Search Results (629)

Background: Binge eating (BE) is frequently associated with negative emotional states, obesity, and physical inactivity. Although yoga may improve binge eating and emotional symptoms, its effects on physical fitness remain unclear. In contrast, high-intensity interval training (HIIT) has been demonstrated to effectively enhance physical fitness. This study compared the effects of low-volume HIIT (LV-HIIT), high-volume HIIT (HV-HIIT), and yoga on binge eating, negative emotional states, and physical fitness in female college students with binge eating. Methods: Fifty-five physically inactive female college students with binge eating (BES ≥ 18) were randomly assigned to LV-HIIT (n = 19), HV-HIIT (n = 18), or yoga (n = 18) for 8 weeks. The Binge Eating Scale (BES), Depression Anxiety Stress Scale-21 (DASS-21), body fat percentage, waist circumference, and maximal oxygen uptake (VO2max) were assessed before and after the intervention. Data were analyzed using intention-to-treat linear mixed models, with per-protocol repeated-measures ANOVA as a supplementary analysis. Results: After 8 weeks of intervention, significant improvements over time were observed across all groups in binge eating, negative emotional states, and cardiorespiratory fitness (all p < 0.05). Waist circumference and body fat percentage did not change significantly in the ITT analysis. No significant time × group interaction effects were detected for any outcome (all p > 0.05), indicating that the improvements did not differ significantly among the LV-HIIT, HV-HIIT, and yoga groups. Conclusions: An 8-week intervention of LV-HIIT, HV-HIIT, and yoga was associated with improvements in binge eating behaviors, negative emotional states, and VO2max in inactive young women with binge eating, with no evidence of differential efficacy between interventions. LV-HIIT may be promising because of its shorter duration and higher adherence; however, this requires confirmation in larger trials. Full article

While high-intensity interval training (HIIT) enhances physical conditioning, its specific impact on the TMG-derived mechanical properties of rowing-related muscles and sport-specific performance remains underexplored. This study investigated the effects of a 4-week rowing ergometer-based HIIT intervention on 2000-m rowing performance and muscle mechanical properties, evaluated via tensiomyography (TMG). Seventeen rowers were randomized into the HIIT group (n = 9) or the control group (CON, n = 8). Over four weeks, the HIIT group completed two weekly rowing ergometer HIIT sessions (ten 60-s all-out sprints, 30-s recovery), while the CON group continued regular training without additional HIIT. Pre- and post-intervention, participants underwent a 2000-m ergometer trial and TMG assessments across five rowing-related muscles. The HIIT group demonstrated a 3.1% reduction in 2000-m completion time, together with increases in mean power output (7.7%) and stroke rate (6.5%) (group × time interaction η²p = 0.53, 0.39, and 0.27, respectively; p < 0.05). TMG analysis showed shortened delay time (Td) and half-relaxation time (Tr) across all targeted muscles after false discovery rate correction. Contraction time (Tc) was shortened in the tibialis anterior and vastus medialis, while the erector spinae showed a nominal uncorrected change that should be interpreted cautiously. Maximal displacement (Dm) and sustain time (Ts) remained unchanged. These findings suggest that short-term rowing-specific HIIT is associated with improved 2000-m performance and TMG-derived peripheral temporal properties; however, unchanged Dm should be interpreted only as no detectable change in radial displacement under the present TMG conditions rather than definitive evidence of unchanged muscle stiffness. Because of the small sample size, unbalanced total training load between groups, and the absence of direct physiological or biomechanical measurements such as VO₂max, lactate, electromyography, and stroke biomechanics, these findings should be interpreted as preliminary. Full article

Background/Objectives: Stroke is a leading cause of long-term disability worldwide and is frequently associated with reduced cardiorespiratory fitness, impaired functional capacity, and cognitive decline. High-intensity interval training (HIIT) has emerged as a promising rehabilitation strategy; however, its effects across multiple domains remain unclear. This systematic review and meta-analysis aimed to evaluate the effects of HIIT on cardiorespiratory fitness, cognitive function, and functional capacity in adults with stroke. Methods: A systematic search was conducted in PubMed, Scopus, CINAHL, and Web of Science up to April 2026. Randomized controlled trials involving HIIT interventions in adults with stroke were included. Outcomes of interest were cardiorespiratory fitness (VO₂peak), functional capacity (gait speed, walking distance, mobility, and balance), and cognitive function. Pooled effect sizes were calculated using a random-effects model. Methodological quality was assessed using the PEDro scale, and risk of bias was evaluated with the Cochrane RoB-2 tool. Results: In total, 17 studies (n = 809 participants) were included, with 12 contributing to the meta-analysis. HIIT significantly improved cardiorespiratory fitness (SMD = −0.849; p = 0.005), gait speed (SMD = 0.693; p = 0.014), walking distance (SMD = 0.604; p < 0.001), functional mobility (SMD = −0.711; p = 0.027), balance (SMD = 2.447; p = 0.002), and cognitive function (SMD = 1.741; p < 0.001). However, substantial heterogeneity was observed across most outcomes. Conclusions: HIIT appears to be an effective intervention for improving cardiorespiratory fitness, functional capacity, and cognitive performance in individuals with stroke. Nevertheless, the variability across studies suggests that its effectiveness is context-dependent. Further research is needed to standardize protocols and determine optimal implementation strategies. Full article

Background/Objectives: Telomeres are critical biomarkers of biological aging, with shortened leukocyte telomere length strongly linked to all-cause mortality and age-related disease risk. Although exercise modulates telomere dynamics, the field’s evolution from descriptive measurements to mechanistic inquiries involving redox biology and epigenetics remains incompletely mapped. This study systematically characterized the global research landscape of telomere–exercise science over 25 years to establish a strategic evidence base for precision exercise prescription. Methods: A bibliometric analysis was conducted on 858 publications from the Web of Science Core Collection (2000–2025). CiteSpace and VOSviewer were used for keyword co-occurrence analysis, strategic thematic mapping, and citation burst detection to visualize global research trends and identify emerging frontiers. Results: Annual publication volume grew from 2 (2000) to 71 (2025), with a compound annual growth rate of 15.4%. China emerged as one of the leading global contributors. Thematic analysis revealed a paradigm shift from descriptive leukocyte telomere length studies toward mechanistic investigations of oxidative stress, mitochondrial homeostasis, and epigenetic clocks. Keyword network analysis confirmed oxidative stress and inflammation as central hubs, mediating telomere protection via redox regulation and non-canonical telomerase functions. Conclusions: Exercise preserves telomere integrity primarily through redox–mitochondrial homeostasis, hormesis-driven antioxidant upregulation, and non-canonical telomerase activation. For aging populations and individuals at metabolic risk, aerobic training and high-intensity interval training (HIIT) are recommended as first-line non-pharmacological interventions for healthspan extension. Leukocyte telomere length and telomerase activity should be integrated as biomarkers in preventive medicine practice. Future large-scale randomized controlled trials incorporating multi-omics approaches and sex-stratified analyses are warranted to establish individualized dose–response guidelines for precision exercise prescription. Full article

Purpose: The current study tested the hypothesis that a bodyweight training (BWT) protocol with a higher weekly time commitment and training volume would produce greater improvements in cardiorespiratory fitness compared to lower time commitment/volume BWT protocols. Methods: Fifty-eight (n = 21 males; n = 37 females) recreationally active, healthy, young adults were randomized to either a 16 (TAB, n = 20), 27 (5BX, n = 19), or 90 min/week (AMRAP, n = 19) BWT protocol for 6 weeks. Peak work rate (WRpeak) was measured pre- and post-intervention using a cycle ergometer graded exercise test. VO₂peak was estimated (eVO₂peak) using a simple linear regression of WRpeak and VO₂peak generated from a previous study (n = 26; 13M/13F). Results: TAB and 5BX yielded non-inferior improvements in eVO₂peak. The 95% confidence intervals of the mean difference in change did not cross our non-inferiority margin of −2.6 mL/kg/min (TAB—AMRAP = 95% CI = −1.16 to 2.07; 5BX—AMRAP 95% CI = −0.29 to 2.89). Conclusions: Our results suggest that 16 and 27 min/week of minimalist BWT yields non-inferior improvements in CRF compared to 90 min/week and provides evidence supporting the efficacy of low-volume BWT protocols compared to higher volume protocols. The study was registered on Open Science Framework on 29 May 2023 (OSF registration). Full article

Background/Objectives: Exercise is pivotal for glycemic control in type 2 diabetes mellitus (T2DM), yet the relative efficacy of various exercise modalities remains inconclusive. This network meta-analysis aimed to evaluate and provide a preliminary ranking of exercise interventions on HbA1c levels in adults with type 2 diabetes mellitus, to facilitate clinically relevant network comparisons and to generate evidence for future large-scale comparative trials. Methods: A systematic review and network meta-analysis were conducted in accordance with PRISMA guidelines. Electronic databases (PubMed, MEDLINE, Cochrane Library, CINAHL, and ProQuest) were searched from inception to Dec 2024. Randomized controlled trials evaluating exercise interventions in adults with T2DM were included. Risk of bias was assessed independently by two reviewers using the JBI critical appraisal tool. The primary outcome was the change in HbA1c level. Results: Six randomized controlled trials involving a total of 511 participants (256 in the treatment group and 255 in the control group) were included in the final analysis. Both high-intensity interval training (MD = −0.322; 95% CI: −0.559 to −0.084; p = 0.008) and yoga (MD = −0.366; 95% CI: −0.534 to −0.198; p < 0.001) significantly reduced HbA1c compared with the active control. Although the preliminary ranking analysis suggested a higher probability of effectiveness for yoga (SUCRA 1) than for HIIT (SUCRA 0.5), the indirect comparison revealed no statistically significant difference in HbA1c reduction between the two interventions (MD = −0.044; 95% CI: −0.335 to 0.247; p = 0.766). Conclusions: These findings provide preliminary, evidence-generating; however, given the sparse network and absence of head-to-head trials, the treatment hierarchy should be interpreted with extreme caution and selected based on patients’ preferences and tolerance. Registration: PROSPERO [CRD42025650162]. Full article

Background: Metabolic dysfunction-associated steatotic liver disease (MASLD) has emerged as a global metabolic disorder. As a non-pharmacological intervention, the effects of high-intensity interval training (HIIT) on MASLD and its molecular mechanisms remain poorly understood. This study aimed to investigate whether HIIT could ameliorate high-fat diet (HFD)-induced liver fibrosis by recalibrating the intrahepatic lactate metabolic axis. Methods: An HFD-induced murine MASLD model combined with HIIT intervention was utilized to evaluate the therapeutic efficacy and underlying mechanisms. Hepatosomatic indices, histological architecture and fibrosis severity were examined. Lactate concentrations within the systemic circulation and hepatic parenchyma, alongside comprehensive lipid profiles, were measured. The expressions of genes and proteins involved in hepatic lactate metabolism were delineated via qPCR and Western blotting. Results: The 8-week HIIT intervention effectively improved liver lipid accumulation, hepatocellular injury, and oxidative stress caused by a high-fat diet. Fibrotic expansion and suppressed hepatic stellate cell activation were restricted markedly, as evidenced by the downregulation of collagen type I alpha 1 chain and alpha-smooth muscle actin(α-SMA). HIIT reversed the HFD-induced accumulation of lactate in both systemic circulation and liver tissues, which was found to positively correlate with hepatic α-SMA. Mechanistically, HIIT regulated the expression of the lactate metabolism-related proteins lactate dehydrogenase A and monocarboxylate transporter 1, while selectively enhancing the expression of the gluconeogenic enzymes. Conclusions: Our findings indicate that HIIT effectively ameliorated MASLD and associated hepatic fibrosis by remodeling the hepatic lactate metabolic axis, specifically through the suppression of lactate production and the enhancement of its clearance. These results indicate that targeting lactate homeostasis might be a promising therapeutic strategy for MASLD. Full article

Objectives: This study aimed to compare the acute effects of high-intensity resistance training (HIRT), low-intensity resistance training (LIRT), and low-intensity resistance training with blood flow restriction (LIRT-BFR) on heart rate variability (HRV), rating of perceived exertion (RPE), total load (kg), and number of repetitions in young trained men. Methods: Thirteen volunteers (21.5 ± 1.6 years; 178.2 ± 8.0 cm; 75.7 ± 8.0 kg) performed three training sessions with six upper- and lower-limb exercises in repetition-to-failure mode. HIRT was performed at 70% 1RM, four sets and 90 s of rest; LIRT at 30% 1RM, four sets and 30 s of rest; and LIRT-BFR at 30% 1RM, four sets, 30 s of rest, and cuff pressure at 80 mmHg. The rest interval between training sessions was 72 h. Results: Total load was higher during LIRT compared with LIRT-BFR (p < 0.05), with no significant difference compared with HIRT (p > 0.05). The number of repetitions was greater in LIRT than in HIRT (p < 0.05), with no significant difference compared with LIRT-BFR (p > 0.05). RPE was lower in LIRT compared with HIRT and LIRT-BFR (p < 0.05). Time-domain parameters SDNN significantly decreased across all protocols (p < 0.001), whereas RMSSD showed no differences. Frequency-domain components (LFnu, HFnu, and LF/HF) showed no significant differences. Conclusions: LIRT elicited lower perceived exertion compared with HIRT and LIRT-BFR and higher repetition performance, whereas LIRT-BFR, despite showing similar autonomic responses, produced greater perceptual stress, resembling that of HIRT. Full article

Background: High-intensity interval training (HIIT) is increasingly used in exercise-based cardiac rehabilitation (ebCR) after myocardial infarction (MI), yet the temporal sequence of physiological, cardiac, biochemical, and functional adaptations remains incompletely characterized. Methods: Stable post-STEMI (ST-segment elevation myocardial infarction, MI-group) and previously inactive participants without known cardiovascular, metabolic or systemic disease (CTRL group) completed 12-week supervised outpatient HIIT (4 × 4 min intervals at 85–90% HRpeak (peak heart rate), ~80–90% of VO₂peak, 3 sessions/week). Assessments were performed at baseline (T1), 4 (T2), 8 (T3), and 12 weeks (T4), including cardiopulmonary exercise testing (CPET), echocardiography, blood biomarkers, body composition, six-minute walk test (6MWT), and RAND-36. Longitudinal changes were analyzed using Friedman tests with Dunn post hoc comparisons; between-group differences used Mann–Whitney U tests with Holm correction. Results: VO₂peak increased significantly in both groups (p < 0.001), increasing by ~22% from T1 to T4 in MI (median 20.1 to 24.5 mL·kg⁻¹·min⁻¹) and ~23% from T1 to T4 in CTRL (median 22.3 to 27.6 mL·kg⁻¹·min⁻¹). LVEF (left ventricular ejection fraction) improved early in MI, increasing from 52.5% (50.0–55.0) at T1 to 57.5% (55.2–58.7) at T2 and up to 60% (55.8–60.0) at T4 (all p < 0.001), while LV dimensions remained stable. NT-proBNP (N-terminal pro-B-type natriuretic peptide) showed no significant longitudinal change (p = 0.510), and CRP (C-reactive protein) decreased from 2.1 to 0.7 mg·L⁻¹ (p = 0.008) in MI. Both groups improved body fat % and 6MWT distance (p < 0.001). Conclusions: In low-risk stable post-STEMI patients, longitudinal changes during supervised HIIT-based ebCR were consistent with improved VO₂peak and LVEF, without clinically relevant increases in cardiac stress biomarkers. However, due to the observational design and absence of clinical comparator groups, these findings should be interpreted as descriptive and support further evaluation in larger randomized studies. Full article

Background/Objectives: Cancer pathophysiology involves metabolic disturbances, and exercise improves muscle metabolism, but little is known about the effect of concurrent high-intensity interval plus resistance training (CT_HIIT+RT) on the resting and exercise metabolism of breast cancer survivors with risk factors related to metabolic syndrome (MetS). The purpose of this study was to determine the effects of 8 weeks of CT_HIIT+RT on the fat and carbohydrate (CHO) metabolism during rest and progressive exercise post-exercise intervention in breast cancer survivors with histories of high- and low-volume chemotherapy. Methods: An experimental study was conducted in which (n = 21) women breast cancer survivors (age: 58.7 ± 8.7 years) were divided by history of high- (HV_chemo, ≥8 to 16 sessions, n = 10) or low-volume (LV_chemo, ≤7 chemo sessions, n = 11) chemotherapy. The fat (RFAT_ox) and CHO oxidation during 10 min of resting was measured (i.e., including the area under curve [AUC] points within this time), as well as the fat (ExFAT_ox) and CHO (ExCHO_ox) oxidation during progressive exercise, before and after 8 weeks of CT_HIIT+RT by indirect calorimetry. Additionally, risk factors related to MetS were described from pre- to post-intervention. Results: At rest, the HV_chemo group showed significant increases in the AUC of RFAT_ox (∆ + 23.7, p < 0.0001), similar to the LV_chemo group (∆ + 14.0, p < 0.0001). The HV_chemo group showed significant increases in the AUC of RCHO_ox (∆ + 109.7, p < 0.0001), similar to the LV_chemo group (∆ + 107.5, p < 0.0001). During progressive exercise, the ExFAT_ox was increased in the HV_chemo group (∆ + 0.12 g/min, p = 0.006), similar to the ExCHO_ox (∆ + 0.52 g/min, p = 0.013) of this group. The proportion of subjects categorized with MetS were significantly reduced in blood pressure, Glu and triglyceride components. Conclusions: Eight weeks of CT_HIIT+RT may promote favorable metabolic and cardiometabolic adaptations in breast cancer survivors regardless of the chemotherapy exposure volume. However, these findings should be interpreted cautiously due to the small sample size and lack of a true non-exercise control group. Full article

Endothelial progenitor cells (EPCs) constitute a cell population that enters the circulation during aerobic exercise and facilitates vascular function. In a similar action, hematopoietic progenitor cells (HPCs) are also released into circulation in response to exercise. Peripheral vascular dysfunction is frequently present in patients with heart failure. Whether acute interval exercise performed with high intensity induces EPC and HPC mobilization and affects microcirculation remains under investigation. The study population consisted of nineteen male patients with chronic heart failure (CHF) and eleven age-matched healthy individuals who underwent a high-intensity interval exercise session. Blood was drawn before, immediately after exercise, and 40 min after exercise to identify the numbers of circulating EPCs and HPCs by flow cytometry. Microcirculatory assessment was performed using near-infrared spectroscopy before and after exercise. Vascular endothelial growth factor (VEGF) change was also assessed before and after exercise in patients with CHF using flow cytometry. The interval exercise protocol revealed significant effects (p < 0.05) on EPC and HPC mobilization and systemic microcirculation (p < 0.05) in patients with CHF and healthy individuals. No significant differences were observed between patients with CHF and healthy individuals during interval exercise. VEGF did not reveal any changes immediately after interval exercise in CHF patients. Acute high-intensity interval training was associated with increased EPC and HPC mobilization and changes in microcirculation in patients with CHF and healthy individuals. Full article

Background/Objectives: This meta-analysis aimed to quantify the combined ergogenic effects of caffeine (CAF) and carbohydrate (CHO) on high-intensity interval exercise (HIIE) performance and to identify potential moderating factors. Methods: Four databases were systematically searched to identify randomized crossover trials assessing CAF combined with CHO (CAF + CHO) on HIIE performance (i.e., exercise time, distance, or total work). A three-level random-effects meta-analysis was performed to calculate pooled Hedge’s g (g) values. Moderator effects were explored through subgroup analyses, including control group (placebo-, CHO-, and CAF-controlled), CHO administration (mouth rinse and ingestion), and training status (recreationally active and trained). Results: Eleven studies met the inclusion criteria (n = 105; 8 female). CAF + CHO significantly enhanced HIIE performance (g = 0.44, 95% CI: 0.23–0.66). Subgroup analyses indicated that CAF + CHO mouth rinsing (g = 0.91, CI: 0.49–1.33) yielded superior effects compared to CAF + CHO ingestion (g = 0.33, CI: 0.14–0.52) (p for subgroup < 0.05). Performance improvements with CAF + CHO were observed for CHO- and placebo-controlled trials, but not in CAF-controlled trials, without significant subgroup effects (p for subgroup > 0.05). Importantly, evidence of publication bias was identified, and the overall certainty of evidence was graded as low according to the GRADE framework. Conclusions: CAF + CHO appears to be effective for enhancing HIIE performance, with greater benefits observed when CHO is administered via mouth rinsing rather than ingestion. Preliminary evidence suggests that CAF may play a key role in CAF + CHO strategies. However, given the limited number of female participants, the generalizability of these findings to both sexes is limited. Additional high-quality trials are needed to establish more definitive recommendations. Full article

Background/Objectives: Patients with prolonged or chronic critical illness (PCI/CCI) represent a subgroup characterized by extended stays in an intensive care unit (ICU), persistent organ dysfunction, and increased susceptibility to recurrent sepsis episodes. Current sepsis prognostic tools have not been specifically tailored for this high-risk population. This study aimed to develop and validate a prognostic nomogram for predicting mortality in septic ICU patients with PCI/CCI. Methods: Data were obtained from the Russian Intensive Care Dataset (RICD). Eligible patients had confirmed sepsis episodes according to Sepsis-3 criteria. The cohort was randomly split into training and testing sets in a 7:3 ratio. Multivariable Cox regression identified predictors of mortality, which were incorporated into a prognostic nomogram. Predictive accuracy was assessed using Harrell’s C-index, and horizon-specific area under the receiver operating characteristic curve (AUROC). Results: A total of 336 septic patients were analyzed, with an overall ICU mortality of 14.0%. Median ICU length of stay was 44 days, and median time to sepsis onset was 10 days. Recurrent sepsis episodes occurred in 28.6% of patients. In multivariable analysis, four predictors of mortality were identified: age, SOFA score at sepsis onset, type 2 diabetes mellitus, and time to sepsis onset. The nomogram demonstrated a C-index of 0.787 (95% confidence interval [CI] 0.669; 0.890) in the training set and one of 0.715 (95% CI 0.584; 0.836) in the testing set. In the testing set, the horizon-specific AUROCs were 0.898, 0.741, and 0.703 for 14-, 28-, and 42-day survival prediction, respectively. Conclusions: The prognostic nomogram, specifically tailored for PCI/CCI septic patients, demonstrated a testing-set C-index of 0.715, with higher 14-day predictive performance, whereas predictive accuracy decreased at later time points. Prospective multicenter validation is necessary before clinical implementation. Full article

High-intensity interval training (HIIT) is an efficient exercise strategy capable of eliciting acute cardiovascular and metabolic responses. Blood flow restriction (BFR) and normobaric hypoxia (NH) have been proposed as exposures to intensify physiological stress during exercise; however, comparative evidence between both strategies remains limited. The aim of this study was to compare acute physiological responses in HIIT protocols performed under BFR and NH in apparently healthy young men. Eight volunteers completed two HIIT sessions in this fixed-order within-subject repeated-measures study: one with BFR and one with NH (simulated altitude: 3536 m above sea level; FiO₂ ≈ 13.5%). Blood glucose, peripheral oxygen saturation (SpO₂), heart rate, and blood pressure were repeatedly measured during the exercise protocol. After Bayesian analysis, no evidence of differences in glycemic response was observed, while heart rate and diastolic blood pressure responses appeared broadly comparable between conditions. However, SpO₂ was consistently lower during NH, whereas systolic blood pressure values were higher under BFR. Although both BFR and NH induced acute physiological responses characteristic of HIIT, distinct physiological profiles were observed. NH was associated with greater systemic hypoxemic stress, whereas BFR showed higher systolic pressor responses. Full article

Background: High-intensity interval training (HIIT) is increasingly implemented in school-based physical education, yet little is known about how exercise intensity changes across repeated sessions and whether such trajectories are associated with physiological adaptations in adolescents. Methods: This study, conducted within the PEER-HEART project (ClinicalTrials.gov: NCT06431230), included 145 adolescents from the experimental arms of a broader school-based trial, stratified by sex and training modality: male HIPT (n = 24), male HIIT (n = 45), female HIPT (n = 46), and female HIIT (n = 30). The 8-week intervention was delivered twice weekly, and exercise intensity was monitored during 16 sessions using heart rate sensors. Intensity trajectories were examined using visual trajectory plots and slope-based statistical analyses, and pre-to-post changes in body fat percentage, systolic and diastolic blood pressure, and predicted VO₂max were analyzed. Results: Visual analyses indicated sex- and modality-specific intensity patterns, with the female HIIT group showing the most dynamic trajectory. Mean changes ranged from −0.63 ± 2.37% to −1.54 ± 2.66% for body fat, from −2.73 ± 5.28 to −5.37 ± 4.32 mmHg for systolic blood pressure, from −0.22 ± 5.00 to −2.62 ± 6.25 mmHg for diastolic blood pressure, and from 0.41 ± 3.25 to 3.81 ± 4.67 mL/kg/min for predicted VO₂max across subgroups. Although most delta values showed no significant main effects, a sex × modality interaction was observed for body fat percentage, and a main effect of sex was observed for predicted VO₂max. Greater intensity progression was associated with larger reductions in diastolic blood pressure in the female HIIT (β = −708.0, p < 0.001, R² = 0.39) and male HIIT groups (β = −377.0, p = 0.014, R² = 0.13) and with greater improvements in predicted VO₂max in the female HIPT (β = 154.0, p = 0.029, R² = 0.104) and male HIIT groups (β = 315.0, p = 0.029, R² = 0.106). Conclusions: Individual intensity trajectories may help explain variability in physiological responses to school-based interval training and may provide additional insight beyond group-level comparisons alone. Full article