Search Results (131)

Background: New Zealand blackcurrant (NZBC) is an anthocyanin-rich supplement with reported ergogenic effects in endurance exercise; however, its effects in resistance-trained adults remain largely unexplored. Objective: This study aimed to examine whether seven days of low- or high-dose NZBC supplementation improves resistance exercise performance, anaerobic capacity, and cognitive function in resistance-trained adults. Methods: Twenty resistance-trained adults completed a randomized, double-blind, placebo-controlled crossover trial with four conditions: no-capsule control (CON), placebo (PL), low-dose blackcurrant (LDBC; 250 mg·day⁻¹), and high-dose blackcurrant (HDBC; 600 mg·day⁻¹), each for seven days. Outcomes included bench press and leg press 1RM, total lifting volume, Tendo-derived bench press power, 30 s Wingate performance, Stroop Color–Word Test scores, readiness, perceived exertion, hemodynamic responses, and adverse events. Results: LDBC and HDBC increased bench press 1RM versus CON and PL, with increases versus CON of +3.33 kg (ES = 0.72; p = 0.005) and +2.34 kg (ES = 0.49; p = 0.041), respectively. Leg press 1RM was higher in PL, LDBC, and HDBC versus CON, with the largest effects observed for LDBC (+37.2 kg, ES = 1.33; p < 0.001) and HDBC (+25.8 kg, ES = 1.11; p < 0.001). Leg press total lifting volume was substantially higher with LDBC (+2627 kg, ES = 1.56; p < 0.001) and HDBC (+1025 kg, ES = 0.74; p = 0.004) versus CON. Bench press volume showed no significant overall treatment effect (p > 0.05). For Tendo-derived power, HDBC exceeded PL for peak (+79.5 W; p = 0.006) and mean power (+46.2 W; p = 0.026). Wingate outcomes did not differ across conditions (all p > 0.05). LDBC exceeded PL on Stroop Color, Color–Word, and total scores (all p < 0.05); HDBC exceeded PL on Color–Word only. Hemodynamic responses and adverse events were comparable across all conditions. Conclusions: Short-term NZBC supplementation improved selected resistance-exercise and cognitive outcomes, with the strongest evidence observed for outcomes that exceeded both CON and PL. The PL response relative to CON suggests that non-specific capsule, expectancy, repeated testing, or period effects may have contributed to some of the lower-body improvements; therefore, placebo-controlled contrasts should be emphasized when interpreting NZBC-specific efficacy. Wingate performance was unaffected, and both doses were well tolerated over the short-term supplementation period. Full article

Background: Optimizing physical performance in youth football requires a comprehensive understanding of the interplay among behavioural factors, structural body composition, and functional cardiorespiratory capacity. While sports nutrition knowledge is hypothesized to influence athletic development, its concurrent relationships with regional body compartments and objective cardiopulmonary exercise testing (CPET) metrics remain poorly characterized in adolescent athletes. Methods: A cross-sectional study approach analysed body composition via bioelectrical impedance analysis (BIA), maximal cardiorespiratory testing, and sports nutrition knowledge evaluation using the Nutrition for Sport Knowledge Questionnaire (NSKQ). Structural associations and functional predictive capacities were analysed. Results: The cohort demonstrated an average VO₂max of 51.18 ± 16.67 mL/kg/min and a mean total nutrition knowledge score of 43.56 ± 18.06 out of 81 (53.8%). Total and domain-specific nutrition knowledge scores were not associated with body mass index (BMI), fat-free mass (FFM), or fat-free mass percentage (FFM%). Higher nutrition knowledge scores were independently associated with superior VO₂max and anaerobic threshold (AT) metrics. Exploratory geographic analyses revealed that rural-residing participants possessed significantly higher cardiorespiratory performance values and greater baseline nutrition knowledge profiles than their urban peers. Conclusions: In adolescent male football players, sports nutrition knowledge was not associated with static body composition measures but showed exploratory positive associations with selected cardiorespiratory fitness markers. These findings should be interpreted as cross-sectional and hypothesis-generating, as some potential confounding mediators were not assessed. These findings suggest that higher sports nutrition literacy may serve as a starting point for performance-supportive behaviours and metabolic conditioning, to some degree, warranting future interventional studies. Full article

Background and Objectives: Post-stroke spasticity is a frequent complication that contributes to impaired mobility, reduced functional independence, and decreased exercise tolerance. While botulinum toxin A (BoNT-A) is widely used to improve muscle tone, its effects on cardiopulmonary exercise capacity remain insufficiently characterized. This study aimed to evaluate the impact of BoNT-A treatment on cardiopulmonary performance and functional outcomes in patients with post-stroke spasticity. Materials and Methods: A prospective before–after study was conducted including 50 patients with post-stroke spasticity. Cardiopulmonary exercise testing was performed before and after BoNT-A administration. The primary outcome was peak oxygen consumption (VO₂ peak), while secondary outcomes included anaerobic threshold (AT), exercise duration, maximal workload, 10 m walk test time, Barthel Index, and modified Rankin Scale (mRS). Paired comparisons and multivariable linear regression analyses were performed to assess changes and associated factors. Results: VO₂ peak increased significantly following treatment (12.96 ± 2.70 vs. 13.55 ± 2.85 mL/kg/min; mean change 0.59 mL/kg/min, 95% CI 0.36–0.82; p < 0.001). Similar improvements were observed for AT (10.47 ± 2.77 vs. 10.97 ± 2.97 mL/kg/min; p < 0.001), exercise duration (6.70 ± 1.48 vs. 7.11 ± 1.55 min; p < 0.001), and maximal workload (44.70 ± 10.97 vs. 48.06 ± 12.60 W; p < 0.001). Functional performance improved, as indicated by reduced 10 m walk time (18.33 ± 4.67 vs. 17.36 ± 4.82 s; p < 0.001) and increased Barthel Index (57.62 ± 19.18 vs. 61.92 ± 21.10; p < 0.001). A modest but significant reduction in disability was observed on the mRS (p = 0.003). Baseline values were the strongest predictors of post-treatment outcomes, while smoking status was associated with worse walking performance. Conclusions: BoNT-A treatment was associated with modest but consistent improvements in cardiopulmonary exercise capacity and functional performance in patients with post-stroke spasticity. These findings suggest that spasticity management may be associated with functional and exercise-related benefits extending beyond local neuromuscular effects, although causal relationships cannot be established based on the present study design. Further controlled studies are needed to confirm these findings and evaluate their long-term clinical significance. Full article

Background/Objectives: The purpose of this proof-of-concept study was to examine the effects oligosaccharide 6′-sialyllactose (6′-SL) supplementation (900 mg/d) during training on exercise performance and training adaptations in recreationally active males. Methods: In a randomized, double-blind design, 19 healthy males (24.4 ± 6.0 yrs, 174.9 ± 5.9 cm, 82.0 ± 15.2 kg, 27.1 ± 4.7 kg/m², 26.4 ± 6.9% body fat) ingested 3 × 300 mg/d of a placebo or 6′-SL for 12 weeks while partaking in a supervised resistance-training program while following their normal diet. Body composition (DXA), body water, submaximal lactate and substrate oxidation, 5RM dynamic muscular strength, ventilatory anaerobic threshold (VANT), peak aerobic capacity (VO₂), blood lactate, cycling anaerobic sprint capacity, and fasting blood samples were obtained at week 0, 6, and 12 of training and supplementation. Data were analyzed using multivariate and univariate general linear models (GLM) with repeated measures, along with assessments of mean changes from baseline and corresponding 95% confidence intervals. Results: Both groups observed positive training adaptations with no significant differences observed between groups in body composition, 5RM dynamic strength, or anaerobic sprint capacity. Significant interaction effects were observed VANT (p = 0.032), VO₂ at VANT (p = 0.028), and submaximal glucose and fat oxidation (p = 0.034) while time to reach peak VO₂ (p = 0.083), absolute (p = 0.075) and relative (p = 0.057) peak VO₂ approached significance. At Week 6, changes in time to peak effort (196 s [−16, 409], p = 0.068), absolute (0.76 L/min [−0.005, 1.53], p = 0.051) and relative (10.9 mL/kg/min [0.52, 21.5], p = 0.045), and fat oxidation (20.5% [3.1, 37.9], p = 0.023) were significantly greater in the 6′-SL group while VANT (−9.2% [−18.3, −0.04], p = 0.049), VO₂ at VANT (−4.8% [−9.8, 0.2], p = 0.06) and submaximal glucose oxidation values (−20.5% [−37.9, −3.1], p = 0.024) were lower with 6′-SL. After 12 weeks of training, VANT (−9.7% [−17.7, −1.5], p = 0.023) and VO₂ at VANT (−6.4% [−11.8, −1.0], p = 0.024) values were significantly lower in the 6′-SL group. No significant differences were observed in resting, submaximal, or maximal exercise blood lactate while the ratios of LDL to HDL (−0.27 [−0.53, −0.01], p = 0.042) and total cholesterol to HDL (−0.32 [−0.60, −0.04], p = 0.028) decreased significantly from baseline after 6 weeks of training with 6′-SL. Conclusions: 6′-SL supplementation did not promote greater gains dynamic strength, fat free mass or changes in body composition. However, while there was some evidence that 6′-SL supplementation influenced training-induced changes in aerobic capacity during the first six weeks, fewer effects were observed after 12 weeks. Moreover, several differences only approached significance in this small proof-of-concept study, so results should be viewed as exploratory and hypothesis generating for additional research. Full article

Background/Objectives: Low-carbohydrate (LCD) and ketogenic diets (KD) are increasingly adopted by athletes due to their ability to enhance fat oxidation and induce metabolic adaptations. While their effects on aerobic power and capacity have been widely investigated, their influence on anaerobic performance remains unclear. Given the strong dependence of high-intensity exercise on glycolytic metabolism and muscle glycogen availability, carbohydrate restriction may have significant implications for short-duration maximal efforts and repeated high-intensity exercise. Therefore, this systematic review and meta-analysis aimed to evaluate the effects of LCD and KD on anaerobic performance outcomes in trained athletes. Methods: A comprehensive search of five electronic databases (PubMed, SCOPUS, Web of Science, SPORTDiscus, and Cochrane Central Register of Controlled Trials) identified 13 unique studies (yielding 15 study-level entries across three anaerobic performance domains) meeting comprehensive inclusion criteria. Individual study sample sizes ranged from n = 5 to n = 65 participants, reflecting substantial inter-study variability that should be considered when interpreting pooled estimates. Outcomes included peak and mean power output, repeated sprint performance, blood lactate responses, and markers of substrate utilization. Study quality was assessed using the Newcastle–Ottawa Scale, and meta-analyses were performed using random-effects models where appropriate. Results: Overall, the effects of carbohydrate-restricted diets on anaerobic performance were domain-specific. Some studies reported maintained or slightly improved peak power during single maximal efforts, while others showed no effect. Impairments were more consistently observed in repeated high-intensity exercise. Repeated sprint performance was impaired in several studies, likely reflecting reduced muscle glycogen availability and limited glycolytic ATP production. Carbohydrate restriction consistently increased fat oxidation and was associated with lower blood lactate concentrations during high-intensity exercise. Random-effects meta-analyses yielded domain-specific pooled effect sizes: maintained-to-slightly-improved anaerobic power output (Cohen’s d = +0.29; 95% CI: −0.08 to +0.66), modestly impaired repeated sprint ability (d = −0.33; 95% CI: −0.80 to +0.14), and a large, consistent reduction in blood lactate concentration (d = −0.89; 95% CI: −1.20 to −0.58). Given substantial between-study heterogeneity in intervention durations (2 days to 12 weeks), dietary composition, athlete populations, and outcome measures (1RM, Wingate, CMJ within the power domain; varied protocols within the RSA and lactate domains), these pooled estimates should be interpreted as exploratory rather than confirmatory. Conclusions: LCD and KD appear to have domain-specific effects on anaerobic performance in trained athletes. Although single, short-duration efforts may be preserved in some contexts, repeated, high-intensity performance appears to be more susceptible to impairment. These findings highlight the importance of aligning dietary strategies with the metabolic demands of training and competition. Full article

In heart failure (HF), elevated blood lactate levels, particularly during exercise or in advanced disease stages, reflect impaired tissue perfusion and altered metabolic regulation. Beyond its traditional role as a marker of anaerobic metabolism, lactate has emerged as a dynamic indicator of metabolic reserve and ventilatory control. This narrative review summarizes current evidence on lactate dynamics at rest and during exercise, highlighting their pathophysiological and clinical relevance. In HF patients, exercise-induced lactate accumulation occurs earlier and at lower workloads, reflecting impaired oxidative capacity and reduced peripheral oxygen utilization. This phenomenon is closely associated with ventilatory inefficiency, as demonstrated by the relationship between lactate levels and the VE/VCO₂ slope during cardiopulmonary exercise testing (CPET). Emerging data suggest that lactate is not only a marker of disease severity but also a potential mediator of chemoreflex activation and abnormal ventilatory responses. Furthermore, both pharmacologic and non-pharmacologic interventions may influence lactate production and utilization, supporting its role as a potential tool for therapeutic monitoring. Overall, the integration of lactate assessment, particularly during exercise, into clinical evaluation may provide additional insight into disease mechanisms, improve risk stratification, and contribute to personalized therapeutic optimization in patients with HF. Full article

Listening to music is a well-established strategy to enhance exercise capacity, yet the specific mechanisms linking music choice to performance enhancement remain fragmented. This scoping review systematically summarizes the existing literature on the effects of music choice (i.e., self-selected, preferred music) on performance and psychophysiological determinants of exercise capacity to establish an updated rationale for the use of personalized music interventions in training. Following PRISMA-ScR guidelines, a systematic search of five databases (PubMed, Web of Science, Embase, Scopus, CINAHL) was performed for studies published between January 2000 and April 2025. Peer-reviewed articles investigating the ergogenic effects of self-selected or preferred music with psychophysiological outcomes were included. Thirty-two studies met inclusion criteria. Overall, evidence supports consistent performance enhancement from choice music (CM) across modes of exercise including aerobic endurance, anaerobic power, and muscular endurance activities while maximal strength was largely unaffected. The most robust and consistent mechanisms underpinning the benefits of CM during exercise were psychological in nature, including improvements in affect, arousal, motivation, and perception of exertion. Notable physiologic benefits were also identified, including altered cortical excitability, autonomic modulation, and improvements in neuromuscular efficiency. Herein, this review provides a psychophysiological framework whereby CM acts as a primary mediator to induce psychological and physiological cascades which synergistically contribute to ergogenic benefits. Evidence heavily supports the superiority of CM to improve exercise performance across various modalities. Full article

Heart failure (HF) with reduced ejection fraction is a systemic disorder that extends beyond cardiac dysfunction and involves peripheral organs, particularly skeletal muscle. Exercise intolerance and fatigue are the hallmark manifestations of HF that strongly predict morbidity and mortality. Accumulating evidence suggests that intrinsic skeletal muscle abnormalities are key contributors to exercise intolerance in HF. In HF, skeletal muscle undergoes metabolic remodeling characterized by shifts in fiber type composition, mitochondrial dysfunction, and increased oxidative stress. Mitochondrial dysfunction, characterized by decreased mitochondrial density, impaired biogenesis, and reduced respiratory capacity, further compromises skeletal muscle performance. These alterations impair adenosine triphosphate (ATP) generation via oxidative phosphorylation, forcing reliance on less efficient anaerobic glycolysis. The resulting metabolic shift exacerbates early lactate accumulation, muscle fatigue, and diminished exercise capacity. In parallel, an increase in oxidative and carbonyl stress, along with a decrease in antioxidant defenses as well as derangements in pathways that remove toxic lipid peroxidation, heightens oxidative and carbonyl stress perpetuating injury and establishing a vicious cycle of progressive muscle dysfunction. Thus, metabolic remodeling in skeletal muscle represents a central determinant of exercise intolerance in HF. While exercise training remains the most effective strategy to restore skeletal muscle health and exercise tolerance, emerging therapies offer novel avenues for intervention. Future research should focus on elucidating the molecular mechanisms underlying skeletal muscle dysfunction and developing therapies that restore metabolic integrity and functional capacity in HF. Full article

Vascular ageing is a complex process marked by progressive endothelial dysfunction, chronic low-grade inflammation (“inflammageing”), and reduced regenerative capacity, driven in part by an imbalance between protective endothelial autophagy and cellular senescence characterized by a proinflammatory senescence-associated secretory phenotype (SASP). Disruption of this autophagy–senescence axis accelerates vascular inflammation, arterial stiffening, and atherogenesis. High-intensity interval training (HIIT), consisting of repeated bouts of near-maximal anaerobic effort with recovery periods, is widely used by both elite and recreational athletes and is increasingly recognized as an effective nonpharmacological strategy to enhance endothelial function, arterial elasticity, and mitochondrial biogenesis. However, excessively intense or poorly structured HIIT, particularly in the absence of adequate recovery or in individuals with underlying cardiometabolic or vascular vulnerability, may induce endothelial stress and promote maladaptive vascular remodelling, including calcification and plaque instability. These considerations underscore the need for refined individualized exercise prescription strategies that balance performance benefits with endothelial protection. Based on these observations, here, we introduce a novel conceptual framework, “shear dose–calibrated HIIT,” designed to understand and define an optimal shear dose capable of maximizing autophagic flux while minimizing SASP activation. Experimental and clinical evidence of HIIT-induced effects on flow-mediated dilation (FMD), pulse wave velocity (PWV), and redox biomarkers is presented, followed by the proposal of a biomarker panel for assessing autophagic flux and cellular senescence in peripheral samples (peripheral blood mononuclear cells (PBMCs), extracellular vehicles (EVs), and plasma). This integrative approach, which combines vascular mechanotransduction, redox biology, and autophagic signalling, provides a novel translational perspective on how individually calibrated HIIT can promote vascular longevity and reduce cardiometabolic risk associated with aging and metabolic syndrome. Full article

Background: Succinic acid plays a central role in human energy metabolism as a key intermediate of the Krebs cycle that releases energy accumulated as guanosine triphosphate (GTP). Through its conversion via succinate dehydrogenase (SDH), succinate directly links the Krebs cycle to oxidative phosphorylation (OXPHOS), contributing to adenosine triphosphate (ATP) production. Exercise induces pronounced changes in succinate concentrations in skeletal muscle, blood, and saliva, with responses influenced by training status, exercise modality, and intensity. Objective: This systematic review evaluated the effects of succinate-containing supplements or sole-ingredient succinic acid supplementation on exercise performance and post-exercise recovery in healthy trained individuals. Methods: The review was conducted in accordance with PRISMA guidelines. PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar were searched without date restrictions. Interventional studies assessing succinate-containing supplementation with outcomes related to exercise performance or recovery were included. Methodological quality was evaluated using the Cochrane Risk of Bias 2 tool. This study was registered in advance with the International Prospective Register of Systematic Reviews (PROSPERO, CRD420251237042). Results: Six studies involving 153 participants (mean age: 23 years) met the inclusion criteria. Five of the six included studies were rated as having a high risk of bias, while the only study judged to be at low risk of bias reported no beneficial effects on exercise performance outcomes. Supplementation protocols included daily doses of 300–2040 mg for up to 21 days and a single acute dose of 30 mg/kg, with most interventions administering succinate as part of multi-ingredient formulations rather than as an isolated compound. Three studies reported ergogenic effects in direct performance metrics, including improvements in maximal oxygen uptake, oxygen consumption, anaerobic threshold power, and total work performed. Two additional studies demonstrated favorable physiological adaptations indirectly relevant to exercise performance, including improved acid-base regulation, hematological markers related to oxygen transport, and antioxidant status, although validated performance outcomes were not assessed. Substantial heterogeneity and overall methodological limitations precluded meta-analysis. Conclusions: Current evidence suggests that succinate-containing supplements or sole-ingredient succinic acid supplementation may enhance direct performance outcomes such as aerobic performance, total workload, and indirect physiological markers, e.g., acid-base balance, hematological indicators and antioxidant capacity in healthy trained individuals. However, given that the majority of included studies were at high risk of bias and the only low-risk study reported no ergogenic effects, current evidence does not provide reliable support for performance-enhancing benefits of succinate supplementation. Interpretation is further limited by the predominant use of multi-ingredient formulations, making it difficult to isolate the effects of succinic acid. While biologically plausible mechanisms exist, well-controlled trials using isolated succinic acid are required before conclusions regarding efficacy can be drawn. Full article

Background: Neuromuscular determinants such as maximal force, maximal velocity, and upper-body power are recognized as key contributors to competitive swimming performance. However, despite the relevance of these dry-land qualities, their relationships with the physiological mechanisms underpinning in-water performance, particularly aerobic and anaerobic capacities, remain insufficiently established. Purpose: This study aimed to investigate the relationships between upper-body load–velocity profile parameters (theoretical maximal force: F₀; theoretical maximal velocity: V₀; and maximal power: P_max), aerobic capacity expressed through critical velocity, and anaerobic capacity in trained swimmers. Methods: Thirty competitive male swimmers (age = 16.50 ± 0.31 years) completed an upper-body load–velocity profile test using the bench press exercise to determine F₀, V₀, and P_max. Swimming performances in the 100, 200, and 400 m freestyle events were used to calculate critical velocity and anaerobic capacity based on a linear distance–time model. Pearson correlation coefficients and linear regression analyses were conducted to examine the relationships between variables. Results: P_max (r = 0.493, p = 0.006) and V₀ (r = 0.697, p < 0.001) showed moderate to strong correlations with critical velocity, whereas F₀ showed no significant association (r = 0.152, p = 0.422). Conversely, anaerobic capacity was strongly correlated with F₀ (r = 0.842, p < 0.001) but not with V₀ (p = 0.119). Regression models indicated that F₀ explained 71% of the variance in anaerobic capacity, while V₀ explained 48% of the variance in critical velocity. Conclusion: The findings demonstrated distinct contributions of neuromuscular qualities: speed and power-oriented parameters are associated with critical velocity, whereas maximal strength strongly associated with anaerobic capacity. Monitoring the upper-body load–velocity profile appears to be a relevant tool for individualizing dry-land training according to the aerobic and anaerobic demands of swimmers. Full article

Regular assessment of aerobic capacity is important in sports medicine and preventive health; however, cardiopulmonary exercise testing (CPX) is often impractical in field or clinical settings. Phase angle (PhA), derived from bioelectrical impedance analysis (BIA), has been proposed as a practical indicator of cellular health and membrane integrity; however, its relevance to aerobic capacity relative to skeletal muscle mass percentage (SMM%) in healthy young adults remains unclear. This cross-sectional study investigated the independent associations of PhA and SMM% with peak oxygen uptake (VO₂peak) and oxygen uptake at the anaerobic threshold (VO₂AT). Forty-one adults underwent same-day BIA and CPX using a cycle ergometer. VO₂peak was obtained from 37 participants who achieved maximal effort, while VO₂AT was identified in all. In multiple regression analyses adjusted for sex, PhA was independently associated with both VO₂peak and VO₂AT, whereas SMM% showed no independent association. These findings indicate that PhA may serve as a stronger determinant of aerobic capacity than SMM% in healthy young adults and highlight its potential utility in settings such as routine health check-ups or preliminary screening of aerobic capacity when CPX is impractical. Full article

Objectives: The present study analyzes the effects of a high-intensity interval training (HIIT) program based on the Tabata method on physiological and psychological variables in contemporary dancers (n = 10) and sedentary individuals (n = 8), who performed a 10-week protocol, with sessions of self-loading exercises structured in intervals of 20 s of effort and 10 s of rest three times a week. Methods: Parameters of body composition, muscle strength, aerobic and anaerobic capacity, heart rate variability, as well as perceptions of health, anxiety, stress, sleep quality, and levels of physical activity and sedentary lifestyle were evaluated. Results: The results showed that no significant changes occurred in most body composition variables, except for visceral fat, where group differences were observed (F = 5.66, p = 0.030, η²ₚ = 0.261). In the indicators of strength and power, the dancers improved the height and relative power of the jump (F = 5.996, p = 0.026, η²ₚ = 0.273), while the sedentary ones increased the strength of the handgrip (p = 0.023). In terms of functional performance, both groups significantly increased anaerobic endurance (F = 10.374, p = 0.005, η²ₚ = 0.393), although no changes were recorded in maximal oxygen consumption or heart rate variability (p > 0.05). On a psychological level, improvements in healthy lifestyle habits and a decrease in the trait anxiety variable were evidenced in dancers (p = 0.023), while in sedentary participants no relevant effects were found. Conclusions: In conclusion, the Tabata protocol may represent an efficient and complementary strategy to enhance strength, anaerobic power, and psychological well-being, particularly among dancers. The observed improvements suggest potential benefits related to movement quality, injury prevention, and general physical conditioning. Full article

Introduction: Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in children. It is believed that children with JIA have lower cardiopulmonary capacity and worse exercise tolerance. The gold standard for assessing physical fitness is aerobic fitness, commonly referred to as the maximum or peak oxygen uptake volume (peakVO₂) measured during a maximum load exercise test. Reduced aerobic fitness may play a key role in predicting the health of JIA patients as it has been associated with cardiovascular diseases and increased adult mortality. Methods: The aim of this study was to assess the oxygen capacity of adolescents with JIA along with other cardiopulmonary parameters in order to determine a group of patients with increased risk of developing cardiovascular diseases in comparison with healthy individuals. Patients were assessed based on parameters such as age, sex, type of JIA, laboratory parameters, physical activity, and treatment. Results: Patients with JIA had lower median values of peakVO₂ (29.05 vs. 38.02 mL/min/kg, p < 0.001), as well as other crucial cardiopulmonary parameters, such as O₂ pulse, minute ventilation, oxygen uptake efficiency slope, and cardiac output than in the healthy control group. The ventilatory anaerobic threshold was achieved earlier and at lower VO₂ values in children with JIA (p = 0.0001). Children with JIA also had lowered respiratory parameters such as maximal voluntary ventilation (p = 0.0031) and tidal volume (p = 0.0002). Patients who were physically active (moderate-intensity physical activity lasting at least 60 min per day) had significantly higher peakVO₂ (p = 0.0099) and ΔVO₂/ΔWR relationship (p = 0.0041) values than JIA patients who were not physically active. Conclusions: Children with JIA show moderate to severe physical impairment. Reduced physical fitness and a low level of activity might be associated with further deterioration of patient’s condition, which might contribute to increased risk of cardiovascular disease, social exclusion and deterioration of quality of life in this group of patients. Exercise programs that improve aerobic fitness and increase muscle strength should be individualized and modified based on the individual needs and capabilities of the patient. Full article

Nitric oxide (NO) plays a crucial role in muscle oxidative capacity, which predicts muscle strength. This study aimed to investigate whether different breathing techniques (nasal or oral breathing) affect muscle performance during acute exhaustive exercise. In our study, 49 healthy individuals (24♀/25♂; age 22.8 ± 3.4 years) performed two Wingate anaerobic tests in a counterbalanced order. Although perceived exertion was significantly higher with oral breathing (Borg Scale: 9.0 ± 1.1 vs. 8.0 ± 1.3, p = 0.04), breathing mode did not impact power output (peak: 749 ± 290 vs. 728 ± 284 W; average: 576 ± 217 vs. 575 ± 216 W, p = 0.2). NIRS data indicated no significant differences in muscle desaturation between the two breathing modes; however, nasal breathing resulted in significantly faster (0.45 ± 0.4 vs. 0.23 ± 0.12%/s, p = 0.02) and greater (75.2 ± 4.0 vs. 73.1 ± 3.6%, p = 0.04) post-exercise muscle recovery. As an indirect marker of NO bioavailability, flow-mediated dilation (FMD) was associated with a significant improvement (Pre: 107.4 ± 3.0% vs. Post: 110.3 ± 3.6%, p < 0.001) via nasal breathing only, with a significant difference between the two breathing modes (p < 0.0001). Therefore, we suggest that the nitrate–nitrite–NO pathway enhances muscle energy and function, which highlights the importance of nasal breathing. Full article