High-intensity Interval Training Group Research Articles

The effects of 8 weeks of sprint interval training on repeated sprinting and specialized ability in college volleyball players.

This study aimed to investigate the effects of 8 weeks of sprint interval training (SIT) on repeated sprinting ability and specialized performance in collegiate volleyball players. Twenty-eight male collegiate volleyball players were randomly assigned to sprint interval training (SIT, n = 14) or high-intensity interval training (HIIT, n = 14) groups. The SIT group performed all-out sprints (6 × 30m with 30s rest) twice weekly in addition to regular volleyball training, while the HIIT group underwent high-intensity interval training alongside identical regular volleyball training. Repeated sprint ability (ideal sprint time IS, total sprint time TS, and performance decrement PD), aerobic capacity (VO₂max, velocity at VO₂max [vVO₂max], ventilatory thresholds VT1 and VT2), and volleyball-specific abilities (modified agility T-test, countermovement vertical jump [CMVJ], and spike jump [SPJ]) were assessed before and after the intervention. Following the intervention, the SIT group showed significantly greater improvements than the HIIT group in VO₂max (46.93 ± 4.25 vs 50.90 ± 4.17 ml/min/kg, p < 0.001), vVO₂max (14.53 ± 1.61 vs 17.03 ± 1.15 km/h, p < 0.001), VT1 (69.61 ± 4.22% vs 74.43 ± 5.25%, p < 0.001), modified agility T-test (7.85 ± 1.04 vs 6.87 ± 0.71s, p < 0.001), CMVJ (35.77 ± 3.91 vs 40.14 ± 2.82 cm, p < 0.001), and SPJ (61.20 ± 3.92 vs 65.57 ± 2.64 cm, p < 0.001). Both groups demonstrated significant improvements in IS and TS (p < 0.05), with larger effect sizes observed in the SIT group (IS: 1.060 vs 0.581; TS: 1.164 vs 0.678). No significant between-group differences were found in PD and VT2. Eight weeks of sprint interval training effectively enhances repeated sprinting ability, aerobic capacity, and specialized skills in collegiate volleyball players, with particularly notable improvements in vertical jumping ability and agility. These findings suggest that SIT represents an effective and time-efficient training method for improving volleyball performance.

Home‐Based High‐Intensity Interval Training for People With Parkinson's: A Randomized, Controlled, Feasibility Trial

ABSTRACTBackground and AimsHome‐based high‐intensity interval training (HIIT) could be feasible and useful for people with Parkinson's (PwP). However, no home‐based HIIT program for PwP has been undertaken. This trial was designed to obtain preliminary data regarding the feasibility, acceptability and safety of HIIT‐Home4Parkinson's (HH4P), a previously co‐created home‐based HIIT program for PwP, explore outcomes that may be sensitive to change, and inform the implementation of a potential full trial.MethodsA randomized, controlled feasibility trial was undertaken. Thirteen independently mobile PwP of Hoehn and Yahr stages 1–3 were randomized to the 12‐week, three times weekly HH4P HIIT program (n = 7), or usual care (n = 6). Feasibility and safety outcomes included aspects such as program completion, adherence, exercise intensity and adverse effects and events. Potential primary outcomes for a full trial were serum brain‐derived neurotrophic factor, maximal oxygen uptake and the Unified Parkinson's Disease Rating Scale part III. Process evaluation with a qualitative aspect explored implementation fidelity and participant thoughts and feelings.ResultsSix HIIT participants completed the program, with one withdrawing due to an unrelated back injury. Mean exercise adherence was 78.4%, while the mean exercise intensity was 77.2% HRmax per session, with three participants not achieving mean 75% HRmax. HIIT related adverse effects were minor and temporary, and the majority of exercise program and delivery procedures were deemed feasible and acceptable by participants. When compared to controls, the HIIT group did not experience benefits in any of the potential primary outcomes.ConclusionPreliminary data suggests that home‐based HIIT could be feasible, safe and acceptable for some PwP, although the capacity to stimulate the required exercise intensity, along with the potential benefits remain uncertain. Progression to a full HH4P trial cannot be recommended until further evaluation of aspects such as exercise type and model of support is undertaken.Trial RegistrationClinicalTrials.gov NCT05485428.

Effects of Therapeutic Ultrasound and Aussie Current With High-Intensity Interval Training on Abdominal Adiposity in Young Adults With Overweight and Obesity: Protocol for a Randomized Controlled Trial.

More than half of the world's population will be overweight or obese by 2035, and it is known that physical exercise, such as high-intensity interval training (HIIT), is a tool for controlling obesity by improving body composition and the metabolic profile. Noninvasive techniques such as therapeutic ultrasound (TUS) and the Aussie current have shown potential in controlling adipose tissue, but their effects combined with HIIT remain unknown. TUS may be combined with the Aussie current to potentiate the specific effects of each intervention, such as lipolysis induced by TUS and lymphatic activation promoted by the Aussie current. The integration of HIIT into this protocol is justified by its ability to stimulate β-oxidation and facilitate the metabolic use of fatty acids mobilized by the electrophysical resources. Furthermore, the use of HIIT as opposed to moderate-intensity continuous training contributes to reducing the total duration of the intervention. This study aims to evaluate the effects of TUS+Aussie current combined with HIIT on body composition, serum metabolic profile, and cardiovascular autonomic modulation (CAM) in individuals with overweight and obesity. This is a randomized, double-blind (researcher and outcome assessor) clinical study. The participants will be randomized into 3 groups: active TUS+Aussie current with HIIT group, placebo for TUS+Aussie current with HIIT group, and TUS+Aussie current-only group. All participants will undergo nutritional monitoring 30 days before the proposed interventions to adjust macronutrients, optimize energy intake, and improve diet quality. Primary outcomes include changes in subcutaneous adipose tissue thickness, body composition, and serum metabolic profile. Secondary outcomes assess perceived stress, body image, blood biochemistry, sleep quality, and CAM. Data analysis involves linear mixed models estimated using the maximum likelihood method with an appropriate covariance matrix structure. A total of 60 participants will be recruited and randomized between February 2024 and June 2025. The baseline assessments and intervention are scheduled to be completed in August 2025, and data collection will be completed by the end of September 2025. Data acquisition is still ongoing; therefore, data analysis has not yet been carried out. This is the first study to combine TUS+Aussie current with HIIT, potentially integrating the effects of lipolysis and fat oxidation and possible changes in the serum metabolic profile and CAM. The results could optimize treatment duration, promote changes in lipid profile, and maintain cardiovascular health in people with overweight and obesity. Brazilian Registry of Clinical Trials RBR-4xh6232, Universal Trial Number: U1111-1287-2345; https://ensaiosclinicos.gov.br/rg/RBR-4xh6232. DERR1-10.2196/71829.

Multidomain Connectivity as a Marker of HIIT-Induced Adaptation in Elite Youth Soccer Players: A Correlational Mapping Approach

This study investigated the effects of high-intensity interval training (HIIT) in elite youth soccer players using a novel multidomain correlational mapping approach. A four-week HIIT intervention was applied in a randomized controlled design, with physiological, cognitive, and neuromuscular data collected through laboratory, field-based, and biochemical tests. Metrics such as VO2max, BDNF levels, lactate dynamics, and cognitive load were analyzed across time points and groups. HIIT elicited statistically significant improvements in aerobic capacity, buffering efficiency, and perceptual-cognitive function, with a notable emergence of cross-domain associations. Unlike the control group, HIIT participants showed strengthened correlations between metabolic, cognitive, and neuromuscular indices, such as lactate slope with exertion perception and BDNF response with cardiac recovery. Hierarchical clustering further revealed tightly integrated multidomain clusters in the HIIT group, absent in the controls, suggesting a reorganization of physiological networks. These findings support the concept that HIIT not only improves discrete capacities but fosters systemic adaptation through enhanced inter-domain coordination. These results align with emerging frameworks in network physiology and highlight the potential for using correlation structures as biomarkers of holistic training adaptation. This multidimensional perspective offers new insights into how targeted training reshapes performance-related systems and may inform individualized athletic programming.

The Effects of Different Types of Exercise on Pulmonary Inflammation and Fibrosis in Mice with Type 2 Diabetes Mellitus.

Background: Diabetic lung disease, characterized by inflammation and fibrosis, is an emerging chronic complication of type 2 diabetes mellitus (T2DM). However, systematic studies on the effects of exercise interventions remain limited. This study aimed to investigate the impact of different exercise types (swimming, resistance training, and high-intensity interval training [HIIT]) on pulmonary inflammation and fibrosis in T2DM mice, and to explore underlying molecular mechanisms. Methods: A T2DM mouse model was established by a high-fat diet (HFD) combined with streptozotocin (STZ) induction. Mice were randomly divided into sedentary control, swimming, resistance training, and HIIT groups, and underwent 8 weeks of exercise intervention. After the intervention, body composition was assessed. Lung histopathological changes were evaluated by hematoxylin&eosin (HE) and Masson staining. Inflammatory cytokines, fibrosis markers, and the expression of the TGF-β1/Smad signaling pathway were detected. Macrophage infiltration and polarization were also analyzed. Results: Exercise intervention improved body composition and reduced oxidative stress in T2DM mice. All three exercise modalities downregulated inflammatory cytokine expression, inhibited macrophage activation and M1 polarization, and promoted M2 polarization. Additionally, exercise improved lung tissue structure, reduced collagen deposition, and decreased the expression of fibrosis-related markers. Furthermore, anti-fibrotic effects were mediated by suppression of the TGF-β1/Smad signaling pathway and inhibition of epithelial-mesenchymal transition (EMT). Among the interventions, HIIT demonstrated the strongest inhibitory effect on the TGF-β1/Smad pathway, while swimming showed the most significant anti-inflammatory benefits. Conclusions: Different types of exercise effectively alleviate pulmonary inflammation and fibrosis in T2DM mice. These effects are closely related to the inhibition of oxidative stress, regulation of macrophage polarization, and suppression of TGF-β1/Smad signaling activation, with swimming and HIIT demonstrating superior protective benefits.

High intensity interval training and selenium nanoparticles protect hippocampal neurons and enhance cognitive function in diabetic rats

Cognitive decline is a common complication of diabetes, and is inadequately addressed by current treatments. This study examined the effects of selenium nanoparticles (SeNPs) and high-intensity interval training (HIIT) on cognitive function and neuroprotection in diabetic rats. Male Wistar rats (n = 31) were induced with diabetes and assigned to five groups entered into 8 weeks intervention: control (CO), control which receive placebo (PCO), SeNPs treatment (0.1 mg/kg) (SeNPs), HIIT (HIIT), and combined SeNPs with HIIT (SeNPs + HIIT). Cognitive function was assessed using the Morris water maze test. Hippocampal tissues were analysed for cell viability, gene expression of BDNF, GLUT4, and Irisin receptor, as well as serum protein levels of Irisin and hippocampal BDNF protein level. Results showed that all treatment groups had a significant effect on learning, memory, cell viability, GLUT4, BDNF and irisin (P < 0.03). Serum Irisin was higher in HIIT and SeNPs + HIIT groups (P < 0.0001), also SeNPs and SeNPs + HIIT groups showed increased GLUT4 expression (P < 0.03). SeNPs + HIIT groups had the significant effect on BDNF both gene and protein compared to the all control (CO, PCO) groups (P < 0.01). These findings suggest that combining SeNPs and HIIT may mitigate cognitive decline and promote neuroprotection in diabetes via modulation of Irisin and BDNF pathways and improved glucose metabolism. While synergy is suggested, mechanistic confirmation requires further study. Translational potential exists, but clinical validation is needed due to species differences. Limitations include unmonitored confounders, sample size, and lack of mechanistic validation, highlighting the need for future research.

The impact of acute morning versus evening high-intensity interval training on circulating irisin levels and metabolic parameters in overweight postmenopausal women.

The impact of acute morning versus evening high-intensity interval training on circulating irisin levels and metabolic parameters in overweight postmenopausal women.

Feasibility and effects of high-intensity interval training in older adults with mild to moderate depressive symptoms: A pilot cluster-randomized controlled trial.

Feasibility and effects of high-intensity interval training in older adults with mild to moderate depressive symptoms: A pilot cluster-randomized controlled trial.

Changes in insulin, leptin, resistin and irisin levels and their associations with blood pressure after an 8-week supervised, online “HIIT Mama” program vs. self-performed moderate-to-vigorous physical activity during pregnancy – A randomized controlled trial

We aimed to determine changes in insulin, leptin, resistin, and irisin levels and their associations with blood pressure (BP) during pregnancy, following an 8-week high-intensity interval training (HIIT) or a self-performed moderate-to-vigorous physical activity (MVPA). The study involved 54 Caucasian women in uncomplicated, singleton pregnancy (age 32 ± 4 years, week of gestation 24 ± 4, mean ± SD). They were randomly allocated to the 8-week supervised, online “HIIT Mama” program (HIIT group, n = 34) or educational intervention and self-performed MVPA (EDU group, n = 20). All participants maintained normotension throughout the study. The HIIT program induced a statistically significant increase in insulin (p = 0.005; ES: r = 0.48; IQR: 0.005) and resistin (p &lt; 0.001; ES: r = 0.66; IQR: 1.07). The only significant change presented by the EDU group was the decrease in resistin (p = 0.037; ES: r = 0.47; IQR: 0.82). We observed a trend towards more frequent increases after the HIIT program than after the EDU intervention in insulin (76% vs. 65%, respectively) and in leptin (63% vs. 50%, respectively). There was also a trend towards a more frequent decrease in irisin in the HIIT group than in the EDU group (65% and 53%, respectively). Despite these different responses in both groups, we observed similar associations of selected biomarkers with BP after eight weeks of interventions. In both groups, higher diastolic BP was significantly correlated with higher insulin (HIIT: r = 0.51; p = 0.002 and EDU: r = 0.45; p = 0.05) and leptin (HIIT: r = 0.39; p = 0.03 and EDU: r = 0.62; p = 0.02). We observed no association of resistin and irisin with systolic or diastolic BP in either group. Both prenatal HIIT and MVPA optimize physiological and biochemical responses maintaining normotension, without negatively affecting the course of pregnancy or neonatal outcomes.

Effect of High-intensity Interval Training Combined with Pomegranate Juice Supplementation on the Granulocyte Colony-Stimulating Factor Signaling Pathway in an Animal Model of Colorectal Cancer Induced by CT26 Cell Line

Background: Low-cost and non-toxic approaches for treating colorectal cancer (CRC) have garnered significant attention from researchers in recent years. Objectives: This study aimed to investigate the effect of high-intensity interval training (HIIT) combined with pomegranate juice (PJ) consumption on the granulocyte colony-stimulating factor (G-CSF) signaling pathway in an animal model of CRC induced by the CT26 cell line. Methods: In this experimental study, 24 male BALB/c mice (weight: 18 - 22 g, age: 8 - 10 weeks) with CRC induced by injection of 5 × 105 viable CT26 cells were randomly divided into four groups: (1) CRC, (2) PJ, (3) HIIT, and (4) HIIT + PJ. Additionally, 6 healthy control (HC) mice were included to assess CRC's effects on study variables. The HIIT protocol was conducted over eight weeks, with 5 - 16 sets of high-intensity sets, at 75 - 90% maximum speed on a 15-degree incline. Pomegranate juice supplementation constituted 5% of daily drinking water. Results: The levels of G-CSFR, Janus kinase 2 (JAK2), STAT3, mitogen-activated protein kinase (MAPK), and ERK were significantly elevated in the Ca group compared to the HC group (P = 0.001). Conversely, the PJ, HIIT, and HIIT+PJ groups exhibited significantly lower levels of G-CSFR, JAK2, STAT3, MAPK, and ERK compared to the Ca group (P = 0.001). Notably, the HIIT+PJ group showed significantly reduced levels of G-CSFR (P = 0.02) and JAK2 (P = 0.001) compared to the PJ group. JAK2 levels were also significantly lower in the HIIT group compared to the PJ group (P = 0.001). Furthermore, STAT3 levels were significantly lower in the PJ and HIIT+PJ groups compared to the HIIT group (P = 0.001), with the HIIT+PJ group also showing significantly lower levels than the HIIT group (P = 0.001). Finally, MAPK and ERK levels were significantly lower in the HIIT+PJ group compared to both the PJ (P = 0.005) and HIIT (P = 0.001) groups. Conclusions: While colon cancer induction increases G-CSFR, JAK2, STAT3, MAPK, and ERK gene expression in the intestinal tissue of laboratory mice, both HIIT and PJ, independently and synergistically, can reduce the expression of these genes through similar antioxidant and anti-inflammatory pathways in the intestinal tissue of mice with colon cancer.

Effects of high-intensity interval training under hypoxic conditions on energy system performance in collegiate football players

Introduction: High-Intensity Interval Training (HIIT) is widely recognized for enhancing athletic performance. However, whether simulated hypoxic conditions amplify the physiological effects of HIIT especially in sports like football that rely on multiple energy systems, remains underexplored. Objective: To investigate whether simulated hypoxic HIIT elicits greater improvements in aerobic and anaerobic performance compared to normoxic HIIT and standard training in collegiate football players. Methodology: Twenty-four male collegiate football players were randomly assigned to three groups: Hypoxic HIIT, Normoxic HIIT, or Control. Over a four-week intervention period, the experimental groups engaged in sport-specific HIIT under their respective environmental conditions, while all participants continued standard team training. Pre- and post-training assessments included VO₂max, Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IR1), Running-Based Anaerobic Sprint Test (RAST), and 30-meter flying sprint. Results: The Hypoxic HIIT group showed significant improvements in VO₂max and Yo-Yo IR1 distance (p &lt; 0.01), with moderate gains in RAST peak power. Minimal changes were observed in ATP-PC system performance. These adaptations exceeded those observed in the Normoxic and Control groups. Discussion: The findings indicate that hypoxic stress provides an additive stimulus to aerobic conditioning. This aligns with existing literature on the role of hypoxia in enhancing oxygen transport, mitochondrial function, and endurance capacity. Conclusions: Simulated hypoxic HIIT effectively enhances aerobic capacity and selectively improves anaerobic performance. It represents a time-efficient and evidence-based conditioning strategy for competitive football.

Combined effects of sodium alginate supplementation with HIIT and MICT on CCK and PYY levels in men with metabolic syndrome.

Abdominal obesity is a prevalent characteristic of individuals with Metabolic Syndrome (MetS). Effective weight management strategies that induce satiety play a crucial role in reducing the risk of obesity and, consequently, MetS. This study aimed to investigate the impact of sodium alginate supplementation in conjunction with High-Intensity Interval Training (HIIT) and Moderate-Intensity Continuous Training (MICT) on the increment of Cholecystokinin (CCK) and Peptide YY (PYY) levels in men with MetS. Forty men with MetS volunteered for this study and were randomly assigned to one of five groups: HIIT (high-intensity interval training), HIIT + S (high-intensity interval training + sodium alginate supplementation), MICT (moderate-intensity interval training), MICT + S (moderate-intensity interval training + sodium alginate supplementation), and control (C), which received no intervention. The HIIT groups performed four bouts of four minutes at 85-95% of their Peak Heart Rate (HR peak), with three minutes of active recovery at 50-70% HR peak, three sessions per week. The MICT groups engaged in 30min of exercise at 60-70% HR peak, three sessions per week. The HIIT + S and MICT + S groups consumed 1.5g of Sigma sodium alginate solution (manufactured in the USA) dissolved in 100mg of sweet water (containing 7g of fructose) 30min before their three main meals, three days per week, for eight weeks. After eight weeks of interventions, CCK and PYY levels significantly increased in all studied groups. The HIIT + S group exhibited a significantly greater increase compared to the other groups. Additionally, the MetS Z score significantly decreased in all studied groups, with the HIIT + S group demonstrating a significantly greater decrease compared to the other groups (P < 0.05). The findings of this study indicate that both HIIT and MICT contribute to overall improvement in men with MetS. However, the combination of sodium alginate supplementation with exercise further enhances these improvements. These findings support integrating sodium alginate and exercise into MetS management to enhance satiety and improve metabolic profiles. Limitations include the short duration (8 weeks) and small sample size, which limit long-term conclusions. The trial, with the reference number IR.KUMS.REC.1398.214, underwent approval by the Research Ethics Committees of Kermanshah University of Medical Sciences. The trial was subsequently registered in the Iranian Clinical Trial Registration Center under the code IRCT20190916044788N1 on 03/12/2020.

Exercise modality-dependent mitochondrial respiratory capacity in satellite cells and conditioned serum-induced responses in cultured myotubes.

Exercise-induced mitochondrial adaptations contribute to muscle function and metabolic health. We aimed to investigate the association of moderate-intensity swimming (MOD) and high-intensity interval training (HIIT) with mitochondrial function in skeletal muscle cells treated with exercise-conditioned serum. Male ICR mice (7-8weeks old) were assigned to the Sedentary, MOD or HIIT group. The MOD group underwent five sessions of 60min. The HIIT group performed weighted high-intensity swimming intervals. This study assessed mitochondrial enzyme activity in the plantaris muscle, mitochondrial respiratory capacity in isolated satellite cells, and mitochondrial function in C2C12 myotubes treated with exercise-derived serum. Serum was obtained immediately and 24h postexercise to assess acute effects and chronic adaptations, respectively. The MOD and HIIT groups demonstrated significantly increased muscle citrate synthase and cytochrome c oxidase activities compared with the Sedentary group, but with no significant differences between the MOD and HIIT groups. Satellite cells exhibited higher basal respiration, ATP production and maximal respiratory capacity in the MOD group than in the Sedentary and HIIT groups. Acute serum notably improved maximal mitochondrial respiration in cultured C2C12 myotubes in the HIIT group, whereas serum from chronic training improved those parameters but demonstrated no modality-specific effects. MOD enhances mitochondrial respiratory function in satellite cells, probably owing to sustained aerobic metabolic signalling, whereas HIIT produces a potent but transient systemic response that acutely boosts mitochondrial function in muscle cells. The differential effects of exercise modalities emphasize the importance of timing and exercise modality in driving specific mitochondrial adaptations, thereby providing valuable insights for tailored exercise prescriptions for optimizing metabolic health.

The Correlation Between Body Mass Index and Body Fat Percentage in Menopausal Women in Padang: A Quasi-Experimental Study

&lt;div&gt;&lt;table cellspacing="0" cellpadding="0" align="left"&gt;&lt;tbody&gt;&lt;tr&gt;&lt;td align="left" valign="top"&gt;&lt;p&gt;&lt;em&gt;The global increase in overweight and obesity has become a critical public health concern, particularly among menopausal women who experience hormonal changes that contribute to increased body fat—especially in the abdominal region. High-Intensity Interval Training (HIIT) has emerged as a time-efficient alternative to conventional exercise, offering potential benefits in reducing Body Mass Index (BMI) and Body Fat Percentage (BFP). This quasi-experimental study, conducted in Padang, Indonesia, aimed to examine the correlation between BMI and BFP in menopausal women aged 50–60 years following a five-month HIIT intervention. A total of 50 obese menopausal women were selected using stratified sampling and assigned to either an experimental group (HIIT) or a control group (aerobic exercise). Pretest and posttest measurements were collected for body weight, BMI, and BFP. Statistical analyses included tests for normality and homogeneity, the Mann–Whitney U test, independent t-test, and Spearman’s rank correlation. The findings revealed significant reductions in both BMI and BFP in the HIIT group compared to the control group. A very strong positive correlation was observed between BMI and BFP (r = 0.914, p &amp;lt; 0.001), suggesting that decreases in BMI are closely linked to reductions in body fat. This study provides preliminary evidence from Indonesia supporting HIIT as an effective and time-efficient intervention for addressing obesity-related outcomes in menopausal women. Further research is warranted to investigate the underlying mechanisms and to generalize these findings to broader menopausal populations.&lt;/em&gt;&lt;em&gt;&lt;/em&gt;&lt;/p&gt;&lt;p&gt; &lt;/p&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/tbody&gt;&lt;/table&gt;&lt;/div&gt;&lt;strong&gt;&lt;em&gt;Keyword: High-Intensity Interval Training, Menopause, Body Mass Index, Body Fat Percentage, Obese Women.&lt;/em&gt;&lt;/strong&gt;

Supervised high-intensity interval training reduces the negative effect of chemotherapy on cardiorespiratory fitness in young breast cancer women: a randomised controlled study.

Younger women are diagnosed more often with aggressive breast cancer (BC) subtypes, the treatment of which usually incorporates chemotherapy. Physical training plays a significant role in mitigating the adverse effects of systemic cancer therapy, improving quality of life, and potentially enhancing treatment efficacy. High-intensity interval training (HIIT) emerged as a promising intervention to counteract the fatigue induced by chemotherapy, which in younger women often causes depression and disruption of employment. This study aimed to investigate whether supervised HIIT employed concurrently with chemotherapy impacts the cardiorespiratory fitness of young BC patients. Twenty-six young (18-40years old) BC patients scheduled for chemotherapy were randomised to intervention comprising supervised HIIT employed concurrently with chemotherapy or no supervised training (control) for 6months. Outcomes measured using cardiopulmonary exercise testing (CPET) and non-invasive cardiac output testing were cardiorespiratory fitness and cardiac output. Compared to control, employment of HIIT mitigated the decrease in relative peakVO2 from 33.630 to 29.540ml/kg/min for HIIT group and from 29.679 to 22.571ml/kg/min for control group (ANCOVA p = 0.018, ES = 0.469), and also a mitigated the decrease in exercise time from 685.600 to 666.500s for HIIT group and from 703.357 to 555.500s for control group (ANCOVA p = 0.008, ES = 0.815) measured during CPET. Supervised HIIT implemented alongside chemotherapy can mitigate the decline in cardiorespiratory fitness caused by BC chemotherapy in young patients. The study was registered in the clinicaltrials.gov registry (#NCT06190600) on 2024-01-05, retrospectively registered.

Effects of high-intensity interval training on executive functions and IGF-1 levels in sedentary young women: a randomized controlled trial.

Sedentary behavior and physical inactivity are widespread among university students, negatively impacting physical and neurocognitive health. Executive functions and insulin-like growth factor 1 (IGF-1) are adversely affected by inactivity. Moreover, physical activity increases IGF-1 concentrations, which may mediate beneficial effects on brain health and cognitive performance. The effect of HIIT exercise combined with increased physical activity on these variables is not well understood. This study evaluated the chronic effects of HIIT, with or without increased physical activity, over 12 weeks of training and a 12-week follow-up period, on executive functions and IGF-1 concentrations in sedentary young university students. This randomized controlled trial included 77 sedentary female university students, assigned to three groups: HIIT (n = 25), HIIT plus increased daily physical activity (HIIT + PA, n = 25), and control group (CG, n = 27). The intervention involved assessments at baseline (T1), post-intervention (T2), and after a 12-week follow-up (T3). Salivary IGF-1 concentrations were measured using enzyme-linked immunosorbent assay (ELISA). Executive functions were evaluated with the Stroop Test, Wisconsin Card Sorting Test, and Digit Span Test. The HIIT protocol consisted of 40-min sessions, three times per week, delivered online. The HIIT + PA group also aimed to complete 10,000 steps per day. No statistically significant changes in IGF-1 concentrations were found over time or between groups, although descriptive increases were observed in both HIIT and HIIT + PA groups at follow-up. For executive functions, improvements over time were found in cognitive flexibility (WCST) and working memory (DST-B and DST-T), but without significant group × time interactions. Only WCST-E-P showed a significant group effect (p = 0.028), indicating possible differences between groups in cognitive rigidity. The HIIT + PA group showed a tendency toward improved inhibitory control (Stroop accuracy), although this was not supported by significant interaction effects. Working memory improvements (DST-B) were significant over time, especially in the HIIT group, but again without significant differences between groups. A 12-week HIIT program, with or without increased daily physical activity, can lead to improvements in executive functions in sedentary young women, particularly in working memory and cognitive flexibility. However, these changes were not exclusive to the intervention groups, suggesting possible contributions from repeated testing or other external factors. While IGF-1 levels showed upward trends, no significant group-level effects were confirmed. These findings highlight the potential cognitive benefits of HIIT but emphasize the need for further research with tighter controls and objective neurobiological measures to clarify the mechanisms involved. Incorporating HIIT into student routines may support cognitive health, but broader lifestyle interventions may be needed to sustain long-term benefits.

Perbedaan Pengaruh Dosis High Intensity Interval Training 1 Kali Seminggu dengan 2 Kali Seminggu terhadap Peningkatan Vo2 Max pada Mahasiswa

Background: Cardiovascular fitness is a crucial aspect of student health, especially after the COVID-19 pandemic, which led to reduced physical activity. One proven method to enhance cardiovascular fitness is High-Intensity Interval Training (HIIT). However, there are differing opinions regarding the minimal HIIT dosage required to improve VO2 max. Objectives: This study aims to compare the effects of performing HIIT once a week versus twice a week on increasing VO2 max in students. Methods: This study employed a two-group pre-test and post-test design with a sample of 30 students who were randomly assigned into two groups. The first group performed HIIT once per week, while the second group performed HIIT twice per week for three consecutive weeks. VO2 max was measured before and after the intervention using the Beep Test. Results: The findings revealed that both groups experienced an increase in VO2 max after the intervention. In the once-per-week HIIT group, the average VO2 max increased from 32.60 ± 1.54 mL/kg/min to 32.75 ± 1.58 mL/kg/min, but the increase was not statistically significant (p &gt; 0.05). In contrast, the twice-per-week HIIT group showed a more significant increase, from 31.58 ± 0.75 mL/kg/min to 32.16 ± 0.84 mL/kg/min (p &lt; 0.05). Conclusion: Performing HIIT twice a week is more effective in improving VO2 max than performing it once a week. Keywords: High-Intensity Interval Training, VO2 max, cardiovascular fitness, students.

Comparison of the Effects of LISS (Low-Intensity Steady State) and HIIT (High-Intensity Interval Training) on Cardiovascular Adaptation

Introduction. Aerobic exercise plays an important role in improving cardiovascular fitness, but each training method has different effectiveness. This study aims to compare the effects of Low-Intensity Steady State (LISS) and High-Intensity Interval Training (HIIT) on cardiovascular adaptation in students from the Department of Physical Education, Health, and Recreation, Universitas Negeri Makassar (UNM). Methods. This study used an experimental method with a pre-test and post-test control group design. A total of 54 students were divided into two groups. The first group underwent LISS training with an intensity of 50-60% of maximum heart rate (HRmax) for 40 minutes per session, while the second group underwent HIIT with an intensity interval of 85-95% HRmax for 20 minutes per session, each performed 4 times per week for 6 weeks. The cardiovascular parameters measured included VO₂ max, resting heart rate, and systolic and diastolic blood pressure. Results. The results showed that both training methods provided a significant increase in VO₂ max and a decrease in resting heart rate (p &lt; 0.05). However, the HIIT group experienced a greater increase in VO₂ max compared to the LISS group (p &lt; 0.05), while the LISS and HIIT pressure reduction variables were significantly able to reduce systolic and diastolic blood pressure, indicating similar benefits in terms of blood pressure control. Conclusion. The conclusion of this study is that HIIT is more effective in increasing cardiovascular adaptation, more effective in heart performance or decreasing heart rate and both are effective in reducing systolic and diastolic blood pressure.

Impact of physical activity vs high-intensity interval training on autonomic nervous system in young sedentary adults – a pilot study

Objective. This study aimed to evaluate the impact of physical activity versus high-intensity interval training (HIIT) on the cardiac autonomic nervous system in young sedentary adults. Method. This randomized pilot study included sedentary adults aged 18 to 40 years, with less than 600 METs in IPAQ and moderate to severe stress on the Perceived Stress Scale. Twenty-eight participants were randomized into three groups: control, HIIT, and physical activity. The HIIT group underwent 30:30 sec circuit training, while the physical activity group engaged in moderate to vigorous aerobic activities for 12 weeks. The control group received education on the importance of exercise. The primary outcome was cardiac autonomic neuropathy assessed using Ewing’s battery of tests, and the secondary outcome was functional capacity. Result. Significant improvement in cardiac autonomic neuropathy was observed in both the physical activity (p &lt; 0.001) and HIIT groups (p &lt; 0.001), but not in the control group (p = 0.25). Physical activity showed a tendency toward parasympathetic dominance (p = 0.0002), while HIIT showed a tendency toward sympathetic dominance (p = 0.004). Significant improvements in functional capacity were noted in the physical activity (p = 0.002), HIIT (p = 0.001), and control (p = 0.021) groups. Conclusion. Both physical activity and HIIT significantly improve the autonomic nervous system and functional capacity. However, the type of training has varying impact on the autonomic nervous system.

Clarifying the Impact of Small-Sided Games and HIIT on Anaerobic Endurance in Adolescent Hockey Players

Background. Given the sport’s complex aerobic-anaerobic demands, optimizing training methodologies is crucial for improving players’ repeated sprint ability, sustaining effort throughout matches, and enhancing overall performance. While hockey requires significant anaerobic power for explosive movements and sprints, the intermittent nature of the game also places considerable demands on aerobic systems for recovery between high-intensity efforts. Objectives. This study aimed to evaluate and compare the effectiveness of Small-Sided Games (SSG) and High-Intensity Interval Training (HIIT) in enhancing anaerobic endurance among adolescent field hockey players. Materials and methods. A total of 36 adolescent male hockey players (aged 15–17 years) participated in this study and were randomly assigned to three groups: SSG (n=12), HIIT (n=12), and an Active Control Group (ACG) (n=12). The intervention lasted for six weeks, with each training group engaging in their respective training modalities three times per week. Anaerobic endurance was evaluated through the Running-Based Anaerobic Sprint Test (RAST) both prior to and following the intervention. A Two-Way Mixed ANOVA was conducted to analyze the interaction between time (pre-test vs. post-test) and group assignment. Results. Both the SSG and HIIT groups demonstrated significant improvements in anaerobic endurance compared to the ACG. The SSG group exhibited a greater reduction in RAST values (5.03%) than the HIIT group (3.71%). Statistical analysis revealed a significant main effect of time and group (F = 14.80, p &lt; 0.001, η²p = 0.47), indicating a meaningful impact of both interventions. Post hoc comparisons showed that the SSG group outperformed the HIIT group, though both significantly improved anaerobic endurance compared to the control. Conclusions. This study confirms the efficacy of both SSG and HIIT in enhancing anaerobic endurance in adolescent hockey players, with SSG demonstrating slightly superior benefits. The findings suggest that integrating sport-specific drills, as seen in SSG, may yield greater physiological and tactical improvements than traditional HIIT protocols. Further research is needed to explore long-term adaptations, injury risk, and the potential benefits of combining both training methods for optimal performance enhancement.