Effect of High-Intensity Interval Training on Total, Abdominal and Visceral Fat Mass: A Meta-Analysis

Lactate coordinated with exercise promoted the browning of inguinal white adipose tissue

Lactate, an important exercise metabolite, induces white adipose tissue browning by upregulated uncoupling protein 1 (UCP1) expression. However, the function of lactate during browning of inguinal white adipose tissue (iWAT) caused by exercise is unclear. Here, we considered lactate as an exercise supplement and investigated the effects of chronic pre-exercise lactate administration on energy metabolism and adipose tissue browning. C57B/L6 male mice (5 weeks of age) were divided into six groups. We evaluated the changes in blood lactate levels in each group of mice after the intervention. Energy expenditure was measured after the intervention immediately by indirect calorimetry. The marker protein levels and gene expressions were determined by western-blot and quantitative real-time PCR. HIIT significantly decreased adipose tissue weight while increased energy expenditure and the expression of UCP1 in iWAT; however, these regulations were inhibited in the DCA+HIIT group. Compared with the MICT and LAC groups, long-term lactate injection before MICT led to lower WAT weight to body weight ratios and higher energy expenditure in mice. Furthermore, the marker genes of browning in iWAT, such as Ucp1 and Pparγ, were significantly increased in the LAC+MICT group than in the other groups, and the expression of monocarboxylate transporter-1 (Mct1) mRNA was also significantly increased. Lactate was involved in exercise-mediated browning of iWAT, and its mechanism might be the increased of lactate transport through MCT1 or PPARγ upregulation induced by exercise. These findings suggest exogenous lactate may be a new exercise supplement to regulate metabolism.

Effects of a Cycling versus Running HIIT Program on Fat Mass Loss and Gut Microbiota Composition in Men with Overweight/Obesity

PURPOSE

High-intensity interval training (HIIT) can efficiently decrease total and (intra-)abdominal fat mass (FM); however, the effects of running versus cycling HIIT programs on FM reduction have not been compared yet. In addition, the link between HIIT-induced FM reduction and gut microbiota must be better investigated. The aim of this study was to compare the effects of two 12-wk HIIT isoenergetic programs (cycling vs running) on body composition and fecal microbiota composition in nondieting men with overweight or obesity.

METHODS

Sixteen men (age, 54.2 ± 9.6 yr; body mass index, 29.9 ± 2.3 kg·m -2 ) were randomly assigned to the HIIT-BIKE (10 × 45 s at 80%-85% of maximal heart rate, 90-s active recovery) or HIIT-RUN (9 × 45 s at 80%-85% of maximal heart rate, 90-s active recovery) group (3 times per week). Dual-energy x-ray absorptiometry was used to determine body composition. Preintervention and postintervention fecal microbiota composition was analyzed by 16S rRNA gene sequencing, and diet was controlled.

RESULTS

Overall, body weight, and abdominal and visceral FM decreased over time ( P < 0.05). No difference was observed for weight, total body FM, and visceral FM between groups (% change). Conversely, abdominal FM loss was greater in the HIIT-RUN group (-16.1% vs -8.3%; P = 0.050). The α-diversity of gut microbiota did not vary between baseline and intervention end and between groups, but was associated with abdominal FM change ( r = -0.6; P = 0.02). The baseline microbiota profile and composition changes were correlated with total and abdominal/visceral FM losses.

CONCLUSIONS

Both cycling and running isoenergetic HIIT programs improved body composition in men with overweight/obesity. Baseline intestinal microbiota composition and its postintervention variations were correlated with FM reduction, strengthening the possible link between these parameters. The mechanisms underlying the greater abdominal FM loss in the HIIT-RUN group require additional investigations.

Endurance exercise preserves physical function in adult and older male C57BL/6 mice: high intensity interval training (HIIT) versus voluntary wheel running (VWR)

Exercise has been shown to improve physical function, mitigate aspects of chronic disease and to potentially alter the trajectory of age-related onset of frailty and sarcopenia. Reliable and valid preclinical models are necessary to elucidate the underlying mechanisms at the intersection of age, exercise, and functional decline. The purpose of this study was to compare, head to head, the effects of two common pre-clinical models of endurance exercise: high intensity interval training (HIIT) and voluntary wheel running (VWR). The hypothesis was that a prescribed and regimented exercise program, HIIT, would prove to be a superior training method to unregulated voluntary exercise, VWR. To investigate this hypothesis, we evaluated adult (n = 24, designated 10 m, aged 6 months at the beginning of the study, 10 months at its completion) and older adult (n = 18, designated 26 m, aging from 22 months to 26 months over the course of the study) C57BL/6 male mice. These mice were randomly assigned (with selection criteria) to a 13-week program of voluntary wheel running (VWR), high intensity interval training (HIIT), or sedentary control (SED). The functional aptitude of each mouse was determined pre- and post-training using our composite CFAB (comprehensive functional assessment battery) scoring system consisting of voluntary wheel running (volitional exercise and activity rate), treadmill (endurance), rotarod (overall motor function), grip meter (forelimb strength), and inverted cling (whole body strength/endurance). To measure sarcopenia, we tracked body mass, body composition (with EchoMRI), plantar flexor torque (in 10 m), and measured muscle wet mass post-training. Overall, adult CFAB scores decreased while body mass and percent body fat increased as they matured; however, exercise significantly mitigated the changes (p < 0.05) compared to SED. Older adults demonstrated preservation of function (CFAB) and reduced body fat (p < 0.05) compared to SED. To conclude, both types of exercise maintained physical function equally in older mice.

Is low-volume high-intensity interval training a time-efficient strategy to improve cardiometabolic health and body composition? A meta-analysis

The present meta-analysis aimed to assess the effects of low-volume high-intensity interval training (LV-HIIT; i.e., ≤5 min high-intensity exercise within a ≤15 min session) on cardiometabolic health and body composition. A systematic search was performed in accordance with PRISMA guidelines to assess the effect of LV-HIIT on cardiometabolic health and body composition. Twenty-one studies (moderate to high quality) with a total of 849 participants were included in this meta-analysis. LV-HIIT increased cardiorespiratory fitness (CRF, SMD = 1.19 [0.87, 1.50]) while lowering systolic blood pressure (SMD = -1.44 [-1.68, -1.20]), diastolic blood pressure (SMD = -1.51 [-1.75, -1.27]), mean arterial pressure (SMD = -1.55 [-1.80, -1.30]), MetS z-score (SMD = -0.76 [-1.02, -0.49]), fat mass (kg) (SMD = -0.22 [-0.44, 0.00]), fat mass (%) (SMD = -0.22 [-0.41, -0.02]), and waist circumference (SMD = -0.53 [-0.75, -0.31]) compared to untrained control (CONTROL). Despite a total time-commitment of LV-HIIT of only 14%-47% and 45%-94% compared to moderate-intensity continuous training and HV-HIIT, respectively, there were no statistically significant differences observed for any outcomes in comparisons between LV-HIIT and moderate-intensity continuous training (MICT) or high-volume HIIT. Significant inverse dose-responses were observed between the change in CRF with LV-HIIT and sprint repetitions (β = -0.52 [-0.76, -0.28]), high-intensity duration (β = -0.21 [-0.39, -0.02]), and total duration (β = -0.19 [-0.36, -0.02]), while higher intensity significantly improved CRF gains. LV-HIIT can improve cardiometabolic health and body composition and represent a time-efficient alternative to MICT and HV-HIIT. Performing LV-HIIT at a higher intensity drives higher CRF gains. More repetitions, longer time at high intensity, and total session duration did not augment gains in CRF.

Effect of high-intensity interval training in physiotherapy primary care for patients with inflammatory arthritis: the ExeHeart randomised controlled trial

OBJECTIVES

To assess the effect of high-intensity interval training (HIIT) delivered in physiotherapy primary care on the primary outcome of cardiorespiratory fitness (CRF) in patients with inflammatory arthritis (IA). Additionally, to explore the effects of HIIT on secondary outcomes, including cardiovascular disease (CVD) risk factors and disease activity.

METHODS

Single-blinded randomised controlled trial with 60 patients randomly assigned to either a control group receiving usual care or an exercise group receiving usual care and 12 weeks of individualised HIIT at 90%-95% peak heart rate. Outcomes were assessed at baseline, 3 months and 6 months post baseline and included CRF measured as peak oxygen uptake (VO2peak), classic CVD risk factors, disease activity, anthropometry and patient-reported physical activity, pain, fatigue, disease impact and exercise beliefs and self-efficacy.

RESULTS

Intention-to-treat analysis demonstrated a significant between-group difference in VO2peak at 3 months (2.5 mL/kg/min, 95% CI 0.9 to 4.0) and 6 months (2.6 mL/kg/min, 95% CI 0.8 to 4.3) in favour of the exercise group. A beneficial change in self-reported physical activity in favour of the exercise group was observed at 3 and 6 months. The HIIT intervention was well-tolerated with minimal adverse events and no apparent impact on disease activity. Differences in secondary outcomes related to CVD risk factors, disease impact, pain, fatigue and exercise beliefs and self-efficacy were generally small and non-significant.

CONCLUSION

After 12 weeks of supervised HIIT delivered in physiotherapy primary care, patients with IA demonstrated a favourable improvement in CRF, with sustained effects at 6-month follow-up.

TRIAL REGISTRATION NUMBER

NCT04922840.

Cardiorespiratory Fitness and Performance Adaptations to High-Intensity Interval Training: Are There Differences Between Men and Women? A Systematic Review with Meta-Analyses

BACKGROUND

It is important to consider biological sex as a variable that might influence exercise adaptation in order to optimize exercise prescription for men and women.

OBJECTIVE

The aim of this study was to quantify the impact of biological sex on maximal oxygen uptake ([Formula: see text]O2max) and performance outcomes after high-intensity interval training (HIIT).

METHODS

A systematic search and review was conducted by two independent reviewers up to 8 September 2022 using MEDLINE, SPORTDiscus, and Sports Medicine & Education Index in ProQuest. Trials including healthy adults were included if they presented data for or compared male and female [Formula: see text]O2max or performance outcomes in response to HIIT. Performance outcomes included measures of exercise performance and concurrently measured physiological adaptations. Where appropriate, a random-effects, pre-post meta-analysis was undertaken. Data were sub-grouped for men and women, baseline training level, mean age, intervention type, and intervention length. Heterogeneity was assessed using Chi2, Cochran's Q, and Higgins I2 and sensitivity analyses, where required. Study quality was assessed using the Newcastle-Ottawa Scale and publication bias was assessed through visual inspection of funnel plots.

RESULTS

Thirty-three references from 28 trials were included in the review (n = 965; 462 women and 503 men). Meta-analyses included 19 studies for [Formula: see text]O2max, eight for peak power output from [Formula: see text]O2max testing (PPO), and five for threshold power (powerAT). Meta-analyses revealed similar increases in [Formula: see text]O2max in women (g = 0.57; 95% CI 0.44-0.69) and men (g = 0.57; 95% CI 0.42-0.72), and powerAT in women (g = 0.38; 95% CI 0.13-0.64) and men (g = 0.38; 95% CI 0.11-0.64). Raw mean differences for change in [Formula: see text]O2max were Δ 0.32 L·min-1 and 3.50 mL·kg-1·min-1 in men, versus Δ 0.20 L·min-1 and 3.34 mL·kg-1·min-1 for women. No significant sex differences were present for the primary analysis of any outcome. After sub-grouping, significant differences were present for PPO where the effect size was higher for well-trained women (g = 0.37) compared with well-trained men (g = 0.17), and for [Formula: see text]O2max where interventions with a duration of 4 weeks or less had significantly smaller effect sizes compared with those longer than 4 weeks (p < 0.001). Unweighted mean percentage change in [Formula: see text]O2max, PPO, and powerAT across studies was 11.16 ± 7.39%, 11.16 ± 5.99%, and 8.07 ± 6.55% for women, and 10.90 ± 5.75%, 8.22 ± 5.09%, and 7.09 ± 7.17% for men, respectively. Significant heterogeneity was present for both [Formula: see text]O2max and PPO (I2, range: 62.06-78.80%). Sub-grouping by baseline training status and intervention length decreased heterogeneity in most groups. A qualitative synthesis of other outcomes indicated similar improvements in fitness and performance for men and women with some evidence suggesting differences in the mechanisms of adaptation.

LIMITATIONS AND RISK OF BIAS

Publication bias is unlikely to have significantly influenced results for [Formula: see text]O2max or powerAT, but the meta-analysis of PPO could have benefitted from additional study data to strengthen results. The overlap in age categories and sensitivity of the analysis limits the accuracy of the results of the sub-grouping by age.

CONCLUSIONS

Findings indicated no sex-specific differences for any fitness or performance outcomes. Baseline training status and intervention length accounted for most variability in outcomes. PROSPERO registration number: CRD42021272615.

Effect of high-intensity interval training on obstructive sleep apnea severity: A randomized controlled trial

Vigorous physical activity has been associated with a reduced risk of developing obstructive sleep apnea (OSA). However, whether high-intensity interval training (HIIT) reduces OSA severity remains unclear. Thus, this study aimed to investigate the impact of 12 weeks of HIIT on the apnea-hypopnea index (AHI) and sleep parameters in participants with moderate-severe OSA. In this randomized controlled trial, 36 adults (19 males; 52.2 ± 9.8 years; body mass index = 34.2 ± 5.8) with moderate to severe OSA (AHI = 42.0 ± 22.9 e/h) were randomly assigned to HIIT [5 periods of 4 min of walking or running on a treadmill at 90-95 % of maximum heart rate (HRmax) interspersed with 3 min of walking at 50-55 % of HRmax performed three times per week for 12 weeks] or a control group (CG; stretching exercises performed two times per week for 12 weeks). Sleep parameters were assessed at baseline and after 12 weeks through overnight polysomnography. Generalized estimated equations assessed differences between groups over time. There was not group × time interaction for body mass index between groups (p = 0.074). However, significant group × time interactions were observed for AHI (CG change = 8.2 ± 3.7, HIIT change = -8.6 ± 4.8; p = 0.005), SaO2 minimum (CG change = -1.6 ± 1.6 %, HIIT change = 0.4 ± 2.3 %; p = 0.030), total sleep time (CG change = -31.5 ± 19.5 min, HIIT change = 33.7 ± 19.3 min; p = 0.049), and sleep efficiency (CG change = -3.2 ± 4.4 %, HIIT change = 9.9 ± 3.5 %; p = 0.026). Moreover, there was a significant time × group interaction for maximum oxygen consumption (VO2max; CG change = -1.1 ± 1.0 mL/kg/min, HIIT change = 4.8 ± 0.9 mL/kg/min; p < 0.001)]. However, In patients with OSA, 12 weeks of HIIT decreases sleep apnea severity, improves sleep quality, and cardiorespiratory fitness. CLINICAL TRIAL REGISTRATION: (Registro Brasileiro de Ensaios Clínicos [ReBec]): # RBR-98jdt3.

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.

High-intensity interval training is not superior to continuous aerobic training in reducing body fat: A systematic review and meta-analysis of randomized clinical trials

Background/Objective

Guidelines on obesity management reinforce regular exercise to reduce body fat. Exercise modalities, including high-intensity interval training (HIIT), appear to produce a similar effect to continuous aerobic training (CAT) on body fat. However, they have not addressed the chronic effect of HIIT vs. CAT on body fat assessed by dual energy X-ray absorptiometry (DEXA). Thus, we compared the effectiveness of CAT vs. HIIT protocols on body fat (absolute or relative) (%BF) and abdominal visceral fat reduction, assessed by DEXA, in adults with overweight and obesity.

Methods

We conducted a systematic review and meta-analysis of randomized clinical trials (RCTs) including both female or male adults with excess body weight. We performed searches in the databases MEDLINE (PubMed), EMBASE, Scopus, LILACS, Web of Science and Cochrane.

Results

In our analysis (11 RCTs), we found no greater benefit on %BF of HIIT vs. CAT (MD -0.55%, 95% CI -1.42 to 0.31; p = 0.209). As for abdominal visceral fat, no training modality was superior (SMD: -0.05, 95% CI -0.29 to 0.19; p = 0.997). Regarding secondary outcomes (body weight, BMI, VO2 max, glycemic and lipid profiles), HIIT shows greater benefit than CAT in increasing VO2 max and fasting blood glucose and reducing total cholesterol.

Conclusion

HIIT is not superior to CAT in reducing %BF or abdominal visceral fat in individuals characterized by excess weight. However, HIIT showed beneficial effects on cardiorespiratory fitness, total cholesterol and fasting blood glucose when compared to CAT.

Effects of low-versus high-volume high-intensity interval training on glycemic control and quality of life in obese women with type 2 diabetes. A randomized controlled trial

Background/objective

Comparison between different training volumes of high-intensity interval training (HIIT) is understudied in type 2 diabetes. This study aimed to compare the effects of low- and high-volume HIIT on glycemic control, blood lipids, blood pressure, anthropometric adiposity measures, cardiorespiratory fitness, and health-related quality of life (HRQoL) in women with type 2 diabetes.

Methods

Seventy-two obese women with type 2 diabetes aged 36-55 were randomly assigned to a low-volume HIIT group (i.e., 2 × 4-min high-intensity treadmill exercise at 85%-90% of peak heart rate, with a 3-min active recovery interval in between), a high-volume HIIT group (i.e., 4 × 4-min high-intensity treadmill exercise at 85%-90% of peak heart rate, with three 3-min active recovery intervals in between), and a non-exercising control group. Patients in HIIT groups exercised three days a week for 12 weeks. All patients received oral hypoglycemic medications with no calorie restrictions. The outcome measures were glycosylated hemoglobin (HbA1c), fasting blood glucose (FBG), 2-hour postprandial blood glucose (2-hr PPBG), total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), waist circumference (WC), waist-to-hip ratio, time to maximal exhaustion determined from a maximal treadmill exercise test (i.e., a measure of cardiorespiratory fitness), and HRQoL assessed by the 12-item Short Form (SF-12) Health Survey.

Results

The low- and high-volume HIIT groups showed significant improvements in all outcome measures compared to the baseline and the non-exercising group (P < 0.05), except for DBP in the low-volume HIIT group (p > 0.05). Also, both low- and high-volume HIIT groups showed similar improvements in TC, HDL, SBP, DBP, BMI, WC, waist-to-hip ratio, and the SF-12 scores, with no significant between-groups difference (p > 0.05). The high-volume HIIT group, however, showed more significant improvements in HbA1c, FBG, 2-hr PPBG, TG, LDL, and treadmill time to maximal exhaustion than the low-volume HIIT group (p < 0.05). The non-exercising group showed non-significant changes in all outcome measures (p > 0.05).

Conclusion

Low-volume HIIT could be equally effective as high-volume HIIT for improving TC, HDL, blood pressure, anthropometric adiposity measures, and HRQoL in obese women with type 2 diabetes. Nevertheless, high-volume HIIT could have a greater impact on glycemic control, TG, LDL, and cardiorespiratory fitness in these patients.

Trial registration

ClinicalTrials.gov, NCT05110404.

High-intensity interval training induces lactylation of fatty acid synthase to inhibit lipid synthesis

BACKGROUND

The aim of study was to observe the effect of increased lactate levels during high-intensity interval training (HIIT) on protein lactylation, identify the target protein, and investigate the regulatory effect of lactylation on the function of the protein.

METHODS

C57B/L6 mice were divided into 3 groups: the control group, HIIT group, and dichloroacetate injection + HIIT group (DCA + HIIT). The HIIT and DCA + HIIT groups underwent 8 weeks of HIIT treatment, and the DCA + HIIT group was injected DCA before HIIT treatment. The expression of lipid metabolism-related genes was determined. Protein lactylation in subcutaneous adipose tissue was identified and analyzed using 4D label-free lactylation quantitative proteomics and bioinformatics analyses. The fatty acid synthase (FASN) lactylation and activity was determined.

RESULTS

HIIT had a significant effect on fat loss; this effect was weakened when lactate production was inhibited. HIIT significantly upregulated the protein lactylation while lactate inhibition downregulated in iWAT. FASN had the most modification sites. Lactate treatment increased FASN lactylation levels, inhibited FASN activity, and reduced palmitate and triglyceride synthesis in 3T3-L1 cells.

CONCLUSIONS

This investigation revealed that lactate produced by HIIT increased protein pan-lactylation levels in iWAT. FASN lactylation inhibited de novo lipogenesis, which may be an important mechanism in HIIT-induced fat loss.

High-intensity interval training in breast cancer patients: A systematic review and meta-analysis

BACKGROUND

Women with breast cancer and improved survival often experience treatment-related impairments. High-intensity interval training (HIIT) has emerged as a promising exercise therapy modality for adult cancer patients. However, the overall effects of HIIT in breast cancer patients remain scarce and controversial. Therefore, we conducted a systematic review and meta-analysis to comprehensively evaluate the impact of HIIT on health-related outcomes in breast cancer patients.

METHODS

We searched the PubMed, Embase, and Web of Science from inception to November 7, 2022. Eligible studies included randomized controlled trials that compared HIIT interventions with usual care (UC) or MICT in breast cancer patients. The primary outcome assessed was physical fitness, and exploratory outcomes included body composition, blood-borne biomarkers, and patient-reported outcomes. Summary data were extracted, and standardized mean differences (SMD) were calculated for meta-analysis. For outcomes that could not be pooled, a systematic review was conducted.

RESULTS

Our analysis included 19 articles from 10 studies, encompassing 532 participants who met the inclusion criteria. Pooled results demonstrated that HIIT was superior to UC in improving peak oxygen uptake (VO2peak ). The SMD for VO2peak (L/min) and VO2peak (mL/kg/min) was 0.79 (95% CI 0.13, 1.45) and 0.59 (95% CI 0.01, 1.16), respectively. No significant differences in VO2peak were found between the HIIT and MICT groups. Meta-analyses on body composition and blood-borne biomarkers showed no significant differences between HIIT and UC. Systematic review indicated favorable effects of HIIT on muscle strength, fatigue, and emotional well-being.

CONCLUSIONS

HIIT is a time-efficient alternative to MICT for improving VO2peak and may also enhance muscle strength and alleviate fatigue and emotional symptoms in breast cancer patients. HIIT should be considered as an important component of exercise prescription in breast cancer care. Further studies with larger cohorts are needed to determine the clinical significance of HIIT-induced changes in terms of other outcomes in women with breast cancer.

Aerobic and Muscle-Strengthening Physical Activity, Television Viewing, and Nonalcoholic Fatty Liver Disease: The CARDIA Study

BACKGROUND

The prevalence of non-alcoholic fatty liver disease (NAFLD) in U.S. adults is over 30%, yet the role of lifestyle factors in the etiology of NAFLD remains understudied. We examined the associations of physical activity, by intensity and type, and television viewing with prevalent NAFLD.

METHODS

Cross-sectional analysis of a population-based sample of 2726 Black (49%) and White (51%) adults (Mean (SD) age, 50 (3.6) years; 57.3% female) from the CARDIA study. Exposures were aerobic activity by intensity (moderate, vigorous; hours/week); activity type (aerobic, muscle-strengthening; hours/week); and television viewing (hours/week), examined concurrently in all models and assessed by validated questionnaires. Our outcome was NAFLD (liver attenuation < 51 Hounsfield Units), measured by non-contrast computed tomography, after exclusions for other causes of liver fat. Covariates were sex, age, race, study center, education, diet quality, smoking status, alcohol consumption, and body mass index or waist circumference.

RESULTS

648 participants had NAFLD. In the fully adjusted modified Poisson regression model, the risk ratios per interquartile range of each exposure were moderate-intensity aerobic activity, 1.10 (95% CI, 0.97-1.26); vigorous-intensity aerobic activity, 0.72 (0.63-0.82); muscle-strengthening activity, 0.89 (0.80-1.01); and television viewing, 1.20 (1.10-1.32). Relative to less active participants with higher levels of television viewing, those who participated in ≥2 h/week of both vigorous-intensity aerobic and muscle-strengthening activity and <7 h/week of television viewing had 65% lower risk of NAFLD (risk ratio = 0.35, 95% CI = 0.23-0.51).

CONCLUSION

Adults who follow public health recommendations for vigorous-aerobic and muscle-strengthening activity, as well as minimize television viewing, are considerably less likely to have NAFLD than those who do not follow the recommendations and who have relatively high levels of television viewing.

Aerobic capacity and [Formula: see text] kinetics adaptive responses to short-term high-intensity interval training and detraining in untrained females

PURPOSE

This study investigated the physical fitness and oxygen uptake kinetics (τ[Formula: see text]) along with the O2 delivery and utilization (heart rate kinetics, τHR; deoxyhemoglobin/[Formula: see text] ratio, ∆[HHb]/[Formula: see text]) adaptations of untrained female participants responding to 4 weeks of high-intensity interval training (HIIT) and 2 weeks of detraining.

METHODS

Participants were randomly assigned to HIIT (n = 11, 4 × 4 protocol) or nonexercising control (n = 9) groups. Exercising group engaged 4 weeks of treadmill HIIT followed by 2 weeks of detraining while maintaining daily activity level. Ramp-incremental (RI) tests and step-transitions to moderate-intensity exercise were performed. Aerobic capacity and performance (maximal oxygen uptake, [Formula: see text]; gas-exchange threshold, GET; power output, PO), body composition (skeletal muscle mass, SMM; body fat percentage, BF%), muscle oxygenation status (∆[HHb]), [Formula: see text], and HR kinetics were assessed.

RESULTS

HIIT elicited improvements in aerobic capacity ([Formula: see text], + 0.17 ± 0.04 L/min; GET, + 0.18 ± 0.05 L/min, P < 0.01; PO-[Formula: see text], ± 23.36 ± 8.37 W; PO-GET, + 17.18 ± 3.07 W, P < 0.05), body composition (SMM, + 0.92 ± 0.17 kg; BF%, - 3.08% ± 0.58%, P < 0.001), and speed up the τ[Formula: see text] (- 8.04 ± 1.57 s, P < 0.001) significantly, extending to better ∆[HHb]/[Formula: see text] ratio (1.18 ± 0.08 to 1.05 ± 0.14). After a period of detraining, the adaptation in body composition and aerobic capacity, as well as the accelerated τ[Formula: see text] were maintained in the HIIT group, but the PO-[Formula: see text] and PO-GET declined below the post-training level (P < 0.05), whereas no changes were reported in controls (P > 0.05). Four weeks of HIIT induced widespread physiological adaptations in females, and the majority of improvements were preserved after 2 weeks of detraining except for power output corresponding to [Formula: see text] and GET.

Interventions to Address Cardiovascular Risk in Obese Patients: Many Hands Make Light Work

Obesity is a growing public health epidemic worldwide and is implicated in slowing improved life expectancy and increasing cardiovascular (CV) risk; indeed, several obesity-related mechanisms drive structural, functional, humoral, and hemodynamic heart alterations. On the other hand, obesity may indirectly cause CV disease, mediated through different obesity-associated comorbidities. Diet and physical activity are key points in preventing CV disease and reducing CV risk; however, these strategies alone are not always sufficient, so other approaches, such as pharmacological treatments and bariatric surgery, must support them. Moreover, these strategies are associated with improved CV risk factors and effectively reduce the incidence of death and CV events such as myocardial infarction and stroke; consequently, an individualized care plan with a multidisciplinary approach is recommended. More precisely, this review explores several interventions (diet, physical activity, pharmacological and surgical treatments) to address CV risk in obese patients and emphasizes the importance of adherence to treatments.

The effects of exercise training on body composition in postmenopausal women: a systematic review and meta-analysis

Introduction

We conducted a systematic review and meta-analysis to investigate the effect of exercise training on body composition outcomes in postmenopausal women.

Methods

PubMed, Web of Science, CINAHL, and Medline were searched to identify the randomized controlled trials which evaluated effect of exercise training versus control in postmenopausal women. Standardized mean differences (SMD), weighted mean differences (WMD) and 95% confidence intervals (95% CIs) were calculated using random effects model.

Results

One hundred and one studies involving 5,697 postmenopausal women were included in the meta-analysis. Results indicated that exercise training effectively increased muscle mass/ volume, muscle and fiber cross-sectional area and fat-free mass, and decreased fat mass, body fat percentage, waist circumference and visceral fat. Furthermore, subgroup analyses results revealed that aerobic and combined training had greater beneficial effects on fat mass outcomes, whereas resistance and combined training had greater beneficial effects on muscle mass outcomes.

Discussion

Overall, our results revealed that exercise training is effective for improving body composition in postmenopausal women. To be specific, aerobic training is effective on fat loss, whereas resistance training is effective on muscle gain. However, combination of aerobic and resistance trainings may be considered a viable strategy to improve body composition in postmenopausal women.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42021283425.

A comparison of the effects of remote coaching HIIT training and combined exercise training on the physical and mental health of university students

Aim

To compare the differences in the effects of based on remote coached high intensity interval training and combined exercise training on the physical and mental health of university students.

Method

Sixty university students were recruited from Shandong Normal University and randomly divided into HIIT group (n = 30) and AR group (n = 30), with the HIIT group using high-intensity interval training intervention and the AR group using combined exercise (aerobic combined with resistance) training intervention for 8 weeks. Mental health indicators, fitness indicators and body composition indicators were measured at the beginning and end of the intervention.

Results

After 8 weeks, among the mental health indicators, the results of the Symptom Self-Rating Scale (SCL-90) test showed a significant improvement in the HIIT group in terms of total score, somatization, obsessive-compulsive, interpersonal sensitivity, depression, hostility, and psychoticism (p < 0.05); the AR group showed significant improvements in psychoticism (P < 0.05). There were no significant differences between the two groups. The results of the Pittsburgh Sleep Quality Index scale (PSQI) showed a significant difference in sleep efficiency in the HIIT group with an inverse improvement in scores; the AR group showed no significant improvement in each test item. The results of the between-group covariance showed significant differences in sleep efficiency and hypnotic drugs in the HIIT group (p < 0.05). Among the fitness indicators, the HIIT group showed significant improvements in maximum oxygen uptake, grip strength and flexibility (P < 0.05); the AR group showed significant improvements in back muscle strength and flexibility (P < 0.05). The results of the between-group covariance showed significant improvements in maximum oxygen uptake in the HIIT group (P < 0.01). Regarding body composition indicators, there was a significant improvement in Body weight, BMI, Body fat percentage and Waist-to-hip ratio in both the HIIT and AR groups (P < 0.01). There were no significant differences between the two groups.

Conclusion

HIIT and combined exercise training based on remote coaching had some improvement on fitness level and body composition of university students, HIIT was more advantageous in improving aerobic endurance, and HIIT based on remote coaching may have better effect than combined exercise in mental health.

Trial registration

Chinese Clinical Trial Register, ChiECRCT20220149. Registered on 16 May 2022.

Association of Hepatic Steatosis with Adipose and Muscle Mass and Distribution in Children

Background: Pediatric studies have shown associations between hepatic steatosis and total body fat, visceral fat, and lean mass. However, these associations have not been assessed simultaneously, leaving their relative importance unknown. Objective: To evaluate associations between hepatic steatosis and total-body adiposity, visceral adiposity, and lean mass in children. Method: In children at risk for fatty liver, hepatic steatosis, adipose, and lean mass were estimated with magnetic resonance imaging and dual-energy X-ray absorptiometry. Results: Two hundred twenty-seven children with mean age 12.1 years had mean percent body fat of 38.9% and mean liver fat of 8.4%. Liver fat was positively associated with total-body adiposity, visceral adiposity, and lean mass (P < 0.001), and negatively associated with lean mass percentage (P < 0.001). After weight adjustment, liver fat was only positively associated with measures of central adiposity (P < 0.001). Visceral adiposity also had the strongest association with liver fat (P < 0.001). Conclusions: In children, hepatic steatosis is more strongly associated with visceral adiposity than total adiposity, and the association of lean mass is not independent of weight or fat mass. These relationships may help guide the choice of future interventions to target hepatic steatosis.

Short High-Intensity Interval Exercise for Workplace-Based Physical Activity Interventions: A Systematic Review on Feasibility and Effectiveness

BACKGROUND

Workplace exercise interventions showed good results, but lack of time was often reported as a barrier to participation. To overcome this problem, several studies attempted to implement short high-intensity interval training (HIT) within the workplace.

OBJECTIVES

The aim of this systematic review is to explore the feasibility and effectiveness of HIT interventions within the workplace setting.

DATA SOURCES

A systematic literature search was conducted in PubMed and SPORTDiscus to identify articles related to HIT within the workplace.

STUDY ELIGIBILITY CRITERIA

Only interventions that consisted of HIT programmes within the workplace and tested at least one physiological, psychological, or work-related outcome were included.

RESULTS

Seven studies (317 participants) met the inclusion criteria. HIT interventions lasted 6-12 weeks, with a frequency of 2-4 sessions/week and a duration of 8-30 min per session. Feasibility was qualitatively investigated in four studies, with key positive aspects reported for HIT time-appeal, the sense of competence driven by individual intensity, and improved intention to exercise; five studies reported adherence rates > 80%. Small-to-large effect sizes were reported for improvements in cardiorespiratory and muscular fitness. Small-to-medium effect sizes were reported for blood parameters and health-related quality of life.

CONCLUSIONS

HIT interventions in the workplace showed limited effectiveness in improving health-related outcomes, while promising results regarding feasibility were reported, mainly due to the time-efficiency and the positive post-exercise psychosocial responses. However, further high-quality studies involving more participants are still needed to make firm conclusions on HIT effectiveness and feasibility compared to other types of exercise in this context.

Intermittent high-intensity exercise for pre- to established hypertension: A systematic review and meta-analysis

OBJECTIVE

To determine the impact of intermittent high-intensity exercise training ([IHIE], including high-intensity interval training [HIIT] and recreational team sports [RTS]) on systolic (SBP) and diastolic blood pressure (DBP) in adults with pre- to established arterial hypertension.

DATA SOURCES

MEDLINE, Cochrane Library, Embase, and SPORTDiscus.

ELIGIBILITY CRITERIA

Randomized controlled trials (RCTs) comparing the impact of IHIE on BP versus a non-exercise control.

DATA COLLECTION AND ANALYSIS

Two authors independently conducted all procedures. Mean differences were calculated using random-effects model. The certainty of the evidence was assessed with GRADE.

RESULTS

Twenty-seven RCTs (18 HIIT and 9 RTS) were analyzed, with median duration of 12 weeks. Participants' (n = 946) median age was 46 years. Overall, IHIE decreased SBP (-3.29 mmHg; 95% CI: -5.19, -1.39) and DBP (-2.62 mmHg; 95% CI: -3.79, -1.44) compared to the control group. IHIE elicited higher decreases in office SBP and DBP of hypertensive subjects (SBP: -7.13 mmHg, [95% CI: -10.12, -4.15]; DBP: -5.81 mmHg, [95% CI: -7.94, -3.69]) than pre-hypertensive (SBP: -2.14 mmHg, [95% CI: -4.36, -0.08]; DBP: -1.83 mmHg, [95% CI: -2.99, -0.67]). No significant differences were found between HIIT (SBP: -2.12 mmHg, [95% CI: -4.78, -0.54]; DBP: -1.89 mmHg, [95% CI: -3.32, -0.48]) and RTS (SBP: -4.18 mmHg, [95% CI: -7.19, -2.43]; DBP: -4.04 mmHg, [95% CI: -6.00, -2.09]). These findings present low/very low certainty of evidence. No adverse cardiovascular events were reported.

CONCLUSIONS

IHIE appears to be safe and to promote substantial decreases in BP, particularly in patients with hypertension. However, the certainty of evidence was low/very low.

PROTOCOL

CRD42020163575.

Effects of eight-week high-intensity interval training on some metabolic, hormonal and cardiovascular indices in women with PCOS: a randomized controlled trail

BACKGROUND

Studies have revealed that high-intensity interval training (HIIT) has beneficial effect on hormonal, cardiovascular indices in women with polycystic ovary syndrome (PCOS). There, however, is still no comprehensive data on the type, intensity and duration of training for these women.

OBJECTIVE

The current study aimed to investigate the effects of high-intensity interval training (HIIT) on metabolic, hormonal and cardiovascular indices in women with PCOS compared to a control group.

METHODS

In a randomized controlled study, 28 patients (age: 23.8 ± 5.3 years, weight: 82.4 ± 9.7 kg, BMI: 30.33 ± 3.99 kg/m²) were divided into two groups including HIIT (n = 14) and the control (n = 14). The training protocol was performed with 100-110 maximum aerobic velocity (MAV), 4-6 sets, 4 laps, 3 sessions per week for eight weeks. Anthropometric indices, aerobic performance, insulin resistance and sensitivity, lipid profiles, testosterone, cortisol and hs-CRP were evaluated.

RESULTS

The HIIT intervention decreased BMI, waist to hip ratio (WHR), visceral fat, insulin, insulin resistance, low density lipoprotein (LDL), atherogenic index, cholesterol and cortisol (P < 0.05). All variables remained unchanged in the control group (P > 0.05). Except for VAI, FBG, HDL, TG and AIP, the rest of the variables in the training and control groups show a significant difference (P < 0.05).

CONCLUSION

The results of the present study indicate that eight weeks of HIIT has beneficial effects on anthropometric, insulin sensitivity, fat profile, and inflammatory and cardiovascular indices in PCOS patients. It seems that the intensity of HIIT (100-110 MAV) is a determining factor in creating optimal adaptations in PCOS patients.

TRAIL REGISTRATION

IRCT20130812014333N143. Registration date: 22/03/2020. URL: https://en.irct.ir/trial/46295 .

Effect of High-Intensity Interval Training vs. Moderate-Intensity Continuous Training on Fat Loss and Cardiorespiratory Fitness in the Young and Middle-Aged a Systematic Review and Meta-Analysis

OBJECTIVES

This systematic review is conducted to evaluate the effect of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on body composition and cardiorespiratory fitness (CRF) in the young and middle-aged.

METHODS

Seven databases were searched from their inception to 22 October 2022 for studies (randomized controlled trials only) with HIIT and MICT intervention. Meta-analysis was carried out for within-group (pre-intervention vs. post-intervention) and between-group (HIIT vs. MICT) comparisons for change in body mass (BM), body mass index (BMI), waist circumference (WC), percent fat mass (PFM), fat mass (FM), fat-free mass (FFM), and CRF.

RESULTS

A total of 1738 studies were retrieved from the database, and 29 studies were included in the meta-analysis. Within-group analyses indicated that both HIIT and MICT can bring significant improvement in body composition and CRF, except for FFM. Between-group analyses found that compared to MICT, HIIT brings significant benefits to WC, PFM, and VO_2peak.

CONCLUSIONS

The effect of HIIT on fat loss and CRF in the young and middle-aged is similar to or better than MICT, which might be influenced by age (18-45 years), complications (obesity), duration (>6 weeks), frequency, and HIIT interval. Despite the clinical significance of the improvement being limited, HIIT appears to be more time-saving and enjoyable than MICT.

Effectiveness of supplementation with date seed (Phoenix dactylifera) as a functional food on inflammatory markers, muscle damage, and BDNF following high-intensity interval training: a randomized, double-blind, placebo-controlled trial

PURPOSE

High-intensity interval training (HIIT) is one of the most effective protocols, even though acute HIIT causes inflammatory and oxidative damage. The aim of this study was to examine the effect of date seeds powder (DSP) during HIIT sessions on inflammation markers, oxidants and antioxidants, brain-derived neurotrophic factor (BDNF), exercise-induced muscle damage, and body composition.

MATERIAL AND METHODS

Thirty-six recreational runners (men and women), aged 18-35 years, were randomly assigned to consume 26 g/day of DSP or wheat bran powder during HIIT workouts for a period of 14 days. At baseline, at the end of the intervention, and 24 h after the intervention, blood samples were obtained to determine inflammatory, oxidant/antioxidant, and muscle damage markers, as well as BDNF.

RESULTS

DSP supplementation resulted in a significant downward trend in high-sensitivity C-reactive protein (Psupplement × time = 0.036), tumor necrosis factor alpha (Psupplement × time = 0.010), interleukin-6 (Psupplement × time = 0.047), malondialdehyde (Psupplement × time = 0.046), creatine kinase (Psupplement × time = 0.045), and lactate dehydrogenase (Psupplement × time = 0.040) after the intervention, as well as a significant increase in total antioxidant capacity (Psupplement × time ≤ 0.001). However, interleukin-10 (Psupplement × time = 0.523), interleukin-6/interleukin-10 (Psupplement × time = 0.061), BDNF (Psupplement × time = 0.160), and myoglobin (Psupplement × time = 0.095) levels did not change significantly in comparison to the placebo group. Moreover, analysis demonstrated that DSP supplementation over 2 weeks had no significant effect on body composition.

CONCLUSION

During the 2 weeks of the HIIT protocol, the consumption of date seed powder by participants who had engaged in moderate or high physical activity alleviated inflammation and muscle damage.

ETHICS AND DISSEMINATION

This study was approved by the Medical Ethics Committee of TBZMED (No.IR.TBZMED.REC.1399.1011).

TRIAL REGISTRATION

Iranian Registry of Clinical Trials website ( www.IRCt.ir/ , IRCT20150205020965N9).

The Effect of Intraabdominal Visceral and Subcutaneous Adipose Volume and Muscle Volume on Lumbar Vertebrae Degeneration

OBJECTIVES

This study aimed to investigate the effect of the volume of subcutaneous, visceral, and total adipose tissue, and paravertebral muscles in patients with lumbar vertebrae degeneration (LVD) through computerized tomography (CT) images.

MATERIALS AND METHODS

One forty-six patients with a complaint of lower back pain (LBP) between January 2019 and December 2021 were included in the study. CT scans of all patients were analyzed retrospectively for abdominal visceral, subcutaneous, and total fat volume, and also paraspinal muscle volume measurements and analysis of lumbar vertebrae degeneration (LVD) using designated software. In CT images, each intervertebral disc space was evaluated in terms of the presence of osteophytes, loss of disc height, sclerosis in the end plates, and spinal stenosis to investigate the presence of degeneration. Each level was scored according to the presence of findings, with 1 point for each finding. The total score at all levels (L1-S1) was calculated for each patient.

RESULTS

An association was observed between the loss of intervertebral disc height and the amount of visceral, subcutaneous, and total fat volume at all lumbar levels (p˂0.05). The amount of all fat volume measurements also showed association with osteophyte formation (p˂0.05). An association was found between sclerosis and the amount of all fat volume at all lumbar levels (p˂0.05). It was observed that spinal stenosis at the lumbar levels was not associated with the amount of fat (total, visceral, subcutaneous) at any level (p˃0.05). No association was found between the amount of adipose and muscle volumes and vertebral pathologies at any level (p˃0.05).

CONCLUSION

The abdominal visceral, subcutaneous, and total fat volumes are associated with lumbar vertebral degeneration and loss of disc height. Paraspinal muscle volume does not show an association with vertebral degenerative pathologies.

High-intensity interval training improves the vascular endothelial function comparing moderate-intensity interval training in overweight or obese adults: A meta-analysis

OBJECTIVE

Obesity is associated with endothelial dysfunction and cardiovascular diseases. Moderate-intensity continuous training (MICT) is a common method to improve endothelial function and the cardiovascular risk profile in obesity. However, in recent times, high-intensity interval training (HIIT) has become a popular alternative for MICT primarily because of its time efficiency. Therefore, we hypothesized that HIIT is superior to MICT in improving vascular function. We aimed to evaluate this hypothesis by conducting a meta-analysis and quantifying the effect of HIIT on flow-mediated dilation (FMD) in overweight/obese adults.

METHODS

Databases (Scopus, Web of Science, and PubMed) were searched up to January 2022 for HIIT vs. moderate-intensity interval training (MICT) and HIIT vs. control (CON) studies on endothelial function assessed by flow-mediated dilation (FMD) in overweight and obese adults. From the included studies, standardized mean difference (SMD) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

8 studies with 208 participants were included in this meta-analysis. According to the 6 studies, HIIT improved the FMD with an overall change of %2.6 [(95% CI: 0.82 to 4.377), p = 0.004] compared to the MICT in overweight and obese adults. Moreover, based on the 5 studies that compared HIIT and CON, the results showed HIIT significantly increased FMD by 1.83% [(95% CI: 0.478 to 3.187), p = 0.008].

CONCLUSIONS

These results showed that exercise training, particularly HIIT, could improve endothelial function in overweight and obese adults.

The effect of 12 weeks of combined training on hepatic fat content and metabolic flexibility of individuals with non-alcoholic fatty liver disease: Protocol of an open-label, single-center randomized control trial

Introduction

Metabolic flexibility (MetF) is the capacity of an organism to oxidate substrate according to substrate availability or demand. The mismatch of substrate availability and oxidation may cause ectopic fat accumulation in the muscle and the liver. The objectives of the study are to examine the effect of 12 weeks of combined exercise on hepatic fat reduction and investigate metabolites related to MetF before and after the high-fat diet between individuals with NAFLD and healthy control with an active lifestyle.

Methods

This study is an open-label, single-center trial randomized controlled clinical study plus a cross-sectional comparison between individuals with NAFLD and healthy control. Individuals with NAFLD were allocated into two groups receiving resistance training (RT) combined with high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT). Anthropometric indicators, clinical blood markers about glucose, lipid metabolism, and hepatic fat content (HFC) were assessed before and after the intervention. The metabolomics was also used to investigate the discrepant metabolites and mechanisms related to MetF.

Discussion

Metabolic flexibility reflects the capacity of an organism to switch the oxidation substrates flexibly, which is associated with ectopic fat accumulation. Our study aimed to explore the discrepant metabolites related to MetF before and after a high-fat diet between individuals with NAFLD and healthy control. In addition, the study also examined the effectiveness of RT combined with HIIT or MICT on hepatic fat reduction and quantificationally analyzed the metabolites related to MetF before and after the intervention. Our results provided a perspective on fatty liver-associated metabolic inactivity.

Trial registration

ClinicalTrials.gov: ChiCTR2200055110; Registered 31 December 2021, http://www.chictr.org.cn/index.aspx.

Effect of High-Intensity Interval Training on Functional Movement in Older Adults: A Systematic Review and Meta-analysis

BACKGROUND

Preserving physiological functional capacity (PFC), the ability to perform the activities of daily life, and the ease with which they can be performed, in older adults, defined for this study as ≥ 50 years of age, is an important consideration for maintaining health and independence through the ageing process. Physical activity, and exercise training in particular, has been positively associated with improvement in PFC. In addition to improving aerobic and anaerobic capacity, promoting and preserving functional movement as a component of PFC is an important goal of physical activity, especially for older adults. High-intensity interval training (HIIT), an exercise protocol where repeated bouts of increased intensity are interspersed with active or passive recovery periods, has often been studied as an alternative to traditional moderate-intensity continuous training (MICT) exercise, where a continuous intensity is maintained throughout the exercise session. A large body of research has determined that both types of exercise programme are effective in improving measures of aerobic and anaerobic fitness in older adults. However, the effect of the two exercise modalities on functional movement has most often been a secondary outcome, with a range of observational techniques applied for measurement.

OBJECTIVES

The primary objective of this research is to systematically review and meta-analyse published studies of HIIT interventions that measured functional movement in older adults to conclude if HIIT is effective for improving functional movement. A secondary objective is to determine if there are significant differences between HIIT and MICT effect on functional movement.

METHODS

A search strategy of terms locating studies of HIIT interventions, functional movement outcome measures, and older adult population samples was executed on seven digital databases. Randomized and pair-matched trials of > 2 weeks were considered for inclusion. Studies of participants with neurological impairment or studies using combined exercise modality were rejected. Standardized mean difference for functional movement outcome measures was calculated. A meta-analysis of the included studies and subgroups was performed along with study quality (risk of bias and publication bias) evaluation.

RESULTS

A total of 18 studies were included in random effects model pooled analysis. Subgroup analysis of HIIT versus MICT on functional movement showed a trivial effect in favour of HIIT (ES 0.13, 95% CI [-0.06, 0.33] p = 0.18) and did not achieve statistical significance. However, HIIT showed a medium, statistically significant favourable effect on functional movement versus non-intervention control (ES = 0.60 95% CI [0.24, 0.95] p = 0.001). Further subgroups analysis using singular and multiple functional movement outcome measures showed similar results.

CONCLUSION

This meta-analysis indicates that HIIT interventions in older adults may be effective at promoting improvements in functional movement, though it is unclear whether HIIT is superior to MICT.

Adipocyte Metabolism and Health after the Menopause: The Role of Exercise

Postmenopausal women represent an important target population in need of preventative cardiometabolic approaches. The loss of estrogen following the menopause eliminates protections against metabolic dysfunction, largely due to its role in the health and function of adipose tissue. In addition, some studies associate the menopause with reduced physical activity, which could potentially exacerbate the deleterious cardiometabolic risk profile accompanying the menopause. Meanwhile, exercise has adipocyte-specific effects that may alleviate the adverse impact of estrogen loss through the menopausal transition period and beyond. Exercise thus remains the best therapeutic agent available to mitigate menopause-associated metabolic dysfunction and represents a vital behavioral strategy to prevent and alleviate health decline in this population.

Evolution of Physical Training in Police Academies: Comparing Fitness Variables

The purpose of this study was to evaluate the effectiveness of three different physical training approaches to improving cadets' fitness variables. Retrospective data for male and female land management law enforcement officers attending a 15-week training program at three separate time points were provided for analysis. The time points reflected the three different training approaches, including calisthenic training (CT) = 83, functional fitness training (FT) = 90, and strength training (ST) = 110. Inferential data analysis was used to find which mode of exercise had the greatest impact on body composition, cardiovascular endurance, muscular strength, agility, and flexibility. All groups displayed decreases in body fat percentage, with weight loss being more significant within the CT and FT groups, while the ST group increased in body weight. The CT group had the greatest flexibility increases compared to the FT and ST groups. ST training elicited significantly smaller changes in cardiovascular endurance than the FT and CT groups. ST training showed greater improvements in lean mass, while CT and FT showed greater increases in flexibility and endurance. These results suggest that training protocols can increase performance and optimize the abilities to perform job tasks in tactical athletes.

High-intensity interval aerobic and resistance training to counteract low relative lean soft tissue mass in middle age: A randomized controlled trial

BACKGROUND

Age-related loss of skeletal muscle mass and function begins in early middle age, yet research to date has focused on older individuals, limiting our understanding of interventions earlier in the lifespan. To date, no high-intensity interval training studies have been conducted in middle-aged adults with low relative lean soft tissue mass.

METHODS

Eighty-two middle-aged adults (40-50 years of age) with low appendicular lean soft tissue mass index confirmed with dual energy x-ray absorptiometry (DXA) were randomly allocated (1:1) to group-based, 20-week, three times a week, high-intensity aerobic and resistance training (HIART) program or 60-min education session (Control). The primary outcome was change in total lean soft tissue mass measured by DXA. Secondary outcomes included cardiorespiratory fitness, physical function (handgrip strength, gait speed, 30-seconds sit-to-stand, quadriceps strength and muscle quality). Measures were obtained at baseline (0 weeks), mid-intervention (10 weeks) and post-intervention (20 weeks).

RESULTS

Mean age in HIART was 44.8 (SD 3.2) and 45.4 (SD 2.9) in Control group. The majority of the participants were female with 88 % in HIART and 83 % in Control group. Mean BMI in HIART was 25.8 kg/m² (SD 3.5) and 26.4 kg/m² (SD 4.1) Control group. Intention to treat analysis showed that post-intervention, HIART increased significantly more total lean soft tissue mass (0.8 kg, 95%CI 0.15, 1.46), appendicular lean soft tissue mass index (0.2 kg/m², 95%CI 0.09, 0.33), peak oxygen uptake (5.18 mL/min/kg, 2.97 to 7.39 95%CI), grip strength (2.2 kg, 95%CI 0.09, 4.32), and 30-s sit-to-stand (1.3 times, 95%CI 0.43, 2.12) with significantly greater reductions in body fat percentage (-1.1 %, 95%CI -2.03, -0.10) and maximum gait speed (-0.2 m/s, 95 % CI -0.34, -0.03) compared Control.

CONCLUSION

The HIART program is an effective exercise intervention to increase total lean soft tissue mass in middle-aged adults with low relative lean soft tissue mass compared to a waitlist control group.

The effect of Tabata-style functional high-intensity interval training on cardiometabolic health and physical activity in female university students

Introduction: The increasing prevalence of metabolic syndrome and physical inactivity enhances exposure to cardiometabolic risk factors in university students. High-intensity interval training (HIIT) improved cardiometabolic health in clinical adults but the evidence in the university setting is limited. Furthermore, few studies examined the effect of low-volume HIIT on habitual physical activity (PA). Therefore, the primary aim of this study was to evaluate the efficacy of 12-week Tabata-style functional HIIT for improving multiple cardiometabolic health outcomes and habitual PA. We also investigated whether changes in habitual PA over the intervention period had an impact on exercise-induced health outcomes. Methods: 122 female freshmen were randomized into the Tabata group (n = 60) and the control (n = 62). The Tabata training protocol involved 8 × 20 s maximal repeated functional exercises followed by 10 s rest with a frequency of 3 times per week for 12 weeks. Body composition, maximal oxygen uptake (VO_2max), blood pressure (BP), blood lipids, fasting glucose and insulin, C-reactive protein and PA were objectively measured using standardized methods. Dietary intake was measured using a valid food frequency questionnaire. All variables were measured pre- and post-intervention. Results: Mixed linear modelling results showed that there were large intervention effects on VO_2max (p < 0.001, d = 2.53, 95% CI: 2.03 to 3.00 for relative VO_2max; p < 0.001, d = 2.24, 95% CI: 1.76 to 2.68 for absolute VO_2max), resting heart rate (p < 0.001, d = -1.82, 95% CI: -2.23 to -1.37), systolic BP (p < 0.001, d = -1.24, 95% CI: -1.63 to -0.84), moderate-to-vigorous intensity physical activity (MVPA) (p < 0.001, d = 2.31, 95% CI: 1.83 to 2.77), total PA (p < 0.001, d = 1.98, 95% CI: 1.53 to 2.41); moderate effects on %BF (p < 0.001, d = -1.15, 95% CI: -1.53 to -0.75), FM (p < 0.001, d = -1.08, 95% CI: -1.46 to -0.69), high-density lipoprotein (HDL) (p < 0.001, d = 1.04, 95% CI: 0.65 to 1.42), total cholesterol (p = 0.001, d = -0.64, 95% CI: -1.00 to -0.26); small effects on BMI (p = 0.011, d = -0.48, 95% CI: -0.84 to 0.11), WC (p = 0.043, d = -0.37, 95% CI: -0.74 to -0.01), low-density lipoprotein (p = 0.003, d = -0.57, 95% CI: -0.93 to -0.19), HOMA-IR (p = 0.026, d = -0.42, 95% CI: -0.78 to -0.05) and fasting insulin (p = 0.035, d = -0.40, 95% CI: -0.76 to -0.03). Regression analysis showed that only the percentage change of HDL was associated with the change of MVPA (b = 0.326, p = 0.015) and TPA (b = 0.480, p = 0.001). Conclusion: From the findings of the study we can conclude that 12-week low-volume Tabata-style functional HIIT was highly effective for university female students to improve cardiorespiratory fitness, body fat, some cardiometabolic health outcomes and habitual PA.

Aging reduces ABHD5 protein content in the adipose tissue of mice: The reversal effect of exercise

Dysfunction of the adipose tissue metabolism is considered as a significant hallmark of aging. It has been proposed that α-β hydrolase domain containing 5 (ABHD5) plays a critical role in the control of lipolysis. However, the role of ABHD5 in the control of lipolysis during aging or exercise is unknown. Here we combined the experimental mouse model with transcriptomic analyzes by using murine and human databases to explore the role of ABHD5 in the adipose tissue during aging and in response to exercise. Transcriptomic data revealed a downregulation of Abhd5 messenger RNA levels in the subcutaneous white adipose tissue (scWAT) over time in individuals from 20 to 69 years old. Aged mice displayed dramatic reduction of ABHD5 protein content and lipolytic-related proteins in the scWAT. Interestingly, 4 weeks of high-intensity interval training increased ABHD5 protein level and restored the lipolytic pathway in the scWAT of aged mice. Altogether, our findings demonstrated that aging affects ABHD5 content in the adipose tissue of mice and humans. Conversely, exercise increases ABHD5 activity, recovering the lipolytic activity in aged mice.

Associations Between Abdominal Obesity, Chewing Difficulty and Cognitive Impairment in Dementia-Free Chinese Elderly

OBJECTIVE

To investigate the independent and synergistic associations between abdominal obesity, chewing difficulty and cognitive impairment in a community-dwelling older adults sample in China.

METHODS

Cognitive function was measured by the 5 min- Montreal Cognitive Assessment (5 min-MoCA) and abdominal obesity was measured by A Body Shape Index (ABSI) in 572 participants recruited from local communities. Chewing difficulty was assessed via a self-report questionnaire. Linear regression and general logistic regression were performed to investigate the association of chewing difficulty and abdominal obesity with cognition.

RESULTS

Chewing difficulty score [β (95% CI) = -.30 (-.49, -.11)] and ABSI [β (95%CI) = -.30 (-.55, -.05)] were independently associated with worse performance on the 5 min-MoCA. Whilst ABSI was not associated with cognitive impairment, the co-existence of chewing difficulty and abdominal obesity [OR (95% CI) = 2.22 (1.18, 4.17)] was found associated with the presence of cognitive impairment.

CONCLUSION

Chewing difficulty and abdominal obesity were independently associated with cognition. Abdominal obesity and chewing may have an additive effect on cognitive function.

The impact of high-intensity interval training on vascular function in adults: A systematic review and meta-analysis

AIM

We performed a systematic review and meta-analysis to investigate the effects of high-intensity interval training (HIIT) compared with moderate-intensity continuous training (MICT) or with no exercise (CON) on vascular function in adults who were free of cardiometabolic diseases and those with cardiometabolic diseases.

METHODS

A search across three electronic databases including Scopus, PubMed, and Web of Science was conducted through February 2022 to identify the randomized trials evaluating HIIT vs. MICT and/or CON on vascular function as measured using brachial artery flow-mediated dilation (FMD) in adults. Separate analyses were conducted for HIIT vs. MICT and/or CON to calculate weighted mean differences (WMD) and 95% confidence intervals (95% CIs) using random or fixed models.

RESULTS

A total of 36 studies involving 1,437 participants who were either free of cardiometabolic diseases or had cardiometabolic diseases were included in the meta-analysis. HIIT effectively increased FMD when compared with MICT [1.59% (95% CI 0.87-2.31), p = 0.001] or CON [3.80% (95% CI 2.58-5.01), p = 0.001]. Subgroup analysis showed that HIIT increased FMD in participants with cardiovascular and metabolic diseases, but not in participants who were free of cardiometabolic diseases. In addition, HIIT effectively increased FMD regardless of age and body mass index.

CONCLUSION

We confirm that HIIT is effective for improving vascular function in individuals with metabolic disorders and cardiovascular diseases and has a superior effect compared to MICT, demonstrating time efficiency.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk/prospero], identifier [CRD42022320863].

Effects of the intensity of interval training on aerobic fitness, body composition and resting metabolic rate of women with overweight or obesity: A randomized trial

BACKGROUND: Moderate-intensity interval training (MIIT) may be a viable exercise format for improving body composition, aerobic fitness, and health-related variables. OBJECTIVES: This randomized trial aimed to analyze the effect of MIIT or high-intensity interval training (HIIT) on aerobic fitness, body composition variables, and resting metabolic rate (RMR) in women with overweight or obesity. METHODS: 31 sedentary adult women with overweight or obesity performed 7 weeks × 3 weekly sessions of either HIIT or MIIT. Physical and physiological tests were applied before and after training. RESULTS: In both analyses (intention-to-treat and by adherence to the training), aerobic fitness showed a time effect (p= 0.041 and p= 0.015), but without differences between groups (p> 0.05). No group (HIIT vs. MIIT), time (pre vs. post), or interaction effects (group vs. time) were found for RMR, body composition markers (fat mass, body fat percentage, lean mass), or body mass index – BMI (p> 0.05). In addition, MIIT induced a relatively high drop-out rate. CONCLUSIONS: This study suggested that the short-term (7-weeks) interval exercise training was effective for increasing aerobic fitness, and moderate-intensity intervals were as effective as high-intensity intervals. However, neither training format was effective for changing RMR, body composition variables, or BMI of women with overweight or obesity. Clinical trial ID: RBR-9jd7b7.

Effects of different exercise types on visceral fat in young individuals with obesity aged 6-24 years old: A systematic review and meta-analysis

Introduction: The prevalence of pediatric obesity remains high all over the world. Various exercise interventions have been applied to decrease the visceral fat in young individuals with obesity. But the evidence remains controversial on the effect of the exercise on visceral fat. Moreover, it is unclear which type of the exercise is the most effective for young individuals with overweight or obesity to reduce visceral fat. Objective: The objective of this review and meta-analysis is to evaluate and compare the effectiveness of different exercise interventions on visceral fat in young individuals with overweight or obesity. Methods: Four databases consisting of PubMed, Web of Science, EBSCO, and Cochrane Library were searched prior to May 2022. Fifteen studies with a total of 30 data points involving 1,134 participants were included in this meta-analysis. And the interventions were limited to 4 exercise types [i.e., aerobic exercise (AE), resistance exercise (RE), aerobic exercise combined with resistance exercise (CE), and high-intensity interval training (HIIT)]. Data Synthesis: The results showed that AE (Standardized Mean Difference = -0.32; 95% CI = -0.50 to -0.13; p = 0.0007; I² = 37%) and HIIT (SMD = -0.59; 95% CI = -0.87 to -0.31; p < 0.0001; I² = 0%) had a significant reduction effect on visceral fat. And the effect of HIIT seemed better than AE. However, RE (SMD = -0.58; 95% CI = -1.34 to 0.17; p = 0.13; I² = 76%) and CE (SMD = -0.21; 95% CI = -0.81 to 0.38; p = 0.48; I² = 63%) had a non-significant effect on visceral fat decline. Additionally, compared with the control group, exercise interventions had a significant effect on reducing visceral fat in adolescents (SMD = -0.54; 95% CI = -0.82 to -0.26; p = 0.0001; I² = 64%) and young adults (SMD = -0.42; 95% CI = -0.69 to -0.15; p = 0.003; I² = 0%) rather than children (SMD = -0.15; 95% CI = -0.32 to 0.02; p = 0.08; I² = 0%). And the gender-based subgroup analysis indicated that the effectiveness of the exercise on the reduction of visceral fat was more significant in males (SMD = -1.27; 95% CI = -1.67 to -0.87; p < 0.00001; I² = 0%) than that in females (SMD = -0.31; 95% CI = -0.48 to -0.14; p = 0.0004; I² = 0%). Conclusion: This review and meta-analysis demonstrates that exercise interventions are efficient to decrease visceral fat in adolescents (12-18 years old) and young adults (18-24 years old). Among different exercise types, AE and HIIT are helpful for young individuals with overweight or obesity to reduce visceral fat and HIIT appears to be the most effective exercise intervention. In addition, the effect of exercise interventions on the consumption of visceral fat is more significant in males than that in females. Systematic Review Registration: [http://www.crd.york.ac.uk/PROSPERO], identifier [CRD42022310878].

Effect of High-Intensity Interval Training Combined with Blood Flow Restriction at Different Phases on Abdominal Visceral Fat among Obese Adults: A Randomized Controlled Trial

BACKGROUND

High-intensity interval training (HIIT) and blood flow restriction (BFR) represent a critical nonpharmacological strategy to reduce the excess deposition of visceral fat, as well as relevant complications, among obese populations. Applying BFR at diverse phases may have different effects. Therefore, the exercise program of this study combined HIIT with BFR, so as to explore the effect of BFR on abdominal visceral fat area and its mechanism in different periods of HIIT. The aim is to provide a more effective exercise prescription for obese people who want to reduce visceral fat quickly.

METHODS

This study was a randomized controlled trial involving 72 obese adults. One week before intervention, both regional and whole-body fat masses, abdominal subcutaneous and visceral fat areas, variables of blood metabolism, and VO_2max were recorded. Additionally, subjects with a matched fat percentage were randomized as a no-training control (C), HIIT (H), HIIT with BFR during interval (I), and HIIT with BFR during exercise (E) groups for 24 sessions within a 12-week period, using a cycle ergometer. During session one, this study recorded blood lactate, specific serum lipolytic hormones, rating of perceived exertion (RPE), and exercise heart rate (HR) and compared them among three groups. The baseline tests were repeated at 1 week after intervention.

RESULTS

There was no significant statistical difference in the indicators of each group at baseline (p > 0.05). The improvement of trunk fat mass and fat percentage of the I and E groups markedly increased relative to the H group (p < 0.05). Meanwhile, the I group had improved android fat mass and whole-body fat mass relative to group H (p < 0.05). Those exercise groups had markedly improved indices compared with the C group (p < 0.05). Additionally, the reduction in the I group had remarkably superior abdominal visceral fat areas (AVFA) to the H and E groups (p < 0.05). Immediately and 30 min following exercise, the E and I groups had remarkably increased growth hormone (GH) compared with the H group (p < 0.05). After exercise, the I group showed markedly increased epinephrine (EPI) compared with the H group (p < 0.05). The LA level in the I group evidently increased relative to the E group (p < 0.05), while that in the E group evidently increased compared with the H group (p < 0.05).

CONCLUSION

Compared with HIIT alone, HIIT with BFR can better improve the body-fat level and glucose metabolism. HIIT with BFR in the interval phase better reduces the abdominal visceral-fat level than in the exercise phase, which may be due to the increase in lipolytic hormone level caused by the higher physiological load.

Effects of high-intensity and moderate-intensity exercise training on cardiopulmonary function in patients with coronary artery disease: A meta-analysis

Purpose

The study aims to evaluate the effects of high-intensity and moderate-intensity exercise training on cardiopulmonary function and exercise endurance in patients with coronary artery diseases (CAD).

Methods

We performed a systematic search of the English and Chinese databases from their inception to March 2022. Randomized controlled trials (RCTs) were included to compare high-intensity and moderate-intensity exercise training on cardiopulmonary function in patients with CAD. The primary outcomes included peak oxygen uptake (peak VO₂) and anaerobic threshold (AT). The secondary outcomes included left ventricular ejection fraction (LVEF), exercises duration (ED), respiratory exchange ratio (RER), resting heart rate (RHR), peak heart rate (PHR) and oxygen pulse (O₂ pulse). The continuous variables were expressed as mean differences (MD) along with their corresponding standard deviations (SD), and the I² test was applied in the assessment of heterogeneity.

Results

After systematically literature search, 19 studies were finally selected for our meta-analysis (n = 1,036), with 511 patients in the experimental group (high-intensity exercise) and 525 patients in the control group (moderate-intensity exercise). The results showed that high-intensity exercise significantly increased patients' Peak VO₂ [MD = 2.67, 95% CI (2.24, 3.09), P < 0.00001], LVEF [MD = 3.60, 95% CI (2.17, 5.03), P < 0.00001], ED [MD = 37.51, 95% CI (34.02, 41.00), P < 0.00001], PHR [MD = 6.86, 95% CI (4.49, 9.24), P < 0.00001], and O₂ pulse [MD = 0.97, 95% CI (0.34, 1.60), P = 0.003] compared with moderate-intensity exercise. However, there were no significant differences in AT [MD = 0.49, 95% CI (−0.12, 1.10), P = 0.11], RER [MD = 0.00, 95% CI (−0.01, 0.02), P = 0.56], and RHR [MD = 1.10, 95% CI (−0.43, 2.63), P = 0.16].

Conclusion

Our results show that high-intensity exercise training has more significant positive effects compared with moderate-intensity exercise training in improving peak VO₂, LVEF, ED, PHR and O₂ pulse in patients with CAD, while no significant differences were observed in AT, RER and RHR. To sum up, high-intensity exercise training is better than moderate-intensity exercise training in improving cardiopulmonary function and exercise endurance in patients with CAD.

Systematic review registration

PROSPERO (CRD42022328475), https://www.crd.york.ac.uk/PROSPERO/.

Effects of exercise training in hypoxia versus normoxia on fat-reducing in overweight and/or obese adults: A systematic review and meta-analysis of randomized clinical trials

Objective: Fat loss theory under various oxygen conditions has been disputed, and relevant systematic review studies are limited. This study is a systematic review and meta-analysis to assess whether hypoxic exercise training (HET) leads to superior fat-reducing compared with normoxic exercise training (NET).

Methods: We searched PubMed, Web of Science, CNKI, ProQuest, Google Scholar, Cochrane Library, and EBSCOhost from inception to June 2022 for articles comparing the effects of hypoxic and normoxic exercise on body composition indicators, glycometabolism, and lipometabolism indicators in obese and overweight adults. Only randomized controlled trials (RCTs) were included. The effect sizes were expressed as standardized mean difference (SMD) and 95% confidence intervals (CI). Between-study heterogeneity was examined using the I² test and evaluated publication bias via Egger’s regression test. The risk of bias assessment was performed for each included trial using Cochrane Evaluation Tool second generation. The meta-analysis was performed by using R 4.1.3 and RevMan 5.3 analytic tools.

Results: A total of 19 RCTs with 444 subjects were analyzed according to the inclusion and exclusion criteria. Among them, there were 14 English literature and five Chinese literature. No significant difference in body composition (SMD -0.10, 95% CI -0.20 to -0.01), glycometabolism and lipid metabolism (SMD -0.01, 95% CI -0.13 to -0.10) has been observed when comparing the HET and NET groups. We only found low heterogeneity among trials assessing glycometabolism and lipometabolism (I² = 20%, p = 0.09), and no publication bias was detected.

Conclusion: The effects of HET and NET on fat loss in overweight or obese people are the same. The application and promotion of HET for fat reduction need further exploration.

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.

Effects of high-intensity interval training (HIIT) and sprint interval training (SIT) on fat oxidation during exercise: a systematic review and meta-analysis

OBJECTIVE

To investigate the effects of high-intensity interval training (HIIT) and sprint interval training (SIT) on fat oxidation during exercise (FatOx) and how they compare with the effects of moderate-intensity continuous training (MICT).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Academic Search Ultimate, CINAHL, Networked Digital Library of Theses and Dissertations, Open Access Theses and Dissertations, OpenDissertations, PubMed/MEDLINE, Scopus, SPORTDiscus and Web of Science.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies using a between-group design, involving adult participants who were not trained athletes, and evaluating effects of HIIT or SIT on FatOx (vs no exercise or MICT) were included.

RESULTS

Eighteen studies of fair-to-good quality were included; nine comparing HIIT or SIT with no exercise and eleven comparing HIIT or SIT with MICT. A significant pooled effect of these types of interval training on FatOx was found (mean difference in g/min (MD)=0.08; 95% confidence interval (CI) 0.04 to 0.12; p<0.001). Significant effects were found for exercise regimens lasting ≥4 weeks, and they increased with every additional week of training (β=0.01; 95% CI 0.00 to 0.02; p=0.003). HIIT and/or SIT were slightly more effective than MICT (MD=0.03; 95% CI 0.01 to 0.05; p=0.005). The effects on FatOx were larger among individuals with overweight/obesity.

CONCLUSION

Engaging in HIIT or SIT can improve FatOx, with larger effects expected for longer training regimens and individuals with overweight/obesity. While some effects seem small, they may be important in holistic approaches to enhance metabolic health and manage obesity.

The effects of date seed (Phoenix dactylifera) supplementation on exercise-induced oxidative stress and aerobic and anaerobic performance following high-intensity interval training sessions: a randomised, double-blind, placebo-controlled trial

High-intensity interval training (HIIT) is an efficient method to improve vascular function, maximal oxygen consumption, and muscle mitochondrial capacity. However, acute HIIT overstresses the oxidative system and causes muscle soreness and damage. The aim of the present study was to investigate the effects of date seeds on exercise-induced oxidative stress and aerobic and anaerobic performance following HIIT sessions. Thirty-six physically active men and women aged 18-35 years were assigned to take 26 g/d of date seed powder (DSP, n 18) or wheat bran powder (placebo, n 18) before and after HIIT workouts for 14 d. Total antioxidant capacity (TAC), oxidative stress index (OSI), total oxidant status (TOS), superoxide dismutase (SOD), glutathione peroxidase (GPx), uric acid, malondialdehyde (MDA), and 8-iso-PGF2α were determined at baseline, at the end of the intervention, and 24-h post-intervention. We used the Cooper and running-based anaerobic sprint test to assess aerobic and anaerobic performance at the study's beginning and end. Independent-samples Student's t tests, ANCOVA and repeated-measures ANOVA were used to compare the quantitative variables. Positive changes were observed in TAC, TOS, OSI, GPx, MDA and visual analogue scale after intervention and at 24-h post-exercise (P < 0·05). Likewise, peak power and fatigue index were significantly improved in DSP in comparison with the placebo group. Levels of SOD, uric acid, 8-iso-PGF2α, VO2 max and average power were not changed after training. Our results showed that date seed supplementation in active participants performing HIIT bouts ameliorated oxidative stress and improved performance parameters.

The effects of prehabilitation on body composition in patients undergoing multimodal therapy for esophageal cancer

Prehabilitation aims to optimize a patient's functional capacity in preparation for surgery. Esophageal cancer patients have a high incidence of sarcopenia and commonly undergo neoadjuvant therapy, which is associated with loss of muscle mass. This study examines the effects of prehabilitation on body composition during neoadjuvant therapy in esophageal cancer patients. In this cohort study, changes in body composition were compared between esophageal cancer patients who participated in prehabilitation during neoadjuvant therapy and controls who did not receive prehabilitation. Assessment of body composition was performed from CT images acquired at the time of diagnosis and after neoadjuvant therapy. Fifty-one prehabilitation patients and 28 control patients were identified. There was a significantly greater fall in skeletal muscle index (SMI) in the control group compared with the prehabilitation patients (Δ SMI mean difference = -2.2 cm2/m2, 95% CI -4.3 to -0.1, p=0.038). Within the prehabilitation cohort, there was a smaller decline in SMI in patients with ≥75% adherence to exercise in comparison to those with lower adherence (Δ SMI mean difference = -3.2, 95% CI -6.0 to -0.5, P = 0.023). A greater decrease in visceral adipose tissue (VAT) was seen with increasing volumes of exercise completed during prehabilitation (P = 0.046). Loss of VAT during neoadjuvant therapy was associated with a lower risk of post-operative complications (P = 0.017). By limiting the fall in SMI and promoting VAT loss, prehabilitation may have multiple beneficial effects in patients with esophageal cancer. Multi-center, randomized studies are needed to further explore these findings.

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.

Effects of Low-Volume High-Intensity Interval Exercise on 24 h Movement Behaviors in Inactive Female University Students

The purpose of this study was to examine if low-volume, high-intensity interval exercise (HIIE) was associated with changes in 24-h movement behaviors. A quasi-experimental study design was used. We collected accelerometry data from 21 eligible participants who consistently wore an ActiGraph for a period of two-weeks. Differences in behaviors were analyzed using a paired t-test and repeated measures analysis of variance. Regression analysis was used to explore relationships with factors that impacted changes. The results indicated a compensatory increase in sedentary time (ST) (4.4 ± 6.0%, p < 0.01) and a decrease in light-intensity physical activity (LPA) (−7.3 ± 16.7%, p < 0.05). Meanwhile, moderate-intensity physical activity (MPA), vigorous-intensity physical activity (VPA), and total physical activity (TPA) increased following exercise (p < 0.001). Sleep duration and prolonged sedentary time were reduced (p < 0.05). Exercise intensity and aerobic capacity were associated with changes in ST. The results from the study indicate that participating in a low-volume HIIE encouraged participants who were previously inactive to become more active. The observations of increases in ST may have displaced a prolonged sitting time. The decrease in sleeping time observed may be reflecting an increased sleep quality in connection with increased higher-intensity PA.

Beneficial Effects of Linseed Supplementation on Gut Mucosa-Associated Microbiota in a Physically Active Mouse Model of Crohn's Disease

The Western diet, rich in lipids and in n-6 polyunsaturated fatty acids (PUFAs), favors gut dysbiosis observed in Crohn's disease (CD). The aim of this study was to assess the effects of rebalancing the n-6/n-3 PUFA ratio in CEABAC10 transgenic mice that mimic CD. Mice in individual cages with running wheels were randomized in three diet groups for 12 weeks: high-fat diet (HFD), HFD + linseed oil (HFD-LS-O) and HFD + extruded linseed (HFD-LS-E). Then, they were orally challenged once with the Adherent-Invasive Escherichia coli (AIEC) LF82 pathobiont. After 12 weeks of diet, total energy intake, body composition, and intestinal permeability were not different between groups. After the AIEC-induced intestinal inflammation, fecal lipocalin-2 concentration was lower at day 6 in n-3 PUFAs supplementation groups (HFD-LS-O and HFD-LS-E) compared to HFD. Analysis of the mucosa-associated microbiota showed that the abundance of Prevotella, Paraprevotella, Ruminococcus, and Clostridiales was higher in the HFD-LS-E group. Butyrate levels were higher in the HFD-LS-E group and correlated with the Firmicutes/Proteobacteria ratio. This study demonstrates that extruded linseed supplementation had a beneficial health effect in a physically active mouse model of CD susceptibility. Additional studies are required to better decipher the matrix influence in the linseed supplementation effect.

Impact of High-Intensity Interval Training on Body Composition and Depressive Symptoms in Adults under Home Confinement

The home confinement derived from the COVID-19 pandemic has led to drastic changes in people’s habits. This situation has influenced their eating, rest, physical activity and socialization patterns, triggering changes in their mental stability. It was demonstrated that physical activity is beneficial for people’s physical and mental health. By its moderate volume and requiring little space or material, high-intensity interval training (HIIT) could prove to be a valid alternative in a situation of confinement. The aim of the present study was to observe the impact of an 8-week HIIT protocol on the body composition and the depressive symptoms of adults in strict home confinement. A total of 21 healthy adults, both male and female, (35.4 ± 5.6 years old; 70.50 ± 12.1 kg; 171 ± 10 cm) were divided into an experimental group (EG, n = 11) who carried out an 8-week Tabata protocol, based upon calisthenic exercises with their own weight in their homes, and a control group (CG, n = 10) who did not carry out any systematic physical activity over the same period. Following the intervention, the EG experienced a significant reduction in percentage (t = 3.86, d = 0.57, p < 0.05) and in kg (t = 4.62, d = 0.29, p < 0.05) of body fat mass (BFM) and body fat mass index (BFMI) (t = 4.61, d = 0.31, p < 0.05), as well as a reduction in depressive symptoms (t = 6.48, d = 1.3, p < 0.05). These results indicate that HIIT is a potential public health tool that could possibly be prescribed to the population in case of future situations of home confinement.

Comparison of visceral fat lipolysis adaptation to high-intensity interval training in obesity-prone and obesity-resistant rats

BACKGROUND/OBJECTIVES

Visceral obesity is one of the key features of metabolic syndrome. High-intensity interval training (HIIT) could effectively reduce visceral fat, but its effects show strong heterogeneity in populations with different degrees of obesity. The mechanism may be related to the differential adaptation to training between obesity phenotypes, namely obesity prone (OP) and obesity resistant (OR). The aim of the present study was to compare adaptive changes of visceral adipose lipolysis adaptation to HIIT between OP and OR animals and further explore the upstream pathway.

METHODS

OP and OR Sprague Dawley rats were established after feeding a high-fat diet for 6 weeks; they were then divided into HIIT (H-OP and H-OR) and control (C-OP and C-OR) groups. After 12 weeks of HIIT or a sedentary lifestyle, animals were fasted for 12 h and then sacrificed for histology as well as gene and protein analysis. Visceral adipocytes were isolated without fasting for catecholamine stimulation and β3-adrenergic receptor (β3-AR) blockade in vitro to evaluate the role of upstream pathways.

RESULTS

After training, there were no differences in weight loss or food intake between OP and OR rats (P > 0.05). However, the visceral fat mass, adipocyte volume, serum triglycerides and liver lipids of OP rats decreased by more than those of OR rats (P < 0.05). Meanwhile, the cell lipolytic capacity and the increase in the expression of β3-AR were higher in the OP compared with OR groups (P < 0.05). Although training did not increase sympathetic nervous system activity (P > 0.05), the cell sensitivity to catecholamine increased significantly in the OP compared with OR groups (P < 0.05). Following blocking β3-AR, the increased sensitivity disappeared.

CONCLUSION

With HIIT, OP rats lost more visceral fat than OR rats, which was related to stronger adaptive changes in lipolysis. Increased β3-AR expression mediated this adaptation.

Exercise, Physical Activity, and Cardiometabolic Health: Pathophysiologic Insights

Physical activity and its sustained and purposeful performance-exercise-promote a broad and diverse set of metabolic and cardiovascular health benefits. Regular exercise is the most effective way to improve cardiorespiratory fitness, a measure of one's global cardiovascular, pulmonary and metabolic health, and one of the strongest predictors of future health risk. Here, we describe how exercise affects individual organ systems related to cardiometabolic health, including the promotion of insulin and glucose homeostasis through improved efficiency in skeletal muscle glucose utilization and enhanced insulin sensitivity; beneficial changes in body composition and adiposity; and improved cardiac mechanics and vascular health. We subsequently identify knowledge gaps that remain in exercise science, including heterogeneity in exercise responsiveness. While the application of molecular profiling technologies in exercise science has begun to illuminate the biochemical pathways that govern exercise-induced health promotion, much of this work has focused on individual organ systems and applied single platforms. New insights into exercise-induced secreted small molecules and proteins that impart their effects in distant organs ("exerkines") highlight the need for an integrated approach towards the study of exercise and its global effects; efforts that are ongoing.

High Intensity Interval Training: A Potential Method for Treating Sarcopenia

Sarcopenia, an age-related disease characterized by loss of muscle strength and muscle mass, has attracted the attention of medical experts due to its severe morbidity, low living quality, high expenditure of health care, and mortality. Traditionally, persistent aerobic exercise (PAE) is considered as a valid way to attenuate muscular atrophy. However, nowadays, high intensity interval training (HIIT) has emerged as a more effective and time-efficient method to replace traditional exercise modes. HIIT displays comprehensive effects on exercise capacity and skeletal muscle metabolism, and it provides a time-out for the recovery of cardiopulmonary and muscular functions without causing severe adverse effects. Studies demonstrated that compared with PAE, HIIT showed similar or even higher effects in improving muscle strength, enhancing physical performances and increasing muscle mass of elder people. Therefore, HIIT might become a promising way to cope with the age-related loss of muscle mass and muscle function. However, it is worth mentioning that no study of HIIT was conducted directly on sarcopenia patients, which is attributed to the suspicious of safety and validity. In this review, we will assess the effects of different training parameters on muscle and sarcopenia, summarize previous papers which compared the effects of HIIT and PAE in improving muscle quality and function, and evaluate the potential of HIIT to replace the status of PAE in treating old people with muscle atrophy and low modality; and point out drawbacks of temporary experiments. Our aim is to discuss the feasibility of HIIT to treat sarcopenia and provide a reference for clinical scientists who want to utilize HIIT as a new way to cope with sarcopenia.