Search Results (1,386)

This study examines how adults with recent exercise participation experience cognitively weigh different perceived constraints on exercise participation and whether these weighting structures can be used for meaningful segmentation. The sample included 283 adults aged 19 years and older who had engaged in exercise at least once per week for a minimum of 30 min over the past three months. This study aimed to identify the relative importance of perceived exercise participation constraints among adult exercisers, examine differences according to involvement level, and segment participants based on constraint importance. The results showed that, within this sample, intrapersonal constraints, particularly lack of interest and physical fatigue, were the most influential, followed by structural constraints such as time and cost. Constraint prioritization varied by involvement level: highly involved individuals emphasized time burden, whereas less involved individuals highlighted a lack of interest. Cluster analysis identified four distinct segments: interest-constrained beginners, fatigue-sensitive participants, time-constrained active participants, and cost-sensitive experienced participants. These segments differed significantly in demographic and behavioral characteristics, including age, exercise frequency, and participation duration. Overall, the findings suggest that among adults with recent exercise participation experience, perceived exercise participation constraints are cognitively weighted and vary across individuals. This study contributes by applying conjoint analysis to assess the relative importance of multiple perceived constraints and by providing a segmentation-based perspective on how adult exercisers perceive constraints. Full article

Background: Mixed martial arts (MMA) involve repeated high-intensity, explosive actions that cause substantial fatigue, underscoring the importance of effective recovery strategies. Purpose: This pilot study investigated short-term performance responses to different post-exercise recovery interventions in Polish MMA athletes. Methods: Sixteen athletes (14 males and 2 females) were randomly assigned to cryosauna (CRYO), cold-water immersion (CWI), foam rolling (FR), or passive recovery (CON), with 4 participants per group. The intervention lasted two weeks, with the assigned recovery intervention applied after each training session. Performance was evaluated before and after the intervention using the countermovement jump (CMJ), isokinetic knee peak torque (flexion and extension), and reactive stress tolerance of the determination test (DT). Data were analyzed using mixed-design ANOVA. Results: CMJ performance improved over time across groups. FR significantly increased knee extension (from 228.67 ± 26.49 N.m to 250.50 ± 22.41 N.m), whereas DT scores significantly increased in the CRYO group (from 247.50 ± 12.50 AU to 291.50 ± 15.61 AU) and significantly decreased in the CON group (from 290.25 ± 24.45 AU to 255.50 ± 24.18 AU). Significant Time × Group interactions were observed for DT (p < 0.001) and knee extension torque (p = 0.008). Conclusions: FR appeared beneficial for knee extension performance, whereas CRYO was associated with improved DT performance. Findings are exploratory and need confirmation in larger, controlled studies. Full article

Sports nutrition products are increasingly expected to deliver bioactive compounds that aid in recovery, reduce fatigue, and support physiological regulation, going beyond merely providing energy and nutrients. However, many bioactive compounds face challenges such as poor aqueous dispersibility, limited stability, low bioaccessibility, or inefficient absorption, which hinder their practical use in real food products. This review critically examines food-grade, gel-based delivery systems for bioactive compounds in sports nutrition from a design-driven perspective. It focuses on hydrogels, microgels, emulsion gels, protein gel matrices, and multicomponent gel architectures that prioritize structural stability, digestion-triggered responsiveness, and compatibility with food. Key design principles are discussed, including the need to maintain stability during processing and storage, balance protection with release, and tailor delivery structures to sports-specific constraints such as gastrointestinal tolerance, osmotic load, nutrient timing, and changes in digestion related to exercise. The review also analyzes the effectiveness of gel-based and hybrid systems in liquid, solid, and semi-solid sports nutrition products, emphasizing how the product format and consumption scenario can influence delivery performance. A design decision framework is proposed to align bioactive properties, food format, target release profile, and exercise-stage requirements with appropriate delivery architectures. Current challenges are also addressed, including difficulties in predicting structure–function relationships, limited robustness during scale-up processes, and inadequate functional evaluation. Overall, gel-based food delivery systems provide a promising solution for improving the stability, release behavior, and practical functionality of bioactives in sports nutrition. Full article

Post-exercise release of cardiac biomarkers reflects physiological adaptations of the myocardium to exercise; however, data on their kinetics after exhaustive exercise under hypoxia remain scarce. We determined the kinetics of cardiac biomarker changes following a single bout of exercise to volitional exhaustion under normoxia and moderate normobaric hypoxia (2000 m and 3000 m a.s.l.) in trained (n = 12; VO_2max 64.2 ± 2.9 mL·kg⁻¹·min⁻¹) and untrained (n = 12; VO_2max 44.1 ± 7.4 mL·kg⁻¹·min⁻¹) men. Participants performed a graded exercise test (GXT) followed by a constant-workload exercise test (CXT) at the lactate threshold under three conditions (FiO₂ = 20.9%, 16.5%, 14.4%). Venous blood was sampled at rest, immediately post-exercise, and at 2, 6, and 24 h of recovery for determination of cardiac troponin T (cTnT) and I (cTnI), myoglobin (Mb), creatine kinase MB isoform (CK-MB), heart-type fatty acid-binding protein (H-FABP), ischemia-modified albumin (IMA), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) by ELISA. Exhaustive exercise induced significant elevations in all biomarkers, peaking at 2–6 h post-exercise and largely returning to resting values by 24 h. Moderate normobaric hypoxia did not augment the cardiac biomarker response; rather, it attenuated the increases in Mb, NT-proBNP, and IMA, likely due to earlier peripheral fatigue and lower absolute mechanical work. The inhibitory effect of hypoxia on cTnI release was observed exclusively in trained men, suggesting an interaction between training-related cardiac adaptations and the hypoxic stimulus. These findings support the safety of high-intensity exercise at simulated altitudes of 2000–3000 m a.s.l. Full article

Background/Objectives: Canine athletes have a higher energy requirement and are more susceptible to nutrient depletion, electrolyte imbalance, and metabolic stress than sedentary pets. The objective of this study was to characterize the plasma metabolome of American Foxhound dogs following a bout of unstructured exercise. Methods: Thirty-nine adult American Foxhound dogs (32 intact males, 7 spayed females; age: 6.2 ± 3.1 yr; BW: 36.3 ± 5.3 kg) were allotted to a standard performance diet (CTRL) or NUTRO^® Natural Choice^® Adult High Endurance Formula (TEST). After 80 d in the study, blood samples were collected prior to (0 h), and 3 h and 25 h post-exercise (average: 17.7 km run over 2–3 h). Plasma samples of the 10 top performers of each treatment group were analyzed for untargeted metabolite profiling. Results: Of the 566 named metabolites identified, >200 and >185 metabolites were impacted (p < 0.05) by exercise and diet, respectively. Principal component analysis indicated distinct clustering by diet. Random forest analysis highlighted several metabolites having a high degree of predictive accuracy based on diet and exercise, with most related to amino acid, lipid, xenobiotic, and cofactor and vitamin metabolism. Relating to exercise, glycolytic end-products and citric acid cycle intermediates were increased at 3 h post-exercise. Similarly, tocopherols and omega-3 polyunsaturated fatty acids were higher in dogs fed TEST than those fed CTRL during recovery, indicating a lower oxidative stress and anti-inflammatory response. Conclusions: Overall, the data suggest a protective effect (lower susceptibility to oxidative stress and muscle fatigue) of feeding a nutrient-fortified diet for dogs undergoing unstructured exercise. Full article

Background/Objectives: To evaluate the associations and concurrent validity between baseline functional and morphofunctional assessments in patients with cardiovascular disease participating in a Phase II cardiac rehabilitation program, as a basis for informing individualized exercise prescription. Methods: We conducted an observational retrospective cross-sectional study of patients enrolled in a Phase II outpatient cardiac rehabilitation program (January 2021–December 2023, Málaga). Functional assessments included handgrip strength (HGS), isometric biceps and quadriceps dynamometry, and direct assessment of 20-repetition maximum (20RM) through dynamic resistance exercises using external loads (defined as the maximum load allowing approximately 20 repetitions to near muscular fatigue). Aerobic capacity was evaluated using the 6-min walk test (6 MWT) and a modified Bruce exercise stress test with estimated METs. Morphofunctional assessment included vector bioimpedance analysis (phase angle [PhA], fat-free mass [FFM], body cell mass [BCM]) and rectus femoris ultrasound (cross-sectional area [RF-CSA] and contracted diameter [RF-CON]). Correlation and linear regression analyses were performed. Results: The sample included 223 participants (78.0% male; age 57.7 ± 8.6 years). HGSmax correlated strongly with 20RM biceps (r = 0.89) and moderately with quadriceps (r = 0.72). 6 MWT distance and speed correlated with ergometry-derived METs (r = 0.38–0.40; p < 0.001), whereas Borg ratings correlated inversely with METs and exercise time (r = −0.32 to −0.34; p < 0.001). PhA, BCM, FFM, and rectus femoris ultrasound measures correlated with both strength and aerobic outcomes (ρ ≈ 0.33–0.50; all p < 0.001). In regression analyses, HGSmax was the main predictor of 20RM biceps (R² = 0.792) and showed moderate predictive capacity for quadriceps performance (R² = 0.521). The MET model demonstrated limited explanatory capacity (R² = 0.288). Conclusions: The integration of simple, accessible, and reproducible tools such as HGS and the 6 MWT with morphofunctional parameters may provide a pragmatic approach to support individualized exercise prescription in cardiac rehabilitation. While stronger associations were observed for upper-limb resistance performance, the predictive capacity for lower-limb strength and aerobic exercise intensity was more moderate and should be interpreted cautiously. These findings support the potential clinical utility of combining functional and morphofunctional assessments in routine cardiac rehabilitation practice. Full article

Beta-alanine, a naturally occurring non-proteinogenic beta-amino acid, is widely used in delaying fatigue, enhancing exercise performance, and alleviating hyperuricemia. It also serves as a three-carbon platform for the synthesis of various high-value compounds, thus showing extremely broad market prospects. However, the practical application of beta-alanine is severely limited by the harsh reaction conditions and abundant by-products in chemical synthesis, as well as the low endogenous content and complex biosynthetic pathway. Recently, advances have been made in the one-pot, one- or two-step production of beta-alanine using genetically engineered recombinant enzymes, and in the microbial synthesis of beta-alanine via whole-cell biocatalysis. These advances are based on a series of attempts, including the enzymatic conversion to beta-alanine using 1,3-diaminopropane (DAP), L-aspartate (L-Asp), fumarate, or 3-aminopropionitrile as substrates, and the whole-cell biosynthesis of beta-alanine by regulating metabolic flux from carbon sources (e.g., glucose, oil, and glycerol) to L-Asp—the precursor for beta-alanine synthesis catalyzed by L-aspartate-α-decarboxylase (ADC). This study provides a rational theoretical basis and valuable practical references for the future industrial application of beta-alanine. Full article

Objectives: Circadian rhythms regulate key physiological processes, including metabolism and energy balance. Emerging evidence suggests that the timing of physical activity may influence metabolic outcomes. However, how the timing of endurance exercise impacts long-term metabolic health and the role of the circadian clock in this process remain unclear. This study aimed to investigate whether time-dependent endurance exercise improves metabolic health via circadian rhythm regulation. Methods: A 12-week endurance exercise protocol was established using wild-type (WT) and circadian-disrupted Clock^Δ19 mice. Mice were assigned to exercise at Zeitgeber time 0 (ZT0) or Zeitgeber time 0 (ZT12), or to sedentary controls. Assessments included rotarod fatigue test, body weight, epididymal fat ratio, fasting blood glucose, serum triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), non-esterified fatty acids (NEFA), intraperitoneal glucose tolerance test (IPGTT), and insulin tolerance test (ITT). Results: Clock^Δ19 mice exhibited circadian phase-dependent fatigue susceptibility on the rotarod, particularly at ZT0. Both exercised Clock^Δ19 groups (ZT0 and ZT12) showed significant weight reduction compared to sedentary controls, indicating that endurance exercise may counteracts circadian disruption-induced weight gain independent of timing. In WT mice, evening exercise (ZT12) led to enhanced lipid regulation and better glucose tolerance. These time-dependent benefits were absent in Clock^Δ19 mutants, demonstrating that the full metabolic advantages of exercise require a functional circadian clock. Notably, endurance training also partially restored serum HDL-C levels in Clock^Δ19 mice, suggesting compensatory metabolic responses. Conclusions: Aligning endurance exercise with the body’s internal clock provides greater metabolic benefits than untimed exercise. The circadian clock is essential for time-dependent improvements in glucose and lipid metabolism, although some beneficial effects occur independently of a functional clock. Full article

Objectives: In lifeguarding, when prevention fails, rapid and safe rescue is essential to prevent submersion and enable appropriate care. These operations demand high physical fitness. High-Intensity Functional Training (HIFT), such as CrossFit^®, has become a widely used training model. This study examined the integration of HIFT into lifeguard training to enhance preparedness for aquatic rescues. The aim was to analyse the external and internal load generated by a lifeguard-specific HIFT protocol and to assess its utility both as a training method and as a fitness evaluation tool. Methods: Twenty-seven lifeguards completed a 15 min HIFT protocol in an AMRAP (As Many Rounds As Possible) format with four stations: running, swimming with a tow, victim extraction, and cardiopulmonary resuscitation (CPR). Variables measured included time per round (TRound), number of completed rounds, maximum and average heart rate (MaxHR, AvgHR), post-exercise blood lactate, rating of perceived exertion (RPE) per round and overall, and CPR quality (Q-CPR). Results: TRound ranged from 238 to 268 s, with significant differences between consecutive rounds, though remaining at submaximal levels. Most participants (74%) completed three rounds, and none completed four. AvgHR was 164 bpm (82% of MaxHR). RPE increased significantly across rounds (p < 0.001), reaching 9 post-AMRAP (p < 0.001). Post-AMRAP blood lactate was 15.50 mmol/L (p < 0.001), indicating high physiological stress. Despite accumulated fatigue, Q-CPR remained consistently high, ranging from 86% to 94%, with no significant differences across rounds. Conclusions: The results of this pilot study suggest that physically active lifeguards can sustain a controlled, high-intensity effort at submaximal heart rates and high perceived exertion without compromising CPR quality. These preliminary findings support the feasibility and potential utility of a lifeguard-specific HIFT programme structured as an AMRAP for high-intensity training and ecological fitness assessment in rescue-specific conditions; formal validation studies are needed before broader recommendations can be made. Full article

Skeletal muscle plasticity is modulated by a delicate equilibrium between reactive oxygen species (ROS)-mediated signaling and oxidative distress. Although excessive oxidant accumulation impairs excitation–contraction coupling, accelerates fatigue, and contributes to muscle dysfunction, transient and compartmentalized ROS signals are now recognized as important modulators of mitochondrial biogenesis, metabolic remodeling, proteostasis, and tissue repair processes after contractile stress. This review synthesizes the biphasic nature of redox biology in exercise physiology, interpreting this duality through the paradigm of hormesis. We discuss modality-specific redox responses associated with endurance, resistance and high-intensity interval training, emphasizing that adaptive outcomes depend not on global redox shifts, but on spatiotemporally confined signaling cascades within specific nanodomains. Furthermore, we evaluate the controversial role of antioxidant supplementation, highlighting evidence that high-dose or poorly timed antioxidant intake attenuates specific exercise-induced adaptive responses. We further discuss how aging and chronic disease narrow the adaptive redox window by impairing mitochondrial quality control, inflammatory resolution, and recovery capacity. This paradigm supports a precision exercise strategy in which training modality, intensity, recovery, and nutritional interventions are aligned to preserve adaptive redox signaling while avoiding cumulative oxidative injury. Full article

Background: Cancer-Related Fatigue (CRF) significantly impairs physical performance and quality of life (QoL) in patients with non-small-cell lung cancer (NSCLC). The OVER-CRF study evaluated the feasibility, safety, and preliminary efficacy of a personalized pulmonary rehabilitation (PR) program combining supervised exercise and education during active treatment. Methods: Patients with stage II–III NSCLC were randomized to Early-PR (initiated at the start of anticancer therapy) or Delayed-PR (initiated three months later). The 3-month intervention included two educational sessions and eight supervised exercise sessions. The primary outcome was adherence; secondary outcomes included safety, CRF (FACIT-FS), QoL (EORTC-QLQ-C30), and physical performance (6MWT). Results: Thirty-one patients were randomized (mean age 67.4 years). Adherence was excellent (Early: 86.7%; Delayed: 91.7%), exceeding feasibility thresholds. No exercise-related adverse events occurred. At 12 months, 50% of participants showed clinically meaningful CRF improvements. While both groups improved 6MWT performance during the intervention, the Delayed-PR group demonstrated more sustained QoL improvements from T1 through T3 compared to the Early-PR group. The dropout rate (25.8%) was consistent with the existing literature. Conclusions: Personalized PR is feasible and safe for NSCLC patients undergoing multimodal therapy. While early intervention provides immediate benefits, initiation timing may influence long-term QoL trajectories. These findings support integrating exercise and education into standard oncological care pathways. Full article

Myalgic Encephalomyelitis (ME) is a chronic, multisystem disease characterized by systemic metabolic dysfunction and post-exertional malaise (PEM). In this study, we investigated the dysregulation of irisin, an exercise-induced myokine, and its potential antagonism by thrombospondin-1 (TSP-1). In a cross-sectional study (92 ME patients vs. 44 sedentary healthy controls), plasma irisin and TSP-1 levels were measured at baseline and after a 90 min mechanical stress challenge applied to induce PEM. ME patients exhibited significantly lower baseline irisin (p < 0.05) and a blunted exertional response (p < 0.05). Paradoxically, baseline irisin was an independent predictor of fatigue severity (β = 0.728, p = 0.018), with moderate-to-severe patients showing elevated levels of both irisin and TSP-1 (p < 0.05), suggesting a compensatory but ineffective response. Functional cellular dielectric spectroscopy indicated that TSP-1 inhibits irisin signaling in a concentration-dependent manner. Irisin signaling was markedly reduced by both αvβ5 blockade and HSP90α inhibition in this experimental system, consistent with a diminished ability to counteract TSP-1. Collectively, these findings support a model in which dysregulation of the irisin–TSP-1 axis contributes to metabolic dysfunction in ME. Elevated circulating TSP-1 levels are associated with symptom severity and are linked to impaired irisin signaling in an HSP90α- and αvβ5-dependent context. This interaction is consistent with defective metabolic adaptation and highlights a potential therapeutic target that warrants further validation to restore energy homeostasis. Full article

Sports drinks have traditionally been formulated as carbohydrate–electrolyte beverages to support fluid replacement and energy provision during exercise. However, commercially available and experimentally tested formulations now include amino acids, proteins, phytochemicals, caffeine, menthol, ketone-related nutrients, and other functional ingredients intended to support thermoregulation, performance, or post-exercise recovery. This narrative review summarizes evidence on sports drinks and related functional beverages, with emphasis on hydration, gastric emptying and intestinal absorption, thermoregulation, biomarkers of hydration and recovery, and potential effects beyond hydration, including fatigue, muscle and organ damage, inflammation, and immune responses. Because available studies vary widely in population, exercise mode, environmental conditions, beverage composition, intake timing, and outcome measures, the evidence should be interpreted cautiously. A functional distinction is made between hydration-oriented carbohydrate–electrolyte beverages and beverages primarily designed for ergogenic or recovery-oriented purposes. Current evidence supports the practical value of appropriate fluid, electrolyte, and carbohydrate intake for maintaining hydration and exercise performance, whereas evidence for broader effects on inflammation, immunodepression, organ protection, and recovery remains context-dependent. Future studies should differentiate acute responses from longer-term adaptations, consider population-specific needs, and use standardized, context-appropriate biomarkers and ecologically valid protocols. Full article

Background and Clinical Significance: Pleural effusion results from an imbalance between fluid production and lymphatic drainage within the pleural space and may arise from a wide range of conditions. Chylothorax, characterized by the accumulation of chyle in the pleural cavity, is an uncommon cause of pleural effusion in the pediatric population. Although octreotide has been widely used in neonatal postoperative chylothorax, evidence supporting its role in acquired chylothorax beyond infancy remains limited, and dosing strategies are not standardized. This report describes the management of massive chylothorax in an adolescent patient. Case Presentation: A 13-year-old girl presented with fatigue, decreased exercise tolerance, vertigo, and diaphoresis and was diagnosed with massive right-sided chylothorax based on imaging and pleural fluid analysis. Treatment consisted of pleural drainage, dietary measures, and continuous intravenous octreotide administered within a multidisciplinary care framework. Chylous drainage declined progressively, with complete resolution of the effusion achieved without surgical intervention. Conclusions: Chylothorax in older children and adolescents may present with nonspecific symptoms and requires a high index of clinical suspicion. Early diagnosis, appropriate drainage, and individualized therapy are essential for favorable outcomes. Continuous octreotide infusion may represent an effective adjunctive treatment in selected pediatric cases, but further studies are needed to define optimal dosing and treatment duration. Full article

Background/Objectives: With the development of the silver economy, older adults have shown increasing interest in digital technologies, such as electronic fitness games (Exergames). This study explores the impact of commercial exergames on the emotional experience of older adults in order to provide novel ideas and applications for healthy aging. Methods: This was a prospective, single-center, unblinded, repeated-measures randomized controlled trial comparing an exergame intervention with traditional indoor exercise. This study included 30 older adults (aged 60–89 years) who were able to move independently. The intervention group performed exergame training using Ring Fit Adventure, whereas the comparison group performed traditional indoor exercise. The intervention lasted four weeks, with two sessions per week (eight sessions). Mood states were assessed using the Brunel Mood Scale, and data were analyzed using a linear mixed-effects model to examine group, time, and interaction effects. Results: Significant group × time interaction effects were observed for confusion, depression, fatigue, tension, and vigor (p < 0.05). No significant interaction effect was found for anger (p = 0.942). Conclusions: This study examined commercial exergames from the perspectives of emotional experience and mental health. Both commercial exergames and traditional indoor exercise were associated with improvements in immediate mood states. The exergame-based training approach was associated with lower levels of confusion, depression, and fatigue, as well as higher vigor scores. The results provide preliminary evidence regarding the role of digital exercise in mood regulation among older adults. Full article