Introduction: Right heart changes and their association with exercise capacity, including sex differences, are still being investigated. We analysed right heart structure and its relationship with exercise capacity parameters in amateur cyclists. Materials and methods: A cross-sectional study involving 215 consecutive adult amateur cyclists, who underwent resting transthoracic echocardiography and a cardiopulmonary exercise test (CPET) to exhaustion was performed. Results: The median age of participants was 29 years (IQR 24-37), 71% of them were men. The mean training time was 6 h/week, and 90% participated in vigorous or moderate physical activity. Men had larger right ventricular diameters (basal - RVD1, mid-cavity - RVD2 and longitudinal - RVD3) compared to women (40.9 vs. 37.6 mm, p = 0.0005, 28.7 vs. 26.3 mm, p = 0.03, 92.2 vs. 81.9 mm, p < 0.0001). Indexing for body surface area revealed comparable right atrial volume (RAVI) between sexes (24.1 vs. 22.7 mL/m2). Men achieved higher peak exercise capacity parameters [O2 pulse, oxygen consumption (VO2) and workload] in CPET. Multivariate linear regression models revealed a positive association between peak VO2, workload and O2 pulse with RAVI in women but not with RVD1 or RVD3. Conversely, these parameters showed a positive association with RVD3 and RVD1 but not with RAVI in men. Conclusion: Sex differences exist in the relationship between right heart structural parameters and peak exercise capacity descriptors in amateur cyclists. Better exercise capacity during CPET to exhaustion is associated with greater RAVI in women but a greater RVD1 and RVD3 in men. These findings suggest different mechanisms of right heart adaptation to training in men and women.

UNASSIGNED: Moderate regular physical activity is indicated to avoid atrial fibrillation (AF), whereas athletes should be counseled that long-lasting vigorous sports engagement may cause AF, according to the 2016 European Society of Cardiology (ESC) recommendations for AF treatment. Exercise and AF are complex.
UNASSIGNED: To evaluate the relationship between Endurance training and AF, in addition to the starting point/trigger by which Endurance Training causes impairment of cardiac function and AF, considering the time and intensity of Endurance training.
UNASSIGNED: We synthesized evidence from articles published in the PubMed, EMBASE, and SciELO databases using their respective Boolean operators. A total of 112 original articles related to AF and endurance athletes published up to the year 2023 were reviewed.
UNASSIGNED: Our study verified multiples aspects of the genesis of AF in athletes, such as cardiac adaptations to exercise, disturbances in cardiac injury biomarkers, sex differences in cardiac adaptations and their role in AF risk, and the relationship between body composition (height, weight, and physical fitness) and AF pathogenesis.
UNASSIGNED: Variations in cardiac structure (increased atrial thickness and size in addition to myocardial fibrosis) and significant increases in vagal tone (sinus bradycardia and imbalances in sympathetic and parasympathetic activation) shorten the refractory period shortening in athletes, induce the onset of re-entrance mechanisms, and serve as ectopic triggers that can lead to AF.

Researchers have studied the effects of exercise on serum methyl-arginine and vitamin D metabolites; however, the effects of exercise combined with antioxidants are not well documented. Since oxidative stress affects the metabolism of vitamin D and methyl-arginine, we hypothesised that the antioxidant coenzyme Q10 (CoQ10) might modulate exercise-induced changes. A group of twenty-eight healthy men participated in this study and were divided into two groups: an experimental group and a control group. The exercise test was performed until exhaustion, with gradually increasing intensity, before and after the 21-day CoQ10 supplementation. Blood samples were collected before, immediately after, and 3 and 24 h after exercise. CoQ10, vitamin D metabolites, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine, methylarginine, dimethylamine, arginine, citrulline, and ornithine were analysed in serum samples. CoQ10 supplementation caused a 2.76-fold increase in the concentration of serum CoQ10. Conversely, the 25(OH)D3 concentration increased after exercise only in the placebo group. ADMA increased after exercise before supplementation, but a decrease was observed in the CoQ10 supplementation group 24 h after exercise. In conclusion, our data indicate that CoQ10 supplementation modifies the effects of exercise on vitamin D and methyl-arginine metabolism, suggesting its beneficial effects. These findings contribute to the understanding of how antioxidants like CoQ10 can modulate biochemical responses to exercise, potentially offering new insights for enhancing athletic performance and recovery.

BACKGROUND: Endurance is an important capacity to sustain healthy lifestyles. Aged garlic extract (AGE) has been reported to exert an endurance-enhancing effect in clinical and animal studies, although little is known about its active ingredients and mechanism of action.
OBJECTIVE: This study investigated the potential effect of S-1-propenylcysteine (S1PC), a characteristic sulfur amino acid in AGE, on the swimming endurance of mice, and examined its mechanism of action by a metabolomics-based approach.
METHODS: Male Institute of Cancer Research (ICR) mice (6 wk old) were orally administered either water (control) or S1PC (6.5 mg/kg/d) for 2 wk. The swimming duration to exhaustion was measured at 24 h after the final administration. Nontargeted metabolomic analysis was conducted on the plasma samples obtained from mice after 40-min submaximal swimming bouts. Subsequently, the enzyme activity of carnitine acyltransferase-1 (CPT-1) and the content of malonyl-coenzyme A (CoA), acetyl-CoA, and adenosine triphosphate (ATP) were quantified in heart, skeletal muscles, and liver of mice.
RESULTS: The duration time of swimming was substantially increased in the S1PC-treated mice as compared with the control group. Metabolomic analysis revealed significant alterations in the plasma concentration of the metabolites involved in fatty acid metabolism, in particular medium- or long-chain acylcarnitines in the mice treated with S1PC. Moreover, the administration of S1PC significantly enhanced the CPT-1 activity with the concomitant decrease in the malonyl-CoA content in the heart and skeletal muscles. These effects of S1PC were accompanied by the elevation of the acetyl-CoA and ATP levels to enhance the energy production in those tissues.
CONCLUSIONS: S1PC is a key constituent responsible for the endurance-enhancing effect of AGE. This study suggests that S1PC helps provide energy during endurance exercise by increasing fatty acid metabolism via CPT-1 activation in the heart and skeletal muscles.

OBJECTIVE: The aim of this study was to determine the influence of the CYP1A2 c.-163 A > C (rs762551) polymorphism on the effect of oral caffeine intake on fat oxidation during exercise.
METHODS: Using a pilot randomized, double-blind, crossover, placebo-controlled trial, 32 young and healthy individuals (women = 14, men = 18) performed an incremental test on a cycle ergometer with 3-min stages at workloads from 30 to 70% of maximal oxygen uptake (VO2max). Participants performed this test after the ingestion of (a) placebo; (b) 3 mg/kg of caffeine; (c) 6 mg/kg of caffeine. Fat oxidation rate during exercise was measured by indirect calorimetry. The influence of the CYP1A2 c.-163 A > C polymorphism in the effect of caffeine on fat oxidation rates during exercise was established with a three-way ANOVA (substance × genotype × intensity).
RESULTS: Eight participants were genotyped as AA, 18 participants were CA heterozygotes, and 6 participants were CC. There was a main effect of substance (F = 3.348, p = 0.050) on fat oxidation rates during exercise with no genotype effect (F = 0.158, p = 0.959). The post hoc analysis revealed that, in comparison to the placebo, 3 and 6 mg/kg of caffeine increased fat oxidation at 40-50% VO2max in AA (all p < 0.050) and 50-60% VO2max in CA and CC participants (all p < 0.050).
CONCLUSIONS: Oral intake of 3 and 6 mg/kg of caffeine increased fat oxidation rate during aerobic exercise in individuals with AA, CA and CC genotypes. This suggests that the effect of caffeine to enhance fat oxidation during exercise is not influenced by the CYP1A2 c.-163 A > C polymorphism.
BACKGROUND: The study was registered on clinicaltrials.gov with ID: NCT05975489.

暂无摘要。

The main objective of this placebo-controlled, triple-blind, balanced crossover study was to assess the acute effects of phenylcapsaicin (PC) intake (2.5 mg) on intraocular pressure (IOP), ocular perfusion pressure (OPP), and heart rate (HR) during a 30-min cycling task performed at 15% of the individual maximal power. Twenty-two healthy young adults performed the cycling task 45 min after ingesting PC or placebo. IOP was measured with a rebound tonometer before exercise, during cycling (every 6 min), and after 5 and 10 min of recovery. OPP was assessed before and after exercise. HR was monitored throughout the cycling task. We found an acute increase of IOP levels related to PC consumption while cycling (mean difference = 1.91 ± 2.24 mmHg; p = .007, ηp2=.30), whereas no differences were observed for OPP levels between the PC and placebo conditions (mean difference = 1.33 ± 8.70 mmHg; p = .608). Mean HR values were higher after PC in comparison with placebo intake (mean difference = 3.11 ± 15.87 bpm, p = .019, ηp2=.24), whereas maximum HR did not differ between both experimental conditions (p = .199). These findings suggest that PC intake before exercise should be avoided when reducing IOP levels is desired (e.g., glaucoma patients or those at risk). Future studies should determine the effects of different ergogenic aids on IOP and OPP levels with other exercise configurations and in the long term.

This study aimed to investigate how intermittent hyperoxic exposure (three cycles of 21% O2 [10 min] and 30% O2 [15 min]) affects exercise performance in mice. Three hours after the acute exposure, there was an observed increase in mRNA levels of phosphofructokinase (Bayes factor [BF] ≥ 10), mitochondrial transcription factor-A (BF ≥10), PPAR-α (BF ≥3), and PPAR-γ (BF ≥3) in the red gastrocnemius muscle (Gr). Four weeks of exercise training under intermittent (INT), but not continuous (HYP), hyperoxia significantly (BF ≥30) increased maximal exercise capacity compared to normoxic exercise-trained (ET) group. INT group exhibited significantly higher activity levels of 3-hydroxyacyl-CoA-dehydrogenase (HAD) in Gr (BF = 7.9) compared to ET group. Pyruvate dehydrogenase complex activity levels were significantly higher in INT group compared to ET group in white gastrocnemius, diaphragm, and left ventricle (BF ≥3). NT-PGC1α protein levels in Gr (BF = 7.7) and HAD activity levels in Gr (BF = 6.9) and soleus muscles (BF = 3.3) showed a significant positive correlation with maximal work values. These findings suggest that exercise training under intermittent hyperoxia is a beneficial strategy for enhancing endurance performance by improving fatty acid and pyruvic acid utilization.

BACKGROUND: Endurance exercise has the potential to affect reproductive function, with amenorrhea in female athletes. However, most studies focus on women. Evidence on the association between endurance exercise and male fertility is limited.
OBJECTIVE: To synthesise existing literature on exercise-induced alterations in semen parameters and to assess the clinical impact on male fertility.
METHODS: Studies reporting on the association between semen parameters and endurance exercise in healthy men were eligible. Men attending fertility clinics were excluded. We searched MEDLINE (PubMed), Embase, SPORTDiscus, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov and International Clinical Trials Registry Platform (ICTRP) from their inception to May 28th 2022. JBI Critical Appraisal Tool was used to assess the potential risk of bias.
RESULTS: Thirteen studies met inclusion criteria, reporting on 280 subjects. Eight articles reported on endurance runners, three on cyclists and four on triathletes. Four studies did not find any statistically significant sperm alterations. Five reported significant changes in semen parameters, but these were not clinically relevant, as semen parameters remained well above World Health Organisation (WHO) thresholds. Four articles reported a decrease in semen quality with potential clinical consequences as they found a reduced number of sperm cells exhibiting normal morphology in cyclists and triathletes and a greater amount of DNA fragmentation in triathletes.
CONCLUSIONS: Endurance exercise can have a negative effect on semen quality, although rarely with a clinically relevant impact on male fertility. Evidence is however limited, with poor quality of the included studies.
BACKGROUND: PROSPERO International prospective register of systematic reviews (CRD42022336753).

BACKGROUND: Although resistance training is frequently prescribed for people with haemophilia (PWH), no previous meta-analyses have quantified the effect of this intervention on muscle strength, nor the implications of the intervention\'s modality and duration.
OBJECTIVE: (1) To determine the effects of resistance training on muscle strength in adults with haemophilia; (2) To determine the most effective duration and modality among the exercise protocols.
METHODS: A systematic search from inception until 28 November 2023 was conducted in PubMed, Embase, Web of Science, CENTRAL and CINAHL databases. We included randomised controlled trials or before-after studies that involved resistance training without other physiotherapy co-interventions. Study selection, data extraction and risk of bias assessment were independently performed by two reviewers. Disagreements were resolved in consultation with a third author. The level of evidence was determined according to the GRADE methodology.
RESULTS: Seven studies were included. Measurements of knee extensor strength and elbow extensor strength were included in the meta-analysis. Subgroup analysis showed significant effects for both elastic resistance protocols (SMD: 0.54; 95% CI: 0.02-1.07) and conventional training (isometric and weight-based equipment) (SMD: 0.88; 95% CI: 0.50-1.25), demonstrating small and moderate effect sizes respectively. Additionally, both protocols of duration 5-7 weeks (SMD: 1.16, 95% CI: 0.63-1.69) as well as those of duration ≥8 weeks (SMD: 0.57, 95% CI: 0.20-0.94) showed a significant difference.
CONCLUSIONS: Resistance training is effective in improving muscle strength of the knee and elbow extensors in PWH. Both elastic resistance and conventional training show benefits.