Search Results (212)

A large number of reservoirs (or hydropower plants) have been constructed for flood control and energy production in the past several decades in the Yangtze River basin in China. The conventional scheduling rule curves (Scheme A) were designed in the reservoir construction period and did not consider river flow alternation, which needs to be modified to increase comprehensive benefits in the reservoir operation period. In this study, six large-scale cascade reservoirs or mega hydropower systems constructed and operated by the China Yangtze Three Gorges Corporation were selected for this case study. The current joint scheduling plans of cascade reservoirs (Scheme B) were introduced, and a joint scheduling and multi-objective coordinating operation model (Scheme C) was proposed for this mega hydropower system. The Gaussian radial basis functions (GRBFs) were used to fit operation policies of each reservoir, and the Borg multi-objective evolutionary algorithm was selected to optimize three-objective functions for Scheme C. The observed daily flow data series at main hydrometric stations from 2003 to 2025 were used to simulate and compare different operation scheduling schemes. The results show that the performance of joint scheduling of cascade reservoirs (both Schemes B and C) is much better than the single-reservoir scheduling (Schemes A) with overall benefit; Scheme C-best achieves a comprehensive target of decreasing average annual spillway wastewater by 12.82 billion m³ (or a decrease of 28.5%), increasing average annual power generation by 31.02 billion kWh (or an increase of 10.7%), and improving average annual impoundment efficiency rate by 5.0%. The GRBFs can fit reservoir operation policies well, while the Borg multi-objective evolutionary algorithm can quickly converge with high-precision non-dominated solution sets. The proposed joint scheduling and multi-objective coordinating operation model will provide a scientific basis for achieving maximum benefits in flood protection and hydropower generation for the mega hydropower system. Full article

Background: Persistent pain, neuropathic symptoms, dyspnea, and impaired quality of life are common components of post-COVID syndrome. However, the long-term trajectory of these symptoms and the factors associated with persistent pain remain incompletely understood. Methods: This longitudinal cohort study included 80 patients previously hospitalized with COVID-19. Participants were evaluated at approximately 1, 4, and 8 months after discharge. Pain severity was assessed using the Visual Analog Scale (VAS), neuropathic symptoms using the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) scale, dyspnea using the modified Medical Research Council (mMRC) scale, functional limitation using the Post-CO9VID Functional Status (PCFS) scale, and health-related quality of life using the EQ-5D-5L and EQ-VAS scales. Functional performance was additionally assessed using the 30 s chair stand test and the Modified Borg Scale. Multivariable linear regression and logistic regression analyses were performed to identify predictors of reduced quality of life and persistent pain at 8 months. Results: A total of 80 patients were included in the study. Median VAS score decreased from 3.0 (0–6) at 1 month to 0 (0–0) at 4 months and 1 (0–1) at 8 months (p < 0.001). Median LANSS score decreased from 0 (0–2) at 1 month to 0 (0–0) at 4 and 8 months (p < 0.001), while the proportion of patients with LANSS ≥ 12 declined from 11.3% to 2.5%. EQ-5D index scores improved from 0.81 (0.72–0.91) to 0.93 (0.88–0.96) during follow-up (p < 0.001). Dyspnea severity, exertional symptoms, and functional limitation also improved significantly over time. Most of the clinical recovery occurred between the 1-month and 4-month evaluations, although smaller but significant improvements continued until 8 months for pain severity, functional performance, and quality-of-life measures. Older age, baseline dyspnea, anxiety, and higher baseline LANSS scores were independently associated with lower EQ-VAS scores at 8 months, whereas only higher baseline LANSS scores remained independently associated with persistent pain. Conclusions: Patients hospitalized with COVID-19 experience persistent pain, dyspnea, neuropathic symptoms, and reduced quality of life during follow-up, although most symptoms improve substantially over time. Early neuropathic symptom burden and baseline dyspnea may help identify patients at risk of poorer long-term recovery, although the associations should be interpreted cautiously. Full article

Background: Acute alcohol consumption may interfere with the dynamics between internal and external load during exercise, potentially attenuating cardiovascular responses. Objective: This study investigated the association between distance covered during a running test and mean heart rate, while examining the moderating role of the rating of perceived exertion (RPE) under conditions with and without acute alcohol ingestion. Methods: This crossover experimental study included 12 physically active male university students (23.7 ± 3.7 years). Participants completed two intermittent running sessions (control and alcohol conditions), separated by ≥48 h. In the alcohol condition, participants consumed 0.4 g of ethanol/kg of body mass. Heart rate was continuously monitored using a Polar RCX5 monitor, and total distance covered and RPE (Borg 6–20 scale) were assessed immediately after test completion. Analyses included paired comparisons, Pearson correlations, and linear regression models with interaction terms. Results: No significant associations between variables were observed in the control condition. With alcohol consumption, distance covered was positively associated with mean heart rate, and RPE significantly moderated this relationship. Conclusions: Acute alcohol ingestion may modify the interaction between external load, perceived exertion, and cardiovascular response during running. These results highlight the importance of integrated monitoring of internal and external load, especially in contexts involving recent alcohol consumption. Full article

This study analysed the potential influence of crew size on performance (stroke rate, strokes/min; distance travelled, m/min; and average power, W), physiological responses (post-exercise heart rate and heart rate measured three minutes after exercise) and perceptual responses (Borg scale). A total of 136 adolescent athletes (100 males and 36 females; mean age = 15.79 ± 1.14 years) performed four three-minute maximal-effort trials on a rowing ergometer across four conditions: individual trials (C1), two-person crews (C2), four-person crews (C3), and eight-person crews (C4). Results showed a significant increase in stroke rate (strokes/min) in both sexes as crew size increased (C1 33.16 ± 2.54 vs. C4 34.19 ± 2.21 strokes/min; C1–C4 p = 0.01; C2–C4 p = 0.003). Men reported greater perceived exertion in C1 compared with C4 (Borg 7.80 ± 0.79 vs. 7.46 ± 0.74; p = 0.032), despite no associated changes in performance (863.88 ± 45.10 vs. 863.26 ± 47.63 m/min) or average power (311.71 ± 46.43 vs. 311.44 ± 50.43 W), whereas no differences in perceived exertion were observed in women (Borg 7.59 ± 0.84 vs. 7.56 ± 0.76). Cardiovascular responses were similar across sexes and experimental conditions. In summary, these preliminary findings could point toward the existence of sex-differentiated patterns. The data appear to suggest a more pronounced tendency toward the ‘crew-size effect’ among the men in the sample, whereas an inclination toward maintaining individual responsibility is observed in the women. Full article

This study examined the influence of the follicular (FP) and luteal phases (LP) of the menstrual cycle on sweat rate, estimated sweat sodium concentration, heart rate, hydration status, fluid intake, and perceived exertion in first-division university female football players. A small sample of eight athletes completed two monitored training sessions, one in each estimated-menstrual phase, following a repeated-measures field-based design under habitual training conditions. Sweat rate was determined using pre- to post-exercise body mass changes and microfluidic sweat patches, while estimated sweat sodium concentration was obtained via wearable colorimetric sensors. Heart rate was continuously monitored, hydration status was assessed using urine specific gravity, fluid intake was recorded, and perceived exertion was evaluated using the Borg CR-10 scale. Sweat rate was significantly higher during LP compared with FP (0.83 ± 0.20 vs. 0.55 ± 0.25 L·h⁻¹, p = 0.026), alongside greater estimated sweat sodium concentration (695 ± 305 vs. 404 ± 159 mg·L⁻¹, p = 0.031) and higher perceived exertion (4.63 ± 1.41 vs. 3.13 ± 0.83, p = 0.021). Fluid intake was also significantly greater during LP (0.99 ± 0.19 vs. 0.49 ± 0.25 L, p < 0.001). No significant differences were observed for urine specific gravity, mean heart rate, or total body mass change (p > 0.05). These findings suggest that the luteal phase may be associated with higher thermoregulatory and perceptual responses during football training, highlighting the potential importance of menstrual cycle-informed hydration and training management strategies in female athletes. Full article

Strategies that support repeated high-intensity sprint performance are of considerable interest in competitive sprinting and team sports; however, evidence regarding acute citrulline malate (CM) supplementation during recovery intervals remains limited. This study examined the effects of acute CM supplementation on repeated 100 m sprint performance and rating of perceived exertion (RPE) in trained sprinters. Eleven trained male collegiate sprinters (100 m personal best: 11.22 ± 0.47 s; range: 10.35–12.16 s) completed randomized, double-blind, crossover trials (CM vs. placebo) on separate days. Each trial consisted of two maximal 100 m sprints separated by an 80–90 min recovery interval, during which 8 g of CM or placebo was ingested. Sprint performance was primarily evaluated using wind-adjusted 100 m sprint time based on Mureika’s model. A significant condition × trial interaction was observed for wind-adjusted sprint time (p = 0.010), with a greater improvement in the CM condition (p = 0.008). RPE (Borg 6–20 scale) before the second sprint was lower (p = 0.004) following CM supplementation. These findings suggest that acute CM supplementation may modestly support repeated sprint performance under extended recovery conditions; however, the results should be interpreted with caution. Full article

Background: Kitesurfing is a wind-propelled water sport performed in highly variable environmental conditions. Scientific evidence describing internal load under standardized ecological sea constraints remains limited. Aim: This study aimed to characterize cardiovascular and perceptual responses during a standardized kitesurfing session and to examine associations among heart rate-based internal load indices, session rating of perceived exertion, and global navigation satellite system-derived external output variables. Methods: A total of 112 male recreational kitesurfers (32.1 ± 6.8 years) completed a 40–50 min standardized session under monitored wind conditions (17–22 knots) along a predefined approximately 800 m course. Heart rate was continuously recorded, and session rating of perceived exertion (Borg Category-Ratio 10 scale) was collected 30 ± 5 min post-session. Training impulse, mean percentage of maximal heart rate, and session rating of perceived exertion load were calculated. Pearson correlation analyses with bootstrapping (1000 resamples) and five percent trimming were performed, with statistical significance set at 0.05. Results: Sessions were performed at 78.4 ± 9.1 percent of maximal heart rate. Training impulse and mean percentage of maximal heart rate were strongly associated (correlation coefficient = 0.90, probability value < 0.001), reflecting the shared heart rate-based structure of these metrics. Training impulse showed a moderate association with session rating of perceived exertion load (correlation coefficient = 0.46, probability value < 0.001). No significant associations were observed between internal load indices and global navigation satellite system-derived mean speed (correlation coefficient = −0.14, probability value = 0.149) or distance (correlation coefficient = 0.06, probability value = 0.555). Sensitivity analyses confirmed the stability of the observed associations. Conclusions: Under standardized ecological sea conditions, kitesurfing sessions were characterized by sustained high submaximal cardiovascular intensity. Heart rate-based and perceptual measures showed consistent associations within this protocol, whereas global navigation satellite system-derived external outputs were not significantly related to internal load indices. Within the limits of this cross-sectional ecological design, the combined use of one heart rate-based indicator and session rating of perceived exertion offers a coherent and practically interpretable description of session internal load in open-water kitesurfing. Full article

Background/Objectives: Diabetic neuropathy (DN), a common complication of type 2 diabetes mellitus, manifests as peripheral nerve dysfunction with symptoms such as fatigue. Although exercise effectively reduces fatigue in neuropathy patients, precise detection methods are crucial to elucidate the role of rehabilitation. Accordingly, this study aimed to evaluate fatigue in DN patients using a multimodal approach (clinical and instrumental) and to compare the efficacy of aerobic versus resistance training on fatigue parameters. Methods: Eligible DN inpatients admitted for rehabilitation at the Neuromotor Rehabilitation Unit of the IRCCS ICS Maugeri Institute of Montescano (PV) were enrolled. Inclusion criteria included age between 65 and 85 years and confirmation via the Michigan Neuropathy Screening Instrument (anamnestic section: ≥7; clinical section: ≥2.5). Patients with confounding orthopedic, neurologic, or unstable cardiopulmonary/diabetic conditions were excluded. Overall, 36 participants were randomized into two groups: 17 underwent aerobic training (treadmill), while 19 received resistance training (elastic bands), both as supplements to a standard rehabilitation program. Assessments at baseline and post-training comprised clinical measures (Borg CR10 scale, Functional Independence Measure (FIM) total and subitems, Six-Minute Walk Test (6MWT), fasting blood glucose) and instrumental evaluations (sEMG of the tibialis anterior muscle to analyze conduction velocity intercept, slope, and changes). Results: All patients completed the protocol without dropout or adverse events. Both groups demonstrated significant improvements in FIM scores and post-exercise perceived exertion over time. Instrumental sEMG analysis confirmed a physiological fatigue trend manifested as conduction velocity reduction, yet revealed no significant differences between groups. Conclusions: Multimodal assessment provides an effective means to characterize fatigue in DN patients. Both aerobic and resistance modalities enhance functional independence and fatigue perception. Its early identification enables clinicians to tailor rehabilitation strategies to overcome exercise barriers. Full article

Background: Water inertia load training using equipment such as water vests provides unstable resistance that enhances trunk muscle activation. However, practical methods for prescribing exercise intensity without expensive electromyography (EMG) equipment remain limited. This pilot study aimed to develop prediction models for estimating trunk muscle activation using rating of perceived exertion (RPE) during water inertia load exercises. Methods: Seventeen healthy adults (20.45 ± 2.02 years) performed lateral trunk flexion exercises wearing a water vest at five progressive loads (8–16 kg in 2 kg increments). Surface EMG was recorded from four trunk muscles (rectus abdominis, external oblique, internal oblique, erector spinae) and normalized to maximal voluntary isometric contraction (%MVIC). Rating of perceived exertion (RPE) was assessed using the Borg CR-10 scale. Load-dependent changes in muscle activation were examined using repeated-measures ANOVA, and relationships between RPE and EMG were analyzed using regression and linear mixed-effects models. Results: All trunk muscles showed significant increases in activation with increasing load (all p < 0.001, ηp² = 0.381). RPE demonstrated significant positive correlations with all abdominal muscles (r = 0.37–0.46, p < 0.001). Simple regression analyses indicated predictive accuracy (R² = 0.267), representing a 29% increase compared with the strongest individual muscle model. Linear mixed-effects modeling confirmed RPE as a significant predictor after accounting for inter-individual variability. Conclusions: This pilot study provides preliminary evidence that RPE can be used to estimate trunk muscle activation during water inertia load exercise. The proposed composite activation index enhances prescription when EMG measurement is not feasible. Full article

Objective: This study evaluated the effects of a 12-week High-Intensity Functional Training (HIFT) program combined with thylakoid supplementation on plasma adipo-myokine levels (Decorin, Myostatin, Follistatin, Activin A, and TGF-β1) in men with obesity. Secondary outcomes included anthropometric indices, lipid profiles, and insulin resistance markers. Methods: Sixty men with obesity (age: 27.6 ± 8.4 years; BMI: 32.6 ± 2.6 kg/m²) were randomly assigned to four groups (n = 15 per group): Placebo (PG), Supplement (SG), HIFT + placebo (TPG), and HIFT + supplement (TSG). To ensure robustness against the 27% attrition rate, statistical analyses included both per-protocol and intention-to-treat (ITT) models. HIFT was performed for 3 sessions/week (Borg scale: 15–17). Results: Following Bonferroni correction for multiple endpoints, repeated-measures ANOVA showed significant Time × Group interactions for most adipo-myokines and metabolic markers. Both training groups (TPG and TSG) demonstrated improvements in body composition and insulin sensitivity compared to PG (p < 0.05). While no significant differences were observed between TPG and TSG for systemic metabolic markers, preliminary data suggested that thylakoid supplementation might provide modest complementary modulations in specific myokines (e.g., decorin and follistatin). However, these observed trends did not reach clinical superiority over exercise alone in the broader metabolic profile. Conclusions: Twelve weeks of HIFT is an effective primary driver for modulating the adipo-myokine network in obese men. Although thylakoid supplementation showed potential for selective complementary effects on certain myokines, these findings are exploratory given the small sample size. The clinical significance and long-term complementary value of thylakoid-exercise interactions require further validation in larger, more diverse cohorts. Full article

Objectives: Central airway obstruction (CAO) caused by malignant tumors may necessitate combined and prompt treatment. The aim is to recanalize and stabilize the airways as palliation. We present our multicentric experience managing malignant CAO through the placement of Y-shaped self-expanding covered metallic or silicone trachea-bronchial stents. Methods: This retrospective study includes patients who underwent placement of Y-shaped stents from 2002 to 2024 across six different centers in Italy and Great Britain. We evaluated outcomes related to the feasibility and safety of the procedure, as well as the palliation of dyspnoea on the Modified Borg Scale of Dyspnoea. Results: Eighty patients (56.2% female) with a mean age of 64.8 ± 9.6 years were included in the study. Successful placement was achieved in 76 (95%) cases, with no cases of intraoperative mortality. The mean procedure time was 36.64 ± 15.7 min. The complications noted included: 7 (8.7%) cases of periprocedural clinical complications and 7 (8.7%) patients requiring intensive care unit admittance after the procedure. Fifty patients (78.1%) received cancer treatment following the procedure. The mean dyspnoea score on the Borg scale decreased from 7.78 ± 0.98 to 4.02 ± 2.2 (p < 0.05). Conclusions: The placement of metal or silicone Y-shaped stents is a feasible and safe procedure for the palliative treatment of dyspnoea in patients with malignant stenosis of the trachea and main bronchi. Stabilizing the airway also enables these patients to access cancer treatments. Full article

This study examined whether the Ringelmann and Köhler effects emerge in adolescent rowing by assessing how crew size influences performance, physiological responses and perceived exertion in youth rowers aged 14–17 years. A total of 136 competitive rowers (mean age = 15.79 ± 1.14 years) completed four three-minute maximal-effort trials on a rowing ergometer under four conditions: individual trials, two-person crews, four-person crews and eight-person crews. Objective performance indicators, including stroke rate, heart rate and perceived exertion (Borg scale), were recorded. Repeated-measures ANOVA indicated that objective performance indicators (distance and power output) remained largely stable across conditions and age groups, although some isolated and non-systematic differences with large intra-subject effect sizes emerged in the younger category (14–15 years), particularly in the two-person crew condition. In contrast, the stroke rate differed consistently across crew sizes, with higher values observed in the eight-person crew condition in both age groups. Cardiovascular responses showed minimal and transient variation between conditions. Perceived exertion differed markedly by age, with older rowers (16–17 years) reporting significantly higher effort during individual trials compared with crew-based conditions, without corresponding gains in objective performance. Overall, although crew size influenced the regulation and perception of effort, the findings do not provide support for a consistent expression of either the Ringelmann or Köhler effects in adolescent rowing, as no systematic performance losses or motivational gains among weaker crew members were evident. These results suggest that developmental differences in self-regulation and effort perception may play a more prominent role than crew size alone in shaping performance responses, with practical implications for training design and crew configuration in youth rowing. Full article

Background/Objective: Pulmonary involvement in systemic sclerosis (SSc) is typically assessed using pulmonary function tests (PFTs), high-resolution CT (HRCT), and composite indices. Patient-reported outcomes (PRO), including ScleroID, provide insight into quality of life, but their relationship with clinical measures and role in overall disease assessment remain unclear. To assess the correlation between ScleroID scores and both lung involvement and disease activity/damage in a cohort of SSc-ILD patients from a large tertiary care center. Methods: Disease activity [European Scleroderma Study Group Activity Index (EScSG-AI), Scleroderma Clinical Trials Consortium Activity Index (SCTC-AI)], disease severity [Medsger severity scale (MSS)], and PRO measure ScleroID were assessed for associations with the extent and severity of SSc-ILD. Results: In 82 patients with SSc-ILD (mean age 56.0 ± 10.8 years; median disease duration 4.2 ± 4.7 years), higher fibrosis extent (>20%) was associated with worse lung function, greater exercise limitation, and higher ScleroID scores, particularly in fatigue, social life, and body mobility domains (all p ≤ 0.03). Patients with >20% fibrosis also had worse NYHA class and Borg scores during 6-MWD (p < 0.001). Cross-sectional correlations showed that ScleroID total and individual domains were negatively associated with FVC% and 6-MWD, and positively with ILD extent on HRCT. Fatigue, social impact, and mobility domains correlated most strongly with disease activity and severity scores, especially in patients with > 20% fibrosis (r = 0.384–0.635, all p ≤ 0.016), whereas breathlessness showed minimal associations (r < 0.2). Conclusions: In SSc-ILD, greater lung fibrosis and functional impairment are associated with worse patient-reported quality of life, particularly in fatigue, mobility, and social domains. ScleroID scores reflect both physiological severity and disease burden highlighting its value as a multidimensional outcome measure in patients with more advanced disease. Full article

Blood Flow Restriction (BFR) training has gained growing attention in musculoskeletal rehabilitation. Effects of resistance training with and without BFR on lower-limb muscle activation were analyzed in a crossover study including 8 subjects (27.5 ± 4.8 years) engaged in regular CrossFit^® training. Two 48 h-separated sessions (high bar back squat), with BFR (80% of individualized arterial occlusion pressure) and without BFR, were performed in a randomized order. Muscle activation (vastus lateralis, vastus medialis (VM), gluteus maximus (GM) and biceps femoris) was electromyographically recorded. The average electromyographic activity of the first four repetitions of the first set (T1), and the last four of the final set (T2) were considered, and intra- and inter-group comparisons were calculated. Pain (VAS) and fatigue (Borg scale) were recorded. Significant differences between BFR and non-BFR conditions were observed only for T1 peak BF activation values. Within the BFR experiments, no significant differences in EMG activation were detected between T1 and T2. In contrast, within the non-BFR experiments, T1 values were statistically significant higher (vs. T2) for mean VL, mean VM, peak VM, mean GM and peak GM. Median pain perception was 3.5 (0.75–6.75) and 4.0 (1.25–6.0), and fatigue perception was 8.0 (7.0–8.0) and 7.0 (7.0–8.0), respectively, with and without BFR. In this exploratory study, BFR maintained EMG activation (VM and GM) and suggests a strategy to minimize mechanical load while preserving muscle activation. Full article

Multiple sclerosis is an inflammatory and neurodegenerative disease that leads to motor, cognitive, and sensory impairments, significantly affecting walking and quality of life. This study aimed to analyze the relationship between quality of life and kinematic walking parameters in individuals with multiple sclerosis, as well as to evaluate the influence of fatigue, balance, and cognitive performance on different aspects of quality of life. A cross-sectional observational study was conducted with 32 patients diagnosed with multiple sclerosis with Expanded Disability Status Scale scores of ≤5.5. Quality of life was assessed using the MusiQoL questionnaire, and clinical variables included fatigue (Fatigue Scale for Motor and Cognitive Functions, Borg scale), balance (Berg Balance Scale), and cognitive performance (Trail Making Test). Walking kinematics were analyzed using the Vicon motion capture system to obtain walking speed, step frequency, and joint asymmetry indices. Spearman correlations and linear regression models were applied. Results showed significant correlations between quality of life and walking speed (rho = 0.506), step frequency (rho = 0.508), and knee asymmetry (rho = −0.525), as well as strong associations with cognitive fatigue (rho = −0.796) and balance (rho = 0.635). Regression models explained up to 58.4% of the variance in the Activities of Daily Living dimension. These findings indicate that quality of life in multiple sclerosis is influenced by both clinical and biomechanical factors, highlighting the importance of comprehensive assessments to guide physiotherapeutic interventions. Full article