Search Results (662)

Background/Objectives: Although SARS-CoV-2 infection is usually mild in children, some develop severe respiratory disease (RD) or multisystem inflammatory syndrome in children (MIS-C). We evaluated long-term respiratory symptoms, pulmonary function, and cardiopulmonary exercise performance in children recovering from SARS-CoV-2-related RD and MIS-C. Methods: This single-center prospective observational study included children hospitalized for SARS-CoV-2-related RD or MIS-C. Pulmonary function tests (PFTs) and cardiopulmonary exercise testing (CPET) were performed at a mean follow-up of 22.8 ± 9.8 months after hospitalization and compared between groups. Results: Forty-two children (25 RD, 17 MIS-C) were included. Persistent post-COVID symptoms were reported by 38.1% of participants and were more frequent in the RD group (56.0% vs. 11.8%; p < 0.01), with fatigue being the predominant symptom (p = 0.02). Pulmonary function and CPET parameters were comparable between groups, with no evidence of clinically significant ventilatory limitation or impaired aerobic capacity. VO₂peak did not differ between groups. Multivariable regression identified the breathing reserve index and OUES normalized to body weight as strong positive predictors of aerobic capacity in both groups. Despite differences in follow-up duration, stratified analyses using a 24-month cut-off showed comparable physiological findings. Conclusions: Children demonstrated preserved pulmonary function and exercise capacity nearly two years after hospitalization for severe SARS-CoV-2-related RD or MIS-C. Despite these favorable objective findings, subjective symptoms persisted in a substantial subset of patients, particularly those recovering from RD, suggesting that symptom resolution may lag behind objective physiological recovery. OUES normalized to body weight and the breathing reserve index may serve as complementary markers of aerobic capacity. Full article

Background: Gut microbiota may influence metabolic and inflammatory responses to exercise through the gut–muscle axis, and probiotic supplementation has been proposed to support adaptation and recovery in endurance athletes. However, evidence in trained populations is inconsistent and is confounded by variability in diet, probiotic strains, dose, and intervention duration. We tested whether a multistrain probiotic, administered against a fully standardized diet, would affect exercise performance and inflammatory, metabolic, and muscle-damage responses. Methods: In this randomized, double-blind, placebo-controlled trial, 30 trained male long-distance runners were randomized and 27 completed the study (probiotic [PRO], n = 13; placebo [PLA], n = 14). All participants followed a standardized, normocaloric meal-box diet for four weeks. Aerobic capacity (peak oxygen uptake, VO₂peak; primary outcome) was assessed by an incremental treadmill test and anaerobic performance by a 30 s Wingate test, before (PRE) and after (POST) supplementation. Interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), creatine kinase (CK), and lactate (LA) were measured around exercise. Outcomes were analyzed with linear mixed-effects models; the primary estimand was the group × phase interaction. Results: VO₂peak did not differ between groups over time (PLA 55.00 ± 7.60 → 57.33 ± 8.41; PRO 55.40 ± 7.85 → 53.14 ± 5.95 mL·kg⁻¹·min⁻¹; group × phase −3.5 mL·kg⁻¹·min⁻¹, 95% CI −7.0 to −0.1; nominal p = 0.044, not significant after FDR correction, adjusted p = 0.707). No group × phase or group × phase × sampling-time interaction was significant for IL-6, TNF-α, LA, or CK (all interaction p > 0.15), indicating that supplementation did not modify the exercise-induced response of any biomarker; exercise itself robustly increased IL-6, TNF-α, and LA in both groups (p < 0.001). Conclusions: In trained male endurance runners consuming a standardized diet, four weeks of multistrain probiotic supplementation did not significantly affect aerobic or anaerobic performance, LA response, muscle-damage markers, or circulating inflammatory cytokines compared with placebo. Adequately powered trials with prespecified primary endpoints and direct microbiome assessment are needed. Full article

Background: Peak oxygen uptake (VO₂peak), as measured by cardiopulmonary exercise testing (CPET), is considered the gold standard for assessing cardiorespiratory fitness (CRF). However, CPET is not always feasible in rehabilitation settings. The 6-min walk test (6MWT) is simple and widely used, yet its relationship with CPET-derived measures in patients with subacute cerebral infarction remains unclear. Methods: A total of 122 patients with subacute cerebral infarction underwent both the 6MWT and CPET. VO₂peak, CPET-derived peak heart rate (CPET HRpeak), 6-min walk distance (6MWD), 6MWTpeak heart rate (6MWT HRpeak), and the ratio of 6MWT HRpeak to age-predicted maximal heart rate were assessed. Results: In multivariate linear regression analysis, 6MWD was independently associated with VO₂peak (unstandardized coefficient B = 0.010, p < 0.001). Partial correlation analyses adjusting for age, sex, and β-blocker use showed that CPET HRpeak was positively correlated with 6MWD (ρ = 0.361, p < 0.001) and 6MWT HRpeak (ρ = 0.217, p = 0.018). The ratio of 6MWT HRpeak to age-predicted maximal heart rate did not mediate the association between 6MWD and VO₂peak. Conclusions: In patients with subacute cerebral infarction, 6MWD was independently associated with VO₂peak, while both 6MWD and 6MWT HRpeak were positively correlated with CPET HRpeak. These findings suggest that the 6MWT may help assess CRF when CPET is not available. Full article

Background: Rugby sevens demands distinct physical profiles across positions. This study investigated anthropometric and physical fitness characteristics of Chinese national team male rugby sevens players. Methods: Twenty-one players (forwards: n = 10, backs: n = 11) completed anthropometric measurements, linear sprints (10 m, 40 m, 50 m, and 60 m), agility tests (T-test, Illinois, 20 shuttle run), Wingate anaerobic test, Yo-Yo intermittent recovery test level 2, goalpost shuttle run, vital capacity, and VO₂peak. Players were split into fast/slow groups by median 40 m time. Results: Forwards were significantly taller (adjusted p = 0.0022, d = 2.78), heavier (adjusted p = 0.0073, d = 1.76), and had greater muscle mass (adjusted p = 0.027, d = 1.47) with large effect sizes compared with backs. Backs showed significantly better agility with large effect sizes (Illinois: adjusted p = 0.018, d = 2.00). When players were classified into fast and slow sprint groups by median 40 m time, the fast group exhibited significantly better 10 m (adjusted p = 0.04, d = −2.00), 50 m (adjusted p = 0.017, d = −1.98), and 60 m (adjusted p = 0.017, d = −1.71) performance. Conclusion: Playing positions in Chinese rugby sevens present significantly different body size and agility profiles. When grouped by sprint speed, faster players possess superior multi-distance sprinting capacities. Both positional and sprint capabilities should guide training and selection. Full article

Background: Cardiopulmonary exercise testing (CPET) is widely used for prognostic assessment and risk stratification in patients with heart failure (HF). However, its feasibility and clinical utility in patients with advanced HF requiring intravenous inotropic support remain unclear. Methods: This observational study included hospitalized patients with HF who received intravenous inotropic therapy and underwent CPET during index hospitalization. The primary outcome was a composite of HF rehospitalization or cardiovascular death. Results: A total of 528 patients hospitalized for HF required intravenous inotropic therapy; 50 patients were included. CPET was safely completed in all patients without exercise-related adverse events. The median peak VO₂ was 12.5 mL/kg/min, and the median VE/VCO₂ slope was 38.3. During a median follow-up of 762 days, 12 primary events occurred. In univariable analysis, the VE/VCO₂ slope, O₂ pulse, and maximal workload were significantly associated with the primary outcome, whereas peak VO₂ was not. A VE/VCO₂ slope > 38.2 was associated with a significantly higher 3-year event rate compared with a slope ≤ 38.2 (40% vs. 8%, p = 0.021). Conclusions: CPET is feasible and safe in highly selected patients with advanced HF requiring inotropic support, and the VE/VCO₂ slope was associated with clinical outcomes in exploratory univariable analyses. Full article

High-intensity interval training (HIIT) is an effective exercise strategy for improving cardiorespiratory fitness (CRF) and cardiometabolic health in laboratory settings, yet its effectiveness in real-world conditions remains less clear. This systematic review and meta-analysis examined the effects of real-world HIIT on CRF and cardiometabolic outcomes in adults. We searched five major databases (inception to December 2025) for controlled and non-controlled reports of ≥1 cardiorespiratory or cardiometabolic outcome. Random-effects models were used to calculate weighted mean differences (WMD), with subgroup and meta-regression analyses to explore moderators. Thirty-one studies (n = 1119) were included. In the pooled pre–post analyses, HIIT was associated with significant within-group improvements in VO_2max/peak (3.9 mL/kg/min), systolic (−4 mmHg) and diastolic blood pressure (−3 mmHg), triglycerides (−8 mg/dL), total cholesterol (−9 mg/dL), LDL (−10 mg/dL), and waist circumference (−1.7 cm) across interventions. In controlled comparisons, HIIT was superior to passive controls for VO_2max/peak (6.9 mL/kg/min) and waist circumference (−2.9 cm), while superiority over active controls was limited to VO_2max/peak (1.1 mL/kg/min). Moderator analyses revealed larger cardiometabolic benefits in overweight and clinical populations, and greater improvements in fasting glucose and blood pressure with higher exercise volume and longer intervention duration. In conclusion, real-world HIIT can effectively improve CRF and selected cardiometabolic outcomes across diverse adult populations. Specific cardiometabolic benefits appear to be pronounced in overweight, clinical, and previously untrained individuals. Notably, substantial heterogeneity and moderate methodological quality warrant cautious interpretation. Full article

To address the challenge of simultaneously achieving broadband absorption, multi-mechanism tunability, and angular stability in terahertz multifunctional devices, this paper proposes a MoS₂/VO₂ composite terahertz metamaterial absorber based on an asymmetric multi-nested C-shaped structure. The device adopts a three-layer configuration consisting of a MoS₂/VO₂ composite plane–SiO₂ dielectric–Au reflector layer. Unlike conventional symmetric structures, which are limited by selection rules and symmetry-protected dark modes that hinder the excitation of higher-order resonances, this design effectively breaks structural symmetry protection through geometric asymmetry. This induces strong mode hybridization between originally orthogonal dark and bright modes, enabling broadband high absorption exceeding 96.7% across the 1.88–3.52 THz frequency range (61% RBW). Notably, the device demonstrates synergistic tuning advantages: the macroscopic on/off switching of broadband absorption characteristics via the phase transition of VO₂, combined with fine blind-spot compensation and enhancement in absorption peaks using the electrical tunability of MoS₂. Furthermore, thanks to its sub-wavelength unit cell design, the structure maintains excellent performance stability over a wide incident angle range from 0° to 60°. This study reveals a synergistic enhancement mechanism combining the asymmetric unit cell and hybrid materials, providing a systematic physical solution for resolving the trade-off between bandwidth extension and dynamic reconfigurability. Full article

This study investigated seasonal changes in anthropometric characteristics, vertical and horizontal jump performance, 30 m sprint performance, estimated maximal aerobic capacity, and repeated-sprint ability in competitive youth soccer players across the preparation, mid-season, and end-season phases. A longitudinal repeated-measures design was employed over one competitive season. Anthropometric variables, vertical and horizontal jump performance, 30 m sprint performance, estimated VO₂max derived from the Vam-Eval field test, and repeated-sprint sets (2 × 5 × 20 m with 15 s recovery between sprints and 1 min between sets) were assessed at three time points. Significant seasonal changes were observed in anthropometric characteristics, with body mass and height increasing progressively and body fat percentage decreasing throughout the competitive season (F ≥ 12.0, p < 0.001, η_p² ≥ 0.32). Body mass increased from 64.1 ± 6.7 to 66.7 ± 6.8 kg, height from 1.69 ± 0.07 to 1.72 ± 0.07 m, and body fat percentage decreased from 11.3 ± 2.0% to 9.4 ± 1.8%. Peak height velocity (PHV) significantly influenced changes in body mass and height but not body fat percentage. Seasonal improvements were observed in several physical performance measures. Squat jump, standing long jump, 15 s repeated jump performance, 10- and 30 m sprint performance, estimated maximal aerobic speed, estimated VO₂max, and repeated-sprint performance changed significantly across the season (F ≥ 3.28, p ≤ 0.046, η_p² ≥ 0.11), whereas countermovement jump, five-jump test, and flying 20 m sprint performance remained unchanged. Estimated VO₂max and maximal aerobic speed improved from preparation to mid-season and were subsequently maintained. Repeated-sprint performance exhibited set-dependent seasonal adaptations, with significant Time × Set interactions indicating progressive improvements during the second repeated-sprint set, whereas the first set showed only transient improvements at mid-season. Significant PHV and Time × PHV effects were also observed for aerobic capacity and repeated-sprint performance. In conclusion, these seasonal variations likely reflect the combined influence of biological maturation, training exposure, and competitive demands rather than training effects alone. Full article

Purpose: The main aim of this study was to compare the average and peak values of heart rate [HR], oxygen consumption [VO₂], and respiratory rate [RR] of professional basketball players between practices and competition. Methods: Data was collected from professional basketball players competing in the First Spanish professional basketball league during five pre-season games and twenty practices using a 9-axis motion sensor. The data collected included internal workload variables recorded as averages (i.e., value per minute considering the entire game) and peak values (i.e., greatest 1 min window): average heart rate (HR), peak HR, average oxygen consumption (VO2), peak VO2, average Respiratory rate (RR) and Peak RR. Results: Higher average VO2 values were observed during training sessions compared to games (F = 4.20, ES = −0.40, trivial). Nevertheless, no significant differences were found between games and training sessions for the remaining average variables. Considering peak demands, all variables were higher during games than during training sessions including peak HR (ES = 1.07, moderate), peak VO2 (ES = 1.14, moderate), and peak RR (ES = 1.02, moderate). Conclusions: In this sample of professional basketball players, competition elicited substantially greater peak HR, VO₂, and RR values than training sessions, whereas average physiological responses were largely comparable between contexts. These findings suggest that monitoring both average and peak physiological responses may provide a more comprehensive understanding of training representativeness relative to competition. Full article

Despite increasing interest in fungal remediation systems for the treatment of persistent contaminants, the mechanisms governing fungal transformation of halogenated organic compounds remain poorly resolved. The aim of this study was to determine whether the transformation of halogenated nitrophenols is driven by isolated extracellular enzymes and cofactor-dependent oxidative activity or instead reflects coordinated system-level fungal metabolism. To address this question, we investigated the transformation of 2-chloro-4-nitrophenol (2C4NP) and 5-fluoro-2-nitrophenol (5F2NP) by ascomycete fungi Caldariomyces fumago (C. fumago) and Curvularia sp. under varying nutrient and cofactor conditions. Whole-culture transformation, crude supernatant activity, purified enzyme assays, intracellular detoxification responses, and genome-resolved functional annotation were integrated to evaluate the relative contributions of extracellular and intracellular processes. Transformation was strongly dependent on fungal species, substrate identity, nutrient availability, and cofactor composition. C. fumago achieved complete transformation of 2C4NP and up to 85.3% transformation of 5F2NP, whereas Curvularia sp. exhibited strict Na₃VO₄-dependent transformation of 5F2NP. Crude supernatants retained partial transformation capacity, achieving ~40–45% substrate depletion under conditions supporting whole-culture activity. Purified chloroperoxidase and laccase showed negligible independent activity and did not reproduce whole-culture transformation behavior. Lignin peroxidase activity was consistently induced during contaminant exposure and peaked during periods of maximum transformation. Cytochrome P450 inhibition did not prevent transformation. Baseline glutathione S-transferase activity was detected in both fungi, and comparative genome analysis identified conserved intracellular detoxification-associated enzyme alongside divergent extracellular oxidative enzyme repertoires. Together, these findings demonstrate that transformation of halogenated nitrophenols by fungi cannot be explained by isolated extracellular enzymes alone but is consistent with coordinated extracellular and intracellular system-level metabolism. These findings highlight an underexplored role for integrated fungal metabolic systems in bioremediation and provide a mechanistic basis for developing a scalable fungal platform for treatment of persistent halogenated contaminants. Full article

Background: Given that true exercise response variation on cardiorespiratory fitness in adults with coronary heart disease (CHD) is not known, this study addressed this gap. Methods: Randomized controlled trials (RCTs) comparing continuous aerobic exercise (CAE) to controls in adults ≥18 years of age with CHD were included. The primary outcome was exercise-associated inter-individual response differences (IIRDs) in cardiorespiratory fitness (VO_2peak in ml·kg⁻¹·min⁻¹). Using the inverse variance heterogeneity (IVhet) model, a standard deviation of individual response difference (SD_ir) meta-analysis was conducted. Ninety-five percent confidence intervals (CIs) and prediction intervals (PIs) were calculated. Results: Twenty-eight RCTs representing 1383 participants (725 CAE, 658 control) were included. Statistically significant and clinically important improvements (≥1.0 mL·kg⁻¹·min⁻¹) were observed for VO_2peak as a result of CAE ($\overline{X}$, 3.6, 95% CI, 2.8 to 4.4 mL·kg⁻¹·min⁻¹, p < 0.001), but no statistically significant or clinically important IIRD based on the SD_ir were found ($\overline{X}$, 0.9, 95% CI, −1.5 to 2.0 mL·kg⁻¹·min⁻¹; 95% PI, −2.4 to 2.7). Based on GRADE, the strength of evidence was of low certainty. Conclusions: There is low certainty evidence that CAE results in statistically significant and clinically important improvements in VO_2peak in adults with CHD, but no exercise-associated IIRD was observed once properly accounted for. Full article

Metformin and aerobic exercise are routinely co-prescribed in the management of metabolic syndrome, yet evidence regarding their interaction on cardiorespiratory fitness and substrate oxidation adaptations remains inconsistent. This study aimed to investigate the effects of combined metformin and aerobic training on peak oxygen uptake (VO₂peak), maximal fat oxidation (MFO), submaximal substrate utilization, and perceived exertion in metformin-naïve adults with metabolic syndrome. In this randomized, placebo-controlled trial, 24 metformin-naïve adults with metabolic syndrome were allocated to receive either metformin (1000 mg/day; MET-EX) or a matched placebo (PLA-EX) combined with supervised aerobic training (5 sessions/week, 60% VO₂peak, 500 kcal/session) for five weeks; 22 participants (n = 11 per group) completed the protocol. VO₂peak, MFO, fat and carbohydrate oxidation, energy expenditure, and rating of perceived exertion (Borg 6–20) were assessed before and after the intervention. The absolute VO₂peak gain was modestly attenuated in MET-EX relative to PLA-EX (group × time interaction p = 0.042; +0.11 vs. +0.26 L·min⁻¹), whereas the interaction for relative VO₂peak did not reach significance (p = 0.088). In contrast, MFO increased substantially more in MET-EX than in PLA-EX (+0.13 vs. +0.04 g·min⁻¹; p = 0.001), accompanied by greater fat oxidation, energy expenditure, and perceived exertion during moderate-to-high submaximal exercise intensities. Moreover, VO₂peak improvement was negatively correlated with age exclusively in MET-EX (r = −0.87, p < 0.001). These findings suggest that metformin induces a dissociated adaptation profile during aerobic training in metabolic syndrome, characterized by enhanced lipid oxidation alongside attenuated cardiorespiratory adaptations and greater perceived effort, particularly in older individuals. 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

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

Objective: The purpose of this exploratory study was to examine mean differences, reliability, and agreement between CP and W′ derived from a 3MAT performed after an ICT and values obtained during a standalone 3MAT performed on a separate day. Methods: Ten recreationally trained cyclists and triathletes completed four laboratory visits, including an ICT followed by a 3MAT after 30 min of recovery (same-day condition) and a standalone 3MAT performed on a separate day. CP and W′ were derived from both conditions and compared using paired t-tests and Bland–Altman agreement methods. Results: No systematic differences, but limited individual-level agreement were observed between same-day and separate-day conditions for CP (mean difference: 1.72 ± 36.5 W) or W′ (mean difference: 0.99 ± 5.9 kJ), with trivial to small effect sizes. Peak VO₂ values were also not significantly different across testing conditions (p = 0.483). However, Bland–Altman analysis revealed wide limits of agreement for both CP (−69.8 to 73.3 W) and W′ (−10.7 to 12.7 kJ), indicating substantial variability at the individual level. Conclusions: Although same-day testing does not introduce systematic bias in CP or W′ estimation, the wide limits of agreement suggest that these protocols are not interchangeable for individual monitoring. Same-day testing may be appropriate for group-level assessments but should be used with caution when applied to individual athlete monitoring. Full article