Impact of a 12-week high-intensity interval training without caloric restriction on body composition and lipid profile in sedentary healthy overweight/obese youth

Effects of HIIT training and HIIT combined with circuit resistance training on measures of physical fitness, miRNA expression, and metabolic risk factors in overweight/obese middle-aged women

OBJECTIVE

The purpose of this study was to examine the effects of 10 weeks of high-intensity interval training (HIIT) and HIIT combined with circuit resistance training (HCRT) on selected measures of physical fitness, the expression of miR-9, -15a, -34a, -145, and - 155 as well as metabolic risk factors including lipid profiles and insulin resistance in middle-aged overweight/obese women.

METHODS

Twenty-seven overweight/obese women aged 35-50 yrs. were randomized to HIIT (n = 14) or HCRT (n = 13) groups. The HIIT group performed running exercises (5 reps x 4 min per session) with active recovery between repetitions for 10 weeks with 5 weekly sessions. The HCRT group performed 10 weeks of HIIT and resistance training with 3 weekly HIIT sessions and 2 weekly HCRT sessions. Anthropometric measures (e.g., body mass), selected components of physical fitness (cardiovascular fitness, muscle strength), levels of miRNAs (miR-9, -15a, -34a, -145, and - 155), lipid profiles (total cholesterol; TC, Triglycerides; TG, low-density lipoprotein cholesterol; LDL-C and high-density lipoprotein cholesterol; HDL-C), and insulin resistance; HOMA-IR index, were measured at baseline and week 10.

RESULTS

An ANOVA analysis indicated no significant group by time interactions (p > 0.05) for all anthropometric measures, and maximum oxygen consumption (VO2max). A significant group by time interaction, however, was found for the one-repetition maximum (IRM; p < 0.001, ES= 0.751 , moderate). A post-hoc test indicated an increase in the pre-to-post mean 1RM for HCRT (p = 0.001, ES = 1.83, large). There was a significant group by time interaction for miR-155 (p = 0.05, ES = 0.014, trivial). Levels for miR-155 underwent pre-to-post HIIT increases (p = 0.045, ES = 1.232, large). Moreover, there were also significant group by time interactions for TC (p = 0.035, ES = 0.187, trivial), TG (p < 0.001, ES = 0.586, small), LDL-C (p = 0.029, ES = 0.200, small) and HDL-C (p = 0.009, ES = 0.273, small). Post-hoc tests indicated pre-post HCRT decreases for TC (p = 0.001, ES = 1.44, large) and HDL-C (p = 0.001, ES = 1.407, large). HIIT caused pre-to-post decreases in TG (p = 0.001, ES = 0.599, small), and LDL-C (p = 0.001, ES = 0.926, moderate).

CONCLUSIONS

Both training regimes did not improve cardiovascular fitness. But, HCRT improved lower/upper limb muscle strength, and HIIT resulted in an increase in miR-155 expression in peripheral blood mononuclear cells. Furthermore, HIIT and HCRT each improved selected metabolic risk factors including lipid profiles and glucose and insulin metabolism in overweight/obese middle-aged women.

TRIAL REGISTRATION

OSF, October, 4th 2023. Registration DOI: https://doi.org/10.17605/OSF.IO/UZ92E . osf.io/tc5ky . "Retrospectively registered".

Evaluating the impact of exercise on intermediate disease markers in overweight and obese individuals through a network meta-analysis of randomized controlled trials

The aim of this study is to investigate the impact of exercise on intermediate disease markers in populations with overweight and obesity, providing evidence-based recommendations for clinicians to utilize these markers in developing exercise prescriptions for this group. The study was conducted by retrieving data from PubMed, Embase, Cochrane Library, Web of Science, and CNKI and only including Randomized Controlled Trials (RCTs) to examine the effect of different exercise interventions on intermediate disease markers in overweight and obese people. The quality of the included studies was evaluated using the Cochrane Bias Risk Assessment tool and the data was analyzed using Stata 15.1 data analysis software. The RCTs were collected from January 2017 to March 2024. A total of 56 RCTs were included and the results of 10 outcomes were analyzed using random effects meta-analysis. The total sample size used in the study was 3193 The results showed that resistance training significantly reduced total cholesterol (SUCRA: 99.9%), triglycerides (SUCRA: 100.0%), low-density lipoprotein (SUCRA: 100.0%), systolic pressure (SUCRA: 92.5%), and increased high-density lipoprotein (SUCRA: 100.0%). Aerobic exercise significantly reduced insulin (SUCRA: 89.1%) and HbA1c (SUCRA: 95.3%). Concurrent training significantly reduced HOMA-IR (SUCRA: 93.8%), diastolic blood pressure (SUCRA: 71.2%) and Glucose (SUCRA: 87.6%). Exercise has a significant impact on intermediate disease markers in populations with overweight and obese. Compared with no exercise, exercise lowers total cholesterol, triglycerides, LDL, systolic blood pressure, diastolic blood pressure, HOMA-IR, insulin, and HbA1c, and increases HDL in people with overweight and obese. These findings provide evidence-based recommendations for exercise interventions aimed at weight reduction and the prevention of chronic diseases in individuals with overweight and obese.

Effects of different exercise modalities and intensities on body composition in overweight and obese children and adolescents: a systematic review and network meta-analysis

Introduction: Childhood and adolescent overweight and obesity are global public health issues. Previous studies on exercise and overweight and obese children have produced inconsistent findings and lacked comparisons between different exercise modalities and intensities. Therefore, a network meta-analysis is necessary to provide evidence-based intervention programs. This study aims to identify the effects of different exercise modalities and intensities on changes in body composition in overweight and obese children and adolescents. Methods: A search for randomized controlled trials was conducted on Web of Science, PubMed, Scopus, and Embase involving exercise interventions aimed at improving body composition (body fat percentage, BMI, fat mass, fat-free mass, body weight) in overweight and obese children and adolescents. A random effects network meta-analysis was performed using STATA 14.0 software within a frequentist framework. The literature quality was assessed using the Cochrane Risk of Bias Tool 2.0. Results: Thirty-two papers involving 1,452 participants were included. There were six types of intervention involved in the study, including moderate intensity aerobic exercise, high-intensity aerobic exercise, moderate intensity resistance exercise, high-intensity resistance exercise, moderate intensity combined exercise, and high-intensity combined exercise. The network meta-analysis results revealed that high-intensity combined exercise was the best exercise mode for improving BMI [mean difference in kg/m² = -1.65, 95% CI (-3.27, -0.02)] and reducing fat mass [mean difference in kg = -2.87, 95% CI (-4.84, -0.91)]. Moderate intensity combined exercise was the best mode for weight loss [mean difference in kg = -4.58, 95% CI (-5.94, -3.22)] and improvement in body fat percentage [mean difference in% = -2.52, 95% CI (-3.83, -1.20)]. High-intensity resistance exercise had the optimal effect in increasing fat-free mass [mean difference in kg = 1.10, 95% CI (0.22, 1.99)]. Conclusion: In conclusion, the study found that combined exercise, whether moderate or high intensity, was more effective than any other exercise modality in improving body fat percentage and BMI, reducing fat mass and weight. Resistance exercise was the most effective in increasing fat-free mass.

The Effects of HIIT vs. MICT and Sedentary Controls on Blood Lipid Concentrations in Nondiabetic Overweight and Obese Young Adults: A Meta-analysis

With rates of obesity and dyslipidemia rising among young adults, this meta-analysis aimed to compare the effects of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) and sedentary controls (CON) on low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), and total cholesterol (TC) in nondiabetic overweight and obese young adults to determine if HIIT or MICT is more efficacious in improving dyslipidemia. Studies included in the analysis had to be randomized controlled trials or quasi-experimental studies, comparing the effects of HIIT versus MICT or CON on at least three variables of interest: LDL, HDL, TG, and TC, in nondiabetic adults, with body mass indexes (BMIs) above 25, and average ages between 18-30. The quality of the studies was evaluated using the Physiotherapy Evidence Database (PEDro) scale. Eight studies fulfilled the selection criteria, with a mean PEDro quality score of 5.8. Compared to CON, HIIT significantly decreased the concentrations of LDL (-12.14 mg/dL, p = < 0.00001) and TC (-9.27 mg/dL, p = 0.003), without significantly affecting HDL or TG. Compared to MICT, HIIT significantly decreased the concentrations of LDL (-6.23 mg/dL, p = 0.05) and TC (-7.85 mg/dL, p = 0.02), without significantly affecting HDL or TG concentrations. HIIT is superior to MICT and CON in improving the concentrations of LDL and TC in our target population. As early management of dyslipidemia improves long-term health, we recommend clinicians consider HIIT training protocols for their nondiabetic overweight and obese young adult patients.

Anti-obesity effects of aerobic exercise along with Rosa canina seed extract supplementation in rats: The role of irisin and adipolin

Aerobic exercise and some bioactive compounds in medicinal plants have anti-obesity effects and can suppress body weight. The aim of this study was to determine the anti-obesity effects of 6 weeks of aerobic exercise (AE) and supplementation of the hydroalcoholic extract of Rosa canina fruit seed (RC) in obese male rats. In this experimental study, 24 high-fat diet (HFD) obese male Wistar rats were used. The animals were randomly divided into 4 groups (6 rat in group), including 1. HFD (the control group), 2. HFD + AE, 3. HFD + RC and 4. HFD + AE + RC. An obesity protocol was implemented for 12 weeks with the consumption of HFD along with the consumption of water containing 1 % fructose. Afterwards, the animals were given access only to HFD food until the end of the study in all the groups. After the obesity protocol, 6 weeks of exercise (50-70 % VO₂ max) and access to the extract (1 % of the consumed food) were given. Bodyweight, subcutaneous adipose tissue mass, and some serum lipid profiles were measured in the experimental groups. The serum levels of irisin and adipolin were evaluated by the ELISA method. Expression of FNDC5 and CTRP12 in adipose tissue were determined by real-time PCR. The findings of this study showed that body weight (P = 0.001), subcutaneous adipose tissue mass (P = 0.001), and lipid profile were significantly reduced in HFD + AE and HFD + AE + RC groups compared with the HFD group. Irisin was significantly increased in the HFD + AE and HFD + AE + RC groups compared with the HFD group (P = 0.019 and P = 0.001; respectively) and in the HFD + AE + RC group compared with the HFD + RC group (P = 0.004). Moreover, adipolin, expression of FNDC5 and CTRP12 were significantly increased in the HFD + AE + RC group compared with the HFD group (P = 0.004, P = 0.023, and P = 0.001; respectively). Altogether, HFD + AE with HFD + RC diet supplementation could reduce weight and the risks of obesity, at least, through the up-regulation of irisin and adipolin.

The Effect of High-Intensity Interval Training Type on Body Fat Percentage, Fat and Fat-Free Mass: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

This systematic review and meta-analysis of randomized controlled trials (RCTs) compared body compositional changes, including fat mass (FM), body fat percentage (BF%), and fat-free mass (FFM), between different types of high-intensity interval training (HIIT) (cycling vs. overground running vs. treadmill running) as well as to a control (i.e., no exercise) condition. Meta-analyses were carried out using a random-effects model. The I2 index was used to assess the heterogeneity of RCTs. Thirty-six RCTs lasting between 3 to 15 weeks were included in the current systematic review and meta-analysis. RCTs that examined the effect of HIIT type on FM, BF%, and FFM were sourced from online databases including PubMed, Scopus, Web of Science, and Google Scholar up to 21 June 2022. HIIT (all modalities combined) induced a significant reduction in FM (weighted mean difference [WMD]: −1.86 kg, 95% CI: −2.55 to −1.18, p = 0.001) despite a medium between-study heterogeneity (I2 = 63.3, p = 0.001). Subgroup analyses revealed cycling and overground running reduced FM (WMD: −1.72 kg, 95% CI: −2.41 to −1.30, p = 0.001 and WMD: −4.25 kg, 95% CI: −5.90 to −2.61, p = 0.001, respectively); however, there was no change with treadmill running (WMD: −1.10 kg, 95% CI: −2.82 to 0.62, p = 0.210). There was a significant reduction in BF% with HIIT (all modalities combined) compared to control (WMD: −1.53%, 95% CI: −2.13, −0.92, p = 0.001). All forms of HIIT also decreased BF%; however, overground running induced the largest overall effect (WMD: −2.80%, 95% CI: −3.89 to −1.71, p = 0.001). All types of HIIT combined also induced an overall significant improvement in FFM (WMD: 0.51 kg, 95% CI: 0.06 to 0.95, p = 0.025); however, only cycling interventions resulted in a significant increase in FFM compared to other exercise modalities (WMD: 0.63 kg, 95% CI: 0.17 to 1.09, p = 0.007). Additional subgroup analyses suggest that training for more than 8 weeks, at least 3 sessions per week, with work intervals less than 60 s duration and separated by ≤90 s active recovery are more effective for eliciting favorable body composition changes. Results from this meta-analysis demonstrate favorable body composition outcomes following HIIT (all modalities combined) with overall reductions in BF% and FM and improved FFM observed. Overall, cycling-based HIIT may confer the greatest effects on body composition due to its ability to reduce BF% and FM while increasing FFM.

Exercise modulation in inflammation and metabolic hormonal disorders of COVID-19 to decrease risk factors in coronary heart disease

OBJECTIVES

Sedentary life style separated during COVID-19 pandemic. Patients with cardiovascular diseases (CVD) are vulnerable with sedentary life style. Therefore, the aim of this study was to investigate the effect of 8 weeks of combined and high intensity interval training (HIIT) on C Reactive protein, galectin-3, leptin, fibrinogen and insulin resistance index in coronary heart disease after COVID-19.

METHODS

Thirty-six cardiovascular patients (55.14 ± 1.4 years, 78.6 ± 5.1 kg) were divided into three groups of combined exercise (n=13), HIIT (n=12) and control group (n=11). Combined exercise consisted of aerobic (4 weeks) and aerobic + HIIT exercise (4 weeks), three sessions per weeks. The protocol of the HIIT group included performing high intensity interval training, three sessions per weeks for 8 weeks. Blood samples were taken 24 h before the first training session and 48 h after the last training. C Reactive protein (CRP), galectin-3, leptin, fibrinogen measured with ELISA kit.

RESULTS

CRP, galectin-3 and fibrinogen decreased significantly after 8 weeks of combined training and HIIT (compare to pre-test). Also, insulin resistance index after 8 weeks of combined exercise showed a significant decrease compare to pre-test (p<0.05). After 8 weeks, CRP, galectin-3 and insulin resistance significantly decreased compare to control group (p<0.05).

CONCLUSIONS

In the patient with CVD, combined exercise training may be more effective than HIIT in reducing metabolic and heart risk factors after an epidemic such as COVID-19. However, change of leptin need to more studies.

The effect of varied exercise intensity on antioxidant function, aortic endothelial function, and serum lipids in rats with non-alcoholic fatty liver disease

This study aimed to compare the effects of diet and exercise of different intensities on antioxidant function, aortic endothelial cell function and serum lipids in NAFLD (nonalcoholic fatty liver disease) rats. Fifty Sprague-Dawley (SD) rats (180-220g) were randomly divided into two experimental groups and fed either a standard rodent chow diet (CON; n=10) or a high-fat diet (HFD; n=40). After 16 weeks, the animals that received the HFD were randomly separated into a high-fat control group (HFC; n=10) or three ex-ercise training groups: HFD and low-intensity exercise (LE; n=10), HFD and moderate-intensity exercise (ME; n=10), and HFD and incremental intensity exercise (IE; n=10). These experimental rats keep sedentary or trained for the next six weeks. A detection kit was used to detect nitric oxide synthase (NOs), nitric oxide (NO), malondialdehyde (MDA) and other markers of aor-tic oxidative stress. The expression levels of endothelial nitric oxide synthase (e-NOS) and endothelin-1 (ET-1) were detected by immunohistochemistry. TC, TG, and other lipid metabolism parameters were detected by an auto-matic analyzer. Exercise with different intensities could improve lipid me-tabolism, enhance antioxidant function, reduce MDA (P<0.01), increase NO (P<0.01), and improve the expression of e-NOS and ET-1 (P<0.01) protein levels in NAFLD rats. Decreased blood lipids were exhibited in all exercise groups. Notably, the moderate-intensity exercise demonstrated more effecton increasing glutathione (GSH) contents (P<0.01) and decreased the ex-pression of ET-1protein levels (P<0.01). The results showed that exercise at different intensities improved lipid metabolism and enhanced anti-oxidation function. Moderate exercise could improve the function of aortic endothelial cells.

Effect of Sprint Interval Training on Cardiometabolic Biomarkers and Adipokine Levels in Adolescent Boys with Obesity

This study investigated the effect of supervised sprint interval training (SIT) on different cardiometabolic risk factors and adipokines in adolescent boys with obesity. Thirty-seven boys were allocated to either a SIT group (13.1 ± 0.3 years; body mass index [BMI]: 30.3 ± 0.9 kg·m^-2) or a control group (CONT) (13.7 ± 0.4 years; BMI: 32.6 ± 1.6 kg·m^-2). The SIT group performed 4-6 × 30 s all-out cycling sprints, interspersed with 4 min rest, for 3 sessions/week, during a 12-week period, while the non-exercising CONT group maintained a habitual lifestyle. Anthropometric measurements, triglycerides, fasting insulin and glucose, total cholesterol (TC), high- (HDLc) and low-density (LDLc) cholesterol, leptin and adiponectin in blood, cardiorespiratory fitness (CRF), and a metabolic syndrome severity risk score (MSSS) were calculated before and after the 12-week period. Compared to baseline values, a significant reduction in MSSS was seen in the SIT group after intervention. LDLc showed favorable changes in SIT compared to CONT (-0.06 ± 0.1 vs. 0.19 ± 0.01 mmol·L^-1; p = 0.025). Additionally, CRF increased in the SIT group compared to the CONT group (5.2 ± 1.1 vs. -2.1 ± 1.1 mL·min^-1·kg^-1, p < 0.001). Moreover, a 12-week all-out SIT training effectively improves cardiometabolic health in adolescent boys with obesity.

Effect of supervised sprint interval training on cardiorespiratory fitness and body composition in adolescent boys with obesity

This study examined the effect of a supervised 12-week sprint interval training (SIT) on cardiorespiratory fitness (CRF) and body composition in adolescent boys with obesity. Twenty-eight adolescents with obesity were allocated to either an intervention group (SIT) (13.1 ± 0.3 yrs; body mass index [BMI]: 30.3 ± 0.9 kg.m^-2) or a control group (CONT) (13.7 ± 0.4 yrs; BMI: 32.6 ± 1.6 kg.m^-2). The SIT group performed 4-6 × 30s "all-out" cycling bouts, interspersed with 4 min of recovery 3 days a week for 12 weeks. CRF was measured by direct peak oxygen consumption (VO₂peak) defined as VO₂peak per kg of body mass (mL.min^-1kg^-1) or by VO₂peak per kg of lean body mass (mL.min^-1LBM^-1) and body composition was assessed by dual-energy X-ray absorptiometry. SIT intervention led to a significant and large between-group difference in VO₂peak (p = 0.004; η² = 0.29). Although SIT group had a significant reduction in body fat percentage (BF%) (from 41.1 ± 1.3% to 39.2 ± 1.5%; p = 0.006), there were no between-group differences in the change of the pre- and post-measures in BF% (p = 0.067). In conclusion, 12-week SIT is effective in increasing CRF and decreasing BF% in adolescent boys with obesity.

Psychophysiological Responses of Exercise Distribution During High Intensity Interval Training Using Whole Body Exercise

The time-efficient nature of HIIT using bodyweight exercises can facilitate the application of exercise programs at home by encouraging more people to perform regular physical exercise. However, there are no studies investigating the influence of the distribution/order of exercises during HIIT training sessions using this method. The aim of the present study was to evaluate the effects of different exercise orders on training load indicators during HIIT sessions using body weight. Twenty male participants performed three 20-min sessions of HIIT using whole body exercise, consisting of 20 sets with 30 s of activity performed at maximal intensity, followed by 30 s of passive recovery. Three designs of exercise protocols were randomly performed according to the following exercise distribution: A: jumping jack, burpee, mountain climb and squat jump); B: jumping jack, mountain climb, burpee, and squat jump) and C: burpee, squat jump, jumping jack and mountain climb. No differences were found between protocols for relative heart rate, perceived exertion, and lactate concentrations. Significant differences (p &lt; 0.001) were found for the number of movements (A:712 ± 59, B:524 ± 49, C:452 ± 65). No differences were observed for the area under curve when examining perceived exertion between protocols. However, the values for perceived recovery significantly differed (p &lt; 0.001) between protocols (A:64 ± 19; B:52 ± 11; C:17 ± 13). Interestingly, protocol B and C induced a displeasure perception compared to protocol A. Our findings suggest that exercise distribution/order using HIIT whole body exercise promotes alterations in psychophysiological responses in HIIT using whole body exercises.

A Short-Term Eccentric HIIT Induced Greater Reduction in Cardio-Metabolic Risk Markers in Comparison With Concentric HIIT in Sedentary Overweight Men

Background: Steady-state eccentric exercise training improves cardiometabolic risk (CMR) despite lesser cardiovascular demands compared with load-matched concentric training. Whether a high-intensity interval eccentric training is also effective reducing CMR is unknown. Aim: To compare the effects of a short-term high-intensity interval eccentric training (ECC-HIIT) with high-intensity interval concentric training (CONC-HIIT) on CMR in sedentary overweight men. Methods: Twenty men (age: 27.9 ± 5.3y, body massindex: 29.1 ± 3.1 kg·m-2) were randomly assigned to ECC-HIIT (n = 10) or CONC-HIIT (n = 10) delivered as six sessions, including 4 x 5:2 min work-to-rest ratio, at 80% peak concentric power output. Heart rate (HR), rate of perceived exertion (RPE) and muscle soreness weremonitored during training sessions. Training effects on lipid profile, insulin sensitivity (HOMA-IR), body composition, thigh circumference, isometric knee extensors maximal strength, resting systolic and diastolic blood pressure (SBP and DBP) were determined. Results: Average training HR and RPE were -29%and -50%lower in ECC-HIIT in comparison with CONC-HIIT. Muscle soreness was initially greater after ECC-HIIT compared with CONC-HIIT. Significant changes in total and low-density lipoprotein cholesterol (-7.0 ± 8.7%; p = .02 and -6.3 ± 14.4%; p = .03), SBP (-9.8 ± 7.8%; p = .002), and maximal thigh circumference (+2.5 ± 3.1%; p = .02) were observed following ECC-HIIT. No changes in any CMR marker were observed after CONC-HIIT. Moderate-to-large training effect sizes were obtained in thigh circumference, SBP, total cholesterol and low-density lipoprotein cholesterol in response to ECC-HIIT. Conclusion: A two-week ECC-HIIT was well-tolerated and induced rapid onset improvements in cholesterol and blood pressure compared to conventional CONC-HIIT in sedentary overweight men.

The Mediation Role of Fatness in Associations between Cardiorespiratory Fitness and Blood Pressure after High-Intensity Interval Training in Adolescents

BACKGROUND

Low cardiorespiratory fitness (CRF), elevated blood pressure (BP), and high fatness are cardiovascular disease risk factors. It remains unknown how fatness affects the influence of CRF on BP. Therefore, the aim was to examine whether the associations between baseline CRF and HIIT-postintervention resting BP were mediated through fatness in adolescents.

MATERIAL AND METHODS

The sample (n = 64) comprised 28 boys 36 girls aged 16 years. The analysed factors were fitness index- reflecting CRF, body fat mass (BFM), fat mass index (FMI), and body mass index (BMI). Bootstrapped mediation procedures were performed. The mediation analysis was conducted concerning the sex moderation effect.

RESULTS

The mediation effect of sex was confirmed; therefore, mediations models were designed separately for boys and girls. The results showed a statistically significant inverse relationship between baseline CRF and post-intervention systolic blood pressure (SBP) in both sexes (boys: B = -0.603, p = 0.010; girls: B = -0.394, p = 0.037). The relations between CRF and SBP revealed the mediation effect of the BFM and the FMI only in boys.

CONCLUSIONS

Fatness mediated associations between CRF and SBP in boys. Therefore, both CRF and fatness are necessary to maintain positive results of the BP revealed in normal SBP ranges after HIIT.

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

Simple Summary

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

Abstract

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

An updated systematic review on the effects of aerobic exercise on human blood lipid profile

Sedentary lifestyle and dyslipidemia are well-recognized risk factors for cardiovascular diseases (CVD). Changes in blood lipid profile (total cholesterol (TC), triglycerides, high-density lipoprotein [HDL], and low-density lipoprotein [LDL]) due to the exercise may be beneficial for decreasing CVD-related events. In this review we aimed to investigate the effect of different types of exercise on lipid profile components in people with different health conditions and age ranges. A systematic search was performed covering PubMed, Web of Science, and Google Scholar for English articles from 2010 until November 2021. Finally, 31 studies were included in our study. Results showed that exercise in younger individuals sometimes resulted in no significant changes of any of the variables or some of them; however, efficient improvement was observed in all studies of older and middle-age groups. In terms of health condition and gender; healthy individuals, overweight people, subjects with type 2 diabetes and obesity, and male participants found to have benefited more from the exercise. In patients with chronic kidney diseases lipid profile improvement was not significant. The cardiac rehabilitation program, particularly comprehensive cardiac rehabilitation, proved to be more beneficial than exercise alone in the case of cardiovascular patients and those at elevated risk of CVD. In conclusion exercise is beneficial in terms of improving lipid profile but for younger population, and those with kidney problems and CVD patients, more further preparations are needed under the supervision of experts in the field of sports and medicine to achieve the desired result. Also, more studies are needed for these groups in order to provide a definite and reliable conclusion.

Exercise Training Intensity and the Fitness-Fatness Index in Adults with Metabolic Syndrome: A Randomized Trial

Background

Cardiorespiratory fitness and fatness (notably central obesity) are mediating factors of the metabolic syndrome (MetS) and consequent cardiovascular disease (CVD)/mortality risk. The fitness-fatness index (FFI) combines these factors and has been reported to be a better indicator of CVD and all-cause mortality risk, beyond the capacity of either fitness or fatness alone.

Objective

This study sought to investigate the effects of different exercise intensities on FFI in adults with MetS.

Methods

This was a sub-study of the ‘Exercise in the prevention of Metabolic Syndrome’ (EX-MET) multicentre trial. Ninety-nine adults diagnosed with MetS according to the International Diabetes Federation criteria were randomized to one of the following 16-week exercise interventions: i) moderate-intensity continuous training (MICT) at 60–70% HRpeak for 30 min/session (n = 34, 150 min/week); ii) 4 × 4 min bouts of high-intensity interval training at 85–95% HRpeak, interspersed with 3-min active recovery at 50–70% HRpeak (n = 34, 38 min/session, 114 min/week); and iii) 1 × 4 min bout of HIIT at 85–95% HRpeak (n = 31, 17 min/session, 51 min/week). Cardiorespiratory fitness (peak oxygen uptake, V̇O2peak) was determined via indirect calorimetry during maximal exercise testing and fatness was the ratio of waist circumference-to-height (WtHR). FFI was calculated as V̇O2peak in metabolic equivalents (METs) divided by WtHR. A clinically meaningful response to the exercise intervention was taken as a 1 FFI unit increase.

Results

Seventy-seven participants completed pre and post testing to determine FFI. While there was no significant between group difference (p = 0.30), there was a small group x time interaction effect on FFI [F(2, 73) = 1.226; η2 = 0.01], with numerically greater improvements following HIIT (4HIIT, + 16%; 1HIIT, + 11%) relative to MICT (+ 7%). There was a greater proportion of participants who had a clinically meaningful change in FFI following high-volume HIIT (60%, 15/25) and low-volume HIIT (65%, 17/26) compared to MICT (38%, 10/26), but with no significant between-group difference (p = 0.12). A similar trend was found when a sub-analysis comparing the FFI between those with type 2 diabetes (MICT, 33%, 3/9; high-volume HIIT, 64%, 7/11; and low-volume HIIT, 58%, 7/12) and without type 2 diabetes (MICT, 41%, 7/17; high-volume HIIT, 57%, 8/14; low-volume HIIT, 71%, 10/14).

Conclusion

Although there were no statistically significant differences detected between groups, this study suggests that the response to changes in FFI in adults with MetS may be affected by exercise intensity, when numerical differences between exercise groups are considered. Further research is warranted.

Trial registration number and date of registration: ClinicalTrials.gov NCT01676870; 31/08/2012.

Chlorella vulgaris in combination with high intensity interval training in overweight and obese women: a randomized double-blind clinical trial

Background

Chlorella vulgaris (CV) as a multifunctional dietary supplement is known with lots of health benefits. It is possible that CV consumption along with high-intensity interval training (HIIT), a short period exercise is more beneficial. This investigation aimed to evaluate the effects of CV and/or HIIT on anthropometric parameters and cardiometabolic risk factors among overweight or obese women.

Methods

Present randomized double-blind clinical trial, included 46 women with overweight or obesity and randomly assigned them to four groups including CV, HIIT, CV+HIIT, and placebo. CV supplementation was 900 mg a day and HIIT program 3 sessions a week. Dietary intake, anthropometric assays and blood samples were taken at the commencement and completion of 8-week intervention.

Results

After 8 weeks, waist circumference (WC) significantly reduced in CV+HIIT group in comparison with placebo group. Significant decreases in triglycerides (TG) and low-density lipoprotein (LDL) cholesterol levels were found after CV supplementation and/or HIIT exercise in comparison with placebo group. A significant rise in high-density lipoprotein (HDL) cholesterol level was observed in HIIT and HIIT + CV groups in comparison with placebo group, however CV consumption failed to affect HDL cholesterol levels. CV and/or HIIT significantly lowered, visceral adiposity index (VAI), lipid accumulating product (LAP) and atherogenic index of plasma (AIP) in comparison with placebo. However, concurrent administration of CV and HII resulted in greater reduction in this indexes. Among glycemic indices a significant reduction in insulin resistance in CV+HIIT group compared with placebo group were seen.

Conclusions

In conclusion, CV and HIIT could improve lipid profile and glycemic status in overweight and obese women.

Effect of high-intensity interval training on cardiometabolic risk factors in childhood obesity: a meta-analysis

INTRODUCTION

This systematic review with meta-analysis aimed to quantify the effectiveness of high-intensity interval training (HIIT) on the cardiometabolic health of obese children and adolescents.

EVIDENCE ACQUISITION

Relevant articles were sourced from PubMed, Embase, the Web of Science, EBSCO, the Cochrane Library and China National Knowledge Infrastructure (CNKI). Randomized controlled trials were included if they employed participants aged 7-19 years. Outcomes included fasting glucose (FG), fasting insulin (FI), homeostasis model assessment-insulin resistance (HOMA-IR), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), triacylglycerol (TG), total cholesterol (TC), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured at baseline and postintervention and compared with those in the control group. Data analysis and synthesis were completed by Revman 5.3 software and Stata 12.0 software (StataCorp LLC., College Station, TX, USA).

EVIDENCE SYNTHESIS

Eight trials involving 379 participants were identified. HIIT significantly decreased the FI, HOMA-IR, TC, TG, LDL-c and SBP in participants with obesity. With regard to changes in blood glucose and lipids, participants who underwent HIIT showed great improvement in FI (mean difference: -3.09 µU/mL, 95% confidence interval [CI] -3.71 to -2.46, P<0.0001), HOMA-IR (mean difference: -0.64, 95% CI -0.82 to -0.46, P<0.0001), TG (mean difference: -0.21 mmol/L, 95% CI -0.31 to -0.10, P<0.0001) and LDL-c (mean difference: -0.35 mmol/L, 95% CI -0.48 to -0.22, P<0.001) than the control group. Similar results were found for SBP (mean difference: -3.61 mmHg, 95% CI -5.85 to -1.37, P=0.002). However, no significant differences in changes in FG, HDL-c and DBP were observed between HIIT and control groups.

CONCLUSIONS

HIIT can produce a positive effect on cardiometabolic risk factors in obese children and adolescents. HIIT may be an alternative and effective training method for managing childhood obesity.

Cardiometabolic efficacy of multidisciplinary weight loss interventions is not altered in adolescents with obesity initially diagnosed or with a persistent metabolic syndrome

The efficacy of weight loss interventions might be affected by the metabolic profile of adolescents with obesity. In this study, we hypothesized that the initial diagnosis of the MS, or its persistence after an intervention, will not reduce the efficacy of a 16-week multidisciplinary weight loss program. Ninety two adolescents (12-15 years; 62 girls) with obesity completed baseline anthropometric and body composition evaluation (DXA). Lipid profile, insulinemia, glycaemia and blood pressure were measured and metabolic syndrome (MS) diagnosed. The adolescents then followed a 4-month inpatient multidisciplinary weight-management program. All measurements were performed before (T0) and after 4 months of intervention (T1). Body weight, body mass index (BMI) and percentage of fat mass (%FM) decreased significantly between T0 and T1 (P< .001), with no difference in fat-free mass (kg). All metabolic variables (except blood pressure) were improved. 47.6% of the whole sample presented with MS at baseline against 35.7% at T1. Body weight (P = 0.006), BMI (P = 0.0261), %FM (P = 0.0211), hip circumference (= 0.0131), BMI percentile (P = 0.0319), and diastolic blood pressure (P = 0.0365) showed a time x group interaction and their deltas (variations between T0 and T1) were significantly different between adolescents with and without MS at baseline. There was no significant difference between adolescents with persistent and nonpersistent MS except for ΔBMI percentile that deceased significantly more in the nonpersistent group (P = 0.0115). According to our results, the efficacy of weight loss interventions is not reduced in adolescents initially diagnosed with MS or different between those who present a persistent or nonpersistent MS after the intervention.

L-Arginine Improves Endurance to High-Intensity Interval Exercises in Overweight Men

The effects of acute consumption of L-Arginine (L-Arg) in healthy young individuals are not clearly defined, and no studies on the effects of L-Arg in individuals with abnormal body mass index undertaking strenuous exercise exist. Thus, we examined whether supplementation with L-Arg diminishes cardiopulmonary exercise testing responses, such as ventilation (VE), VE/VCO2, oxygen uptake (VO2), and heart rate, in response to an acute session of high-intensity interval exercise (HIIE) in overweight men. A double-blind, randomized crossover design was used to study 30 overweight men (age, 26.5 ± 2.2 years; body weight, 88.2 ± 5.3 kilogram; body mass index, 28.0 ± 1.4 kg/m2). Participants first completed a ramped-treadmill exercise protocol to determine VO2max velocity (vVO2max), after which they participated in two sessions of HIIE. Participants were randomly assigned to receive either 6 g of L-Arg or placebo supplements. The HIIE treadmill running protocol consisted of 12 trials, including exercise at 100% of vVO2max for 1 min interspersed with recovery intervals of 40% of vVO2max for 2 min. Measurements of VO2 (ml·kg-1·min-1), VE (L/min), heart rate (beat per min), and VE/VCO2 were obtained. Supplementation with L-Arg significantly decreased all cardiorespiratory responses during HIIE (placebo+HIIE vs. L-Arg+HIIE for each measurement: VE [80.9 ± 4.3 L/min vs. 74.6 ± 3.5 L/min, p < .05, ES = 1.61], VE/VCO2 [26.4 ± 1.3 vs. 24.4 ± 1.0, p < .05, ES = 1.8], VO2 [26.4 ± 0.8 ml·kg-1·min-1 vs. 24.4 ± 0.9 ml·kg-1·min-1, p < .05, ES = 2.2], and heart rate [159.7 ± 6.3 beats/min vs. 155.0 ± 3.7 beats/min, p < .05, d = 0.89]). The authors conclude consuming L-Arg before HIIE can alleviate the excessive physiological strain resulting from HIIE and help to increase exercise tolerance in participants with a higher body mass index who may need to exercise on a regular basis for extended periods to improve their health.

Hemodynamic Adaptations Induced by Short-Term Run Interval Training in College Students

Perceived lack of time is one of the most often cited barriers to exercise participation. High intensity interval training has become a popular training modality that incorporates intervals of maximal and low-intensity exercise with a time commitment usually shorter than 30 min. The purpose of this study was to examine the effects of short-term run interval training (RIT) on body composition (BC) and cardiorespiratory responses in undergraduate college students. Nineteen males (21.5 ± 1.6 years) were randomly assigned to a non-exercise control (CON, n = 10) or RIT (n = 9). Baseline measurements of systolic and diastolic blood pressure, resting heart rate (HRrest), double product (DP) and BC were obtained from both groups. VO_2max and running speed associated with VO_2peak (sVO_2peak) were then measured. RIT consisted of three running treadmill sessions per week over 4 weeks (intervals at 100% sVO_2peak, recovery periods at 40% sVO_2peak). There were no differences in post-training BC or VO₂max between groups (p > 0.05). HRrest (p = 0.006) and DP (p ≤ 0.001) were lower in the RIT group compared to CON at completion of the study. RIT lowered HRrest and DP in the absence of appreciable BC and VO_2max changes. Thereby, RIT could be an alternative model of training to diminish health-related risk factors in undergraduate college students.

Effect of HIIT with Tabata Protocol on Serum Irisin, Physical Performance, and Body Composition in Men

High-intensity interval training (HIIT) is frequently utilized as a method to reduce body mass. Its intensity of work results in a number of beneficial adaptive changes in a relatively short period of time. Irisin is a myokine and adipokine secreted to the blood during exercise and it takes part in the regulation of energy metabolism. It is a vital issue from the prophylaxis point of view as well as treatment through exercise of different diseases (e.g., obesity, type-2 diabetes). The aim of this study was to evaluate changes in irisin concentration, body composition, and aerobic and anaerobic performance in men after HIIT. Eight weeks of HIIT following the Tabata protocol was applied in the training group (HT) (n = 15), while a sedentary group (SED) (n = 10) did not participate in fitness activities within the same time period. Changes of irisin, body composition, and aerobic and anaerobic performance were evaluated after graded exercise test (GXT) and Wingate anaerobic test (WAnT) before and after eight weeks of training. Training resulted in an increased of blood irisin concentration (by 29.7%) p < 0.05), VO_2max increase (PRE: 44.86 ± 5.74 mL·kg⁻¹·min⁻¹; POST: 50.16 ± 5.80 mL kg⁻¹·min⁻¹; p < 0.05), reduction in percent body fat (PRE: 14.44 ± 3.33%; POST: 13.61 ± 3.16%; p < 0.05), and increase of WAnT parameters (p < 0.05) in the HT group. No changes were observed in the SED group. HIIT resulted in beneficial effects in the increase in blood irisin concentration, physical performance, and reduced fat content. The HIIT may indicate an acceleration of base metabolism. This effect can be utilized in the prevention or treatment of obesity.

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

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

Effects of high-intensity interval training and nutrition advice on cardiometabolic markers and aerobic fitness in adolescent girls with obesity

The aim of the study was to compare the effects of high-intensity interval training (HIIT) and nutrition advice on cardiometabolic biomarkers, hormonal parameters, and cardiorespiratory fitness in adolescent girls with obesity. Adolescent girls with obesity (n = 44, aged 13-19 years) were randomized into a 12-week intervention as follows: (i) dietary advice and HIIT (n = 22), and (ii) dietary advice only (n = 22). The concentration of biomarkers of inflammation, biochemical and hormonal testing, oral glucose tolerance test, cardiorespiratory fitness, physical activity levels, and nutrition were assessed. After a 3-month intervention, the diet+HIIT group significantly increased insulin sensitivity index (-0.34 ± 1.52 vs. 1.05 ± 3.21; p = 0.001) and work load (0.6 ± 11.3 W vs. 14.6 ± 20.2 W; p = 0.024) and decreased glucose area under the curve (-0.29 ± 4.69 vs. -0.98 ± 4.06; p = 0.040), insulin area under the curve (-9.65 ± 117.9 vs. -98.7 ± 201.8; p = 0.003), and high-sensitivity C-reactive protein (hs-CRP) (0.12 ± 1.92 mg/L vs. -1.47 ± 3.67 mg/L; p = 0.039) in comparison with the diet group. Regarding within-group changes, both groups had significant improvements in body mass index (BMI), BMI-standard deviation score, body fat percentage, and systolic blood pressure. Positive impact on waist circumference, waist circumference/height ratio, diastolic blood pressure, hs-CRP, work load, maximal heart rate, and resting heart rate was observed only after the diet+HIIT intervention. No significant change was noted in peak oxygen uptake, lipid profile, and hormonal parameters between groups after intervention. Novelty HIIT and nutrition advice increased insulin sensitivity and decreased BMI, body fat, systolic blood pressure, and diastolic blood pressure. Nutrition advice decreased BMI, body fat, and systolic blood pressure in adolescent girls with obesity.

Impact of different exercise training modalities on energy and nutrient intake and food consumption in sedentary middle-aged adults: a randomised controlled trial

BACKGROUND

Exercise could influence energy and macronutrient intake, which could have an important role on body composition changes in response to exercise. The present study aimed to investigate the effects of different training modalities in energy and macronutrient intake, and whether changes in energy and macronutrient intake influences changes in body composition in response to different training modalities.

METHODS

A 12-week randomised controlled trial was conducted. Eighty middle-aged sedentary adults were randomised to: (i) a control group; (ii) physical activity recommendation from the World Health Organization; (iii) high-intensity interval training; and (iv) whole-body electromyostimulation training. Dietary intake was assessed using the average of three 24-h recalls.

RESULTS

High-intensity interval training and whole-body electromyostimulation training groups showed lower fibre intake and higher dietary energy density. Our results showed a negative association was found between changes in energy intake and changes in lean mass index. No association was found between changes in protein intake and changes in lean mass index.

CONCLUSIONS

In conclusion, we observed a higher dietary energy density and lower fibre intake in high-intensity training groups.