Effects of high-intensity intermittent training on some inflammatory and muscle damage indices in overweight middle-aged men

Introduction: Recently, the use of various high-intensity intermittent training (HIIT) that have quick recovery periods are of great importance. Therefore, the purpose of this research was to investigate the acute effect of HIIT training on the serum levels of inflammatory and muscle damage indices in overweight middle-aged men, as well as the kinetics of these markers at 1, 24, and 48 h after HIIT training.MethodsTwenty-two middle-aged men (40–60 years, BMI 25–30 kg/m2) were divided into two training (n=12) and control (n=10) groups. The HIIT training program consisted of running on treadmill for 30 s with an intensity of 100% maximum aerobic speed (MAV), 30 s active recovery with 50% aerobic speed (4 sets, 4 repetitions and 5 min of rest between each round). Cortisol, IL-6, CRP, ALT, AST, CPK and LDH were evaluated in pre-test, one- hour, 24 and 48 h after HIIT training.ResultsExcept for the CRP variable, Cortisol, IL-6, CPK, LDH, ALT and AST had a significant increase in one- hour after HIIT compared to the pre-test (P<0.05). Also, IL-6 and CPK variables had a significant increase in 24 h and only CPK had a significant increase in 48 h after HIIT training compared to pre-test (P<0.05).ConclusionOverall, due to long rest intervals and low activity time during HIIT, inflammatory responses and muscle damage are not severe. The recovery periods of inflammatory and muscle damage markers are faster, so this type of response can be considered an advantage for overweight middle-aged men. (AU)

A Methodological Checklist for Studies of Pleasure and Enjoyment Responses to High-Intensity Interval Training: Part I. Participants and Measures.

For decades, the exercise psychology research literature echoed the conclusion that exercise makes most people feel better, with no clear evidence that this "feel-better effect" is moderated by intensity. An overhaul of the methodological approach subsequently showed that high-intensity exercise is experienced as unpleasant, and the "feel-better effect," although possible, is conditional and therefore not as robust or prevalent as initially thought. Recently, several studies investigating high-intensity interval training (HIIT) have concluded that HIIT is pleasant and enjoyable, despite the high intensity. Considering that HIIT is emerging as an option in physical activity recommendations and exercise prescription guidelines, in part due to these claims, a methodological checklist is presented to aid researchers, peer reviewers, editors, and other readers in critically appraising studies examining the effects of HIIT on affect and enjoyment. This first part addresses the characteristics and number of participants, as well as the selection of measures of affect and enjoyment.

A Methodological Checklist for Studies of Pleasure and Enjoyment Responses to High-Intensity Interval Training: Part II. Intensity, Timing of Assessments, Data Modeling, and Interpretation.

Recent studies have concluded that high-intensity interval training should be seen as a "viable alternative" to, and may be more enjoyable than, moderate-intensity continuous exercise. If true, these claims have the potential to revolutionize the science and practice of exercise, establishing high-intensity interval training as not only a physiologically effective exercise modality but also a potentially sustainable one. However, these claims stand in contrast to voluminous evidence according to which high levels of exercise intensity are typically experienced as less pleasant than moderate levels. To help researchers, peer reviewers, editors, and critical readers appreciate possible reasons for the apparently conflicting results, we present a checklist that identifies crucial methodological elements in studies investigating the effects of high-intensity interval training on affect and enjoyment. This second installment covers how "high-intensity" and "moderate-intensity" experimental conditions are defined, the timing of assessments of affect, the modeling of affective responses, and data interpretation.

Perceptions and Experiences of High-Intensity Interval Training in Kidney Transplant Recipients: A Big HIIT?

High-intensity interval training (HIIT) is considered a novel and time-efficient method to reduce cardiovascular disease risk, a leading cause of mortality in kidney transplant recipients. However, research in this population is severely limited. The aim of this study was to understand kidney transplant recipients' perceptions and experiences of HIIT and their readiness to participate in HIIT. Individual, semi-structured interviews were conducted in adults with a kidney transplant (n = 13; 53±13 years). Interviews were audiorecorded, transcribed verbatim, and subjected to framework analysis. Overall, participants had a good knowledge of HIIT and were open to participation. Acknowledgment of the superior benefits to cardiovascular, mental, and general health, as well as the lower time commitment, were all motivators for participation. There were some heightened concerns around damaging the kidney and 'knowing your limits. Personalization, physician's approval, and supervision were all important factors in participation. This study provides evidence that HIIT would be, in principle, largely accepted by recipients of a kidney transplant. However, several considerations are also identified in the present study, which would be essential to the success of any future efficacy trial or rehabilitation program.

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

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

High-Intensity Interval Training Minimizes the Deleterious Effects of Arterial Hypertension on the Urinary Bladder of Spontaneously Hypertensive Rats.

Arterial hypertension promotes urological complications by modifying the functional capacity of the urinary bladder. On the other hand, physical exercise has been suggested as a nonpharmacological tool to improve blood pressure regulation. High-intensity interval training (HIIT) can effectively increase peak oxygen consumption, body composition, physical fitness, and health-related characteristics of adults; however, its action on the urinary bladder is little discussed. In the present study, we verified the effect of HIIT on the modulation of the redox state, morphology, and inflammatory and apoptotic processes of the urinary bladder of hypertensive rats. Spontaneously hypertensive rats (SHR) were divided into two groups: SHR sedentary and SHR submitted to HIIT. Arterial hypertension promoted an increase in the plasma redox state, modified the volume of the urinary bladder, and increased collagen deposition in detrusor muscle. It was also possible to identify, in the sedentary SHR group, an increase in inflammatory markers such as IL-6 and TNF-α in the urinary bladder, as well as a reduction in BAX expression. However, in the HIIT group, reduced blood pressure levels were observed, together with an improvement in morphology, such as a decrease in collagen deposition. HIIT also regulated the proinflammatory response, promoting increases in IL-10 and BAX expressions and in the number of plasma antioxidant enzymes. The present work highlights the intracellular pathways involved with the oxidative and inflammatory capacity of the urinary bladder and the potential effect of HIIT on the regulation of the urothelium and detrusor muscle of hypertensive rats.

[Research Progress of High-intensity Interval Training in Cardiac Rehabilitation of Patients with Acute Coronary Syndrome].

Acute coronary syndrome (ACS),with increasing mortality year by year,has become a major public health problem in China.Exercise rehabilitation as an important part of the out-of-hospital rehabilitation for the patients with heart diseases can further reduce the mortality of patients on the basis of drug treatment.The available studies have proved that high-intensity interval training (HIIT) is more effective and efficient than moderate-intensity continuous training (MICT) such as walking and jogging on chronic cardiovascular diseases such as heart failure,stable coronary heart disease,and hypertension and has high security.According to the latest research,HIIT can reduce the platelet response,mitigate myocardial ischemia-reperfusion injury,and increase the exercise compliance of ACS patients more significantly than MICT.Moreover,it does not increase the risk of thrombotic adverse events or malignant arrhythmia.Therefore,HIIT is expected to become an important part of exercise prescription in out-of-hospital cardiac rehabilitation strategy for the patients with ACS.

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

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

Comparison of moderate-intensity continuous training and high-intensity interval training effects on the Ido1-KYN-Ahr axis in the heart tissue of rats with occlusion of the left anterior descending artery.

Myocardial infarction (MI) affects many molecular pathways in heart cells, including the Ido1-KYN-Ahr axis. This pathway has recently been introduced as a valuable therapeutic target in infarction. We examined the effects of moderate-intensity continuous training (MICT) and high-intensity interval training (HIIT) on the axis in the heart tissue of male Wistar rats with occluded left anterior descending (OLAD). Thirty rats (age 10-12 weeks, mean weight 275 ± 25 g) were divided into five groups with 6 animals: Control (Ct) group, MICT group, rats with OLAD as MI group, rats with OLAD treated with MICT (MIMCT group) and rats with OLAD treated with HIIT (MIHIIT group). Rats performed the training protocols for 8 weeks, 5 days a week. HIIT included 7 sets of 4 min running with an intensity of 85-90% VO2max and 3 min of recovery activation between sets. MICT included continuous running at the same distance as HIIT with an intensity of 50-60% VO2max for 50 min. The expressions of Ahr, Cyp1a1, and Ido1 were assayed by real-time PCR. Malondialdehyde (MDA) and Kynurenine levels, and AHR, CYP1A1, and IDO1 proteins were detected using ELISA. Data were analyzed using the ANOVA and MANOVA tests. Compared to the CT group, MI caused an increase in all studied factors, but only statistically significant (P < 0.05) for MDA and IDO1. With a greater effect of HIIT, both protocols significantly lowered the proteins expressions in the MIHIIT and MIMCT groups, compared with the MI group (P < 0.001). In healthy rats, only AHR protein significantly decreased in the MICT group compared to the Ct group (P < 0.05). HIIT and MICT protocols significantly reduced the gene and protein expression of Cyp1a1 (P < 0.05) and Ido1 (P < 0.01), and HIIT had a greater effect. In conclusion, both protocols were effective at reducing the levels of Ido1-Kyn-Ahr axis components and oxidative stress in the infarcted heart tissue and HIIT had a higher significant effect.

Hypermethylation of ACADVL is involved in the high-intensity interval training-associated reduction of cardiac fibrosis in heart failure patients.

BACKGROUND: Emerging evidence suggests that DNA methylation can be affected by physical activities and is associated with cardiac fibrosis. This translational research examined the implications of DNA methylation associated with the high-intensity interval training (HIIT) effects on cardiac fibrosis in patients with heart failure (HF). METHODS: Twelve HF patients were included and received cardiovascular magnetic resonance imaging with late gadolinium enhancement for cardiac fibrosis severity and a cardiopulmonary exercise test for peak oxygen consumption ([Formula: see text]O2peak). Afterwards, they underwent 36 sessions of HIIT at alternating 80% and 40% of [Formula: see text]O2peak for 30 min per session in 3-4 months. Human serum from 11 participants, as a means to link cell biology to clinical presentations, was used to investigate the exercise effects on cardiac fibrosis. Primary human cardiac fibroblasts (HCFs) were incubated in patient serum, and analyses of cell behaviour, proteomics (n = 6) and DNA methylation profiling (n = 3) were performed. All measurements were conducted after completing HIIT. RESULTS: A significant increase (p = 0.009) in [Formula: see text]O2peak (pre- vs. post-HIIT = 19.0 ± 1.1 O2 ml/kg/min vs. 21.8 ± 1.1 O2 ml/kg/min) was observed after HIIT. The exercise strategy resulted in a significant decrease in left ventricle (LV) volume by 15% to 40% (p < 0.05) and a significant increase in LV ejection fraction by approximately 30% (p = 0.010). LV myocardial fibrosis significantly decreased from 30.9 ± 1.2% to 27.2 ± 0.8% (p = 0.013) and from 33.4 ± 1.6% to 30.1 ± 1.6% (p = 0.021) in the middle and apical LV myocardium after HIIT, respectively. The mean single-cell migration speed was significantly (p = 0.044) greater for HCFs treated with patient serum before (2.15 ± 0.17 µm/min) than after (1.11 ± 0.12 µm/min) HIIT. Forty-three of 1222 identified proteins were significantly involved in HIIT-induced altered HCF activities. There was significant (p = 0.044) hypermethylation of the acyl-CoA dehydrogenase very long chain (ACADVL) gene with a 4.474-fold increase after HIIT, which could activate downstream caspase-mediated actin disassembly and the cell death pathway. CONCLUSIONS: Human investigation has shown that HIIT is associated with reduced cardiac fibrosis in HF patients. Hypermethylation of ACADVL after HIIT may contribute to impeding HCF activities. This exercise-associated epigenetic reprogramming may contribute to reduce cardiac fibrosis and promote cardiorespiratory fitness in HF patients. TRIAL REGISTRATION: NCT04038723. Registered 31 July 2019, https://clinicaltrials.gov/ct2/show/NCT04038723 .

Evaluating the feasibility and efficacy of a home-based combined high intensity interval and moderate intensity training program for increasing physical activity among low-active adults: A randomized pilot trial.

BACKGROUND: High intensity interval training (HIIT), which includes short bursts of high-intensity physical activity (PA) followed by recovery, can increase PA by addressing time barriers and improving PA enjoyment. The purpose of this pilot study was to examine the feasibility and preliminary efficacy of a home-based HIIT intervention on PA. METHODS: Low active adults (n = 47) were randomly assigned to a home-based HIIT intervention or wait-list control lasting 12 weeks. Participants in the HIIT intervention received motivational phone sessions based on Self-Determination Theory and accessed a website that included workout instructions and videos demonstrating proper form. RESULTS: The HIIT intervention appears feasible based on retention, recruitment, adherence to the counseling sessions, follow-up rates, and the consumer satisfaction survey. HIIT participants reported more minutes of vigorous intensity PA at six weeks relative to control (no differences at 12 weeks). HIIT participants reported higher levels of self-efficacy for PA, enjoyment of PA, outcome expectations related to PA, and positive engagement with PA than the control. CONCLUSIONS: This study provides evidence for feasibility and possible efficacy of a home-based HIIT intervention for vigorous intensity PA; however, additional studies are needed with larger samples sizes to confirm efficacy of home-based HIIT interventions. TRIAL REGISTRATION: Clinical Trials Number: NCT03479177.

High intensity interval training is superior to moderate intensity continuous training in enhancing the anti-inflammatory and apoptotic effect of pentoxifylline in the rat model of endometriosis.

This study investigated the effects of pentoxifylline (PTX), high intensity interval training (HIIT) and moderate intensity continuous training (MICT) separately and in combination, on inflammatory and apoptotic pathways in the rat model of induced endometriosis. Endometriosis was induced through surgery on female Sprague-Dawley rats. Six weeks after the first surgery, the second look laparotomy was performed. After induction of endometriosis in rats, they were divided into control, MICT, PTX, MICT+ PTX, HIIT, HIIT+PTX groups. Two weeks after the second look laparotomy, PTX and exercise training interventions were performed for eight weeks. Endometriosis lesions were assessed histologically. Proteins content of the NF-κB, PCNA and Bcl-2 were measured by immunoblotting and genes expression of the TNF-α and VEGF were measured by Real-time PCR methods. Findings of the study indicated that, PTX significantly decreased volume and histological grading of lesions, proteins of NF-κB and Bcl-2; and genes expression of the TNF-α, and VEGF in lesions. HIIT significantly decreased volume and histological grading of lesions, NF-κB, TNF-α and VEGF in lesions. MICT did not induce any significant effect on the study variables. Although, MICT+PTX decreased significantly volume and histological grading of lesions, as well as NF-κB, and Bcl-2 in lesions, however, these factors were not significantly different with the PTX group. HIIT+PTX decreased significantly all of the study variables compared to other interventions, except for VEGF when compared to PTX. In summary, combination of PTX and HIIT can induce enhancing effect on suppression of endometriosis through suppressing inflammation, angiogenesis, and proliferation and enhancing apoptosis.

A Meta-Analysis of the Influence on Inflammatory Factors in Type 2 Diabetes among Middle-Aged and Elderly Patients by Various Exercise Modalities.

The purpose of this study was to investigate the effects of various exercise modalities on inflammatory factors in middle-aged and elderly patients with type 2 diabetes (MEPT2D), as lifestyle changes, such as physical activity and dietary modifications, are considered important in the prevention of type 2 diabetes. For the study methodology, Pubmed, CNKI, EBSCO, Wanfang Data, and Web of Science were selected for the search. The methodological quality of the included studies was assessed by the Cochrane Risk of Bias (ROB) tool, and statistically analyzed using the RevMan 5.4.1 analysis software, which included 18 investigations involving 853 study subjects. Meta-analysis findings indicated that aerobic training (AT), resistance training (RT), combined training (CT), and high-intensity interval training (HIIT) showed significant reductions in CRP, TNF-α, IL-6, and IL-10 levels in MEPT2D. Among them, HIIT was superior to other training modalities in reducing TNF-α levels, while CT was superior to AT, RT, and HIIT in decreasing IL-6, IL-10, and CRP in MEPT2D. Meanwhile, RT had limited effects in reducing CRP and TNF-α levels in MEPT2D. However, HIIT had no significant effect on IL-6 and IL-10 in MEPT2D. In conclusion, long-term regular AT, RT, CT, and HIIT all contributed to the reduction of inflammatory status (CRP, TNF-α, IL-6, and IL-10) in MEPT2D, while CT (for CRP, IL-6, and IL-10) and HIIT (for TNF-α) represent the best approaches to counteract the inflammatory response in MEPT2D.

Shorter High-Intensity Cycling Intervals Reduce Performance and Perceived Fatigability at Work-Matched but Not Task Failure.

INTRODUCTION: The intensity, duration, and distribution of work and recovery phases during high-intensity interval training (HIIT) modulate metabolic perturbations during exercise and subsequently influence the development of performance fatigability and exercise tolerance. This study aimed to characterize neuromuscular, perceptual, and cardiorespiratory responses to work-to-rest ratio-matched HIIT protocols differing in work and rest interval duration. METHODS: Twelve healthy individuals (six women) first completed a ramp incremental test to determine 90% of peak power output, and then in three randomized visits, they completed three cycling protocols to task failure at 90% of peak power output: (i) 3- to 3-min work-to-passive rest ratio HIIT (HIIT 3min ), (ii) 1- to 1-min work-to-passive rest ratio HIIT (HIIT 1min ), and (iii) constant load (CL). Interpolated twitch technique, including maximal voluntary isometric knee extensions and femoral nerve electrical stimuli, was performed at baseline, every 6 min of work, and task failure. Perceptual and cardiorespiratory responses were recorded every 3 min and continuously across the exercises, respectively. RESULTS: The work completed during HIIT 1min (8447 ± 5124 kJ) was considerably greater than HIIT 3min (1930 ± 712 kJ) and CL (1076 ± 356) ( P < 0.001). At work-matched, HIIT 1min resulted in a lesser decline in maximal voluntary contraction and twitch force compared with HIIT 3min and CL ( P < 0.001). Perceived effort, pain, and dyspnea were least in HIIT 1min and HIIT 3min compared with CL ( P < 0.001). At task failure, HIIT 1min resulted in less voluntary activation than HIIT 3min ( P = 0.010) and CL ( P = 0.043), and engendered less twitch force decline than CL ( P = 0.021). CONCLUSIONS: Overall, the mitigated physiological and perceptual responses during shorter work periods (HIIT 1min ) enhance exercise tolerance in comparison to longer work intervals at the same intensity (HIIT 3min , CL).

Patients with Adolescent Idiopathic Scoliosis Have Higher Metabolic Cost during High-Intensity Interval Training.

BACKGROUND: Patients with adolescent idiopathic scoliosis (AIS) are found to have a lower level of physical activity, and may have reduced exercise capacity due to spinal deformity. Previous study showed the benefits of high-intensity interval training (HIIT), named E-Fit, which is specifically designed for patients with AIS to improve musculoskeletal health and psychological well-being. To optimize the beneficial effects of training, the current study aimed to investigate the appropriate exercise intensity and metabolic demand in patients with AIS when performing E-Fit. METHODS: In all, 22 female subjects, 10 diagnosed with AIS and 12 gender-matched healthy controls, aged between 10 and 16 years, were recruited. Subjects were instructed to perform two trials of a seven min E-Fit. Breath-by-breath gas exchange parameters including oxygen consumption (VO2), heart rate (HR) and the rate of perceived exertion (PRE) were measured during exercise. Demographic data and clinical features of AIS and body composition were obtained. Metabolic demand between AIS and control groups was compared using MANOVA with covariates adjustment. RESULTS: Patients with AIS had an earlier onset of menarche (p = 0.01), higher visceral adipose tissue (p = 0.04) and percentage body fat (p = 0.03) as compared to controls. Patients with AIS showed a significantly higher adjusted means of VO2 average in both the first (p = 0.014) and second trials (p = 0.011) of E-Fit. The adjusted mean of the highest measured VO2 was higher than healthy controls and reached statistical significance in the second trial (p = 0.004). Both the AIS and control group exercised at a similar percentage of VO2 peak (64.26% vs. 64.60%). CONCLUSION: Patients with AIS showed higher oxygen consumption during E-Fit than heathy controls, which might indicate a higher metabolic cost. Patients with AIS could carry out exercise at a moderate exercise intensity similar to that of healthy controls, but special considerations in designing an exercise program, such as frequent rest intervals, would be useful to avoid fatigue among patients with AIS.

Aerobically trained older adults show impaired resting, but preserved exercise-induced circulating progenitor cell count, which was not improved by sprint interval training.

Older adults exhibit a reduced number and function of CD34 + circulating progenitor cells (CPC), a known risk factor for cardiovascular disease. Exercise promotes the mobilisation of CPCs from bone marrow, so whether ageing per se or physical inactivity in older age reduces CPCs is unknown. Thus, this study examined the effect of age on resting and exercise-induced changes in CPCs in aerobically trained adults and the effect of 8 weeks of sprint interval training (SIT) on resting and exercise-induced CPCs in older adults. Twelve young (22-34 years) and nine older (63-70 years) adults participated in the study. Blood was sampled pre and immediately post a graded exercise test to exhaustion in both groups. Older participants repeated the process after 8 weeks of SIT (3 × 20 s 'all-out' sprints, 2 × a week). Total CPCs (CD34+) and endothelial progenitor cells (EPCs: CD34+KDR+) were determined by flow cytometry. Older adults exhibited lower basal total CD34+ CPCs (828 ± 314 vs. 1186 ± 272 cells·mL-1, p = 0.0149) and CD34+KDR+ EPCs (177 ± 128 vs. 335 ± 92 cells·mL-1, p = 0.007) than younger adults. The maximal exercise test increased CPCs in young (CD34+: p = 0.004; CD34+KDR+: p = 0.017) and older adults (CD34+: p < 0.001; CD34+KDR+: p = 0.008), without difference between groups (p = 0.211). SIT did not alter resting or exercise-induced changes in CPCs in the older cohort (p > 0.232). This study suggests age per se does not impair exercise-induced CPC counts, but does lower resting CPC counts.

HIIT is most effective than mict on glycemic control of older people with glucose metabolism impairments: A systematic review and metanalysis.

INTRODUCTION: Physical exercise can improve glucose metabolism; however, the best type, volume, intensity, and frequency aren't knowledge. High-Intensity Interval Training (HIIT), an emergent exercise type implicated as a short time-efficient exercise to improve metabolic health, needs more investigation regarding the traditional Moderate-Intensity Continuous Training (MICT). OBJECTIVE: To identify the effects of MICT and HIIT on glycemic control of older people with glucose metabolism impairments. METHODS: Our research question was based on the PICO model and the systematic review of the literature according to the guidelines of the preferred report items for systematic reviews and PRISMA meta-analyses. An extensive search was conducted in the Web of Science, PubMed, and Scielo databases. Only English language papers were included. The keywords used were "HIIT and metabolism of the elderly", "HIIT and glucose metabolism of the elderly", and "MICT and metabolism of the elderly", which were crossed with the Boolean operators "AND" and "OR" or both according to the guidelines of the PRISMA. RESULTS: Seventy papers were retrieved in the initial search. After applying all inclusions and exclusion parameters, 63 articles were excluded. In the end, six papers were classified as eligible for this study. All data categorically demonstrates that both HIIT and MICT can improve glucose metabolism with a larger effect size towards the HIIT model after the meta-analysis, pointing to HIIT as the most effective strategy. CONCLUSION: Both modalities can improve glucose metabolism in the elderly with a clear advantage for HIIT over MICT.

Effect of Menstrual Cycle Phase on Fuel Oxidation Post HIT in Women Reproductive Age: A Pilot Study.

Women of childbearing age have variations in substrate oxidation rates that can lead to overweight, type II diabetes, and other conditions that may be associated with metabolic inflexibility and the variations in estrogen concentrations observed during the monthly ovarian cycle. PURPOSE: This study aimed to verify and compare the influence of eight treadmill high-intensity interval training (HIT) sessions on carbohydrate and lipid oxidation rates (CHOox and LIPox, respectively) and intensities of ventilatory anaerobic thresholds (VATs) of women in different phases of the monthly ovarian cycle. METHODS: Eleven irregularly active women performed incremental treadmill exercise testing followed by submaximal work-rate running for 45 min to determine VATs, VO2peak, peak velocity (Vpeak), and substrate oxidation rates, before and after a training period, in different phases of their monthly ovarian cycle (follicular phase group, FL, n = 6; luteal phase group, LT, n = 5). The training period consisted of eight HIT sessions, composed each one of eight sets of 60 s running at 100%Vpeak interspersed by 75 s recovery every 48 h. RESULTS: Our results showed no significant differences in VATs intensities between groups. The comparison between groups showed significant differences in relative energy derived from CHO pre- and post-training of -61.42% and -59.26%, respectively, and LIP pre- and post-training of 27.46% and 34.41%, respectively. The relative energy derived from CHO after the training period was 18.89% and 25.50% higher for FL and LT, respectively; consequently, the relative energy derived from LIPox after the training period was 8,45% and 3.46% lower for FL and LT, respectively. Over the training period, Vpeak was ~13.5 km/h, which produced the relative intensities of ~89%VO2peak e ~93%HRpeak for both groups. CONCLUSION: The monthly ovarian cycle phases promote significant changes in substrate oxidation rates leading to a decrease in CHOox. High-intensity interval training can minimize the differences observed and constitute an alternative intervention.

Targeted Lipidomics and Inflammation Response to Six Weeks of Sprint Interval Training in Male Adolescents.

Lipids play an important role in coordinating and regulating metabolic and inflammatory processes. Sprint interval training (SIT) is widely used to improve sports performance and health outcomes, but the current understanding of SIT-induced lipid metabolism and the corresponding systemic inflammatory status modification remains controversial and limited, especially in male adolescents. To answer these questions, twelve untrained male adolescents were recruited and underwent 6 weeks of SIT. The pre- and post-training testing included analyses of peak oxygen consumption (VO2peak), biometric data (weight and body composition), serum biochemical parameters (fasting blood glucose, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triacylglycerol, testosterone, and cortisol), inflammatory markers, and targeted lipidomics. After the 6-week SIT, the serum C-reactive protein (CRP), interleukin (IL)-1ß, IL-2, IL-4, IL-10, tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-ß significantly decreased (p < 0.05), whereas IL-6 and IL-10/TNF-α significantly increased (p < 0.05). In addition, the targeted lipidomics revealed changes in 296 lipids, of which 33 changed significantly (p < 0.05, fold change > 1.2 or <1/1.2). The correlation analysis revealed that the changes in the inflammatory markers were closely correlated with the changes in some of the lipids, such as LPC, HexCer, and FFA. In conclusion, the 6-week SIT induced significant changes in the inflammatory markers and circulating lipid composition, offering health benefits to the population.

Feasibility study of high-intensity interval training to reduce cardiometabolic disease risks in individuals with acute spinal cord injury.

INTRODUCTION: Individuals ageing with spinal cord injury (SCI) experience an accelerated trajectory of diseases and disorders, such as cardiovascular disease and diabetes, that resemble those experienced with ageing alone. Currently, an evidence-based approach toward managing this problem does not exist and therefore the purpose of this study is to determine the feasibility of conducting a high-intensity exercise intervention in individuals with acute (<6 months postinjury) SCI to improve cardiometabolic health. METHODS AND ANALYSIS: We will conduct a single-centre, two parallel-arm, randomised feasibility study of a high-intensity interval training (HIIT) intervention in individuals with acute SCI. We will enrol 40 individuals (20 intervention, 20 control) with acute SCI attending inpatient rehabilitation at Salisbury District Hospital. Participants will be randomly allocated to the intervention group (HIIT) or control group for 18 weeks. Both groups will participate in standard care throughout the duration of the study. The HIIT group only will also perform supervised HIIT exercise on an arm cycle ergometer three times per week. Over the course of the intervention, most participants will be discharged from the hospital, and at this time, an arm cycle ergometer will be installed in their home and the intervention will transition into outpatient care. We will assess cardiorespiratory fitness, glycaemic control, lipid profile and body habitus as well as qualitative assessments of acceptability at weeks 0, 9 and 18 with the primary outcome being the feasibility of a full Randomised Controlled Trial (RCT). ETHICS AND DISSEMINATION: This study will inform a longer-term, definitive, multicentre RCT to establish the impact of this exercise intervention in maintaining the cardiometabolic health of patients during the acute phase following SCI. Results will be disseminated in different formats including peer-reviewed journal articles, conference presentations and internet media, to a wide audience including clinicians, researchers and individuals with SCI. TRIAL REGISTRATION NUMBER: ISRCTN57514022.