Effects of linear and change of direction high-intensity interval training on physical performance of elite female soccer players.

The aim of this study was to determine the effects of linear and change of direction high-intensity interval training (HIIT) on physical performance in elite female soccer players. Thirty elite female soccer players (age: 19.6 ± 4.6 years; height: 166.5 ± 4.8 cm; body weight: 60.5 ± 8.3 kg; BMI: 21.9 ± 2.9 kg/m2) were randomly allocated to HIIT linear (HIITLIN) and HIIT change of direction (HIITCOD) training groups. The HIITLIN group performed linear running for 15, 20 or 25 s by keeping constant pace during the entire distance. In contrast, the HIITCOD group performed three changes of direction (COD) with a 180° turn during each interval run at 15, 20 or 25 s. Physical performance was assessed using sprinting, agility, vertical jumps, repeated sprint ability (RSA) and 30-15 Intermittent Fitness Test (30-15 IFT). In both groups, all physical performance measurements improved (p ≤ 0.05), except RSAbest in HIITLIN (p = 0.45). Both interventions significantly improved speed over 10 m, 20 m, 30 m, Pro-agility, Zig-zag, RSAavg, fatigue index, maximal oxygen uptake, and velocity at 30-15 IFT, while moderate improvements were observed in countermovement jump (CMJ), CMJ with arm swing and squat jump. However, HIITCOD did not achieve superior improvements in any of the aforementioned measurements compared to HIITLIN. Based on the obtained results, we concluded that different types of HIIT training have a positive effect on physical performance in elite female soccer players.

Effects of controlled supramaximal high-intensity interval training on muscle capacities and physical functions for older adults: analysis of secondary outcomes from the Umeå HIT study-a randomised controlled trial.

OBJECTIVE: This study investigated the effectiveness of supramaximal high-intensity interval training (supramaximal HIT) on muscle capacities and physical function compared to moderate-intensity training (MIT) for older adults. METHODS: Sixty-eight older adults (66-79 years, 56% women), not engaged in regular exercise, were randomised to 3 months of twice-weekly supramaximal HIT (20 minutes including 10 × 6-second intervals) or MIT (40 minutes including 3 × 8-minute intervals). Both groups performed the training on stationary bicycles in a group setting. Target intensity was watt-controlled, with standardised cadence and individualised resistance. Outcomes analysed with linear-mixed models included leg power (Nottingham Power Rig), hand grip strength (Jamar dynamometer), static and dynamic balance (One leg stance, 30-second step test), chair stand (30-second chair stand), and anaerobic cycling performance (modified Borg Cycle Strength Test). RESULTS: Baseline values were (supramaximal HIT/MIT, mean ± SD) leg power 198 ± 60/189 ± 53 W, hand grip strength 4.2 ± 1.0/4.3 ± 1.1 N/kg, static balance 64 ± 41/62 ± 41 s, dynamic balance 39 ± 7/38 ± 5 steps, chair stands 22 ± 6/22 ± 6 and anaerobic cycling performance 224 ± 60/217 ± 55 W. At 3-month follow-up, a between-group difference in favour of supramaximal HIT [95% CI] was observed in anaerobic cycling performance of 19[3;35] W. Within-group mean changes for supramaximal HIT/MIT were for leg power 8.4[0.9;15.8]/6.0[-1.3;13.3] W, hand grip strength 0.14[0.00;0.27]/0.13[-0.01;0.26] N/kg, static balance 11[3;20]/10[1;18] s, dynamic balance 1.6[0.3;2.8]/2.3[1.1;3.6] steps, 2.1[1.1;3.1]/1.4[0.4;2.3] chair stands and anaerobic cycling performance 31.3[19.6;43.0]/12.0[0.4;23.5] W. CONCLUSION: Supramaximal HIT showed superior effect on anaerobic cycling performance when compared to MIT. Additionally, the results indicate that supramaximal HIT is comparably beneficial as MIT in terms of effects on muscle capacity and physical function for older adults.

Effectiveness of a game-based high-intensity interval training on executive function and other health indicators of children with ADHD: A three-arm partially-blinded randomized controlled trial.

Background: Children with ADHD demand for effective intervention with minimum side effect to improve executive function (EF) and health well-being. Method: This study used a three-arm partially-blinded randomized controlled trial to test the effects of two different kinds of 8-week game-based training programs (game-based HIIT program, GameHIIT; and game-based structured aerobic exercise program, GameSAE) on EF and other health indicators of children with ADHD, which was compared with a non-treatment control group. Results: A total of 49 children with ADHD completed the program. Analyses of EF tests and parental survey indicated that (i) there is no significant intragroup difference among all measures between pre-/post-intervention tests for two game-based intervention groups. The only significant intergroup difference was observed in self-monitor score of parent-reported child's EF between GameSAE group and the control (large effect). Similarly, cerebral hemodynamic responses also found no significant group effect for all EF tests. However, the time effects were observed in several channels in the GameHIIT group in two EF tests (Color Words Stroop Test and Tower of London Test). No significant change of participants' overall ADHD symptoms was found in the pre-/post-tests for three groups. Nonetheless, further analyses revealed that both of two game-based training programs exhibited the significant positive effects on child's PA levels and the large effects on levels of physical fitness, when they were compared to the control. Conclusion: By this study, a significant enhancement in physical fitness and PA levels were found in both game-based PA interventions when they were compared with control group. However, the effectiveness of game-based PA interventions on improving EF or reducing ADHD symptoms remains unclear. This implies that a larger intervention dosage or a tailored intervention design may be warranted to improve the EF of children with ADHD.

Comparing the effect of high-intensity interval exercise and voluntary exercise training on cognitive functions in rats.

It is known that exercise increases brain-derived neurotrophic factor (BDNF) levels in the hippocampus, the brain region responsible for learning and memory, resulting in improved cognitive functions and learning processes. However, it is claimed that different types of exercise cause different responses in the brain. It is thought that lactate and osteocalcin secreted in response to exercise are associated with an increase in BDNF levels. However, there are not enough studies on this subject. This study aimed to compare the effects of high-intensity interval training (HIIT) and voluntary exercise training on cognitive performance and molecular connections. Male rats were randomly divided into control, voluntary exercise training and HIIT groups. The voluntary exercise group had free access to the voluntary wheel for 8 weeks. The HIIT group performed HIIT on the treadmill 3 days a week for 8 weeks. The rats underwent open field (OF), elevated plus maze (EPM) and Morris water maze (MWM) tests 24 h after the last exercise training. Then, after blood was drawn under anesthesia, the rats were sacrificed and their hippocampus tissues were separated. Glucocorticoid and BDNF levels in the blood were evaluated by enzyme-linked immunosorbent assay (ELISA), and osteocalcin and BDNF expressions in the hippocampus were evaluated by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). Neither voluntary exercise training nor HIIT had any significant effect on behavioral parameters assessed by OF, EPM and MWM tests. However, BDNF expression in hippocampus tissue was higher in the HIIT group than in the control group. In addition, osteocalcin expression in hippocampus tissue was higher in the HIIT and voluntary exercise groups than in the control group. In conclusion, according to the findings we obtained from this study, although it does not have a significant effect on cognitive functions, the effect of HIIT on brain functions seems to be more effective than voluntary exercise.

Short-term HIIT impacts HDL function differently in lean, obese, and diabetic subjects.

Introduction: High density lipoproteins (HDL) exert cardiovascular protection in part through their antioxidant capacity and cholesterol efflux function. Effects of exercise training on HDL function are yet to be well established, while impact on triacylglycerol (TG)-lowering has been often reported. We previously showed that a short-term high-intensity interval training (HIIT) program improves insulin sensitivity but does not inhibit inflammatory pathways in immune cells in insulin-resistant subjects. The purpose of this study is to evaluate HDL function along with changes of lipoproteins after the short-term HIIT program in lean, obese nondiabetic, and obese type 2 diabetic (T2DM) subjects. Methods: All individuals underwent a supervised 15-day program of alternative HIIT for 40 minutes per day. VO2peak was determined before and after this training program. A pre-training fasting blood sample was collected, and the post-training fasting blood sample collection was performed 36 hours after the last exercise session. Results: Blood lipid profile and HDL function were analyzed before and after the HIIT program. Along with improved blood lipid profiles in obese and T2DM subjects, the HIIT program affected circulating apolipoprotein amounts differently. The HIIT program increased HDL-cholesterol levels and improved the cholesterol efflux capacity only in lean subjects. Furthermore, the HIIT program improved the antioxidant capacity of HDL in all subjects. Data from multiple logistic regression analysis showed that changes in HDL antioxidant capacity were inversely associated with changes in atherogenic lipids and changes in HDL-TG content. Discussion: We show that a short-term HIIT program improves aspects of HDL function depending on metabolic contexts, which correlates with improvements in blood lipid profile. Our results demonstrate that TG content in HDL particles may play a negative role in the anti-atherogenic function of HDL.

Effects of High-Intensity Interval Training on the Parameters Related to Physical Fitness and Health of Older Adults: A Systematic Review and Meta-Analysis.

BACKGROUND: As a novel and time-efficient exercise form, high-intensity interval training (HIIT) has shown great potential in improving health-related physical fitness among diverse populations. However, empirical evidence on its efficacy among the elderly has not been well summarized. This systematic review and meta-analysis aimed to determine the effect of HIIT interventions on the parameters related to physical fitness and health of older adults, including resting heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), cardiorespiratory fitness (CRF), body mass index (BMI), body fat percent (BF%), waist circumference (WC), muscular endurance (ME), muscular strength (MS), muscular power (MP), balance and flexibility, compared to non-exercise and other-exercise (e.g., moderate-intensity continuous training, resistance training) conditions. METHODS: Literature published from January 2000 to May 2023 was collected through extensive searches across eight databases and relevant review papers. Randomized controlled trials (RCTs) featuring a minimum 2-week exercise intervention for older adults (≥ 60 years) were included. The pooled effect size of Hedges'g was estimated using random-effects models in R. Meta-regression was performed for both categorical (health status, duration of training programme, and frequency) and continuous moderators (mean age, male rate, and attrition rate). RESULTS: Forty-four eligible RCTs with 1863 participants (52.1% female; 60.5-81.2 years) were included in the quantitative analysis. Compared to non-exercise condition, HIIT significantly improved resting HR (g = -0.36, 95%CI = [-0.67, -0.05], P = 0.032), SBP (g = -0.29, 95%CI = [-0.54, -0.03], P = 0.008), CRF (g = 0.77, 95%CI = [0.51, 1.04], P < 0.001), BF% (g = -0.26, 95%CI = [-0.41, -0.11], P = 0.006), MS (g = 0.47, 95%CI = [0.23, 0.71], P = 0.004), ME (g = 0.65, 95%CI = [0.10, 1.19], P = 0.036), and balance (e.g., timed-up-and-go) (g = -0.79, 95%CI = [-1.19, -0.40], P = 0.035). Compared to other-exercise condition, HIIT significantly improved resting HR (g = -0.11, 95%CI = [-0.21, -0.01], P = 0.029), SBP (g = -0.14, 95%CI = [-0.28, -0.01], P = 0.038), and CRF (g = 0.23, 95%CI = [0.07, 0.38], P = 0.008). No significant difference was found between HIIT and non-exercise condition for DBP, BMI and WC, as well as between HIIT and other-exercise condition for DBP, BMI, BF%, WC, ME, and balance (all P > 0.05). Meta-regression indicated that mean age moderated the HIIT effect on resting HR (b = -0.02, P = 0.014; HIIT vs. other-exercise condition) and SBP (b = 0.03, P = 0.048; HIIT vs. non-exercise), and attrition rate moderated the effect on CRF (b = 0.03, P = 0.007; HIIT vs. non-exercise). CONCLUSION: This study supports the efficacy of HIIT in improving resting HR, SBP, CRF, BF%, MS, ME and balance among older adults. More empirical evidence is needed to determine the efficacy of HIIT for MP and flexibility in this population. TRIAL REGISTRATION: PROSPERO CRD42022316246.

Effect of high-intensity interval training vs. moderate-intensity continuous training on cardiometabolic risk factors in overweight and obese individuals.

OBJECTIVES: Our study aims to compare the effects of an 8-week high-intensity interval training (HIIT) vs. moderate-intensity continuous training (MICT) on cardiometabolic risk factors and on serum leptin levels in overweight and obese individuals. METHODS: Our quasi-experimental study involved 36 students who were assigned to HIIT, MICT or the control group. Using a bicycle ergometer, participants in the HIIT group performed 25 min of HIIT and those in the MICT group performed 35 min of moderate-intensity continuous exercise for three days a week for 8 weeks. Body composition estimated by bioimpedance analysis, blood lipids and serum leptin were measured pre-exercise and 8 weeks post-exercise. RESULTS: After 8 weeks of exercise, the participants in the MICT group showed a significant reduction in weight (p<0.01) and body mass index (BMI) (p<0.05). In the HIIT group, although weight reduction was noticed, the difference was not statistically significant compared to the pre-exercise values. In the control group, participants had a significant increase in their weight, BMI, and total body fat (p<0.05). On performing an inter-group comparison of the magnitude of change in body weight and BMI over 8 weeks of exercise, no difference was seen between the HIIT and MICT groups. No difference was observed in body fat indices and levels of random blood glucose, blood lipids and serum leptin pre and 8 weeks post-exercise. CONCLUSIONS: On comparing the change in body weight and BMI over 8 weeks, no significant difference was found between the HIIT and MICT groups. However, HIIT was notably more time efficient.

High-intensity interval training alleviates liver inflammation by regulating the TLR4/NF-κB signaling pathway and M1/M2 macrophage balance in female rats with cisplatin hepatotoxicity.

Cisplatin (CDDP) is an antineoplastic drug whose adverse effects include hepatotoxicity. The inflammatory process is crucial in the progression of liver injuries. Exercise is known for its anti-inflammatory effects, but the influence of different training modalities on hepatoprotection is still unclear. This study aims to compare the impacts between preconditioning with high-intensity interval training (HIIT) and traditional continuous training of low (LT) and moderate (MT) intensities on inflammatory markers in Wistar female rats with CDDP-induced hepatotoxicity. Thirty-five rats were divided into five groups: control and sedentary (C + Sed), treated with CDDP and sedentary (CDDP + Sed), treated with CDDP and subjected to LT (CDDP + LT), treated with CDDP and subjected to MT (CDDP + MT), and treated with CDDP and subjected to HIIT (CDDP + HIIT). The training protocols consisted of treadmill running for 8 weeks before CDDP treatment. The rats were euthanized 7 days after the treatment. Liver samples were collected to evaluate the expression of various inflammatory markers and types of macrophages. Our results indicated that HIIT was the only protocol to prevent the increase in all analyzed pro-inflammatory cytokines and reduce the number of ED-1-positive cells, attenuating the TLR4/NF-κB signaling pathway in the liver. Additionally, HIIT increased the anti-inflammatory cytokine IL-10 and regulated M1/M2 macrophage polarization. Thus, this study suggests that preconditioning with HIIT is more effective in promoting hepatoprotective effects than LT and MT, regulating inflammatory markers through modulation of the TLR4/NF-κB signaling pathway and M2 macrophage polarization in the hepatic tissue of female rats treated with CDDP.

Circulating CD31+ Angiogenic T cells are reduced in prediabetes and increase with exercise training.

AIMS: To investigate circulating angiogenic cells in adults with prediabetes and the effect of a structured exercise program. METHODS: A cohort of adults with overweight/obesity and either normal glucose (NG) or prediabetes were randomised to receive exercise (Exercise) (as twice weekly supervised combined high intensity aerobic exercise and progressive resistance training, and once weekly home-based aerobic exercise) or an unsupervised stretching intervention (Control) for 12 weeks. Circulating angiogenic T cells, muscle strength, and cardiovascular disease risk factors, including blood lipids, arterial stiffness, central haemodynamic responses, and cardiorespiratory fitness (VO2peak) in those with prediabetes (n = 35, 16 Control, 19 Exercise) and NG (n = 37, 17 Control, 20 Exercise) were analysed at baseline and after the 12-week intervention. RESULTS: At baseline, compared with NG those with prediabetes demonstrated reduced VO2peak, angiogenic CD31+CD8+ T cells and VEGFR2+CD4+ T cells, and increased systolic blood pressure. CD31+ T cells were negatively correlated with cardiovascular disease (CVD) risk. Compared with Control, exercise training increased muscle strength, VO2peak, and CD31+CD4+ and CD31+CD8+ T cells in NG and prediabetes. CONCLUSIONS: Circulating angiogenic CD31+ T cells are decreased in people with prediabetes and are enhanced with exercise training. Exercise increases CD31+ T cells, and through this mechanism it is proposed that it may reduce CVD risk. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry number: ACTRN12617000552381.

Effect of high-intensity interval training and moderate-intensity continuous training on blood lactate clearance after high-intensity test in adult men.

This study compared the effects of High-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on blood lactate clearance. 21 adult males were equally and randomly assigned to the HIIT and MICT groups, and completed 8 weeks of training. Before the training intervention, after 4 weeks and 8 weeks of training, all subjects were tested for blood lactate levels between 0 and 55 min after the same high-intensity test. The results show that after 8 weeks, blood lactate levels were significantly lower than pre-tests in both the HIIT and MICT groups at "0-55 min" after high-intensity test (p < 0.05), and the blood lactate clearance percentage at15-min and 30-min in both groups were significantly higher than the pre-tests (P < 0.01). The blood lactate levels in the HIIT group were significantly lower than those in the MICT group at 15 min and 30 min after test (P < 0.05), and the blood lactate clearance percentage at 30 min in the HIIT group was significantly higher than those in the MICT group (P < 0.05). In conclusion, both HIIT and MICT enhance blood lactate clearance in adult males post high-intensity test, with HIIT demonstrating superior effectiveness, making it a viable alternative to MICT.

Exercise and brain health in patients with coronary artery disease: study protocol for the HEART-BRAIN randomized controlled trial.

Introduction: Patients with coronary artery disease (CAD) have a higher risk of developing cognitive impairment and mental health disorders compared to the general population. Physical exercise might improve their brain health. The overall goal of the HEART-BRAIN randomized controlled trial (RCT) is to investigate the effects of different types of exercise on brain health outcomes in patients with CAD, and the underlying mechanisms. Methods: This three-arm, single-blinded RCT will include 90 patients with CAD (50-75 years). Participants will be randomized into: (1) control group-usual care (n = 30), (2) aerobic high-intensity interval training (HIIT) (n = 30), or (3) HIIT combined with resistance exercise training (n = 30). The 12-week intervention includes 3 supervised sessions (45-min each) per week for the exercise groups. Outcomes will be assessed at baseline and post-intervention. The primary outcome is to determine changes in cerebral blood flow assessed by magnetic resonance imaging. Secondary outcomes include changes in brain vascularization, cognitive measures (i.e., general cognition, executive function and episodic memory), and cardiorespiratory fitness. Additional health-related outcomes, and several potential mediators and moderators will be investigated (i.e., brain structure and function, cardiovascular and brain-based biomarkers, hemodynamics, physical function, body composition, mental health, and lifestyle behavior). Conclusion: The HEART-BRAIN RCT will provide novel insights on how exercise can impact brain health in patients with CAD and the potential mechanisms explaining the heart-brain connection, such as changes in cerebral blood flow. The results may have important clinical implications by increasing the evidence on the effectiveness of exercise-based strategies to delay cognitive decline in this high-risk population. Clinical trial registration: ClinicalTrials.gov, identifier [NCT06214624].

Exercise induced hypoalgesia after a high intensity functional training: a randomized controlled crossover study.

BACKGROUND: Acute physical activity often induces an acute reduction in pain sensitivity known as exercise induced hypoalgesia (EIH). The aim of this study was to investigate the effects of a high intensity functional training (HIFT) on EIH compared to a control session. METHODS: 50 (age: 26.0 ± 2.7; 23 female) participants successfully conducted this study consisting of a pre-experimental test as well as a 12-minute HIFT (body-weight exercises) and a 12-minute control (supervised breathing) session in a randomized crossover design. Pre and post, pressure pain thresholds (PPT) were measured at the ankles, knees, elbows, and forehead. RESULTS: The HIFT resulted in a relative maximum and average heart rate of 96.2% (± 3.6%) and 91.1% (± 4.2%), respectively, and maximum and average RPE values of 19.1 (± 1.2) and 16.2 (± 1.4), respectively. Results reveal a significant 'Intervention' × 'Time point' interaction (p < 0.001) for PPT (pooled for one average value) with hypoalgesia observed following the HIFT (p < 0.001; pre: 56.0 ± 16.8, post: 61.6 ± 19.0 [Newton]) and no change following the control (p = 0.067; pre: 56.6 ± 18.4, post: 55.3 ± 18.9 [Newton]). Further, a significant 'Time' × 'Intervention' × 'Landmark' interaction effect (p = 0.024) is observed and all landmarks showed significant hypoalgesia following HIFT (p < 0.01), except for the right elbow and forehead. Following control, no hypoalgesia was observed at any landmark. Analysing male and female participants separately, it was observed that EIH occured only in men. CONCLUSION: A HIFT using bodyweight exercises reduces pain sensitivity. Hence, combining strength and aerobically demanding exercises in a short but high intensity manner, as done in HIFT, can be seen as a usable tool to induce hypoalgesia. Yet, these results were observed only in male participants, necessitating future sex-specific research. TRIAL REGISTRATION: DRKS00034391, retrospectively registered on the 4th of June 2024.

Protein Supplementation Increases Adaptations to Low-Volume, Intra-Session Concurrent Training in Untrained Healthy Adults: A Double-Blind, Placebo-Controlled, Randomized Trial.

Combined endurance and resistance training, also known as "concurrent training", is a common practice in exercise routines. While concurrent training offers the benefit of targeting both cardiovascular and muscular fitness, it imposes greater physiological demands on the body compared to performing each modality in isolation. Increased protein consumption has been suggested to support adaptations to concurrent training. However, the impact of protein supplementation on responses to low-volume concurrent training is still unclear. Forty-four untrained, healthy individuals (27 ± 6 years) performed two sessions/week of low-volume high-intensity interval training on cycle ergometers followed by five machine-based resistance training exercises for 8 weeks. Volunteers randomly received (double-blinded) 40 g of whey-based protein (PRO group) or an isocaloric placebo (maltodextrin, PLA group) after each session. Maximal oxygen consumption (VO2max) and overall fitness scores (computed from volunteers' VO2max and one-repetition maximum scores, 1-RM) significantly increased in both groups. The PRO group showed significantly improved 1-RM in all major muscle groups, while the PLA group only improved 1-RM in chest and upper back muscles. Improvements in 1-RM in leg muscles were significantly greater in the PRO group versus the PLA group. In conclusion, our results indicate that adaptations to low-volume concurrent training, particularly leg muscle strength, can be improved with targeted post-exercise protein supplementation in untrained healthy individuals.

Comparative efficacy of neuromodulation and structured exercise program on pain and muscle oxygenation in fibromyalgia patients: a randomized crossover study.

Introduction: This study investigates the comparative efficacy of neuromodulation therapy using the EXOPULSE Mollii Suit and a structured exercise program in pain modulation and muscle oxygenation in Fibromyalgia patients. Methods: A randomized, crossover, longitudinal, and experimental study design was employed, involving 10 female Fibromyalgia patients. Participants were subjected to two distinct treatment modalities: neuromodulation therapy with the EXOPULSE Mollii Suit and a strength-based High-Intensity Interval Training (HIIT) exercise program, each conducted over 16 sessions. Outcome measures included pain severity, assessed using the Numeric Rating Scale (NRS), and muscle oxygenation variables measured via Near-Infrared Spectroscopy (NIRS). Results: Both interventions demonstrated significant reductions in NRS scores and improvements in muscle oxygenation. However, the exercise program yielded more pronounced long term basal adaptations in muscle oxygenation compared to the neuromodulation therapy. Discussion: The findings underscore the potential of integrating non-pharmacological treatments, particularly structured exercise programs, in managing Fibromyalgia. While neuromodulation therapy presents a viable alternative, the exercise regimen's capacity to induce basal muscle oxygenation adaptations suggests its superiority in addressing the complex symptoms of Fibromyalgia. Furthermore, these therapeutic approaches may enhance patients' vocational values and employability opportunities by improving their functional capabilities and overall quality of life.

The Impact of Low-Volume High-Intensity Interval Training (LV-HIIT) on Fatty Liver Index (FLI) and Estimated Glomerular Filtration Rate (eGFR) in Patients with Type 2 Diabetes Mellitus (T2DM).

BACKGROUND: Prevention and reduction of liver fat accumulation and maintenance of Glomerular Filtration Rate (GFR) have been proposed as important therapeutic goals in patients with Type 2 Diabetes Mellitus (T2DM). AIM: This study aimed to determine the effect of Low-Volume High-Intensity Interval Training (LV-HIIT) on fatty liver index (FLI) and GFR estimation in patients with T2DM. METHODS: This randomized controlled trial included 80 patients with T2DM and a sedentary lifestyle, randomly divided into HIIT (n=40) and a control group (n=40). Patients with a history of T2DM for at least one year and HbA1C levels between 6.4% and 10% were selected. The intervention group underwent a 4-week LV-HIIT course, comprising 3 sessions per week, while the control group did not receive any intervention. FLI, eGFR, anthropometric measurements, and laboratory variables were assessed in all participants before and after the intervention. RESULTS: FLI (62.0 at baseline, 53.0 at follow-up) significantly decreased in the LV-HIIT group after the intervention, while eGFR (71.0 at baseline, 73.6 at follow-up) significantly increased (P<0.001). However, the control group showed a significant reduction only in Fasting Blood Sugar (FBS) (P<0.05). After the intervention, the LV-HIIT group had significantly lower FBS (129.0 at baseline, 121.0 at follow-up), Alanine Aminotransferase (ALT) (24.0 at baseline, 18.0 at follow-up), and Gamma-Glutamyl Transferase (GGT) (22.0 at baseline, 19.0 at follow-up), as well as higher eGFR, compared to the control group (P<0.05). CONCLUSIONS: LV-HIIT exercise appears to be a promising and effective training method for improving FLI and eGFR in patients diagnosed with T2DM.

Inflammatory markers and noncoding-RNAs responses to low and high compressions of HIIT with or without berberine supplementation in middle-aged men with prediabetes.

This study compared the capacity of two different models of HIIT [high-(HC) and low-(LC) compression], with or without the use of berberine (BBR), on NOD-like receptor pyrin domain-containing protein-3 (NLRP3), H19, interleukin (IL)-1ß, high-sensitivity C-reactive protein (hs-CRP), and insulin resistance markers. Fifty-four middle-aged men with overweight or obesity and prediabetes [fasting blood glucose (FBG) 110-180 mg/dL] were randomly and equally assigned to the HC, LC, HC + BBR, LC + BBR, BBR, and non-exercising control (CON) groups. The HC (2:1 work-to-rest) and LC (1:1 work-to-rest) home-based training programs included 2-4 sets of 8 exercises at 80%-95% HRmax, twice a week for 8 weeks. Participants in the berberine groups received approximately 1000 mg daily. All exercise interventions led to a significant reduction in hs-CRP, IL-1ß, insulin, FBG, and insulin resistance index (HOMA-IR) versus CON. Notably, there was a significant reduction in FBG and HOMA-IR with the BBR group compared to the baseline. Both NLRP3 and H19 experienced a significant drop only with LC in comparison to the baseline. While both exercise protocols were beneficial overall, LC uniquely exhibited more anti-inflammatory effects, as indicated by reductions in H19 and NLRP3. However, the addition of berberine to the exercise programs did not demonstrate additional benefits.

Effectiveness of high intensity and sprint interval training on metabolic biomarkers, body composition, and physical fitness in adolescents: randomized controlled trial.

Objective: The aim of this study was to evaluate the effect of HIIT and SIT programmes on body composition, blood pressure, lipid profile, glucose, cardiorespiratory fitness, and strength of adolescents and to compare the effect between those different protocols. Methods: Sixty adolescents were recruited from a high school and were randomly placed into three groups. SIT and HIIT undertook a training for 8 weeks, twice a week, for 12 min per session, during their Physical Education lessons. SIT group performed 6 sets of 60 s of work (90-95%HRmax) / 60 s of rest (50-55%HRmax), and HIIT group performed 3 sets of 2 min of work (80-85%HRmax) / 2 min of rest (50-55%HRmax). Results: After adjustment by sex, both experimental groups exhibited a significant reduction in fat mass (p < 0.01), and trunk fat mass (p < 0.01), as well as a significant increase in lean mass (p = 0.01; <0.01), hand-grip strength (p < 0.01) and standing long jump (p = 0.05-0.04, respectively). In addition, HIIT showed a significant (p < 0.05) improvement in blood pressure, diastolic blood pressure, heart rate and VO2max, and a tendency toward a significant reduction in low density lipoprotein. Conclusion: The implementation of a HIIT protocol within high school Physical Education sessions, maintained for 8 weeks, at a rate of 3 sets of 2 min of work (80-85% RHR)/2 min of rest (50-55% RHR) generated adaptations such as improved fitness condition, changes in body composition, and improvements in blood parameters and blood pressure. However, the group of adolescents who performed SIT, shorter but more intense sets, did not experience as many benefits.

Exercise-activated hepatic autophagy combined with silymarin is associated with suppression of apoptosis in rats subjected to dexamethasone induced- fatty liver damage.

AIM: There is a need for effective treatments for non-alcoholic fatty liver disease (NAFLD) that are economically inexpensive, and have few side effects. The present study aimed to investigate exercise training and silymarin on hepatocyte death factors in rats with liver damage. METHODS: Forty-nine male Wistar rats were assigned to seven groups: sedentary control, fatty liver control (DEX), fatty liver + high-intensity interval training (HIIT), fatty liver + HIIT + silymarin (HIIT + SILY), fatty liver + continuous training (CT), fatty liver + CT + silymarin (CT + SILY), and fatty liver + silymarin (SILY). A subcutaneous injection of dexamethasone for 7 days was used to induce fatty liver in rats. Masson's trichrome and hematoxylin-eosin staining were done to evaluate hepatic injury. The hepatocyte apoptosis was determined by TUNEL assay. Real-Time PCR was conducted to evaluate the gene expressions of caspase-9, adenosine monophosphate-activated protein kinase (AMPKα1), mitofusin 2 (Mfn2), and damage-regulated autophagy modulator (DRAM). Liver tissue changes and serum levels of liver enzymes were also evaluated. RESULTS: Liver apoptosis was decreased in the CT, HIIT, HIIT + SILY and CT + SILY groups compared to the DEX group. Both continuous and high-intensity training models produced beneficial alterations in liver morphology and hepatic injuries that were significant in exercise training + silymarin group. This impact was accompanied by increased AMPKα1 and DRAM gene expression and decreased caspase-9 and Mfn2 gene expression. Liver enzyme levels were high in the DEX group and treatment with silymarin significantly reduced it. CONCLUSION: Silymarin supplementation combined with interval or continuous training substantially improves DEX-induced hepatic steatosis and hepatocyte injury mostly through suppressing liver apoptosis and upregulating autophagy, which may provide a novel perspective for NAFLD treatment.

Effects of different HIIT protocols on exercise performance, metabolic adaptation, and fat loss in middle-aged and older adults with overweight.

Introduction: There is evidence that aging and obesity are associated with increased oxidative stress and chronic inflammation. High-intensity interval training (HIIT) may be superior to moderate-intensity continuous training (MICT) in anti-inflammatory and anti-obesity benefits. Therefore, the objective of this study is to determine which HIIT prescriptions will be more effective in reducing fat accumulation, inflammation, and improving metabolic adaptation and exercise performance in middle-aged and older overweight adults. Methods: Thirty-six middle-aged with overweight adults were divided into one of three groups: 1. L-HIIT group: the long-interval HIIT group (4 × 4 min Exercise/4 min Rest), 2. M-HIIT group: the medium-interval HIIT group (8 × 2 min Exercise/2 min Rest), 3. Control group: no exercise training intervention. All groups underwent the training stage for eight weeks (three sessions per week), followed by a detraining stage of four weeks in order to investigate the effects induced by different HIIT interventions on inflammation, metabolic adaptation, anti-fatigue and exercise performance, and fat loss Results: There was a significant physiological response in the change rate of heart rate (HR) after an acute L-HIIT session compared with an acute M-HIIT session (ΔHR: ↑49.66±16.09% vs ↑33.22±14.37%, p=0.02); furthermore, systolic blood pressure (SBP) and diastolic blood pressure (DBP) decreased significantly following a single L-HIIT session. After an eight-week training stage, the L-HIIT and M-HIIT groups exhibited a significant increase in aerobic capacity (ΔVO2peak), with values of +27.93±16.79% (p<0.001) and +18.39±8.12% (p<0.001), respectively, in comparison to the control group. Furthermore, in the L-HIIT group, the anaerobic power of relative mean power (RMP) exhibited a significant increase (p=0.019). However, following a four-week detraining stage, the adiponectin concentration remained 1.78 times higher in the L-HIIT group than in the control group (p=0.033). The results of blood sugar, blood lipids, body composition, and inflammatory markers did not indicate any improved it did not indicate any improvements from the two different HIIT protocols. Conclusions: The results indicate that an eight-week L-HIIT or M-HIIT intervention (three sessions per week, 32 minutes per session) may be an effective approach for improving aerobic capacity. It can be posited that L-HIIT may be a more advantageous mode than M-HIIT for enhancing anaerobic power, adipokine levels, and improving blood pressure in an aged and overweight population due to the induced physiological responses.

Effects of volume-matched once-weekly and thrice-weekly high-intensity interval training (HIIT) on body adiposity in adults with central obesity: Study protocol for a randomized controlled trial.

Objective: This study aims to examine the comparative effects of 75 min of volume-matched once-weekly and thrice-weekly high-intensity interval training (HIIT) on body adiposity in adults with central obesity. Methods: This assessor-blinded, three-arm, randomized controlled trial will recruit 315 physically inactive adults with central obesity (aged ≥18 years, body mass index ≥23, waist circumference ≥90 cm for men and ≥80 cm for women). Participants will be randomly allocated to the once-weekly HIIT, thrice-weekly HIIT or usual care control group. Participants in the HIIT groups will receive weekly exercise training sessions for 16 weeks, prescribed either once or three times weekly. Each HIIT session will consist of a supervised program of four 4-min high-intensity intervals at 85%-95% peak heart rate (HRpeak) interspersed with 3-min active recovery intervals at 50%-70% HRpeak. Participants in the once-weekly HIIT group will perform the 25-min HIIT bout three times with a break between each 25-min HIIT bout. The usual care control group will receive bi-weekly health education classes. The outcome assessments will be conducted at baseline, 16 weeks (post-intervention) and 32 weeks (follow-up). The primary outcome will be total body adiposity assessed by dual-energy X-ray absorptiometry (DXA). The secondary outcome measures will include markers of cardiovascular and metabolic health (body composition, cardiorespiratory fitness, blood pressure, and blood lipids), mental health, cognitive performance, health-related quality of life, sleep quality, habitual physical activity, diet, medication, adverse events and adherence to the intervention. Impact of the project: The findings from this study are expected to consolidate the therapeutic efficacy of HIIT for the management of central obesity and inform the comparative compliance, feasibility and suitability of once-weekly and thrice-weekly HIIT as exercise strategies to manage obesity. In particular, the present study is expected to provide a novel perspective on the utility of low-frequency HIIT (i.e., once-weekly) as an effective and sustainable exercise strategy to tackle the obesity pandemic. The anticipated findings will hold substantial translational value by informing public health policies and enhancing exercise compliance in the physically inactive obese population. Trial registration: ClinicalTrials.gov (NCT04887454).