Literature selection, data extraction, and methodological quality assessment (AMSTAR-2) were conducted independently by two reviewers. Meta-analyses were performed using a random-effects model. Subgroup analyses were conducted based on the type of interval training [high-intensity interval training (HIIT) and sprint interval training (SIT)], intervention duration, body mass index, exercise modality, and volume of HIIT protocols.

RESULTS

Sixteen systematic reviews, including 79 RCTs and 2474 unique participants, met the inclusion criteria. Most systematic reviews had a critically low (n = 6) or low (n = 6) AMSTAR-2 score. Interval training demonstrated significantly greater reductions in total body fat percent (BF%) compared with MICT [weighted mean difference (WMD) of - 0.77%; 95% confidence interval (CI) - 1.12 to - 0.32%] and CON (WMD of - 1.50%; 95% CI - 2.40 to - 0.58%). Significant reductions in fat mass, visceral adipose tissue, subcutaneous abdominal fat, and android abdominal fat were also observed following interval training compared to CON. Subgroup analyses indicated that both HIIT and SIT resulted in superior BF% loss than MICT. These benefits appeared to be more prominent in individuals with overweight/obesity and longer duration interventions (≥ 12 weeks), as well as in protocols using cycling as a modality and low-volume HIIT (i.e., < 15 min of high-intensity exercise per session).

CONCLUSIONS

This novel umbrella review with large-scale meta-analysis provides an updated synthesis of evidence with implications for physical activity guideline recommendations. The findings support interval training as a viable exercise strategy for reducing adiposity in the general population.

Effects of different exercise modalities on inflammatory markers in the obese and overweight populations: unraveling the mystery of exercise and inflammation

In the realm of obesity and overweight, the risk of chronic diseases significantly escalates, closely intertwined with inflammatory factors. Research suggests that specific exercise interventions, particularly aerobic exercise and resistance exercise, can have beneficial effects on inflammation levels. However, debates persist regarding the actual impact of exercise in the obese and overweight population. We employed meta-analysis research methods and searched the China National Knowledge Infrastructure Wanfang Data, PubMed, and Web of Science databases to gather controlled experiments on the effects of resistance exercise or aerobic exercise on C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). Two researchers independently conducted literature screening and data extraction. The quality of the literature was assessed according to the Cochrane Handbook standards, and subgroup analyses of CRP, IL-6, and TNF-α were performed using RevMan 5.4 software. Through quantitative synthesis of results from 22 selected studies encompassing a total of 1,135 research subjects, this study systematically explored the specific regulatory effects of different exercise modalities on inflammatory markers in the obese and overweight population. The findings indicate that both aerobic exercise and resistance exercise effectively reduce CRP levels in obese individuals, with aerobic exercise demonstrating a more pronounced effect. Aerobic exercise also significantly lowers IL-6 levels, while the impact of resistance exercise on IL-6 is relatively minor. However, in terms of reducing TNF-α levels, neither modality appears to exert a significant effect. Overall, exercise, especially aerobic exercise, emerges as a positive regulator of inflammatory markers in the context of obesity and overweight.

Effects of 6-Week Motor-Cognitive Agility Training on Football Test Performance in Adult Amateur Players - A Three-Armed Randomized Controlled Trial

Agility, defined as the ability to rapidly respond to unforeseen events, constitutes a central performance component in football. Existing agility training approaches often focus on change of direction that does not reflect the complex motor-cognitive demands on the pitch. The objective of this study is to examine the effects of a novel motor-cognitive dual-task agility training (Multiple-object tracking integrated into agility training) on agility and football-specific test performance parameters, compared to agility and a change of direction (COD) training. Adult male amateur football players (n = 42; age: 27±6; height: 181±7cm; weight: 80±12kg) were randomly allocated to one of the three intervention groups (COD, agility, agility + multiple object tracking). The Loughborough Soccer Passing Test (LSPT), a dribbling test with/without cognitive task as well as the Random Star Run (with/without ball) and the modified T-Test were assessed before and after a 6-week training period. Time effects within the T-Test (F = 83.9; p < 0.001; η2 = 0.68) and dribbling test without cognitive task (F = 23.9; p < 0.001; η2 = 0.38) with improvements of all intervention groups (p < 0.05) were found. Dribbling with cognitive task revealed a time effect (F = 7.8; p = 0.008; η2 = 0.17), with improvements exclusively in the agility and dual-task agility groups (p < 0.05). Random Star Run with and without ball exhibited a time (F = 38.8; p < 0.001; η2 = 0.5; F = 82.7; p < 0.001; η2 = 0.68) and interaction effect (F = 14.14; p < 0.001; η2 = 0.42; F = 27.8; p < 0.001; η2 = 0.59), with improvements for the agility and dual-task agility groups. LSPT showed no time, group or interaction effect. The effects of change of direction training are limited to change of direction and dribbling test performance within preplanned scenarios. In contrast, motor-cognitive agility interventions result in notable enhancements in football-specific and agility tests, incorporating decision-making and multitasking components. No differences were observed between agility and agility + multiple object tracking. To achieve a transfer to game-relevant performance, coaches should focus on integrating cognitive challenges into motor training.

NLRP3 inflammasome and pyroptosis in cardiovascular diseases and exercise intervention

NOD-like receptor protein 3 (NLRP3) inflammasome is an intracellular sensing protein complex that possesses NACHT, leucine-rich repeat, and pyrin domain, playing a crucial role in innate immunity. Activation of the NLRP3 inflammasome leads to the production of pro-inflammatory cellular contents, such as interleukin (IL)-1β and IL-18, and induction of inflammatory cell death known as pyroptosis, thereby amplifying or sustaining inflammation. While a balanced inflammatory response is beneficial for resolving damage and promoting tissue healing, excessive activation of the NLRP3 inflammasome and pyroptosis can have harmful effects. The involvement of the NLRP3 inflammasome has been observed in various cardiovascular diseases (CVD). Indeed, the NLRP3 inflammasome and its associated pyroptosis are closely linked to key cardiovascular risk factors including hyperlipidemia, diabetes, hypertension, obesity, and hyperhomocysteinemia. Exercise compared with medicine is a highly effective measure for both preventing and treating CVD. Interestingly, emerging evidence suggests that exercise improves CVD and inhibits the activity of NLRP3 inflammasome and pyroptosis. In this review, the activation mechanisms of the NLRP3 inflammasome and its pathogenic role in CVD are critically discussed. Importantly, the purpose is to emphasize the crucial role of exercise in managing CVD by suppressing NLRP3 inflammasome activity and proposes it as the foundation for developing novel treatment strategies.

The effect of different high-intensity interval training protocols on cardiometabolic and inflammatory markers in sedentary young women: A randomized controlled trial

Few studies have reported the cardiovascular health effects of different high-intensity interval training (HIIT) protocols among sedentary young women. We investigated the impact of a traditional HIIT programme and a high-intensity circuit training (HICT) programme on lipid profiles and inflammatory cytokine levels in sedentary young women. Forty-two women were randomly assigned to HICT (body weight-based training), HIIT (cycling-based training), or control groups (n = 14 each). HICT and HIIT participants completed an 8-week training programme of three sessions per week. Total cholesterol (TC), triglyceride, high- and low-density lipoprotein, leptin, resistin, tumour necrosis factor-alpha (TNF-α), interleukin-8, and interferon-gamma levels were measured before and after the intervention. Post-intervention, TC and leptin were decreased in the HICT group. The HICT group also demonstrated increased lean mass, upper and lower limb strength, and balance, while the HIIT group displayed improved lower limb strength. Additionally, the control group showed significant increases in triglyceride levels, weight, body mass index, and fat mass. In conclusion, although both HICT and HIIT interventions showed improvements in cardiovascular health and physical fitness, participants in the HICT group experienced more health benefits.

Effect of High-Intensity Interval, Moderate-Intensity Continuous, and Self-Selected Intensity Training on Health and Affective Responses

Purpose: To compare the effects of 12-week high-intensity interval (HIIT), moderate-intensity continuous (MICT), and self-selected intensity training (SSIT) on health outcomes and affective responses. Methods: Seventy-three overweight/obese inactive adults (62% woman; age, 31.4 ± 7.2 years; height, 1.66 ± 0.09 cm; Body mass index, 28.9 ± 2.7 kg.m-2) who were randomized into HIIT (n = 23), MICT (n = 24) and SSIT (n = 26) groups. The training was conducted three times per week in an outdoor environment, with 4 weeks under direct supervision and 8 weeks with semi-supervision. Cardiorespiratory fitness, body composition, and metabolic profile were evaluated at baseline and at the end of the 4th and 12th weeks. Core affect was measured during all training sessions. Results: Peak oxygen uptake improved in all groups after 4 and 12 weeks compared with baseline. Only the SSIT had reductions in body fat throughout the intervention. No improvements were observed in the metabolic profile across all groups. SSIT was perceived as more pleasurable than HIIT; however, there were no differences in affective responses between SSIT and MICT. Affective responses in-task (e.g. negative and positive peak, rate of change and affect at the end of the exercise session) predicted the HIIT and SSIT exercises attendance rate. Conclusion: Regardless of the exercise training protocol, overweight/obese inactive adults improved health outcomes, which suggests the prescribing HIIT, MICT, and SSIT in outdoor environments. SSIT should be considered in order to optimize the pleasure during training sessions. Affective response more positive in-task of the HIIT and SSIT is associated with greater attendance rate in these exercise protocols.

Physiological and psychological outcomes of high intensity interval training in patients with heart failure compared to moderate continuous training and usual care: A systematic review with meta analysis

BACKGROUND

An important component of secondary prevention of CVD (including HF) is comprehensive cardiac rehab, including exercise. Novel, individualised approaches are needed to increase uptake and adherence to exercise programmes, one area offering potential is HIIT. HIIT has been shown to be both safe and effective for improving cardiovascular fitness in both coronary artery disease and HF patients.

OBJECTIVES

To provide a current and up to date evaluation of the physiological and psychological outcomes of HIIT in patients with HF compared to MCT and UC. Secondly to perform sub-group analyses comparing short and long HIIT protocols.

METHODS

A systematic review and meta-analysis of randomised controlled trials was undertaken. Medline, Embase, Scopus, CINAHL and SportDISCUS were searched up to July 2022. Trials were included if they carried out a HIIT intervention (defined at intensity ≥ 80% peak HR or ≥ 80% VO2peak) in HF patients (HFpEF or HFrEF) for at least 6 weeks. Comparator group was UC or MCT.

RESULTS

HIIT was shown to be superior to MCT and UC for improving VO2peak (HIIT mean improvement 3.1 mL.kg-1min-1). HITT was superior to MCT and UC for improving LVEF (HIIT mean improvement 5.7%). HIIT was superior to MCT and UC for improving HRQoL, using the MLHFQ (HIIT mean point change of -12.8). Subgroup analysis showed no difference between long and short HIIT.

CONCLUSION

HIIT improves VO2peak, LVEF and HRQoL in patients with HF, the improvements seen in VO2peak and LVEF are superior in HIIT compared to MCT and UC.

Effects of low-volume functional and running high-intensity interval training on physical fitness in young adults with overweight/obesity

Objectives: This study examined and compared the effects of functional and running high-intensity interval training (HIIT) on body composition, cardiorespiratory fitness, and muscular fitness of young adults with overweight or obesity. Methods: Forty-five participants (22.1 ± 2.1 years, BMI = 25.2 ± 1.0 kg/m2) were assigned to functional HIIT (HIIT-F; n = 15), running HIIT (HIIT-R; n = 15), or non-training control group (CON; n = 15). Participants in HIIT-F and HIIT-R performed functional exercise based-HIIT (four sets of all-out whole-body exercises including jumping jacks, squats, twist jumps and mountain climbers, et al.) and running HIIT (four sets of running on a treadmill) for 12 weeks, respectively. Body composition, muscular fitness, and cardiorespiratory fitness were assessed pre and post intervention. Results: Both HIIT-F and HIIT-R significantly improved the body composition and cardiorespiratory fitness, with HIIT-F induced greater improvements in lean mass (+1.623 vs. -1.034 kg, p < 0.001), back strength (+6.007 vs. +3.333 kg, p < 0.01), and push-ups (+5.692 vs. 1.923 reps, p < 0.001) than that in HIIT-R. HIIT-R reduced more visceral fat area (VFA) (-11.416 vs. -4.338 cm2, p = 0.052) and induced similar improvement in cardiorespiratory fitness (VO2max, +2.192 vs. +2.885 mL/kg/min, p = 0.792) with HIIT-F. Conclusion: Twelve weeks of HIIT-R or HIIT-F improved physical fitness among young adults with overweight or obesity. Despite the similar impact on cardiorespiratory fitness, HIIT-F generates a better positive effect on muscular fitness relative to HIIT-R, which could be partly explained by the greater increase in lean mass after HIIT-F intervention.

Effects of crossover point exercise and high-intensity interval training on vascular health in young overweight females

This study investigated the effects of 10 weeks of crossover point (COP) exercise training and high-intensity interval training (HIIT) on cardiovascular risk factors and vascular health in overweight young women. Overweight young women were randomized into HIIT and COP groups. Participants in the HIIT group (n = 10; age = 22 ± 2, body mass index (BMI) = 25.72 ± 0.90) and COP group (n = 10, age = 21 ± 2, BMI = 25.90 ± 1.90) took part in 10 weeks of HIIT and COP exercise training, respectively. Cardiorespiratory fitness, cardiovascular health, and oxidative stress indicators were measured before and after the intervention period. After 10 weeks of exercise intervention, both COP exercise and HIIT led to a significant increase in maximal oxygen uptake (p < 0.001). The systolic blood pressure (p = 0.006), diastolic blood pressure (p = 0.006), and brachial-ankle pulse wave velocity (p = 0.002) were significantly decreased in both COP group and HIIT group, while serum interleukin-6 levels were increased in HIIT and COP groups. The present study shows that a training program at COP could be an effective strategy to protect vascular health.

Feasibility of Different Exercise Modalities for Community-Dwelling Residents With Physical Inactivity: A Randomized Controlled Trial

BACKGROUND

Exercise interventions can promote health, but they can be difficult to implement. Moreover, no consensus has been reached regarding which exercise modality promotes the most significant improvement in metabolic health.

PURPOSE

This feasibility study was conducted to (a) determine the implementation efficacy of supervised and home-based exercise interventions by investigating their respective rates of intervention adherence, adherence to targeted intensity, attrition, and adverse events and (b) explore the preliminary efficacy of 12-week exercise programs among aerobic exercise, aerobic exercise combined with resistance exercise, and high-intensity interval training on body composition, anthropometric parameters, and lipid profiles for community-dwelling residents with physical inactivity.

METHODS

This randomized controlled trial was conducted from April to October 2020. Seventy-two sedentary participants aged 40-70 years were enrolled and randomized into one of four groups: 12-week aerobic exercise, aerobic exercise combined with resistance exercise, high-intensity interval training, and control. The three exercise groups performed at least moderate-intensity supervised exercise twice a week and home-based exercise once a week, whereas the control group maintained their usual daily activities. The target variables, including body composition, anthropometric parameters, and lipid profiles, were measured before and after the 12-week intervention.

RESULTS

The intervention adherence rates were 74.01%-87.54% for the supervised exercise group, 64.98%-83.90% for the home-based exercise group, and 82.65%-92.65% for the target exercise intensity group. The attrition rate ranged from 12.50% to 17.65%, and no adverse events were reported in any of the exercise groups. Preliminary efficacy data show the reductions in body weight (95% CI [0.01, 1.20], p = .048) and low-density lipoprotein (95% CI [2.76, 30.32], p = .02) were greater in the exercise groups than the control group, although the intergroup differences were not significant.

CONCLUSIONS/IMPLICATIONS FOR PRACTICE

Body weight and low-density lipoprotein may be efficiently reduced in a 12-week period using any of the three exercise modalities with at least 82.65% adherence to moderate-intensity exercise and 70.84% adherence to exercising 3 times a week.

Shorter Versus Longer Durations of Rowing-Based Interval Exercise Attenuate the Physiological and Perceptual Response

Purpose: This study compared physiological and perceptual variables between short and long durations of rowing-based high intensity interval exercise (HIIE). Methods: Fourteen active adults (age = 26.4 ± 7.2 yr) performed incremental rowing exercise to fatigue to measure maximal oxygen uptake (VO2max) and peak power output (PPO). The subsequent 20 min sessions required HIIE (eight 60 s efforts at 85%PPO with 90 s of active recovery at 20%PPO or 24 20 s efforts at 85%PPO with 30 s of active recovery at 20%PPO) or moderate intensity continuous exercise (MICE) at 40%PPO. During exercise, VO2, heart rate (HR), blood lactate concentration (BLa), rating of perceived exertion (RPE), and affective valence were measured. Results: Data show significantly (p < 0.001) higher peak VO2 (84 ± 7 vs. 76 ± 5%VO2peak, d = 0.99), peak HR (94 ± 4%HRpeak vs. 90 ± 4%HRpeak, d = 1.12), BLa (7.0 ± 2.5 mM vs. 4.1 ± 1.0 mM, d = 1.22), end-exercise RPE (12.8 ± 2.0 vs. 11.0 ± 1.7, d = 1.29), and lower affective valence (2.1 ± 1.6 vs. 2.9 ± 1.2, d = 0.61) with long versus short HIIE. Time spent above 85%HRpeak was significantly higher (p < 0.001) in short versus long HIIE (606 ± 259 vs. 448 ± 26 s, d = 0.91). Conclusion: Longer rowing-based intervals elicit greater cardiometabolic and perceptual strain versus shorter efforts, making the latter preferable to optimize perceptual responses to HIIE.

Rates of compliance and adherence to high-intensity interval training: a systematic review and Meta-analyses

BACKGROUND

To determine rates of compliance (i.e., supervised intervention attendance) and adherence (i.e., unsupervised physical activity completion) to high-intensity interval training (HIIT) among insufficiently active adults and adults with a medical condition, and determine whether compliance and adherence rates were different between HIIT and moderate-intensity continuous training (MICT).

METHODS

Articles on adults in a HIIT intervention and who were either insufficiently active or had a medical condition were included. MEDLINE, EMBASE, PsychINFO, SPORTDiscus, CINAHL, and Web of Science were searched. Article screening and data extraction were completed by two independent reviewers. Risk of bias was assessed using RoB 2.0 or ROBINS-I. Meta-analyses were conducted to discern differences in compliance and adherence between HIIT vs. MICT. Sensitivity analyses, publication bias, sub-group analyses, and quality appraisal were conducted for each meta-analysis.

RESULTS

One hundred eighty-eight unique studies were included (n = 8928 participants). Compliance to HIIT interventions averaged 89.4% (SD:11.8%), while adherence to HIIT averaged 63% (SD: 21.1%). Compliance and adherence to MICT averaged 92.5% (SD:10.6%) and 68.2% (SD:16.2%), respectively. Based on 65 studies included in the meta-analysis, compliance rates were not different between supervised HIIT and MICT interventions [Hedge's g = 0.015 (95%CI: - 0.088-0.118), p = .78]. Results were robust and low risk of publication bias was detected. No differences were detected based on sub-group analyses comparing medical conditions or risk of bias of studies. Quality of the evidence was rated as moderate over concerns in the directness of the evidence. Based on 10 studies, adherence rates were not different between unsupervised HIIT and MICT interventions [Hedge's g = - 0.313 (95%CI: - 0.681-0.056), p = .096]. Sub-group analysis points to differences in adherence rates dependent on the method of outcome measurement. Adherence results should be interpreted with caution due to very low quality of evidence.

CONCLUSIONS

Compliance to HIIT and MICT was high among insufficiently active adults and adults with a medical condition. Adherence to HIIT and MICT was relatively moderate, although there was high heterogeneity and very low quality of evidence. Further research should take into consideration exercise protocols employed, methods of outcome measurement, and measurement timepoints.

REGISTRATION

This review was registered in the PROSPERO database and given the identifier CRD42019103313.

Are Self-Selected Intervals as Effective as Fixed Intervals in Controlling Acute Responses in High-Intensity Interval Resistance Training?

Physical conditioning programs often apply high-intensity resistance training (HIRT), but there is a lack of research investigating the effects of using fixed or self-selected resting intervals between exercises on the performance, relative intensity, and affective perception during this modality of training. This study compared fixed versus self-selected rest intervals in HIRT sessions on cardiorespiratory responses, number of repetitions, and enjoyment perception in trained young men. Sixteen trained males (27.1 ± 3.9 years; 56.6 ± 7.5 mL.kg-1.min-1) performed HIRT circuits with 30-s and self-selected recovery interval. The duration of resting intervals was longer in HIRT performed with fixed than self-selected intervals (14.04 ± 5.82 s; p < 0.0001; ES = 3.2). Both sessions elicited similar relative HRR (79.4 ± 6.2 % vs. 81.6 ± 4.2 %; p = 0.14), VO2R (43.0 ± 12.2% vs. 47.7 ± 9.6%; p = 0.10), and enjoyment reflected by scores in the PACES questionnaire (107.9 ± 15.1 vs. 109.2 ± 12.8; p = 0.65). The total number of repetitions (403.4 ± 45.5 vs. 353.1 ± 27.4; p < 0.01, ES = 1.3) and caloric expenditure (154.4 ± 28.6 kcal vs. 121.4 ± 21.6 kcal; p < 0.001, ES = 0.13) were greater in HIRT performed with fixed vs. self-selected intervals. In conclusion, HIRT performed with fixed and self-selected rest intervals elicited similar relative intensity and enjoyment perception. However, the number of repetitions and caloric expenditure were greater in sessions performed with fixed 30-s.

Extraordinary Claims in the Literature on High-Intensity Interval Training (HIIT): I. Bonafide Scientific Revolution or a Looming Crisis of Replication and Credibility?

The literature on high-intensity interval training (HIIT) contains claims that, if true, could revolutionize the science and practice of exercise. This critical analysis examines two varieties of claims: (i) HIIT is effective in improving various indices of fitness and health, and (ii) HIIT is as effective as more time-consuming moderate-intensity continuous exercise. Using data from two recent systematic reviews as working examples, we show that studies in both categories exhibit considerable weaknesses when judged through the prism of fundamental statistical principles. Predominantly, small-to-medium effects are investigated in severely underpowered studies, thus greatly increasing the risk of both type I and type II errors of statistical inference. Studies in the first category combine the volatility of estimates associated with small samples with numerous dependent variables analyzed without consideration of the inflation of the type I error rate. Studies in the second category inappropriately use the p > 0.05 criterion from small studies to support claims of 'similar' or 'comparable' effects. It is concluded that the situation in the HIIT literature is reminiscent of the research climate that led to the replication crisis in psychology. As in psychology, this could be an opportunity to reform statistical practices in exercise science.

Effect of high-intensity interval training compared to moderate-intensity continuous training on body composition and insulin sensitivity in overweight and obese adults: A systematic review and meta-analysis

Objective

To compare the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on adults with overweight and obesity. Outcomes, including changes in insulin sensitivity, weight, body mass index (BMI), waist circumference, and body fat, were analyzed.

Methods

A systematic literature review was conducted. This review is registered in the International Prospective Register of Systematic Reviews (PROSPERO) under the number CRD42021281899. Clinical trials involving individuals who are overweight and obese and comparing HIIT with MICT effects on insulin sensitivity, weight, BMI, body fat percentage, and waist circumference were included. PubMed, Web of Science, Embase, and Scopus databases were searched using controlled vocabulary and free-text terms related to HIIT, obesity, and overweight. The search included studies published until September 2022. The Rob2 tool was used to assess the risk of bias. The results were presented through meta-analyses that provided summary estimators and confidence intervals. Subgroup analyses were conducted to assess the effect of the risk of bias on the outcomes. This research did not receive any specific funding.

Results

Of the 2534 articles, 30 met the eligibility criteria. The intervention duration ranged from 4 to 16 weeks. The observed effects for each outcome were as follows: insulin sensitivity (p = 0.02), weight (p = 0.58), BMI (p = 0.53), waist circumference (p = 0.87), body fat percentage (p = 0.07), body fat mass in kilograms (p = 0.39). The level of evidence obtained was moderate except for waist circumference, which was rated as low. Limitations included heterogeneity in training protocols, measurements, and study duration. Additionally, a risk of bias was identified in these studies.

Conclusion

HIIT and MICT did not significantly differ in their effects on weight, BMI, waist circumference, or body fat mass in adults with overweight and obesity. However, a moderate beneficial effect of HIIT was observed on insulin sensitivity. Therefore, further evidence is required to confirm these findings.

High-Intensity Interval Training Ameliorates High-Fat Diet-Induced Metabolic Disorders via the Cyclic GMP-AMP Synthase-Stimulator of Interferon Gene Signaling Pathway

Metabolic diseases are growing in prevalence worldwide. Although the pathogenesis of metabolic diseases remains ambiguous, the correlation between cyclic GMP-AMP synthase (cGAS)-stimulator of interferon gene (STING) and metabolic diseases has been identified recently. Exercise is an effective intervention protecting against metabolic diseases, however, the role of the cGAS-STING signaling pathway in this process is unclear, and the effect and mechanism of different exercise intensities on metabolic disorders are still unknown. Thus, we explored the association between exercise to ameliorate HFD-induced metabolic disorders and the cGAS-STING signaling pathway and compared the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT). Male C57BL/6 mice (6-8 weeks old) were fed HFD for 8 weeks to establish a metabolic disease model and were subjected to 8-week MICT or HIIT training. Glucose tolerance tests (GTT) and insulin tolerance tests (ITT) were used to assess glucose metabolism. Serum triglyceride (TG) and total cholesterol (TC) were measured to evaluate lipid metabolism. Oil red staining was used to observe the lipid droplets in the gastrocnemius muscle. An enzyme-linked immunosorbent assay was used to detect the serum inflammatory factors IL-6 and IFN-β. The protein expression of the cGAS-STING signaling pathway was detected by the WesTM automatic protein expression analysis system. We reported that HFD induced metabolic disorders with obesity, abnormal glucolipid metabolism, and significant inflammatory responses. Both HIIT and MICT ameliorated the above adverse reactions, but MICT was superior to HIIT in improving glucolipid disorders. Additionally, HIIT significantly increased the expression of STING protein, as well as the phosphorylation of TBKI and the ratio of p-IRF3/IRF3. MICT only increased the expression of STING protein. Our findings suggest that HIIT may alleviate HFD-induced metabolic disorder phenotype through the cGAS-STING signaling pathway. However, the improvement of MICT on metabolic disorder phenotype is less associated with the cGAS-STING pathway, which needs to be further explored.

Effects of increasing light versus moderate-to-vigorous physical activity on cardiometabolic health in Chinese adults with obesity

Increasing daily physical activity (PA) is a practical way to decrease the risk of cardiometabolic diseases, while the studies on exercise intensity remain limited. The purpose of the present study was to compare the effects of increasing light PA (LPA) or moderate-to-vigorous PA (MVPA) for 12 weeks on cardiometabolic markers in Chinese adults with obesity. Fifty-three adults were randomly assigned to the 1) control group, 2) LPA group, and 3) MVPA group in free-living settings. The intervention effects on body composition, cardiorespiratory fitness, and cardiometabolic biomarkers were analysed using a generalized estimated equation model adjusted for baseline values and potential confounders. Compared with the control group, the MVPA group showed improvements in body composition, lipids, C-peptide, monocyte chemoattractant protein-1 (MCP-1), interleukin-8, leptin, and E-selectin. A favourable change in triglycerides and E-selectin were observed in the LPA group when compared to the control group. Lastly, improvements in waist circumference, C-reactive protein, and MCP-1 were observed in the MVPA group when compared to those in the LPA group. Although increasing both LPA and MVPA improved certain cardiometabolic biomarkers, the latter may have more benefits. These findings imply that MVPA may reduce cardiometabolic disease risk more effectively than LPA, especially in Chinese adults with obesity.

High-intensity interval training versus moderate-intensity continuous training on patient quality of life in cardiovascular disease: a systematic review and meta-analysis

This systematic review and meta-analysis aimed to compare the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on the quality of life (QOL) and mental health (MH) of patients with cardiovascular disease (CVDs). Web of Science, Medline, Embase, Cochrane (CENTRAL), CINAHL, China National Knowledge Infrastructure, Wanfang, and China Science and Technology Journal databases were searched from their date of establishment to July, 2023. A total of 5798 articles were screened, of which 25 were included according to the eligibility criteria. The weighted mean difference (WMD) and standardized mean difference (SMD) were used to analyze data from the same and different indicator categories, respectively. The fixed-effects model (FE) or random-effects model (RE) combined data based on the between-study heterogeneity. There were no statistically significant differences regarding QOL, physical component summary (PCS), mental component summary (MCS), and MH, including depression and anxiety levels, between the HIIT and MICT groups [SMD = 0.21, 95% confidence interval (CI)  - 0.18-0.61, Z = 1.06, P = 0.290; SMD = 0.10, 95% CI  - 0.03-0.23, Z = 1.52, P = 0.128; SMD = 0.07, 95% CI  - 0.05-0.20, Z = 1.13, P = 0.25; SMD = - 0.08, 95% CI  - 0.40-0.25, Z = - 0.46, P = 0.646; WMD = 0.14. 95% CI  - 0.56-0.84, Z = 0.39, P = 0.694, respectively]. HIIT significantly improved PCS in the coronary artery disease (CAD) population subgroup relative to MICT. HIIT was also significantly superior to MICT for physical role, vitality, and social function. We conclude that HIIT and MICT have similar effects on QOL and MH in patients with CVD, while HIIT is favorable for improving patients' self-perceived physiological functioning based on their status and social adjustment, and this effect is more significant in patients with CAD.

Elucidating the primary mechanisms of high-intensity interval training for improved cardiac fitness in obesity

Obesity is a global and rising multifactorial pandemic associated with the emergence of several comorbidities that are risk factors for malignant cardiac remodeling and disease. High-intensity interval training (HIIT) has gained considerable attention due to its favorable outcomes of cardiometabolic health in individuals with overweight or obese. The primary aim of this review is to discuss the fundamental processes through which HIIT improves cardiac impairment in individuals with obesity to develop viable treatments for obesity management. In this review, a multiple database search and collection were conducted from the earliest record to January 2013 for studies included the qualitative component of HIIT intervention in humans and animals with overweight/obesity related to cardiac remodeling and fitness. We attempt to integrate the main mechanisms of HIIT in cardiac remolding improvement in obesity into an overall sequential hypothesis. This work focus on the ameliorative effects of HIIT on obesity-induced cardiac remodeling with respect to potential and pleiotropic mechanisms, including adipose distribution, energy metabolism, inflammatory response, insulin resistance, and related risk profiles in obesity. In conclusion, HIIT has been shown to reduce obesity-induced risks of cardiac remodeling, but the long-term effects of HIIT on obesity-induced cardiac injury and disease are presently unknown. Collective understanding highlights numerous specific research that are needed before the safety and effectiveness of HIIT can be confirmed and widely adopted in patient with obesity.

Effect of a novel 90-second "Gear" exercise programme on markers of inflammation and cardiorespiratory fitness measurements in person at risk of cardiovascular disease

The study compared the effect of the novel "Gear" exercise programmes on inflammatory markers and cardiorespiratory fitness measurements. The participants mean age was 38 ± 5.74 years, with a mean body mass of 83 ± 16.93kg. Participants were randomly assigned to either the "Gear" exercise programme repeated at different times during the day (GEP-DT): cycled for 90 seconds, repeated three times per day, three days per week; the "Gear" exercise programme repeated at one point in time (GEP-OT): cycled for 90 seconds followed by four minutes and 30 seconds rest, repeated three times at one point in time, three days per week; moderate-intensity continuous exercise group (MICE): cycled for 30 minutes at 55-69% of HRmax or the control group (CTRL): did not exercise. The GEP-DT demonstrated a moderate increase in load at ventilation threshold (VT-L) (MD = 8.18 ± 12.30, % Δ = 14.53, d = 0.77, d (95% CI): (-0.17, 1.64)). The GEP-OT group demonstrated a large effect size for VT-L (MD = 11.79 ± 18.77, % Δ = 18.86, d = 0.81, d (95% CI): (-0.02, 1.63)). The GEP-DT and GEP-OT raised the VT-L, which prevented premature fatigue and improved the efficiency of the cardiorespiratory system.

High-intensity interval training prevents muscle mass loss in overweight Chilean young adults during a hypocaloric-Mediterranean diet: a randomized trial

The hypocaloric Mediterranean diet (MD) mainly reduces fat mass but inevitably causes a loss of skeletal muscle mass. High-intensity interval training (HIIT) seems to have advantages in preserving muscle mass during a hypocaloric regime. Our study compares body composition and metabolic changes in overweight and obese Chilean women and men after 3 months of weight loss treatment with a Mediterranean-type hypocaloric diet, HIIT, or a combination of both. The study included 83 overweight or obese women and men between the ages of 25 and 50. The subjects were randomly assigned to one of the three intervention groups: (1) MD, (2) EX, and (3) MD + EX. Baseline and post-intervention measurements included: (a) body composition by dual-beam densitometry, muscle, and fat measurements by thigh ultrasound and computed tomography; (b) handgrip and quadriceps muscle strength; (c) exercise performance by peak oxygen consumption, peak load, work efficiency, and exercise energy expenditure; and (d) metabolic parameters. Out of 83 participants, the retention rate was 49% due to low compliance with the interventions. As expected, the MD group resulted in significantly greater weight loss (MD -7%, EX -0.6% and MD + EX -5.3%) and appendicular fat mass loss (MD -11.1%, EX -2.9, MD + EX -10.2%) but was associated with significant lean tissue loss (2.8%), which was prevented by HIIT (EX -0.1 and MD + EX -0.6%). Metabolic and glycoxidative parameters remained unchanged, irrespective of changes in body composition. Hypocaloric diets remain the most effective means to lose weight and body fat. However, it induces a loss of lean body mass when not accompanied by exercise training. This study shows that HIIT prevents the loss of muscle mass caused by a hypocaloric Mediterranean diet.

Psychological and Physiological Responses Across Six Weeks of HIIT and MICT in Previously Inactive, Young Adults

High-intensity interval training (HIIT) is suggested as a public health strategy to increase engagement in, and adherence to, physical activity. However, debate exists regarding the efficacy in inactive individuals.

PURPOSE

To determine the physiological and psychological responses to three weeks of supervised and three weeks of unsupervised HIIT or moderate-intensity continuous training (MICT) in previously inactive adults.

METHODS

Young adults (n = 20; 21.4 ± 2.2 years; 13 females) were randomized to six weeks of HIIT or MICT. Pre- and post-testing included anthropometric measures, an incremental exercise test, and body composition. Psychological outcomes (i.e., perceived competence, self-efficacy, and enjoyment) were assessed at the end of the first, ninth, and eighteenth training sessions. Differences in physiological outcomes were analyzed using repeated measures factorial ANCOVAs. Differences in psychological outcomes were analyzed using repeated measures factorial ANOVAs.

RESULTS

Maximal oxygen consumption (Δ 2.8 ml·kg-1·min-1; p = .03) and peak power output (Δ 20.2 W; p = .01) improved over time with no group differences (p > .05). No changes occurred in body composition or self-efficacy (p ≥ .27). Perceived competence increased with supervised training (p = .01) with no further increases during unsupervised training. There was no difference in enjoyment across supervised training (p = .07), but enjoyment decreased during unsupervised training (p = .003).

CONCLUSIONS

Cardiorespiratory fitness improved comparably for HIIT and MICT but with a shorter time commitment for HIIT. Perceived competence increased across supervised training suggesting it may be important to provide support at the beginning of an exercise intervention.

"I just had the feeling that the interval training is more beneficial": young adults' subjective experiences of physical fitness and the role of training modes

Objective

Compelling evidence has shown that high-intensity interval training (HIIT) is associated with substantial increases in physical fitness. However, little is known about whether and how individuals experience these adaptations over time. The purpose of this study is, therefore, to explore how physically inactive young adults subjectively experience physical fitness and its development as they start to exercise and how these experiences relate to different intensity domains (i.e., moderate and severe) as well as to training modes [i.e., HIIT and moderate intensity continuous training (MICT)] and their sequential administration (i.e., HIIT-MICT and MICT-HIIT).

Methods

Thirty-one inactive participants completed a 15-week two-period sequential exercise intervention in which they first trained for six weeks in a HIIT or a MICT group and subsequently switched training modes. Interviews using the biographical mapping method were conducted at the end of the intervention to assess participants' exercise- and fitness-related experiences over the past weeks. To assess experiential patterns, we conducted a reflexive thematic analysis.

Results

We developed three themes that represent the temporal and processual character of starting to exercise after a prolonged period of inactivity: (1) Inactive young adults are not all the same when starting to exercise; (2) Developing physical fitness is a multi-faceted and individual experience; and (3) Feeling physically fit (or not) fosters large-scale effects.

Conclusion

Our results show that, in retrospect, participants mostly deemed HIIT to be more effective than MICT. Our findings also emphasize that physical fitness is a complex and subjective experience that manifests in various ways over time. The idiosyncrasy of physical fitness experiences reiterates the necessity for individually tailored exercise prescriptions instead of one-size-fits-all approaches.

Moderate-Intensity Continuous Training Versus Moderate-Intensity Interval Training: Effects on Cardiometabolic Factors in Spanish Obese Adults

BACKGROUND

Excess weight and obesity are related to cardiometabolic diseases and limit physical activity. Until now, the effects of moderate-intensity continuous training (MICT) compared with moderate-intensity interval training (MIIT) in Spanish obese adults have not been analyzed.

OBJECTIVE

This study aimed to investigate the effect of MICT and MIIT together with a 1300-to-1400 caloric restrictive diet on cardiovascular disease risk factors in overweight and obese patients.

METHODS

The MICT and MIIT groups trained during 4 sessions a week for 12 weeks while performing the diet. The MICT group trained for 32 minutes per session in a cycloergometer, initially at 60% maximal oxygen uptake during the first month and increasing by 10% every 4 weeks. The MIIT group performed 4 × 4 intervals (at 60% maximal oxygen uptake and active rest at 60% maximal oxygen uptake minus 20 W), with a 10% increase every 4 weeks. The control group neither trained nor followed the restrictive diet.

RESULTS

One hundred fifty-nine obese adults participated in the study. The control group did not present any significant changes during the study. The MICT group significantly improved in all the variables (P < .05) except for high-density lipoproteins. The MIIT group improved in all the variables (P < .05) except for high-density lipoproteins and triglycerides. The MIIT group lost weight in less time than the MICT group.

CONCLUSIONS

Overweight and obese adults of both the MICT and MIIT groups decreased their risk for cardiovascular disease, although the MIIT group lost weight in a shorter amount of time.

Serum Osteocalcin, Sclerostin and Lipocalin-2 Levels in Adolescent Boys with Obesity over a 12-Week Sprint Interval Training

The aim of the study was to examine the effects of supervised cycling sprint interval training (SIT) on serum osteocalcin, lipocalin-2 and sclerostin levels, and bone mineral characteristics among obese adolescent boys. Untrained obese adolescent boys aged 13.4 ± 0.3 were assigned to either a 12-week SIT group (3 sessions/week), or a non-exercising control group who continued with their habitual everyday life. Serum osteocalcin, lipocalin-2 and sclerostin concentrations, and bone mineral values were assessed before and after intervention. After 12-week intervention, where 14 boys in both groups ended the study, there were no significant differences in serum osteokine levels between the groups after 12 weeks, while whole body bone mineral content and lower limb bone mineral density increased in the SIT group (p < 0.05). Change in body mass index was negatively correlated with the change in osteocalcin (r = -0.57; p = 0.034), and positively correlated with the change in lipocalin-2 levels (r = 0.57; p = 0.035) in the SIT group. Supervised 12-week SIT intervention improved bone mineral characteristics, but did not change osteocalcin, lipocalin-2 or sclerostin levels in adolescent boys with obesity.

Long-term effects of different exercise training modes on cytokines and adipokines in individuals with overweight/obesity and cardiometabolic diseases: A systematic review, meta-analysis, and meta-regression of randomized controlled trials

The present study aimed to investigate the evidence on the effects of different long-term training interventions (aerobic [AeT], resistance [RT], and combined [COMB]) and spontaneous physical activity (PA) in modifying cytokines and adipokines in individuals with overweight or obesity with or without cardiometabolic diseases while considering potential confounders. Although exercise interventions have become a potentially effective tool for preventing and treating metabolic diseases, the evidence provided by previous systematic reviews is inconclusive since several potential confounders have yet to be addressed. Therefore, we conducted a systematic literature search in Medline, Cochrane, and Embase databases from January 2000 to July 2022 and performed a meta-analysis. Inclusion criteria retrieved 106 full texts comprising 8,642 individuals with a range BMI of 25.1-43.8 kg m^-2 . We found that independently of the training mode, exercise had a beneficial effect on diminishing Adiponectin, C-reactive protein (CRP), IL-6, IL-18, IL-20, Leptin, sICAM, and TNF-α levels circulating levels. Furthermore, by subsequent analysis, we detected differential effects of AeT, RT, and COMB, with sex, age, body composition, and trial length acting as moderators. The comparison of training modes revealed a difference favoring COMB over AeT for regulating the increase in CRP with no differences in the remaining biomarkers. Meta-regression analysis revealed an effect of change in maximal oxygen uptake (VO_2max ) on CRP, IL-6, and TNF-α, while IL-10 was influenced by the change in body fat. The results suggest that all interventions, except PA, are effective in lessening this population's inflammatory status, provided that exercise results in an increase of VO_2max .

Retro walking treadmill training reduces C-reactive protein levels in overweight and obese young adults: A randomized comparative study

Background and Aims

Retro walking has been shown to acquire a greater metabolic cost, placing a higher cardiopulmonary demand on the body, when compared with forward walking at a similar speed. The aim of this study was to compare the effect of retro walking with that of forward walking on C-reactive protein (CRP) levels, body mass index (BMI) and blood pressure (BP) and to understand the influence of independent factors namely systolic blood pressure (SBP), diastolic blood pressure (DBP) and BMI on CRP in untrained overweight and obese young adults.

Methods

This was a randomised controlled trial whereby 106 participants underwent either retro walking (n = 53) or forward walking (n = 53) treadmill training four times a week for 12 weeks before and after which CRP, BMI, and BP levels were measured. Comparison of the measured values before and after intervention and between the groups was done and influence of BMI and BP on CRP levels was determined.

Results

Both groups recorded a significant decrease (p < 0.001) in CRP, BMI, and BP levels postintervention. The participants who underwent retro walking training showed a significantly (p < 0.001) higher decrease in all the outcomes as compared with the forward walking group. C-reactive protein levels were seen to be influenced by BMI and DBP.

Conclusion

Retro-walking training leads to greater decrease in CRP, BMI, and BP when compared with forward walking, and CRP levels are influenced by BMI and DBP. Retro walking treadmill training can be used preferentially to bring about reduction in cardiovascular risk factors.

Does Exercise Modality Matter Affectively? Contrasting Type and Sequence of Moderate-Intensity Continuous Training Versus High-Intensity Interval Training in a Randomized Within-Subject Study

Over the past two decades, affective determinants of exercise behavior have received increasing attention in research on health promotion and prevention. To date, however, little is known about changes in affective exercise determinants during multi-week training programs in insufficiently active individuals. This applies in particular to the currently discussed advantages and disadvantages of high-intensity interval training (HIIT) compared with moderate-intensity continuous training (MICT) with regard to the affective experience of these two training types (e.g., reduced monotony vs. more aversive response during HIIT), which is important for exercise adherence. Referring to the Affect and Health Behavior Framework (AHBF), this within-subject study investigated changes in affective exercise determinants as a function of training type and sequence consisting of MICT and HIIT. Forty insufficiently active healthy adults (M _age = 27 ± 6 years; 72% women) underwent two 6-week training periods in a randomized sequence (MICT - HIIT vs. HIIT - MICT) within 15 weeks. Pre-post questionnaires and in-situ measurements, during and after a standardized vigorous-intensity continuous exercise session (VICE), were used to assess affective attitude, intrinsic motivation, in-task affective valence, as well as post-exercise enjoyment. These four affect-related constructs were collected before, between, and after the two training periods. Mixed models revealed a significant effect for training sequence (p = 0.011) - but not for training type (p = 0.045; non-significant after Bonferroni alpha adjustment) - on changes in in-task affective valence in favor of the MICT - HIIT sequence. Moreover, no significant training type or sequence effects were found for the constructs of reflective processing: exercise enjoyment, affective attitude, and intrinsic motivation. Therefore, individual-based training recommendations should consider the effects of variety and training sequence to develop tailored interventions that lead to more positive affective experiences - in particular during exercise - and promote the maintenance of exercise behavior in previously inactive individuals.

Exercise training reduces circulating cytokines in male patients with coronary artery disease and type 2 diabetes: A pilot study

Low-grade inflammation is central to coronary artery disease (CAD) and type 2 diabetes (T2D) and is reduced by exercise training. The objective of this study was to compare the anti-inflammatory potential of moderate-to-vigorous intensity continuous training (MICT) and high-intensity interval training (HIIT) in patients with CAD with or without T2D. The design and setting of this study is based on a secondary analysis of registered randomized clinical trial NCT02765568. Male patients with CAD were randomly assigned to either MICT or HIIT, with subgroups divided according to T2D status (non-T2D-HIIT n = 14 and non-T2D-MICT n = 13; T2D-HIIT n = 6 and T2D-MICT n = 5). The intervention was a 12-week cardiovascular rehabilitation program consisting of either MICT or HIIT (twice weekly sessions) and circulating cytokines measured pre- and post-training as inflammatory markers. The co-occurrence of CAD and T2D was associated with increased plasma IL-8 (p = 0.0331). There was an interaction between T2D and the effect of the training interventions on plasma FGF21 (p = 0.0368) and IL-6 (p = 0.0385), which were further reduced in the T2D groups. An interaction between T2D, training modalities, and the effect of time (p = 0.0415) was detected for SPARC, with HIIT increasing circulating concentrations in the control group, while lowering them in the T2D group, and the inverse occurring with MICT. The interventions also reduced plasma FGF21 (p = 0.0030), IL-6 (p = 0.0101), IL-8 (p = 0.0087), IL-10 (p < 0.0001), and IL-18 (p = 0.0009) irrespective of training modality or T2D status. HIIT and MICT resulted in similar reductions in circulating cytokines known to be increased in the context of low-grade inflammation in CAD patients, an effect more pronounced in patients with T2D for FGF21 and IL-6.

The impact of high intensity interval training on serum omentin-1 levels, lipid profile, and insulin resistance in obese men with type 2 diabetes mellitus

BACKGROUND: High-intensity interval training (HIIT) is an effective exercise method that could lead to favorable changes in obese and diabetic subjects. OBJECTIVE: To investigate the effects of HIIT on serum omentin-1 levels, lipid profile, and insulin resistance in diabetic obese men. METHODS: Fifty obese men suffering from T2DM with ages between 40 and 60 years were enrolled. Subjects were divided into two groups: the HIIT (n= 26) and control group (n= 24). The HIIT group subjects underwent 12 weeks (3 sessions per week) of HIIT program, while the control group subjects kept to their normal daily activities. Fasting blood glucose levels, serum omentin-1 levels, lipid profile, and insulin resistance were evaluated at baseline and after the experiment. RESULTS: HIIT resulted in significant improvements in the subjects’ body composition, serum omentin-1 levels, lipid profiles, fasting insulin, HOMA-IR (p< 0.05). Further, highly significant negative correlations were observed between serum omentin levels, on the one hand, and body mass index, body weight, and waist circumference, on the other. CONCLUSIONS: Twelve weeks of HIIT may be an effective training strategy to improve serum omentin-1 levels, body composition, lipid profile, and insulin sensitivity in diabetic obese men.

Longitudinal affective response to high-intensity interval training and moderate-intensity continuous training in overweight women with polycystic ovary syndrome: A randomised trial

BACKGROUND

Women with polycystic ovary syndrome (PCOS) experience general and PCOS-specific barriers that limit their engagement with exercise and contribute to high attrition from exercise programs, hindering the potential benefits of exercise to address their increased cardio-metabolic risk. A positive remembered affective response can predict future intentions and adherence to exercise prescription.

OBJECTIVES

To compare the longitudinal changes in remembered affect to high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) in women with PCOS and to determine whether longitudinal changes in remembered affect are correlated with changes in fitness, body mass index, adherence and exercise enjoyment.

METHODS

Physically inactive, overweight women with PCOS were randomly assigned to 12 weeks of either HIIT (n = 15) or MICT (n = 14) (3 sessions per week). Remembered affective valence (Feeling Scale) was collected after each exercise session. Cardiorespiratory fitness (VO2peak) was assessed at baseline and post-intervention. Exercise enjoyment was assessed post-intervention.

RESULTS

The longitudinal changes in the remembered affect were more positive in the HIIT group compared to MICT (β = 0.017, p = 0.047). HIIT was also considered more enjoyable than MICT (p = 0.002). Adherence was high in both groups (>90%). We found a moderate correlation with longitudinal changes between the remembered affect and change in fitness (rs = 0.398) and exercise enjoyment (rs = 0.376) using the combined group, however, these were not statistically significant (p = 0.054 and p = 0.064, respectively).

CONCLUSIONS

HIIT demonstrated a more positive longitudinal remembered affective response and greater exercise enjoyment compared to MICT in overweight women with PCOS.

Rural-Urban Differences in Physical Activity Tracking and Engagement in a Web-Based Platform

OBJECTIVES

Despite the well-established health benefits of regular participation in physical activity, most adults do not meet recommended exercise guidelines. In rural communities, limited local resources and geographic dispersion make engaging in regular activity particularly difficult. Web-based solutions offer a potential solution for addressing physical activity disparities between rural and urban areas.

METHODS

This study examined the physical activity logs of users (n = 6695) of a web-based platform called Walk Georgia, comparing residents of metropolitan and nonmetropolitan areas. We tabulated descriptive statistics for variables of interest, cross-tabulated for metropolitan and nonmetropolitan groups. We then used independent-samples t tests to compare logged activity between metropolitan and nonmetropolitan residing user groups.

RESULTS

In the analysis of group type (n = 6654), users were more likely to enroll in the program as part of a group than as individuals (n = 4391; 65.9%), particularly for users in metropolitan areas (3558 of 5192; 68.5%). Although the groups shared certain activities, nonmetropolitan residents were more likely than metropolitan residents to engage in maintenance-based activities. Nonmetropolitan residents earned fewer program points for their activity than metropolitan users (P = .007), largely because of lower average exercise difficulty (P < .001).

CONCLUSIONS

The web-based platform was effective in helping individuals track physical activity. Despite engaging in similar amounts of physical activity by time, on average, users in nonmetropolitan areas engaged in less rigorous and more maintenance-based tasks than users in metropolitan areas. One strategy for increasing physical activity among rural populations may be to leverage social support provided by group enrollment in such programming.

Effects of High-Intensity Interval Vs. Moderate-Intensity Continuous Training on Body Composition and Gene Expression of ACE2, NLRP3, and FNDC5 in Obese Adults: A Randomized Controlled Trial

Background: Obesity is considered a multisystem disease associated with higher mortality and morbidity in adults. This study explored the effects of two Moderate-Intensity Continuous Training (MICT) and High-Intensity Interval Training (HIIT) on body composition, maximal oxygen uptake (VO2max), and the gene expression of angiotensin-converting enzyme 2 (ACE2), fibronectin type III domain-containing protein 5 (FNDC5), and NLR family pyrin domain containing 3 (NLRP3) in adults with obesity. Methods: In a randomized controlled trial, 36 obese, inactive subjects (age: 45.16 ± 3.13 yrs.; mean, BW: 112.38 ± 20.1 kg, Height: 1.67 ± 0.07, and BMI: 39.66 ± 6.07 kg/m2) were randomly assigned to one of three groups: HIIT: (n = 12), MICT (n = 12), and control (n = 12). Both exercise groups received 40 min of training per session (three times/week) for eight weeks. Body composition, body fat percentage (BFP), VO2max, and the gene expression of ACE2, and NLRP3, were taken pre- and post-intervention using the qRT-PCR technique. The data were analyzed using SPSS software via parametric (ANOVA and ANCOVA) and non-parametric tests (Mann Whitney U and Kruskal-Wallis). Results: Our results showed that HIIT and MICT protocols could be effective in normalizing body composition measurements and VO2max, but HIIT could reduce body fat percentage (BFP) in obese subjects. Moreover, HIIT and MICT could significantly reduce the gene expression of NLRP3 (p < 0.0001) and ACE2 (p < 0.0001), while increasing the gene expression of FNDC5 (p < 0.0001). There were negative correlations between the gene expression of FNDC5 and NLRP3, as well as ACE2. Furthermore, increased FNDC5 was negatively correlated with BFP (r = 0.392, p < 0.001). Conclusion: Overall, our results indicated that HIIT and MICT protocols had the greatest impact on the gene expression of NLRP3, ACE2, and FNDC5.

Effects of an 8-week Baduanjin intervention combined with low-carbohydrates diet among overweight people who struggle with drug addiction

Background

Prior studies have consistently revealed that a combination of physical activity with caloric restriction results in a reduction in body weight in the general population. Both overweight and drug abuse are risk factors for poor physiological health, and poor mental health has been associated with drug abuse and unhealthy body mass index (BMI). However, the effects of low-carbohydrates diet (LC) combined with mind-body exercise intervention on improving anthropometric characteristics, lipid metabolism, quality of life, and craving among overweight people who struggle with drug addiction have yet to be clarified.

Methods

Fifty-four eligible male patients were randomly assigned to the control group (CON; n = 18), the Baduanjin intervention group (BA, 60 min × 5 times/week, 8 weeks; n = 18), and the Baduanjin combined with LC intervention group (LC; n = 18). We compared the anthropometric characteristics, blood biochemical parameters, quality of life, and drug craving responses between the three groups at baseline (week 0), week 4, and week 8.

Results

After repeated measurements in the general linear model, both the BA and LC groups exerted significant effects on decreasing waist circumference, BMI, body weight, hip circumference, body fat percentage, total cholesterol level, and triglyceride level (P < 0.05). There was no significant difference in the HDL-C level observed among the BA and LC groups at 8 weeks (P > 0.05); however, there was an overall upwards trend. A significant change in trends in the quality of life scale score was determined in the three groups (P < 0.001). The three groups showed reductions in visual analog scale score distribution over time (P < 0.05).

Conclusions

Either Baduanjin or an 8-week Baduanjin combined with LC can significantly reduce anthropometric characteristics and body composition, enhance the quality of life, and reduce craving in overweight/obese patients. Baduanjin combined with LC is particularly effective in improving lipid metabolism.

Changes in the Fitness Fatness Index following reduced exertion high-intensity interval training versus moderate-intensity continuous training in physically inactive adults

Background

Many adults do not reach the recommended exercise participation guidelines, often citing lack of time as a barrier. Reduced exertion high-intensity training (REHIT) is a mode of exercise that takes as few as 10 min and has been shown to be as effective as other modalities. The Fitness Fatness Index (FFI) is a recently developed index that is used to predict cardiovascular disease (CVD) risk. The aim of this study was to determine the efficacy of a REHIT vs. a traditional moderate-intensity continuous training (MICT) on FFI in physically inactive adults.

Methods

Thirty-two participants were randomized into one of two 8-week exercise intervention groups: (i) REHIT (n = 16); (ii) MICT (n = 16). The REHIT group performed 10 min of individualized cycling intervals on 2–4 days of the week. The MICT group were prescribed aerobic exercise at 50–65% of their heart rate reserve (HRR) on 3–5 days of the week. FFI was recorded at baseline and post 8-weeks, with FFI being calculated as cardiorespiratory fitness (CRF) (expressed as metabolic equivalents) divided by waist to height ratio (WtHR). A 1-unit increase in FFI was recognized as a clinically significant change in FFI.

Results

The REHIT group showed significantly greater (+1.95, ±0.63) improvements in FFI compared to those in the MICT (+0.99, ±0.47) group (between group difference, p &lt; 0.001). Furthermore, there was a greater proportion of participants who achieved a clinically significant change in FFI in the REHIT group (12/12, 100%) than in the MICT group (8/15, 53%) (between group difference, p = 0.01).

Conclusion

This study suggests that REHIT may be a more efficacious exercise modality to increase FFI than MICT. This outcome is beneficial as the clinician can prescribe REHIT to physically inactive adults who cite lack of time as a barrier to physical activity participation and achieve significant reductions in CVD risk.

Clinical and Biological Adaptations in Obese Older Adults Following 12-Weeks of High-Intensity Interval Training or Moderate-Intensity Continuous Training

Sarcopenia and obesity are considered a double health burden. Therefore, the implementation of effective strategies is needed to improve the quality of life of older obese individuals. The aim of this study was to compare the impact of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on functional capacities, muscle function, body composition and blood biomarkers in obese older adults. Adipose tissue gene expression and markers of muscle mitochondrial content and quality control involved in exercise adaptations were also investigated. Sixty-eight participants performed either HIIT (n = 34) on an elliptical trainer or MICT (n = 34) on a treadmill, three times per week for 12 weeks. HIIT produced significantly higher benefits on some physical parameters (six-minute walking test (HIIT: +12.4% vs. MICT: +5.2%); step test (HIIT: +17.02% vs. MICT: +5.9%); ten-repetition chair test (HIIT: −17.04% vs. MICT: −4.7%)). Although both HIIT and MICT led to an improvement in lower limb power (HIIT: +25.2% vs. MICT: +20.4%), only MICT led to higher improvement in lower limb muscle strength (HIIT: +4.3% vs. MICT: +23.2%). HIIT was more beneficial for increasing total lean body mass (HIIT: +1.58% vs. MICT: −0.81%), while MICT was more effective for decreasing relative gynoid fat mass (HIIT: −1.09% vs. MICT: −4.20%). Regarding adipose tissue gene expression, a significant change was observed for cell death-inducing DFFA (DNA fragmentation factor-alpha)-like effector A (CIDEA) in the HIIT group (A.U; HIIT at T0: 32.10 ± 39.37 vs. HIIT at T12: 48.2 ± 59.2). Mitochondrial transcription factor A (TFAM) content, a marker of mitochondrial biogenesis, increased significantly following HIIT (+36.2%) and MICT (+57.2%). A significant increase was observed in the HIIT group for Translocase of Outer Membrane 20 (TOM20; +54.1%; marker of mitochondrial content), Mitofusin-2 (MFN2; +71.6%; marker of mitochondrial fusion) and Parkin RBR E3 Ubiquitin Protein Ligase (PARKIN; +42.3%; marker of mitophagy). Overall, our results indicate that even though MICT (walking on treadmill) and HIIT (on an elliptical) are effective intervention strategies in obese older adults, HIIT appears to have slightly more beneficial effects. More specifically, HIIT led to higher improvements than MICT on functional capacities, lean mass and skeletal muscle markers of mitochondrial content, fusion, and mitophagy. Thus, MICT but also HIIT (time-efficient training) could be recommended as exercise modalities for obese older adults to maintain or improve mobility, health and quality of life.

The Effect of Self-Selected Exercise Workloads on Perceived Enjoyment and Self-Efficacy in Sedentary Adults

Self-selected workloads are shown to be more enjoyable than researcher-selected workloads. In addition, it is unclear if sedentary adults find aerobic interval or continuous exercise more pleasant. Therefore, the primary purpose of this study was to determine the effects of two acute bouts (interval vs. continuous) of self-selected moderate-intensity treadmill exercises on perceived enjoyment and self-efficacy towards exercise in a sedentary cohort. Methods: Sixteen sedentary adults completed two 30 min bouts of moderate-intensity treadmill activity, one interval and one continuous. Participants blindly (could not see speed, grade, and heart rate) selected their own treadmill workload with guidance from the Borg RPE 6-20 scale. Post-exercise self-efficacy and perceived enjoyment were assessed using the Self-Efficacy for Exercise Scale and the Physical Activity Enjoyment Scale, respectively. Exercise workloads using treadmill speed and grade and exercise heart rate were compared between trials. Results: No significant differences were found between conditions for self-selected workloads (p = 0.62), self-efficacy (p = 0.58), perceived enjoyment (p = 0.41), and heart rate (p = 0.12). Discussion: Sedentary individuals reported no difference in self-efficacy or perceived exercise enjoyment. Participants were, however, adequate in self-selecting their own intensities with RPE guidance as there were no differences in the workloads across conditions. These results suggest that when able to self-select moderate-intensity exercise workloads, sedentary individuals equally enjoy both interval and continuous exercise.

High-intensity interval training elicits more enjoyment and positive affective valence than moderate-intensity training over a 12-week intervention in overweight young women

Background

The purpose of this study was to compare the differences in enjoyment and affect in response to four weight control intervention protocols over 12 weeks.

Methods

Sixty overweight young females were randomised into four intervention groups: repeated sprint training (RST, 6-sec all-out sprint interspersed with 9-sec rest), high-intensity interval training (HIIT) with short interval (HIIT₁₂₀, 1-min effort at 120% V̇O_2peak) and long interval (HIIT₉₀, 4-min effort at 90% V̇O_2peak), and moderate-intensity continuous training (MICT, 60% V̇O_2peak) by cycling over 12 weeks. The total workload in each training session in HIIT₁₂₀, HIIT₉₀, and MICT was confined to 200 kJ, while it was lower in RST with 57 ± 4 kJ. Enjoyment (Physical Activity Enjoyment Scale, PACES) and affective valence (Feeling Scale, FS) were measured throughout the intervention.

Results

The score of the PACES on average over 12 weeks showed a significant between-group effect that was lower in MICT (80.8 ± 11.8) compared with HIIT₁₂₀ (92.5 ± 11.4) and HIIT₉₀ (96.8 ± 13.9) (p < 0.05). In the 8th week, enjoyment was scored higher in two HIITs compared with MICT. In the 12th week, HIITs and RST were more enjoyable than MICT, where two HIITs were better than RST. The score of FS showed a significant between-group effect that was higher in HIIT₉₀ (1.5 ± 1.4) compared with HIIT₁₂₀ (0.2 ± 1.2) (p < 0.05), but a non-significant time or group-by-time interaction effect. A significant weight loss occurred in three interval training protocols (p < 0.05), but not in MICT. The V̇O_2peak significantly increased in four groups without between-group difference.

Conclusion

Interval training, especially the long-interval type, is an enjoyable and pleasant long-term exercise intervention for overweight young women. RST could be an alternative for weight control considering its time efficiency with comparable enjoyment and overall pleasure.

Effect of Exercise Training on Body Composition and Inflammatory Cytokine Levels in Overweight and Obese Individuals: A Systematic Review and Network Meta-Analysis

Objective

This study aimed to compare and rank the effectiveness of aerobic exercise (AE), resistance training (RT), combined aerobic and resistance training (CT), and high-intensity interval training (HIIT) on body composition and inflammatory cytokine levels in overweight and obese individuals by using network meta-analysis (NMA).

Methods

We searched the PubMed, Cochrane, Embase, Web of Science, and EBSCO databases to identify randomized controlled trials investigating the effects of exercise training on inflammatory cytokines in overweight and obese patients. The retrieval period was from inception to November 2021. Two reviewers independently screened the retrieved articles, extracted the pertinent data, and assessed the risk of bias of the included studies; then, they used Stata 16.0 and Review Manager 5.3 to perform an NMA.

Results

A total of 38 studies involving 1317 patients were included in this study. The results of the NMA indicated that AE had the greatest effect on weight loss (SUCRA=78.3; SMD=−0.51, 95% CI: −0.70, −0.33); CT had the greatest effect on reducing body mass index (SUCRA=70.7; SMD=−0.46, 95% CI: −0.81, −0.10), waist circumference (SUCRA=93.4; SMD=−1.86, 95% CI: −2.80, −0.93), percentage body fat (SUCRA=79.6; SMD=−1.38, 95% CI: −2.29, −0.48), interleukin-6 level (SUCRA=86.4; SMD=−1.98, 95% CI: −3.87, −0.09), and tumor necrosis factor-α level (SUCRA=79.4; SMD=−2.08, 95% CI: −3.75, −0.42); AE (SMD=0.51, 95% CI: −1.68, 2.69), RT (SMD=0.15, 95% CI: −3.01, 3.32), CT (SMD=1.78, 95% CI: −1.35, 4.92), and HIIT (SMD=2.29, 95% CI: −1.27, 5.86) did not significantly increase the adiponectin level.

Conclusion

The current results suggest that CT is the best exercise modality for improving body composition and inflammatory status in overweight and obese individuals. More rigorous randomized control trials are needed for further validation.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022303165.

Tai Chi for Overweight/Obese Adolescents and Young Women with Polycystic Ovary Syndrome: A Randomized Controlled Pilot Trial

Background

Exercise is one of the recommended interventions for polycystic ovary syndrome (PCOS), and current evidence has shown that Tai chi may have favorable effects. The objective of this randomized controlled pilot trial was to study the feasibility and potential effects of Tai chi for overweight/obese adolescents and young women with PCOS, so a future definitive randomized controlled trial (RCT) can be well designed and implemented.

Materials and Methods

This study recruited 50 patients who were randomly assigned to two groups (Tai chi and self-monitored exercise) at a ratio of 3 : 2. The intervention lasted for 3 months, and the feasibility and effectiveness outcomes were measured.

Results

A total of 42 patients completed the study, including 24 in the Tai chi group and 18 in the control group. Compared with the self-monitored exercise group, there was a significantly decreased body mass index (BMI) in the Tai chi group adjusted for baseline BMI. The testosterone level and lipid profile were also decreased compared to controls; the same tendency was also observed for the homeostasis model assessment of insulin resistance (HOMA-IR), but the difference did not achieve statistical significance. Twenty-four (out of 30, 80%) patients in the Tai chi group and 18 (out of 20, 90%) patients in the self-monitored exercise group completed the data collection. A total of 36 exercise sessions were held in both groups. Patients in the Tai chi group took a mean of 34.0 ± 2.21 classes (93.06%), and those in the self-monitored exercise group engaged in 32 ± 3.06 exercise sessions (88.27%) out of the 36 required exercise sessions.

Conclusions

The present pilot study was feasible to deliver; there was a decrease in BMI, testosterone level, and lipid profile for PCOS patients in the Tai chi group at 3 months. In a future definitive trial, lower recruitment rate and outcome measurements lead to poor patient acceptance such as the 5-time point oral glucose tolerance test need to be considered and one fixed type of aerobic exercise and supervision from the investigator for the control group are also needed. Trial registration: ClinicalTrials.gov, NCT02608554.

Effects of High-Intensity Interval Training on Selected Adipokines and Cardiometabolic Risk Markers in Normal-Weight and Overweight/Obese Young Males-A Pre-Post Test Trial

The study aimed to assess effects of high-intensity interval training (HIIT) on plasma adipokines and cardiometabolic markers in normal and excess weight youth. Eighteen healthy young males (18.2 ± 1.06 yrs.) were divided in normal-weight group (NWG; body mass index (BMI), 20.5 ± 1.51 kg/m2; n = 9) and excess-weight group (EWG; BMI, 30.8 ± 4.56 kg/m2; n = 9). Participants performed an eight-week HIIT program without caloric restriction. Body composition, plasma leptin, adiponectin, chemerin, omentin-1, lipids, C-reactive protein (CRP), and the homeostasis model assessment index for insulin resistance (HOMA-IR) were assessed before and after the HIIT program. The program resulted in significant increases in omentin levels (p < 0.01) in EWG (27%) and NWG (22%), but no changes in leptin, adiponectin, and chemerin in both groups. BMI (−1.62%; p = 0.015), body fat (−1.59%; p = 0.021), total cholesterol (−11.8%; p = 0.026), triglycerides (−21.3%; p = 0.023), and HOMA-IR (−31.5%; p = 0.043) decreased in EWG only. Repeated measures detected significant interaction “Time x Group” for body mass and BMI only. Eight-week HIIT program improved body composition, lipid profile, and insulin sensitivity in excess-weight individuals. It resulted in an increase in omentin levels in both normal- and excess-weight groups, but no changes in leptin, adiponectin, and chemerin. Body composition has not influenced the response of the four adipokines to HIIT.

Psychological Adaptations to High-Intensity Interval Training in Overweight and Obese Adults: A Topical Review

Regular exercise has been reported as a fundamental piece of the management and treatment puzzle of obesity, playing a vital role in numerous psychological indicators. However, it is unclear whether high-intensity interval training (HIIT) can improve critical psychological health markers such as adherence, exercise enjoyment, affective responses, health-related quality of life, anxiety, and depression in overweight and obese adults. The purpose of this topical review was to catalogue studies investigating the psychological responses to HIIT in order to identify what psychological outcomes have been assessed, the research methods used, and the results. The inclusion/exclusion criteria were met by 25 published articles investigating either a traditional, single-component (84%) or a hybrid-type, multi-component (16%) HIIT protocol and involving 930 participants with overweight/obesity. The present topical review on HIIT-induced psychological adaptations shows that this popular exercise mode, but also demanding for the masses, can meaningfully increase the vast majority of the selected mental health-related indices. These improvements seem to be equal if not greater than those observed for moderate-intensity continuous training in overweight and obese adults. However, further research is needed in this area, focusing on the potential mechanisms behind positive alterations in various psychological health parameters through larger samples and high-quality randomized controlled trials.

Affective Valence and Enjoyment in High- and Moderate-High Intensity Interval Exercise. The Tromsø Exercise Enjoyment Study

Introduction

Exercise at high intensity may cause lower affective responses toward exercise compared with moderate intensity exercise. We aimed to elucidate affective valence and enjoyment in high- and moderate-high interval exercise.

Methods

Twenty recreationally active participants (9 females, 11 males, age range: 20-51 years) underwent three different treadmill running exercise sessions per week over a 3-week period, in randomized order; (1) CE70: 45 min continuous exercise at 70% of heart rate maximum (HR_max), (2) INT80: 4 × 4 min intervals at 80% of HR_max, (3) INT90: 4 × 4 min intervals at 90% of HR_max. Pre-tests included graded submaximal steady state intensities and a test to exhaustion for determining peak oxygen uptake and HR_max. Affective valence (pleasure/displeasure) was measured before, during and after the sessions using the Feeling Scale (FS). Enjoyment was assessed before and after the sessions applying the Physical Activity Enjoyment Scale (PACES) and during the sessions using the Exercise Enjoyment Scale (EES).

Results

The participants felt lower pleasure (between-sessions effect: p = 0.02, _p η²: 0.13) during INT90 sessions (FS: 1.08, 95% CI: 0.35-1.92) compared with INT80 (FS: 2.35, 95% CI: 1.62-3.08, p = 0.052) and CE70 sessions (FS: 2.45, 95% CI: 1.72-3.18, p = 0.03), with no differences between INT80 and CE70 sessions (p = 1.00). There were higher enjoyment after INT80 sessions (PACES: 101.5, 95% CI: 95.7-107.3) versus CE70 sessions (PACES: 91.3 95% CI: 85.5-97.1, p = 0.046), and no differences between INT90 (PACES: 98.2, 95% CI: 92.4-103.4) and CE70 (p = 0.29) or INT80 (p = 1.00). For enjoyment during exercise, CE70 were perceived more enjoyable, and INT80 and INT90 less enjoyable in week 2 (EES: week x session: p = 0.01, _p η²: 0.11; CE70: 4.3, 95% CI: 3.6-4.9, INT80: 4.6, 95% CI: 3.9-5.2, INT90: 4.0, 95% CI: 3.4-4.7) and 3 (EES: CE70: 4.2, 95% CI: 3.7-4.8, INT80: 4.8, 95% CI: 4.2-5.3, INT90: 4.3, 95% CI: 3.8-4.9) than in week 1 (EES: CE70: 3.5, 95% CI: 3.0-4.0, INT80: 5.0, 95% CI: 4.5-5.5, INT90: 4.5, 95% CI: 4.0-5.0).

Conclusion

The negative affective consequences associated with high intensity interval exercise can be alleviated by keeping the intensity at or around 80% of HR_max while preserving the beneficial enjoyment responses associated with interval exercise.

Effects of linear periodization of combined training on quality of life of adults with obesity: a blind randomized controlled trial

This study aimed to compare the effect of 16-weeks of combining aerobic and strength training with a linear increase or fixed intensity on the health-related quality of life (HRQoL) of obese adults. This single-blinded clinical trial involved adults with obesity (BMI ≥ 30 kg/m2), randomized into control (CG), fixed intensity (FG), or linear increase (LG) groups. The FG and LG performed 16 weeks of combined (aerobic + strength) training for 60 min, three times a week. The FG performed aerobic exercises between 50 and 59% of the heart rate reserve (HRres) and strength at 10-12 maximum repetitions (RM). The LG started with 40-49% of HRres and 12-14 RM and progressively increased the intensity (50-59% and 10-12 RM; 60-69% and 8-10 RM). The HRQoL was assessed using the SF-36 questionnaire. Generalized estimation equations and mean differences (∆) were used. Of the 69 participants (23 per group), 36 completed the intervention (CG = 13, FG = 9, and LG = 14). A significant difference was observed in the time of the physical function, with superiority in the training groups (CG: ∆ = 1.2 vs. FG and LG, respectively: ∆ = 10.0). The mental health component and mental health domain showed significant differences for the FG (∆ = 30.2 and ∆ = 23.1, respectively). In conclusion, the combined training improved physical functioning. Specifically, fixed-intensity training effectively enhanced mental health indicators.Trial Registration: This study is registered at www.ensaiosclinicos.gov.br/ (No. RBR-3c7rt3), Date of registration: 07/02/2018.

Effects of low-volume, high-intensity interval training on maximal oxygen consumption, body fat percentage and health-related quality of life in women with overweight: A randomized controlled trial

Background

Several investigations suggest that high-intensity interval training (HIIT) provokes larger changes in VO_2max compared to moderate-intensity continuous training (MICT); other studies associate HIIT with significant decreases in total, abdominal and visceral fat mass. However, some meta-analyses express that the enhancements with HIIT on VO_2max are slightly higher concerning MICT. These studies had low-to-moderate methodological quality, and the exercise protocols were completed mostly on treadmills or cycle ergometers. Thus, the objective of this study was to compare the effect of a low-volume HIIT versus a MICT program on VO_2max, body fat percentage (BFP), and health-related quality of life (HRQoL) in overweight women. It followed a research protocol with high methodological rigor and good reporting quality.

Methods

After two physical adaptation weeks (run-in period), thirty-five volunteers were randomized to HIIT (n = 16) or MICT (n = 19). Both groups performed 24 sessions on a grass sports field (walking, jogging or running). The HIIT group completed 15 bouts of 30 s [90–95%, maximal heart rate (HR_max)], while the MICT group completed 30 min of continuous exercise (65–75% HR_max).

Results

The difference between HIIT and MICT post-intervention on VO_2max was not statistically significant (0.8 ml/kg/min. CI 95%, −1.0 to 2.7, p = 0.37). Similarly, no statistically significant differences were found between groups for BFP and HRQoL.

Conclusions

Low-volume HIIT program has no quantitative advantage compared with that resulting from MICT, in VO2max, BFP, and HRQoL. ClinicalTrials.gov Identifier: NCT03300895.

Effects of 8 Weeks of High-Intensity Interval Training and Spirulina Supplementation on Immunoglobin Levels, Cardio-Respiratory Fitness, and Body Composition of Overweight and Obese Women

Simple Summary

Overweight and obese, like other forms of malnutrition, have been shown to affect immune function through changing immunoglobin or cardio-respiratory fitness levels and cell-mediated immune responses. Although calorie restriction and exercise are the most common therapies for obesity or overweight, it is unclear what kind of supplementation these people should take or how much exercise they should perform. Hence, in this study, we examined the effect of 8 weeks of high-intensity interval training (HIIT) with spirulina supplementation on the humoral immunity, cardio-respiratory fitness, and body composition of overweight and obese women. The results demonstrated that spirulina supplementation with HIIT not only decreased fat free mass but also boosted immunoglobin-A, which plays an important role in the immune system.

Abstract

Our study examined the effect of 8 weeks of high-intensity interval training (HIIT) and spirulina supplementation on the humoral immunity, cardio-respiratory fitness, and body composition of overweight and obese women. Thirty sedentary women (height: 161.7 ± 2.8 cm, body mass: 75.8 ± 8.4 kg, body mass index [BMI]: 28.8 ± 2.5 kg/m², age: 25.1 ± 6.7 years) were divided into three groups: placebo with HIIT group, spirulina group (SG), or combined group (CG). Exercise groups performed HIIT for 8 weeks, with three sessions per week and four to seven repetitions in each session of 30 s running and 30 s walking; the intensity was established at 90% of the maximum heart rate. Supplementation groups received 6 g of spirulina powder per day. Fasting blood samples were collected before and after 8 weeks to determine the concentrations of immunoglobulins (IgA and IgG). There was a significant group-by-time interaction for fat free mass (FFM; p = 0.001, f = 8.52, ηp² = 0.39) and IgA (p = 0.036, f = 3.86, ηp² = 0.22). The post hoc analysis revealed that CG reduced FFM significantly (p = 0.012, g = −0.55) after training. CG and SG showed significantly greater IgA concentrations after 8 weeks (p = 0.02, g = 0.70 and p = 0.001, g = 0.34, respectively). We conclude that spirulina supplementation with HIIT affects the body composition (lower FFM) but also boosts IgA, which plays an important role in the immune system.

Alternating high-intensity interval training and continuous training is efficacious in improving cardiometabolic health in obese middle-aged men

Background

High-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) alone has been shown to improve metabolic health, but the effects of alternating the two training approaches as often practiced in real life remained unclear.

Purpose

To examine the effects of HIIT or MICT alone or alternating HIIT-MICT on cardiometabolic responses in inactive obese middle-aged men.

Methods

Forty-two participants (age: 42 ± 5 y; BMI: 26.3 ± 2.1 kg m⁻²) were randomly assigned to four groups: HIIT (12 x 1-min running bouts at 80–90% HR_max interspersed with 1-min active recovery at 50% HR_max), MICT (40-min brisk walk at 65–70% HR_max), alternating HIIT-MICT or a non-exercise control group (CON). Exercise sessions were conducted three times per week for 16 weeks. Maximal oxygen uptake (VO_2max), body composition (by bioelectrical impedance analysis), blood pressure, fasting blood glucose, insulin resistance (HOMA-IR) and lipid profile were assessed at baseline and after the 16-week intervention. Enjoyment and self-efficacy were also assessed at the end of intervention.

Results

All exercise groups showed a similar VO_2max increase of ∼15% (HIIT: 34.3 ± 4.4 vs 39.1 ± 5.4; MICT: 34.9 ± 5.0 vs 39.4 ± 7.2; and alternating HIIT-MICT: 34.4 ± 5.0 vs 40.3 ± 4.6 mL kg⁻¹min⁻¹) compared to baseline and CON (all p < 0.05). Weight, BMI, % fat and waist circumference also showed similar reductions in all exercise groups compared to baseline and CON (all p < 0.05). No significant group difference was observed for all blood markers. Compared to baseline, total cholesterol decreased after HIIT-MICT, while HIIT significantly decreased fasting insulin level and improved insulin resistance (p < 0.05). Enjoyment, self-efficacy and adherence were similar among all exercise groups.

Conclusion

HIIT or MICT alone or alternating HIIT-MICT similarly improve cardiovascular fitness and body composition in obese middle-aged men despite differences in total training volume and time commitment.

The Role of Exercise Training on Low-Grade Systemic Inflammation in Adults with Overweight and Obesity: A Systematic Review

Low-grade systemic inflammation leads to critical alterations of several tissues and organs that can promote the appearance of non-communicable diseases, a risk that is increased in adults with obesity. Exercise training may counteract low-grade systemic inflammation, but there is a lack of consensus on how cytokines are modulated by training in adults with obesity. This study aimed of examining the effects of exercise training on circulating pro- and anti-inflammatory cytokines in adults with overweight and obesity, and whether exercise-induced fat mass reduction could mediate that effect. The search was conducted on Medline (Pubmed), SPORTDiscus and Web of Science databases from January 1998 to August 2021, using keywords pertaining to inflammation, exercise, and obesity. A total of 27 studies were selected, in which the circulating concentration levels of cytokines were analyzed. Endurance training (ET) decreased circulating CRP, IL-6 and TNF-α levels. TNF-α was reduced after resistance and concurrent training (CT), while IL-10 increased after resistance training (RT). Changes in IL-10 and CRP coincided with fat mass reduction, while decreased TNF-α levels were concomitant with changes in IL-6 and IL-10. Exercise training may reduce systemic low-grade inflammation profile in adults with overweight and obesity.