Weeks Of High-intensity Interval Training Training Research Articles

High-intensity interval training attenuates renal injury induced by myocardial ischemia-reperfusion in rats

Background: High-Intensity Interval Training (HIIT) has been recognized as an effective form of short-duration exercise. The purpose of this study was to assess whether HIIT could reduce renal injury induced by myocardial ischemia-reperfusion in rats. Methods: Male Sprague-Dawley rats were randomly assigned to the Sham Group (SHAM), Coronary Artery Occlusion (CAO) group, HIIT group, and Ischemic Precondition (IPC) group. Rats underwent 40 minutes of left anterior descending coronary artery occlusion under anesthesia, followed by 3 hours of reperfusion, to induce myocardial ischemia-reperfusion (MIR). Post-surgery, rats were sacrificed, and their blood, heart, and kidney tissues were examined. The HIIT group underwent 4 weeks of HIIT training before surgery. Results: HIIT intervention significantly reduced renal injury after MIR and the concentrations of Blood Urea Nitrogen (BUN) and Creatinine (CRE) in the serum. Moreover, pro-inflammatory cytokines, including Tumor Necrosis Factor-α (TNF-α), Interleukin-1β (IL-1β), and IL-6, were significantly decreased, while the anti-inflammatory cytokine IL-10 was significantly increased in the serum. Additionally, HIIT intervention suppressed the expression of FoxO1, BAX/Bcl-2 ratio, TNF-α, and Cleaved-caspase-3/caspase-3 ratio in kidney tissues, ultimately reducing renal cell apoptosis. Conclusion: This study is the first to demonstrate that HIIT has effects similar to IPC, significantly reducing renal injury after MIR. HIIT regulates the production of pro-inflammatory and anti-inflammatory cytokines, inhibits renal cell apoptosis, thereby reducing the occurrence of cardio-renal syndrome.

The Effect of an 8-Week Online High-Intensity Interval Training Program on Body Composition and Performance in Thai Professional Football Players During the Covid-19 Epidemic

Background/objectives. High-intensity interval training (HIIT) was used to be a strategy for improving physical performance. Especially, athletic training which were disturbed by the Covid-19 pandemic. Therefore, the objectives of this study were to determine the effects of an 8-week online HIIT program on the body composition, aerobic and anaerobic performances in professional football players. Materials and methods. Thirty professional football players in Thai league division 2 were randomly assigned into the onsite group (n = 15) and the online group (n = 15). All participants performed the HIIT program at 85% maximal heart rate (HRmax), five times a week for 8 weeks. Body composition, aerobic and anaerobic performance at baseline, after 4 weeks and 8 weeks of training were calculated by repeated measures ANOVA and unpaired t-test. Results. Weight, BMI and % fat were significantly decreased after 4 weeks of training in the onsite group and after 8 weeks of training in the online group (p < 0.05). FFM in the onsite and online groups was significantly increased after 4 weeks and 8 weeks of training, respectively (p < 0.05). Aerobic performance was significantly increased after 4 and 8 weeks of training (p < 0.05), whereas anaerobic performance was found increased after 8 weeks of training in both groups (p < 0.05). There were no significant differences between the groups. Conclusions. Eight weeks of HIIT training can improve body composition, aerobic performance and anaerobic performance in both onsite and online conditions. It may be implied that an online HIIT training program should have beneficial effects similar to those provided in onsite condition.

Effect of High Intensity Interval Training on Reducing Insulin Resistance, Serum Asprosin, and Body Fat Percentage in Obese Men with Type 2 Diabetes

Background and Objectives Asprosin is an adipokine that has a positive relationship with obesity and type 2 diabetes mellitus (T2DM). It plays an important role in the pathogenesis of insulin resistance due to its gluconeogenic and metabotropic effects. The aim of this study was to determine the effect of six weeks of high intensity interval training (HIIT) on insulin resistance, body fat percentage, and asprosin serum in obese men with T2DM. Subjects and Methods In this quasi-experimental research, 24 obese men with T2DM were randomly divided into HIIT and control groups. Participants in the HIIT group did six weeks of HIIT training with an intensity of 80-85% heart rate reserve in 3 training sessions per week. Fasting blood samples and anthropometric variables were measured 48 hours before and after the intervention. Paired sample t-tests and analysis of covariance were used for statistical analysis. Results After the intervention, there was a significant difference (P<0.001) between the two groups in terms of serum asprosin (-10.47% vs. +0.13%), body fat percentage (-5.17% vs. +0.13%), and insulin resistance (-23.94% versus +10.02%). Conclusion According to the results, it can be stated that adjustment of fasting asprosin to body fat percentage is one of the effective mechanisms for reducing insulin resistance in T2DM via adaptation to HIIT.

High-Intensity Interval Training Improves Glycemic Control, Cellular Apoptosis, and Oxidative Stress of Type 2 Diabetic Patients.

Background and Objectives: Physical exercise is an important therapeutic modality for treating and managing diabetes. High-intensity interval training (HIIT) is considered one of the best non-drug strategies for preventing and treating type 2 diabetes mellitus (T2DM) by improving mitochondrial biogenesis and function. This study aimed to determine the effects of 12 weeks of HIIT training on the expression of tumor suppressor protein-p53, mitochondrial cytochrome c oxidase (COX), and oxidative stress in patients with T2DM. Methods: A total of thirty male sedentary patients aged (45-60 years) were diagnosed with established T2DM for more than five years. Twenty healthy volunteers, age- and sex-matched, were included in this study. Both patients and control subjects participated in the HIIT program for 12 weeks. Glycemic control variables including p53 (U/mL), COX (ng/mL), total antioxidant capacity (TAC, nmole/µL), 8-hydroxy-2'-deoxyguanosine (8-OHdG, ng/mL), as well as genomic and mitochondrial DNA content were measured in both the serum and muscle tissues of control and patient groups following exercise training. Results: There were significant improvements in fasting glucose levels. HbA1c (%), HOMA-IR (mUmmol/L2), fasting insulin (µU/mL), and C-peptide (ng/mL) were reported in T2DM and healthy controls. A significant decrease was also observed in p53 protein levels. COX, 8-OhdG, and an increase in the level of TAC were reported in T2DM following 12 weeks of HIIT exercise. Before and after exercise, p53; COX, mt-DNA content, TAC, and 8-OhdG showed an association with diabetic control parameters such as fasting glucose (FG), glycated hemoglobin (HbA1C, %), C-peptide, fasting insulin (FI), and homeostatic model assessment for insulin resistance (HOMA-IR) in patients with T2DM. These findings support the positive impact of HIIT exercise in improving regulation of mitochondrial biogenesis and subsequent control of diabetes through anti-apoptotic and anti-oxidative pathways. Conclusions: A 12-week HIIT program significantly improves diabetes by reducing insulin resistance; regulating mitochondrial biogenesis; and decreasing oxidative stress capacity among patients and healthy controls. Also; p53 protein expression; COX; 8-OhdG; and TAC and mt-DNA content were shown to be associated with T2DM before and after exercise training.

Effect of High-Intensity Interval Training and Portulaca Oleracea Extract Supplementation on FGF-21 Level and Insulin Resistance in Rats with Non-Alcoholic Fatty Liver Disease

Introduction: The aim of this study was to investigate the effect of eight weeks of high-intensity interval training (HIIT) and Portulaca Oleracea extract on FGF-21 levels and insulin resistance in rats with NAFLD. Methods: Twenty male Wistar rats at six weeks old and 160 to 185 g weight were randomly divided into four groups: fatty liver control, HIIT, Portulaca Oleracea extract, and HIIT+Portulaca Oleracea extract. According to the weight of the mice, Portulaca Oleracea supplement with a dose of 400 mg/kg was given to the two respective groups. The HIIT training protocol was performed for 8 weeks, 5 sessions per week, and each session was performed at 80-90% of maximum speed. Hepatic FGF21 level and insulin resistance were measured after 8 weeks of HIIT training and consumption of purslane extract. One-way analysis of variance and Tukey's post hoc test were used to compare groups at a significance level of p<0.05. Results: Insulin resistance in HIIT (P=0.005), Portulaca Oleracea extract (P=0.011), and HIIT+Portulaca Oleracea extract (P=0.002) groups were significantly lower than fatty liver control group. The level of liver FGF-21 in the HIIT (p=0.023), Portulaca Oleracea extract (p=0.005) and HIIT+ Portulaca Oleracea extract (p=0.001) groups was significantly higher than the fatty liver control group. Conclusion: It seems that HIIT and Portulaca Oleracea extract could improve insulin resistance in NAFLD by increasing FGF-21 levels and can play an important role in controlling the progress of this disease.

The Exercise Preconditioning Effect on Cardiac Tissue Injury following Induction of Myocardial Infarction in Male Rats.

Twenty-four male rats were divided into 4 groups including MI, Sham, HIIT, and HIIT+MI (N = 6). HIIT and HIIT+MI which underwent high-intensity interval training (HIIT) for 4 weeks (5 days a week). The training protocol included 10 intervals of 1-minute running, with 2 minutes rest between each interval. The training intensity was different every week according to the peak treadmill running speed (v peak) percentage of each rat. Isoproterenol injection was used to induce myocardial infarction (MI). Expressions of creatine kinase-MB (CK-MB), PGC-1α troponin-I, mitochondrial transcription factor A (TFAM), vascular endothelial growth factor (VEGF), and microRNA 126 (miR-126) genes were measured. The variables were measured using biochemical and RT-PCR methods. The significance level (P value≤0.05) was analyzed using ANOVA test. The results showed that 4 weeks of HIIT training led to a significant increase in PGC-1α, TFAm, and VEGF levels in the MI, HIIT, and HIIT+MI groups compared to the sham group (P = 0.001). HIIT exercises increased miR-126 in the different groups compared to the sham group; however, it was not significant. The results obtained showed that HIIT exercise exerts cardio-protective effects to reduce cardiac tissue injury and necrosis against MI. These effects increase mitochondrial biogenesis and angiogenesis by inducing the increased expression of VEGF, TFAM, PGC-1α, and miR-126 genes in the heart tissue. Therefore, HIIT training, as a preconditioning program, was able to protect the cardiac tissue against MI.

The effect of high-intensity interval training (HIIT) on protein expression in Flexor Hallucis Longus (FHL) and soleus (SOL) in rats with type 2 diabetes.

In people with diabetes, one of the problems for patients is muscle wasting and inhibition of the protein synthesis pathway. This study aimed to evaluate the effects of HIIT on protein expression in two skeletal muscles, flexor hallucis longus (FHL) and soleus (SOL) in rats with type 2 diabetes mellitus (T2DM). Diabetes initially was induced by streptozotocin (STZ) and nicotinamide. Rats with type 2 diabetes were randomly and equally divided into control (n = 6) and HIIT groups (n = 6). After 8 weeks of training, the content of total and phosphorylated proteins of serine/threonine-protein kinases (AKT1), mammalian target of rapamycin (mTOR), P70 ribosomal protein S6 kinase 1 (P70S6K1), and 4E (eIF4E)-binding protein 1 (4E-BP1) in FHL and SOL muscles were measured by Western blotting. While body weight and blood glucose were also controlled. In the HIIT training group, compared to the control group, a significant increase in the content of AKT1 (0.003) and mTOR (0.001) proteins was observed in the FHL muscle. Also, after 8 weeks of HIIT training, protein 4E-BP1 (0.001) was increased in SOL muscle. However, there was no significant change in other proteins in FHL and SOL muscle. In rats with type 2 diabetes appear to HIIT leading to more protein expression of fast-twitch muscles than slow-twitch muscles. thus likely HIIT exercises can be an important approach to increase protein synthesis and prevent muscle atrophy in people with type 2 diabetes.

High-intensity interval training attenuates the effects caused by arterial hypertension in the ventral prostate.

The prostatic effects induced by arterial hypertension is very controversial and its mechanism is unclear. High-intensity interval training (HIIT) is an exercise considered to be hypotensive. The objective of this work was to investigate the molecular, biochemical, and morphological effects of 8 weeks of HIIT in the prostatic tissue of spontaneously hypertensive rats (SHR). Twenty male SHR rats, 51.4 weeks old, were used. The SHR animals were divided into two groups: spontaneously sedentary hypertensive and spontaneously hypertensive submitted to HIIT. We analyze androgens receptor and glucocorticoid receptors in the prostate. Still, we verify effects of the hypertension and HIIT on the physiopathology prostatic, for immunohistochemistry investigated BCL-2, BAX, IGF-1, FAS/CD95, data's inflammatory tumour necrosis factor α, nuclear factor kappa B and interleukin (IL)-6, anti-inflammatory IL-10. The echocardiographic evaluation was performed at the baseline and after the training period. Arterial hypertension promote high prostatic intraepithelial neoplasia incidence in the prostate, increases IGF-1, BCL-2 (p < 0.05), and inflammatory proteins (p < 0.05). Eight weeks of HIIT training reduced the arterial pressure and increase the concentration of tissue collagen and intracellular glycogen and showed a higher expression of BAX, FAS/CD95, and IL-10 proteins (p < 0.05), coinciding with a lower incidence of lesions and lower prostate weight (p < 0.05) and reduction of the BCL-2 and IGF-1. Our data suggested that arterial hypertension suppressed apoptosis and increased damage prostatic. On other hand, HIIT promotes morphology and function improves in the prostatic environment, inhibited inflammation, and increased apoptosis.

The Effect of a HIIT Training Course on the Expression of PGC-1α, SIRT1, and SIRT3 Genes in the Cardiac Tissue of Elderly Female Rats

Background and Aim: Exercise improves the function of mitochondrial proteins and enzymes in old age. This study aimed to investigate the effect of a high-intensity interval training (HIIT) training course on the expression of PGC-1α, SIRT1, and SIRT3 genes in the cardiac tissue of elderly female rats. Materials and Methods: In this experimental study, 14 female Sprague-Dawley rats with a mean age of 16-18 months and a weight range of 280-320 g were randomly divided into 2 groups of 7, including the control group and the HIIT training group. The experimental group performed HIIT training for 8 weeks and 5 days a week with an intensity of 85%- 110% VO2max. Forty-eight hours after the last training session, rats were anesthetized by intraperitoneal injection of ketamine and xylazine, and the target tissue was immediately removed for examination. Shapiro-Wilk statistical test and one-way analysis of variance in SPSS software v. 22 analyzed the findings (P≥0.05). Results: The results showed that the expression of PGC-1α, SIRT1, and SIRT3 genes increased in the cardiac tissue of the experimental group compared to the control group after 8 weeks of HIIT training, but this increase was not significant (P≤0.05). Conclusion: It seems that in elderly conditions, exercise from pathways other than PGC- 1α improves mitochondrial function. However, further research is needed on the effect of HIIT exercise on the expression of these genes in cardiac tissue.

The effect of preconditioning with high-intensity training on tissue levels of G-CSF, its receptor and C-kit after an acute myocardial infarction in male rats

BackgroundExercise training is known as a practical way to increase cardioprotection against stress, and it seems that stem cell recruitment is one of its mechanisms. The purpose of the present study was to investigate the effect of preconditioning with High-intensity interval training (HIIT) on tissue levels of G-CSF, its receptor and C-Kit following acute myocardial infarction in male rats.MethodsTwenty Male Wistar rats were randomly divided into 4 groups of control, MI, HIIT, and HIIT+MI. Training groups performed 2 weeks of high intensity interval training in 4 sections. The first section consisted training in 3 days and 2 sessions in each day (4 × 2 min with 35–40 m/min and 3 × 2 min with 25–30 m/min between high intervals. The second part included 2 days of training (4 × 2 min with 40 to 45 m/min and 3 × 2 min with 28 to 32 m /min). The third part was performed in 3 days with one more repetition. The fourth section consisted 2 days of training and with one more repetition compared to section 3. For induction of myocardial infarction, subcutaneous injection of isoprenaline was used. CK, total CK, LDH, and troponin T were measured in serum and G-CSF, G-CSFR and C-Kit proteins were measured by the Western Blot method in the heart tissue.ResultsThe results of this study showed that enzymes of CK, total CK, LDH, troponin T had a significant increase in both MI and HIIT+MI groups compared to the other two groups (P < 0.001) and these indices in the MI group were significantly higher than the HIIT+MI group. Also, the results demonstrated that G-CSF, G-CSFR and C-Kit protein expression in the heart tissue significantly increased after MI. As well as, 2 weeks of HIIT training significantly increased G-CSF and C-kit in the training group compared to the control group, but the training caused that these proteins does not increase in HIIT+MI group as much as MI group.ConclusionsAlong with other protective pathways, high intensity interval training can increase cardioprotection and decrease heart injuries through the increase in G-CSF, G-CSFR and C-kit level.

The effect of high intensity interval training on telomere length and telomerase activity in non-athlete young men

Introduction: Telomeres are DNA portions that are located on the two ends of the chromosome. Telomeres play an important role in cellular life. Exercise is one of the factors that contributes to their control. The purpose of the present study was to investigate the effect of 8 weeks of high intensity interval training (HIIT) on telomere length and telomerase activity in non-athletic young men. Materials and methods: 30 inactive students were selected as sample and randomly divided into two groups of exercise (15 people) and control (15 people) in this semi-experimental study. The exercise group performed 8 weeks of HIIT exercise in 3 sessions per week with an intensity of 150 to 175% of their maximum power (Pmax). Control group subjects did not do regular sport activities. To measure telomere length and telomerase activity, 10 ml of blood was taken from the brachial vein of the subjects 24 hours before the first and after the last exercise session. The dependent t was used to analyze intra-group and independent t for within-group differences. Results: The findings of this study showed that 8 weeks of HIIT training in non-athlete young men resulted in a significant increase in telomere length (P = 0.001) and telomerase activity (P = 0.001). Conclusion: It seems that HIIT can alter telomerase activity and telomere length. Therefore, these training may have a positive effect on cell biology.

High-intensity interval training induces a modest systemic inflammatory response in active, young men

The purpose of this study was to determine: 1) the extent to which an acute session of high-intensity interval training (HIIT) increases systemic inflammatory cytokines and chemokines, and 2) whether 2 weeks of HIIT training alters the inflammatory response. Eight recreationally active males (aged 22±2 years) performed 2 weeks of HIIT on a cycle ergometer (six HIIT sessions at 8–12 intervals; 60-second intervals, 75-second active rest) at a power output equivalent to 100% of their predetermined peak oxygen uptake (VO2max). Serum samples were collected during the first and sixth HIIT sessions at rest and immediately, 15, 30, and 45 minutes post-exercise. An acute session of HIIT induced significant increases in interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor-α, and monocyte chemotactic protein-1 compared with rest. The concentrations of interferon-γ, granulocyte macrophage-colony-stimulating factor, and IL-1β were unaltered with an acute session of HIIT Two weeks of training did not alter the inflammatory response to an acute bout of HIIT exercise. Maximal power achieved during a VO2max test significantly increased 4.6%, despite no improvements in VO2max after 2 weeks of HIIT. These data suggest that HIIT exercise induces a small inflammatory response in young, recreationally active men; however, 2 weeks of HIIT does not alter this response.

The Effects Of Four Weeks Of High-Intensity Interval Training And Creatine Supplementation On Critical Power And Anaerobic Working Capacity In College-Aged Men

The critical power test provides two measures, critical power (CP) and anaerobic working capacity (AWC). In theory, the CP measurement represents the maximal power output that can be maintained without fatigue, which is regarded as an aerobic measure. AWC is an estimate of work capacity associated with muscle energy reserves adenosine triphosphate (ATP) and phosphocreatine (PCr). High- intensity interval training (HIIT) has been shown to be an effective training method for improving endurance performance, including CP and AWC measures. In addition, creatine (Cr) supplementation has been reported to improve AWC without training; however, Cr had no effect on CP. To date, no one has examined the effect of Cr supplementation during HIIT on CP and AWC. The purpose of this study was to examine the effects of four weeks of HIIT in conjunction with Cr supplementation on CP and AWC in college-aged men. Forty-two recreationally active men (mean ± SD; age 23.62 ± 4.78 yrs; height: 177.48 ± 7.05 cm; weight: 82.23 ± 12.70kg) volunteered to participate in this study. Participants were assigned to one of three groups: Cr (n = 16) 10g Cr + 10g dextrose powder blend; placebo (PL, n = 16) 20g dextrose powder blend; control (CON, n = 10) no treatment. Prior to and following supplementation, each participant performed a continuous maximal oxygen consumption test (o2PEAK) on a cycle ergometer to establish peak power output (PPO). Participants then completed a CP test, consisting of three exercise bouts to exhaustion with the workloads set as a percentage of their PPO to determine CP and AWC. Following initial testing, a 2-week familiarization period of training and supplementing occurred. Baseline values were then measured and all participants in the Cr and PL groups engaged in 4 weeks of HIIT training on a cycle ergometer. Training consisted of either five or six sets of 2-minutes work with 1-minute passive rest, five days per week. Training intensity followed an undulating model starting at 80% PPO and reaching 120%. Significant two-way interactions [time (base- vs. post-) × treatment (Cr vs. PL vs. CON)] were discovered for CP (p = 0.007). Follow-up analyses indicated that the Cr group increased 6.72% ± 2.54%, while PL and CON showed no significant change in CP (3.87% ± 2.30% and -6.27% ± 2.38%, respectively). Furthermore, no changes in AWC were observed in any of the groups following treatment. The current findings suggest that the HIIT and supplementation protocol may be an effective method for improving CP, but had no effect on AWC. It would appear that Cr supplementation may enhance the effect of intense interval endurance training on aerobic performance changes as measure by the CP test. ACKNOWLEGMENTS: This investigation was supported by FSI Nutrition, Omaha, Nebraska.

Effects of β-alanine supplementation and high-intensity interval training on endurance performance and body composition in men; a double-blind trial

BackgroundIntermittent bouts of high-intensity exercise result in diminished stores of energy substrates, followed by an accumulation of metabolites, promoting chronic physiological adaptations. In addition, β-alanine has been accepted has an effective physiological hydrogen ion (H+) buffer. Concurrent high-intensity interval training (HIIT) and β-alanine supplementation may result in greater adaptations than HIIT alone. The purpose of the current study was to evaluate the effects of combining β-alanine supplementation with high-intensity interval training (HIIT) on endurance performance and aerobic metabolism in recreationally active college-aged men.MethodsForty-six men (Age: 22.2 ± 2.7 yrs; Ht: 178.1 ± 7.4 cm; Wt: 78.7 ± 11.9; VO2peak: 3.3 ± 0.59 l·min-1) were assessed for peak O2 utilization (VO2peak), time to fatigue (VO2TTE), ventilatory threshold (VT), and total work done at 110% of pre-training VO2peak (TWD). In a double-blind fashion, all subjects were randomly assigned into one either a placebo (PL – 16.5 g dextrose powder per packet; n = 18) or β-alanine (BA – 1.5 g β-alanine plus 15 g dextrose powder per packet; n = 18) group. All subjects supplemented four times per day (total of 6 g/day) for the first 21-days, followed by two times per day (3 g/day) for the subsequent 21 days, and engaged in a total of six weeks of HIIT training consisting of 5–6 bouts of a 2:1 minute cycling work to rest ratio.ResultsSignificant improvements in VO2peak, VO2TTE, and TWD after three weeks of training were displayed (p < 0.05). Increases in VO2peak, VO2TTE, TWD and lean body mass were only significant for the BA group after the second three weeks of training.ConclusionThe use of HIIT to induce significant aerobic improvements is effective and efficient. Chronic BA supplementation may further enhance HIIT, improving endurance performance and lean body mass.

The effects of beta-alanine supplementation and high-intensity interval training on neuromuscular fatigue and muscle function

The purpose of this study was to determine the effects of beta-alanine supplementation and high-intensity interval training (HIIT) on electromyographic fatigue threshold (EMG(FT)) and efficiency of electrical activity (EEA). A total of 46 men completed four, 2-min work bouts on a cycle ergometer. Using bipolar surface electrodes, the EMG amplitude was averaged and plotted over the 2-min. The resulting slopes were used to calculate EMG(FT) and EEA. Following initial testing, all participants were randomly assigned to either placebo (PL; n = 18), beta-alanine (BA; n = 18) or control groups (CON; n = 10). Following randomization, participants engaged in 6 weeks of HIIT training. Significant improvements in EMG(FT) and EEA resulted for both training groups. In conclusion, HIIT appeared to be the primary stimulus effecting EMG(FT) or EEA, suggesting adaptations from HIIT may be more influential than increasing skeletal muscle carnosine levels on delaying fatigue in recreationally active men.