High-intensity Interval Training Training Research Articles

The Effect of High-Intensity Interval Training and Sleep Regulation on Some Inflammatory Markers, Anaerobic Capacity, and Body Composition in Teenage Girls with Sleep Disorders

Introduction: The present study aimed to compare the effect of high-intensity interval training (HIIT), sleep regulation, and the combined method on interleukin-6 (IL-6), high-sensitivity reactive protein (hs-CRP), anaerobic capacity, and body mass index (BMI) of adolescent girls with sleep disorders. Method: Eighty teenage girls with sleep disorders were randomly assigned to HIIT, sleep regulation, a combination of the two (HIIT+ sleep regulation), and control groups. All girls participated in pre-test and post-test sessions for the measurements two days before and after the research process. The participants in the HIIT and combined groups underwent a HIIT training program for four weeks, three sessions per week, and the subjects in the sleep regulation and combined groups performed the sleep regulation program by extending the sleep time duration by five minutes every night. Results: The findings showed a significant difference between groups for the serum levels of IL-6 and hs-CRP, BMI, and anaerobic power (P<0.001). Bonferroni's post hoc test showed a significant decrease in BMI and serum levels of IL-6 and hs-CRP and a significant increase in the minimum power in the combined group compared to the other three groups (P<0.001). In addition, a significant increase in anaerobic power (peak and average power) was respectively observed in the combined and HIIT groups, compared to the sleep regulation and control groups (P<0.001). Conclusion: The HIIT+ sleep regulation combined intervention can be a valuable interventional treatment to improve the care of sleep disorders in adolescent girls and, consequently, reduce the problems and costs of treatment for these individuals and their families

High-intensity Interval Training On Muscle Strength And Rate Of Torque Development In Female Lacrosse Players.

Sports, which include lacrosse, require sudden directional changes and rapid alterations in pace both of which are highly dependent on explosive skeletal muscle force production. Previous research has shown that high-intensity interval training (HIIT) increases maximal sprint speed, muscle power, and overall performance in field sports. Limited research on the potential of HIIT to impact skeletal muscle strength and rate of torque development in lacrosse players exist. PURPOSE: To determine the effects of HIIT in combination with lacrosse specific training on lower-limb skeletal muscle strength and rate of torque development in female high school lacrosse players (15 ± 2 yrs.). METHODS: Fourteen healthy female lacrosse players from a local high school performed HIIT three times per week in addition to their specific lacrosse training program for 11 weeks (preseason plus competitive season). Right lower-limb skeletal muscle performance was assessed Pre, Mid, and Post-HIIT training with concentric knee extensor contractions at three angular velocities (0, 1.6, and 3.1 rad·s-1). Outcome measures included: peak torque (Nm), time-to-peak torque (s), and rate of torque development (Nm·s-1). RESULTS: Isometric and concentric (3.1 rad·s-1) strength increased across the HIIT and lacrosse specific training period by 20% and 10%, respectively (p < 0.05). Combined training had no influence on time-to-peak torque (Pre: 2.2 ± 0.9 s; Post: 2.6 ± 0.5 s; p > 0.05). Rate of torque development for the first 50 ms of contraction increased by 42% at the mid-point [Pre: 607.3 ± 451.1; Mid: 862.7 ± 292.7 Nm·s-1, p < 0.05) and remained elevated at the Post-HIIT assessment (Post: 864.7 ± 255.4 Nm·s-1). No change in rate of torque development was observed over the 100-200 ms period of contraction. CONCLUSIONS: Combined HIIT with lacrosse specific training improved both static and dynamic knee extensor strength and enhanced rate of torque development within the first 50 ms of contraction in female high school lacrosse players. The inclusion of HIIT to standard pre-season and competitive lacrosse season training demonstrated no negative effects on lower-limb skeletal muscle performance.

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.

The Effects of High-Intensity Power Training versus Traditional Resistance Training on Exercise Performance.

Background: High-intensity interval training (HIIT) features short, repeated bursts of relatively vigorous exercise with intermittent periods of rest or low-intensity exercise. High-intensity power training (HIPT), in combination with HIIT and traditional resistance training (TRT), is characterized as multijoint high-intensity resistance exercises with low interset rest periods. HIPT requires people to finish the exercise as fast as possible, which increases acute physiological demands. The aim of the study was to investigate the differences between eight-week HIPT or TRT on exercise performance. Methods: Twenty-four college students were recruited and randomly assigned to either the HIPT or TRT group in a counterbalanced order. The power of upper and lower limbs (50% 1RM bench press and vertical jump) and anaerobic power were tested before and after the training (weeks 0 and 9). The results were analyzed by two-way analysis of variance (ANOVA) or Friedman’s test with a significance level of α = 0.05 to compare the effects of the intervention on exercise performance. Results: There were significant differences in the explosive force of the upper and lower limbs between the pretest and post-test in both the HIPT and TRT groups (p < 0.05). However, only the HIPT group showed a significant difference in the mean power on the Wingate anaerobic test between the pretest and post-test (p < 0.05). Conclusions: Both HIPT and TRT can improve upper and lower limb explosive force. HIPT is an efficient training protocol, which took less time and produced a better improvement in mean anaerobic power.

Is High-intensity Interval Training a Feasible Therapy Option in Geriatric Rehabilitation? A Randomized Controlled Pilot Study

Abstract Background With an increasing number of inpatients in geriatric rehabilitation, there is continuing interest in efficient training measures regarding physical performance.Objectives To examine the feasibility and outcomes of high-intensity interval training (HIIT) in geriatric patients. Methods Single-centre randomized controlled study of HIIT vs. moderate continuous training (MCT) for patients ≥65 years old referred to inpatient rehabilitation. Cardiopulmonary exercise testing (CPET) was performed before the first and last training in order to measure participant’s cardiorespiratory fitness. At the same time-points patients completed a series of questionnaires regarding subjective improvements and acceptance of the training methods. Results Regarding feasibility, HIIT showed a completion rate of 82.4% and an adherence rate of completed sessions of 83.3%. HIIT significantly improved cardiorespiratory fitness (+13% for VO2peak, p=0.01), respiratory quotient (+9%, p=0.01) and power output (+12% for Watt peak, p=0.01) compared with MCT. Significant improvements were also seen over time for physical and mental scores of PROMIS-10 and quality of life. Conclusion A HIIT intervention has proven feasible for elderly patients in a geriatric rehabilitative setting. Further research should specify the HIIT intervention in order to offer this training to more patients. Long-term observations are also needed.

Effect of performing high-intensity interval training and resistance training on the same day vs. different days in women with type 2 diabetes.

Type 2 diabetes (T2D) is associated with chronic inflammation as a critical factor for muscle atrophy and disease progression. Although the combination of aerobic and resistance training leads to more significant improvements in health-related indices for T2D patients, the interference effect in concurrent training can decrease positive adaptations. The purpose of this study was to investigate the physiological adaptations in performing high-intensity interval training (HIIT) and resistance training on the same day vs. different days in T2D patients. Twenty-four non-athletic 45-65-year-old women with T2D participated in an 8-week intervention. They were randomly divided into three groups: same days (SD), different days (DD), and treatment as usual (control). SD group had resistance training followed by HIIT on Saturday, Monday, and Wednesday. In contrast, the DD group had the same volume of resistance training on Saturday, Monday, and Wednesday and HIIT on Sunday, Tuesday, and Thursday, with Friday as a resting day. Blood samples were collected 24h before the first and 48h after the last session in each group to measure glucose, insulin, glycosylated hemoglobin, IGF1, IL1β, CRP, lipid profile, miR-146a, and miR-29b. Three subjects dropped out during the study, and 21 participants (SD = 7, DD = 6, Control = 8) completed the 8-week intervention. MiR-146a changed significantly (P = 0.006) in both SD and DD groups compared to the control group. IGF1 (P = 0.001) and fat-free mass (P = 0.001) changed significantly in SD and DD groups compared to the control group, and also DD led to more significant increases in IGF1 and fat-free mass in comparison with SD. MiR-29 (P = 0.001) changed significantly in the DD group compared to the control group. The reduction of IL-1β, fat mass and insulin resistance was significant in SD and DD compared to the control group; DD showed more potent effects than the SD group on the fat mass (P = 0.001) and insulin resistance (P = 0.001). This study demonstrated that a combination of HIIT and resistance training could be practical for improving health-related outcomes in T2D. Our study indicated for the first time that training strength and HIIT on separate days appeared to be more effective to combat muscle atrophy and insulin resistance.

Short- and Long-Term Effects of High-Intensity Interval Training vs. Moderate-Intensity Continuous Training on Left Ventricular Remodeling in Patients Early After ST-Segment Elevation Myocardial Infarction-The HIIT-EARLY Randomized Controlled Trial.

AimDue to insufficient evidence on the safety and effectiveness of high-intensity interval training (HIIT) in patients early after ST-segment elevation myocardial infarction (STEMI), we aimed to compare short- and long-term effects of randomized HIIT or moderate-intensity continuous training (MICT) on markers of left ventricular (LV) remodeling in STEMI patients receiving optimal guideline-directed medical therapy (GDMT).Materials and MethodsPatients after STEMI (<4 weeks) enrolled in a 12-week cardiac rehabilitation (CR) program were recruited for this randomized controlled trial (NCT02627586). During a 3-week run-in period with three weekly MICT sessions, GDMT was up-titrated. Then, the patients were randomized to HIIT or isocaloric MICT for 9 weeks. Echocardiography and cardiopulmonary exercise tests were performed after run-in (3 weeks), end of CR (12 weeks), and at 1-year follow-up. The primary outcome was LV end-diastolic volume index (LVEDVi) at the end of CR. Secondary outcomes were LV global longitudinal strain (GLS) and cardiopulmonary fitness.ResultsSeventy-three male patients were included, with the time between STEMI and start of CR and randomization being 12.5 ± 6.3 and 45.8 ± 10.8 days, respectively. Mixed models revealed no significant group × time interaction for LVEDVi at the end of CR (p = 0.557). However, there was a significantly smaller improvement in GLS at 1-year follow-up in the HIIT compared to the MICT group (p = 0.031 for group × time interaction). Cardiorespiratory fitness improved significantly from a median value of 26.5 (1st quartile 24.4; 3rd quartile 1.1) ml/kg/min at randomization in the HIIT and 27.7 (23.9; 31.6) ml/kg/min in the MICT group to 29.6 (25.3; 32.2) and 29.9 (26.1; 34.9) ml/kg/min at the end of CR and to 29.0 (26.6; 33.3) and 30.6 (26.0; 33.8) ml/kg/min at 1 year follow-up in HIIT and MICT patients, respectively, with no significant group × time interactions (p = 0.138 and 0.317).ConclusionIn optimally treated patients early after STEMI, HIIT was not different from isocaloric MICT with regard to short-term effects on LVEDVi and cardiorespiratory fitness. The worsening in GLS at 1 year in the HIIT group deserves further investigation, as early HIIT may offset the beneficial effects of GDMT on LV remodeling in the long term.

Effects of Different Types of High-Intensity Interval Training (HIIT) on Endurance and Strength Parameters in Children and Adolescents.

High-Intensity Interval Training (HIIT) promises high training effects on aerobic fitness in children, adolescents and adults in a relatively short time. It is therefore well-established in professional training settings. HIIT methods could also be suited to Physical Education (P.E.) lessons and contribute to students’ health and fitness. Since HIIT sessions need little time and equipment, they can be efficiently implemented in P.E. However, there are few studies which have examined non-running-based HIIT programs in the school sport setting. We therefore conducted an intervention study including 121 students aged 11–15 attending a secondary school in Baden Württemberg, Germany. The effects of three different forms of HIIT training varying in duration and content (4 × 4 HIIT, 12 × 1 HIIT, CIRCUIT) were analyzed. The training was conducted twice a week over 6 weeks (10–12 sessions). Strength and endurance performances were determined in pre- and posttests prior to and after the intervention. Results verified that all three HIIT programs led to significant improvements in aerobic fitness (p < 0.001; part ŋ2 = 0.549) with no significant interaction between time x group. In contrast to the running-based HIIT sessions, CIRCUIT training also led to significant improvements in all of the measured strength parameters. Retrospectively, students were asked to assess their perception of the training intervention. The HIIT sessions were well-suited to students who considered themselves as “athletic”. Less athletic students found it difficult to reach the necessary intensity levels. The evaluation showed that endurance training conducted in P.E. lessons needs a variety of different contents in order to sufficiently motivate students. Students perceiving themselves as “unathletic” may need additional support to reach the required intensities of HIIT. Circuit training sessions using whole-body drills can be efficiently implemented in the P.E. setting and contribute to students’ health and fitness.

Isolated and combined impact of dietary olive oil and exercise on markers of health and energy metabolism in female mice

An olive oil (OO) rich diet or high-intensity interval training (HIIT) independently improve markers of health and energy metabolism, but it is unknown if combining OO and HIIT synergize to improve these markers. This study characterized the isolated and combined impact of OO and HIIT on markers of health and energy metabolism in various tissues in C57BL/6J female mice. Nine-week-old mice were divided into four groups for a 12-week diet and/or exercise intervention including: (1) Control Diet without HIIT (CD), (2) Control Diet with HIIT (CD+HIIT), (3) OO diet (10% kcal from olive oil) without HIIT, and (4) OO diet with HIIT (OO+HIIT). Neither dietary OO or HIIT altered body weight, glucose tolerance, or serum lipids. HIIT, regardless of diet, increased aerobic capacity and HDL cholesterol levels. In liver and heart tissue, OO resulted in similar adaptations as HIIT including increased mitochondrial content and fatty acid oxidation but combining OO with HIIT did not augment these effects. In skeletal muscle, HIIT increased mitochondrial content in type II fibers similarly between diets. An RNA sequencing analysis on type I fibers revealed OO reduced muscle regeneration and lipid metabolism gene abundance, whereas HIIT increased the abundance of these genes, independent of diet. HIIT training, independent of diet, induced subcutaneous white adipose tissue (sWAT) hypertrophy, whereas OO induced gonadal white adipose tissue (gWAT) hypertrophy, an effect that was augmented with HIIT. These data highlight the pleiotropic effects of OO and HIIT, although their combination does not synergize to further improve most markers of health and energy metabolism.

Effects of aquatic high-intensity interval training and moderate-intensity continuous training on central hemodynamic parameters, endothelial function and aerobic fitness in inactive adults

Background/ObjectiveThe effects of land-based high-intensity interval training (HIIT) on the cardiovascular system have already been demonstrated. However, the water environment is different from that on land. Therefore, we investigated the effects of 6-week aquatic HIIT and moderate-intensity continuous training (MICT) on central hemodynamic parameters, endothelial function, and aerobic fitness in inactive adults. MethodsThirty-one inactive adults were randomly assigned to HIIT or MICT group. HIIT group performed twelve 30-s swimming exercise bouts with the intensity of 95% HRmax and 15–18/20 RPE with a 60-s rest period between each bout. MICT group performed a 30-min uninterrupted swimming exercise with the intensity of 70%–75% HRmax and 12–14/20 RPE. Training frequency for both groups was three times a week. The pulse wave analysis and flow-mediated dilation (FMD) were measured by non-invasive equipments. ResultsThe aerobic fitness significantly increased after HIIT, but no change was seen after MICT. Augmentation pressure (AP) and augmentation index normalized at 75 bpm (AIx@HR75) significantly decreased after HIIT but not MICT, whereas MICT rather than HIIT improved subendocardial viability ratio (SEVR), central and peripheral blood pressure, and resting HR. Only HIIT significantly increased brachial endothelial function. ConclusionA six-week aquatic HIIT and MICT had no differences in hemodynamic parameters, endothelial function, and aerobic fitness, however 6 weeks of aquatic HIIT reduced arterial stiffness, increased endothelial function and aerobic fitness, while 6 weeks of aquatic MICT reduced arterial blood pressure and resting HR and increased the coronary blood flow reserve.

High Intensity Exercise Improves Cardiorespiratory Capacity in a Mouse Model of Hypertrophic Cardiomyopathy

IntroductionCardiorespiratory capacity (pVO2) is an important prognostic indicator in patients with HCM. Individuals with HCM that have a lower pVO2 possess a greater risk for heart failure (HF) and mortality. High intensity exercise (HIE) can increase pVO2 to a greater degree compared to other training modalities, including when used for cardiac rehabilitation for in cardiac disease states (e.g., HF and Cardiovascular disease). The effects of HIE on HCM, however, are largely unknown. Our study sought to evaluate the effects of High Intensity Interval Training (HIIT) on pVO2, as well as cardiac structural and functional parameters, in a preclinical mouse model of HCM.MethodsFemale and male C57BL/6J non‐transgenic nTG (n=27) and TG (n=32) mice were subjected to HIIT protocol that mirrored methods used clinically in cardiac rehabilitation. A single treadmill training session included 4‐4 minute high intensity intervals (~80% preVO2 max speed) interspersed by 5‐3 minute recovery intervals (~50% preVO2 max speed) for 31 total minutes. Exercise training sessions were repeated 3 times per week for 6 weeks. Pre and post pVO2 and murine echocardiography were measured and analyzed by a blinded technician.ResultsFollowing 6 weeks of the HIIT, nTG female (+13.5 mL/kg/min ± 3.6, p&lt;0.01), nTG male (+13.5 mL/kg/min ± 3.6, p&lt;0.01) and TG female (+7.06 ± 3.3 mL/kg/min, p&lt;0.05) mice demonstrated an average increase in pVO2. A change in pVO2 observed in TG male mice did not reach statistical significance (+4.34 ± p=0.12). Sedentary female (‐15.9 mL/kg/min ± 3.3, p&lt;0.001) and male (‐13.1 mL/kg/min ± 3.9, p&lt;0.01) TG control mice experienced a significant decrease in pVO2 following the same period, while no change was observed in nTG sedentary controls. Independent of sex, nTG and TG HIIT mice had a significantly greater change in pVO2 compared to sedentary counterparts. HIIT training did not result in changes to the following echocardiography measures in either nTG or TG mice: LV mass, LA volume, cardiac output, or stroke volume.ConclusionOur results indicate that a translationally derived HIIT protocol improved cardiorespiratory capacity in a preclinical HCM mouse model, absent of adverse events or worsening of organ level disease pathology.

Addition of strength training modifies the aerobic exercise inflammatory response in heart failure patients – Comments on the underlying pathophysiology

Aim: The present study investigates the effect of Strength Training addition in a High Intensity Interval Training (HIIT) program, on the inflammatory profile of chronic heart failure (CHF) patients.&#x0D; Materials and Methods: Forty-six CHF patients were randomized into the two different exercise rehabilitation groups. A patient group (control) performed HIIT and another group performed Combined (HIIT and strength training) Exercise Training (COM) for a three- month period. Before and after rehabilitation, all patients performed a maximal cardiopulmonary exercise testing (CPET). Microcirculatory parameters were assessed by Near Infrared Spectroscopy; CRP, IL-2, IL-6, IL-10 and VEGF levels were measured in plasma.&#x0D; Results: Cardiopulmonary parameters and microcirculatory indices improved after rehabilitation. CRP and the IL-6/IL-10 ratio decreased after rehabilitation. By linear regression analysis, a negative correlation was noted between IL-2, IL-6 and IL-10 changes (post-CPET values) and the VE/VCO2 slope change, for the entire patient cohort. The correlation was separately maintained only in the COM group.&#x0D; Conclusions: Overall, the results of the present study reinforce the view of an anti-inflammatory effect of exercise in CHF patients. The significant correlations demonstrated between the cytokine responses and the ventilatory response to exercise, particularly in the COM group, probably ensue from the special effect of strength training on peripheral muscle function.

The Effect of High Intensity Interval Training on the Intrinsic and Extrinsic Pathways of Myocardial Apoptosis in Diet-Induced Obese Rats

Background: Diet-induced obesity is associated with several cardiovascular diseases and myocardial apoptosis. This study aimed to investigate the effect of high intensity interval training (HIIT) on the myocardial apoptosis in the diet-induced obese rats. Methods: Thirty-two male rats, after an obesity induction period, were randomly selected and assigned to four groups including non-obese control (NOC; n=8), basal obese control (BOC; n=8), obese control (OC; n=8), and obese+HIIT (OT; n=8). NOC and BOC groups were sacrificed before the training period. The OT group underwent a HIIT program performed 5 times/week over 12 weeks. Rat hearts were removed 48 hours after the last training session. The Bax, Bcl-2, cytochrome-c, Bid, caspase-8, as well as caspase-3 protein expressions were analyzed using western blotting. Data were analyzed using independent t test. Results: After obesity induction period, the Bax, Bid, cytochrome-c, caspase-8, caspase-3 proteins, and Bax/Bcl-2 in BOC were found to be significantly higher than those in NOC (P=0.025, P=0.0001, P=0.013, P=0.017, P=0.01, P=0.18, respectively). However, Bcl-2 protein in BOC was detected to be significantly lower than that in NOC (P=0.025). The results obtained after completing HIIT training showed that Bid, cytochrome-c, caspase-8, caspase-3, and Bax/Bcl-2 in OT were lower than those in OC (P=0.005, P=0.039, P=0.001, P=0.04, P=0.05, respectively). However, Bcl-2 protein in OT was significantly higher than that in OC (P=0.004). No significant difference was found between OT and OC regarding Bax protein (P=0.32). Conclusion: Diet-induced obesity may have exacerbated the myocardial apoptosis through both intrinsic and extrinsic pathways. However, it seemed that HIIT training significantly prevented the increase of myocardial apoptosis in obese rats.

Biological Response of Irisin Induced by Different Types of Exercise in Obese Subjects: A Non-Inferiority Controlled Randomized Study.

Simple SummaryAmong healthy male and female obese individuals undergoing a 12-week aerobic exercise program with either moderate intensity endurance or high-intensity interval training for losing weight, a reduction of circulating irisin was observed. Irisin is an important adipo-myokine implicated in the regulation of energy metabolism and cardiovascular health. Sex differences in the circulating levels of this biomarker have been previously reported and are likely related to the different anthropometric features between the sexes. A sex-specific modulation of circulating irisin levels should be further explored to tailor sex-specific training approaches for improving the cardiovascular health of obese subjects.Background: Weight loss through physical exercise is warranted among obese individuals. Recently, a greater benefit in cardiorespiratory fitness was achievable with high-intensity interval training (HIIT) as compared with moderate intensity continuous training. The beneficial effect of training on CV health might be related to a specific modulation of circulating irisin, an adypo-myokine implicated in the regulation of energy expenditure. Methods: The present study investigates the circulating plasma levels of irisin at baseline and in response to 12-week of training program either with HIIT or moderate-intensity continuous training (MICT) among young female and male obese subjects. Clinical, anthropometric, and training characteristics for each participant were available. A sex-disaggregated data for circulating plasma levels of irisin pre- and post-training are provided as well as an adjusted multivariate linear regression model to identify the determinants of post-training irisin levels. Results: Data from a total of 32 obese healthy individuals (47% female, mean age 38.7 years, mean BMI 35.6 kg/m2), randomized in a 1:1 manner to HIIT or MICT were analyzed. Circulating plasma levels of irisin similarly and significantly decreased in both MICT and HIIT interventional groups. Females had higher post-exercise irisin levels than males (6.32 [5.51–6.75] vs. 4.97 [4.57–5.72] μg/mL, p = 0.001). When stratified by an interventional group, a statistically significant difference was observed only for the MICT group (male, 4.76 [4.20–5.45] μg/mL vs. female 6.48 [4.88–6.84] μg/mL p = 0.03). The circulating post-training level of irisin was independently associated with post-training fat-free mass (β −0.34, 95% confidence interval, CI −0.062, −0.006, p = 0.019) in a model adjusted confounders. When female sex was added into the adjusted model, it was retained as the only factor independently associated with irisin levels (β 1.22, 95% CI, 0.50, 1.93, p = 0.002). Conclusions: In obese healthy subjects, circulating irisin levels were reduced in response to 12-weeks of exercise involving either HIIT or MICT. A sex-specific differences in circulating irisin levels at baseline and as biological response to chronic exercise was described. Sex-specific biological response of irisin to exercise should be further explored to tailor sex-specific training approaches for improving the cardiovascular health of obese healthy subjects.

High-intensity Interval Training for Older Adults: Safety Issues

High-intensity interval training (HIIT) has been reported to become an alternative of moderate-intensity continuous training and adapted even in older adults. However, to implement the use of HIIT for older adults, who are very often associated with life-style related and chronic diseases, safety issues should be considered in the first place. However, at present, the evaluation of the safety of HIIT among older adults is compromised by the limited availability of relevant data due to the low proportion of studies reporting adverse events. In this review, update data regarding safety and check-up methods for older adults are described in submaximal HIIT and spring interval training.

High-intensity interval training reduces blood pressure in older adults: A systematic review and meta-analysis.

The current systematic review and meta-analysis evaluated the effects of High-Intensity Interval Training (HIIT) on blood pressure (BP) in older adults and compared the efficacy of HIIT versus moderate-intensity continuous training (MICT). Search was conducted using the databases at PubMed, Scopus, Cochrane Library and EMBASE, for randomized trials comparing the chronic effects (≥4weeks) of HIIT versus MICT or control group (non-exercise) on BP in older adults (≥60years) with or without hypertension. A total of 10 articles (n=266 participants) were included in this meta-analysis. HIIT were associated with reductions in systolic BP (MD -7.36; 95%CI -11.80 to -2.92; P<0.01; I2=24%) and diastolic BP (MD -5.48; 95%CI -8.71 to -2.25; P<0.01; I2=40%) versus control group. No differences were found between HIIT and MICT in systolic BP (MD -2.09; 95%CI -9.76 to 5.58; P=0.59; I2=0%) and diastolic BP (MD -1.00; 95%CI -6.01 to 4.01; P=0.69; I2=0%). HIIT reduces BP in older adults. Additionally, HIIT and MICT provided comparable reductions on BP in this population.

Can Popular High-Intensity Interval Training (HIIT) Models Lead to Impossible Training Sessions?

High-Intensity Interval Training (HIIT) is a time-efficient training method suggested to improve health and fitness for the clinical population, healthy subjects, and athletes. Many parameters can impact the difficulty of HIIT sessions. This study aims to highlight and explain, through logical deductions, some limitations of the Skiba and Coggan models, widely used to prescribe HIIT sessions in cycling. We simulated 6198 different HIIT training sessions leading to exhaustion, according to the Skiba and Coggan-Modified (modification of the Coggan model with the introduction of an exhaustion criterion) models, for three fictitious athlete profiles (Time-Trialist, All-Rounder, Sprinter). The simulation revealed impossible sessions (i.e., requiring athletes to surpass their maximal power output over the exercise interval duration), characterized by a few short exercise intervals, performed in the severe and extreme intensity domains, alternating with long recovery bouts. The fraction of impossible sessions depends on the athlete profile and ranges between 4.4 and 22.9% for the Skiba model and 0.6 and 3.2% for the Coggan-Modified model. For practitioners using these HIIT models, this study highlights the importance of understanding these models’ inherent limitations and mathematical assumptions to draw adequate conclusions from their use to prescribe HIIT sessions.

Effects of High Intensity Interval Training Using Ifittkids Module on Memory Strength, Attention and Aerobic Capacity

Executive function, attention, and memory are an important indicator of cognitive health of children. Cardiovascular fitness has a positive relationship with cognitive function performance. IFITTKIDS module is a training programme guided by High Intensity Interval Training (HIIT) used to see the effect on memory strength, attention and aerobic capacity. This HIIT training is able to increase the fitness level optimally in a short period of time. This study was conducted quantitatively using a ‘Pre and post control group design’. The study subjects consisted of 64 primary school students aged 11 years who were divided into two groups namely 32 participants in the treatment group and 32 in the control group. The intervention was conducted for 12 weeks with a training frequency of two times a week for 20 minutes per session. The results using ANCOVA test analysis showed that by adjusting the pre-test score as a covariate, the post-test score for memory strength, attention and aerobic capacity of the treatment group was significantly higher with the score from the control group with F (1.61) = 68.15, p <.05, and eta squared = .53, F(1,61) = 54.906, p < .05, eta squared = .47 and F (1.61) = 63,987, p <.05, and eta squared = .51. Substantially, the findings of this study show that HIIT training guided by IFITTKIDS MODULE for 8 weeks is productive in improvising aerobic capacity and memory strength in 11-year-old school children. The results of this study, recommend that this IFITTKIDS MODULE can be used as one of the training programme to increase the level of memory strength, attention and aerobic capacity in children.

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.

SMALL-SIDED GAMES VERSUS INTERVAL TRAINING IN ADOLESCENT SOCCER PLAYERS: EFFECTS ON BODY COMPOSITION

The aim of this research was to determine the effects of small-sided games (SSGs) and high-intensity interval training (HIIT) on body composition in adolescent soccer players. A total of 60 young male soccer players (Age: 15.6±0.6 years) were recruited. We registered the following body composition variables: body fat, percentage of fat mass (BF%), muscle mass, body mass, total body water (TBW), and BMI. Players were randomly assigned to the SSG or HIIT group during the last eight weeks of the season. The HIIT group showed significantly improved body fat and body fat % (p≤0.05), whereas no change was observed for body mass, BMI, body water and muscle mass in both groups. In conclusion, HIIT training improved or maintained body composition status in adolescent soccer players. On the contrary, SSG training seems to increase body fat and consequently affect players’ performance at the end of the season.