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Journal of Sports Sciences May 2024We assessed the accuracy and inter-sessional reliability of traditional (manual) compared to automatic (AutoHR) heart rate (HR) clamping methods during submaximal...
We assessed the accuracy and inter-sessional reliability of traditional (manual) compared to automatic (AutoHR) heart rate (HR) clamping methods during submaximal intensity continuous cycling. On separate occasions, thirteen males cycled at an HR corresponding to 80% of the ventilatory threshold for 18 min. Cycling power output was adjusted using either manual or AutoHR methods, encompassing three trials per method. For the manual method, cycling power output was adjusted every 30 s by 0, 5 or 10 W at the experimenter's discretion. Conversely, AutoHR automatically adjusted power output based on the difference between target and actual HR. Participants' HR was measured at 1 Hz. Root-mean square error (RMSE) and intraclass correlation coefficients (ICC) were calculated from the difference between measured and target HR to represent accuracy and reliability of each method. The RMSE for the manual method (3.2 ± 2.6 bpm) was significantly higher compared to AutoHR (2.8 ± 2.3 bpm) ( < 0.01, = 0.13); inter-day ICC were 0.92 and 0.89 for manual adjustment and AutoHR, respectively. Automatic methods to clamp HR are more accurate than manual approaches during submaximal intensity continuous cycling and can be easily implemented for uniform HR control in individual and group training sessions at minimal cost.
Topics: Humans; Male; Heart Rate; Bicycling; Reproducibility of Results; Young Adult; Adult; Ergometry; Exercise Test; Oxygen Consumption
PubMed: 38916194
DOI: 10.1080/02640414.2024.2369353 -
The Journal of Sports Medicine and... Jul 2024Oxygen uptake efficiency slope (OUES) is an objective physiological measure that can be obtained from a standard graded exercise test. However, there is conflicting...
BACKGROUND
Oxygen uptake efficiency slope (OUES) is an objective physiological measure that can be obtained from a standard graded exercise test. However, there is conflicting evidence regarding sex differences in OUES values in children. Therefore, this study investigated potential sex differences in absolute, ratio-scaled, and allometrically scaled OUES in 8.0- to 12.0-year-old children.
METHODS
Retrospective and prospective data of 18 boys and 22 girls were utilized. All participants had undergone familiarization before performing a maximal cycle ergometer test to determine OUES. These values were also ratio-scaled and allometrically scaled to mass and body surface area (BSA). Group differences were tested via independent sample t-tests (or Mann-Whitney U if not normally distributed).
RESULTS
Absolute OUES values (VO
2 mL∙min/log10 VE L∙min) were significantly higher in boys compared to girls (1860.8±359.3 vs. 1514.3±212.6). When scaled to mass (VO2 mL∙kg∙min/log10 VE L∙kg∙min), OUES was no longer significantly different between groups, but when scaled to BSA (VO2 mL∙m∙min/log10 VE L∙m∙min), OUES was significantly higher in the boys than the girls (1414.4±204.2 vs. 1268.9±134.6). When allometry was applied for mass (OUES/mass) boys had significantly higher value than girls (350.8±46.7 vs. 305.0±31.5).CONCLUSIONS
The present study demonstrated that boys had greater OUES values scaled to BSA and allometrically scaled to body mass. These findings provide further evidence of sex differences with OUES values in preadolescent children and implies the need for sex-specific reference values prior to using OUES for the assessment of cardiorespiratory pathology in children.
Topics: Humans; Male; Child; Female; Exercise Test; Oxygen Consumption; Sex Factors; Retrospective Studies; Prospective Studies; Body Surface Area
PubMed: 38916085
DOI: 10.23736/S0022-4707.24.15597-1 -
The Journal of Sports Medicine and... Jul 2024An athlete's career inevitably goes through periods of forced physical exercise interruption like a knee injury. Advanced echocardiographic methods and cardiopulmonary...
BACKGROUND
An athlete's career inevitably goes through periods of forced physical exercise interruption like a knee injury. Advanced echocardiographic methods and cardiopulmonary exercise testing (CPET) are essential in evaluating athletes in the period elapsing after the injury. However, the feasibility of a maximal pre-surgery CPET and the capacity of resting advanced echocardiographic techniques to predict cardiorespiratory capacity still need to be clarified.
METHODS
We evaluated 28 non-professional athletes aged 18-52, involved in prevalently aerobic or alternate aerobic/anaerobic sports activities, affected by a knee pathology with indications for surgical treatment. The evaluation was performed at rest by trans-thoracic echocardiography, including global longitudinal strain (GLS) and myocardial work (MW) assessment, and during exercise by CPET.
RESULTS
The percent-predicted peak oxygen consumption (peak VO
2 %) was 82.8±13.7%, the mean respiratory exchange ratio was 1.16±0.08, and the mean ventilation/carbon dioxide (VE /VCO2 ) slope was 24.23±3.36. Peak VO2 % negatively correlated with GLS (r=-0.518, P=0.003) and global wasted work (GWW) (r =-0.441, P=0.015) and positively correlated with global work efficiency (GWE) (r=0.455, P=0.012). Finally, we found that the VE /VCO2 slope during exercise was negatively correlated with GWE (r=-0.585, P=0.001) and positively correlated with GWW (r=0.499, P=0.005).CONCLUSIONS
A maximal CPET can be obtained in deconditioned athletes because of a knee injury, allowing a comprehensive functional pre-surgery evaluation. In these patients, peak VO
2 is reduced due to decreased physical activity after injury; however, a lower cardiopulmonary efficiency may be a concause of the injury itself. In addition, we demonstrated that the MW indexes obtained at rest could predict exercise capacity and ventilatory efficiency as evaluated by CPET.Topics: Humans; Exercise Test; Adult; Oxygen Consumption; Male; Knee Injuries; Young Adult; Female; Middle Aged; Echocardiography; Adolescent; Cardiorespiratory Fitness; Athletes
PubMed: 38916084
DOI: 10.23736/S0022-4707.24.15496-5 -
The Impact Plant-Based Diets Have on Athletic Performance and Body Composition: A Systematic Review.Journal of the American Nutrition... Jun 2024Plant-based diets have gained popularity among athletes in recent years. Some believe that plant-based diets will improve performance owing to higher intakes of... (Review)
Review
Plant-based diets have gained popularity among athletes in recent years. Some believe that plant-based diets will improve performance owing to higher intakes of carbohydrates and antioxidants. Some believe it that will harm performance due to lower intakes of complete protein and creatine. This systemic review was conducted using Covidence software. A literature search of PubMed, Embase (Elsevier), CINAHL Plus (EBSCO), and Web of Science was completed on 22 March 2022. Following the development of clear objectives and a research question that identified the population, intervention, comparison, and outcomes, initial search criteria and keywords were identified. Extracted results totaled 2249, including 797 duplicates. The initial screening resulted in 1437 articles being excluded. The remaining 15 articles proceeded to full-text screening. A final 8 articles were included in the review, with 7 excluded. This paper will review the impact plant-based diets have on athletic performance and body composition in healthy young adults aged 18 to 45 years.
PubMed: 38913935
DOI: 10.1080/27697061.2024.2365755 -
Environmental Monitoring and Assessment Jun 2024Changes to the physicochemical parameters of water in alpine/mountain streams can provide evidence of ongoing natural and anthropogenic processes in their catchment. In...
Changes to the physicochemical parameters of water in alpine/mountain streams can provide evidence of ongoing natural and anthropogenic processes in their catchment. In this study, we analysed a mountain stream (Javorinka) on the north-eastern side of the Tatra Mountains (Western Carpathians), which is minimally influenced by human activity. The stream was monitored weekly for 5 years (2017-2021) and evaluated for its seasonal variations in physicochemical parameters. These seasonal variations were influenced by the large summer flash flood in July 2018. We hypothesise that floods are essential for the oligotrophic profile of alpine/mountain streams. To support this idea, our main objective was to compare the seasonal trends of the main physicochemical parameters in the stream before and after floods or periods of high flow. We found evidence to support our hypothesis. For example, there was a significant decrease in the chemical consumption of oxygen and ammonia, and, conversely, an increase in the ratio of saturated oxygen and nitrate concentrations. Stream bed erosion also resulted in increased phosphates (over the next 2 years) and high enrichment of the water by dissolved solids in the spring. Interestingly outside of the main objectives, we observed a significant decrease in sulphates, especially in the summer and autumn of 2020 and 2021, which may be related to suppressed emissions due to the restriction of the COVID-19 lockdown. The observed trends and their changes therefore support the idea that alpine/mountain streams are excellent indicators of ongoing environmental processes, and that occasional summer flash floods support the oligotrophic profile of the stream system.
Topics: Rivers; Floods; Environmental Monitoring; Seasons; COVID-19
PubMed: 38913150
DOI: 10.1007/s10661-024-12835-4 -
Inorganic Chemistry Jun 2024New diruthenium complexes based on the scaffold RuCp(CO) (Cp = η-CH) and containing a bridging vinyliminium ligand, [-]CFSO, were synthesized through regioselective...
New diruthenium complexes based on the scaffold RuCp(CO) (Cp = η-CH) and containing a bridging vinyliminium ligand, [-]CFSO, were synthesized through regioselective coupling of alkynes with an aminocarbyne precursor (85-90% yields). The reaction involving phenylacetylene proceeded with the formation of a diruthenacyclobutene byproduct, []CFSO (10% yield). Complexes [-] undergo partial alkyne extrusion in contact with alumina or CDCl. All products were characterized by elemental analysis, infrared and multinuclear NMR spectroscopy, and single crystal X-ray diffraction in two cases. Complexes [-] revealed an outstanding stability in DMEM cell culture medium at 37 °C (<1% degradation over 72 h). These complexes exhibited cytotoxicity in human colon colorectal adenocarcinoma HT-29 cells in the low micromolar range, with lower IC values than those obtained with the homologous diiron complexes previously reported. Evaluation of ROS (reactive oxygen species) production and O consumption rate (OCR) highlighted the higher potential of Ru complexes, compared to the Fe counterparts, to impact mitochondrial activity, with the heterometallic Ru-ferrocenyl complex [] showing the best performance.
PubMed: 38912873
DOI: 10.1021/acs.inorgchem.4c01119 -
PeerJ 2024(Thunb.) Makino, a well-known edible and medicinal plant, has anti-aging properties and is used to treataging-associated conditions such as diabetes, metabolic...
BACKGROUND
(Thunb.) Makino, a well-known edible and medicinal plant, has anti-aging properties and is used to treataging-associated conditions such as diabetes, metabolic syndrome, and cardiovascular diseases. Gypenosides (GYPs) are the primary constituents of . Increasing evidence indicates that GYPs are effective at preserving mitochondrial homeostasis and preventing heart failure (HF). This study aimed to uncover the cardioprotective mechanisms of GYPs related to mitochondrial regulation.
METHODS
The bioactive components in GYPs and the potential targets in treating HF were obtained and screened using the network pharmacology approach, followed by drug-disease target prediction and enrichment analyses. The pharmacological effects of GYPs in cardioprotection, mitochondrial function, mitochondrial quality control, and underlying mechanisms were further investigated in Doxorubicin (Dox)-stimulated H9c2 cardiomyocytes.
RESULTS
A total of 88 bioactive compounds of GYPs and their respective 71 drug-disease targets were identified. The hub targets covered MAPK, EGFR, PI3KCA, and Mcl-1. Enrichment analysis revealed that the pathways primarily contained PI3K/Akt, MAPK, and FoxO signalings, as well as calcium regulation, protein phosphorylation, apoptosis, and mitophagy process. In Dox-stimulated H9c2 rat cardiomyocytes, pretreatment with GYPs increased cell viability, enhanced cellular ATP content, restored basal oxygen consumption rate (OCR), and improved mitochondrial membrane potential (MMP). Furthermore, GYPs improved PINK1/parkin-mediated mitophagy without influencing mitochondrial fission/fusion proteins and the autophagic LC3 levels. Mechanistically, the phosphorylation of PI3K, Akt, GSK-3β, and the protein level of Mcl-1 was upregulated by GYP treatment.
CONCLUSION
Our findings reveal that GYPs exert cardioprotective effects by rescuing the defective mitophagy, and PI3K/Akt/GSK-3/Mcl-1 signaling is potentially involved in this process.
Topics: Gynostemma; Mitophagy; Glycogen Synthase Kinase 3 beta; Signal Transduction; Myeloid Cell Leukemia Sequence 1 Protein; Proto-Oncogene Proteins c-akt; Cardiotonic Agents; Plant Extracts; Phosphatidylinositol 3-Kinases; Animals; Rats; Myocytes, Cardiac; Cell Line
PubMed: 38912051
DOI: 10.7717/peerj.17538 -
BMJ Military Health Jun 2024Administering supplemental oxygen is a standard of care for trauma casualties to minimise the deleterious effects of hypoxaemia. Forward deployment of oxygen using...
INTRODUCTION
Administering supplemental oxygen is a standard of care for trauma casualties to minimise the deleterious effects of hypoxaemia. Forward deployment of oxygen using pressurised cylinders is challenging, for example, logistics (weight and finite resource) and environmental risk (fire and explosion). Oxygen concentrators may overcome these challenges. Although previous studies successfully demonstrated fractional inspired oxygen (FiO) >0.8 using oxygen concentrators and ventilators, the systems did not fulfil the size, weight and power requirements of agile military medical units. This study evaluated whether a modular system of commercially available clinical devices could supply high FiO to either ventilated or spontaneously breathing casualties.
METHODS
As a proof of principle, we configured an Inogen One G5 oxygen concentrator, Ventway Sparrow ventilator and Wenoll rebreather system to ventilate a simulated lung (tidal volume 500 mL). Casualty oxygen consumption (gas withdrawal inspiratory limb) and carbon dioxide (CO) production (CO added expiratory limb) were simulated (respiratory quotient of 0.7-0.8). Three circuit configurations were evaluated: open (supplementary oxygen introduced into air inlet of ventilator); semiclosed (ventilator replaces rebreather bag of Wenoll, oxygen connected to either ventilator or Wenoll); and semiclosed with reservoir tubing (addition of 'deadspace' tube between ventilator patient circuit and Wenoll). Data presented as mean and 95% reference range.
RESULTS
There were modest increases in FiO with increasing Inogen settings in 'open' configuration 0.23 (0.23-0.24) and 0.30 (0.28-0.32) (Inogen output 420 and 1260 mL/min, respectively). With the 'semiclosed' configuration and oxygen added directly into rebreather circuit, FiO increased to 0.36 (0.36-0.37). The addition of the 'reservoir tubing' elevated FiO to 0.78 (0.71-0.85). FiO remained stable over a 4-hour evaluation period. Fractional inspired carbon dioxide CO increased over time, reaching 0.005 after 170 (157-182) min.
CONCLUSION
Combining existing lightweight devices can deliver high (>0.8) FiO and offers a potential solution for the forward deployment of oxygen without needing pressurised cylinders.
PubMed: 38909997
DOI: 10.1136/military-2024-002727 -
Aquatic Toxicology (Amsterdam,... Jun 2024Microplastics (MPs) are a heterogeneous class of pollutants fouling aquatic environments and they are hazardous to aquatic organisms. This study investigated the...
Microplastics (MPs) are a heterogeneous class of pollutants fouling aquatic environments and they are hazardous to aquatic organisms. This study investigated the size-dependent effects of polystyrene microspheres (PSMPs) on the swimming ability, metabolism, and oxidative stress of juvenile grass carp (Ctenopharyngodon idella). Test fish were exposed to four sizes of PSMPs (0.07, 0.5, 5, and 20-μm), and swimming ability was tested after different exposure times (2, 7, and 15 days). To measure the effect on swimming ability, critical swimming speed (U) was determined, and to assess metabolic effects, oxygen consumption (MO), routine metabolic rate (RMR), maximum oxygen consumption (MMR), and excess post-exercise oxygen consumption (EPOC) were determined. To assess the effects on oxidative stress, the activities of two antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT) were determined in the liver and gills of test fish. After exposure to 20 μm PSMPs, there was a significant drop in U compared to the control group (P<0.05), with decreases of 22 % on Day 2 and Day 7, and 21 % on Day 15. The RMR and MMR increased significantly (P<0.05), the RMR by 23.9 % on Day 2 and the MMR by 17.2 % on Day 2 and on Day 15, 44.7 % and 20.0 % respectively. The EPOC decreased with exposure time, by 31 % (0.07-μm), 45 %-(0.5-μm), 49 % (5-μm), and 57 % (20-μm) after 15 days. Exposure to the larger PSMPs increased CAT and SOD activity more than the smaller PSMPs and the increases began with SOD activity in the gills. The larger PSMPs were consistently more harmful to juvenile grass carp than the smaller PSMPs. Our results clearly show that PSMPs have detrimental effects on juvenile grass carp and provide additional scientific evidence that environmental monitoring and regulation of microplastic pollution is necessary.
PubMed: 38909584
DOI: 10.1016/j.aquatox.2024.107009 -
Scientific Reports Jun 2024Microglia, brain-resident macrophages, can acquire distinct functional phenotypes, which are supported by differential reprogramming of cell metabolism. These...
Microglia, brain-resident macrophages, can acquire distinct functional phenotypes, which are supported by differential reprogramming of cell metabolism. These adaptations include remodeling in glycolytic and mitochondrial metabolic fluxes, potentially altering energy substrate availability at the tissue level. This phenomenon may be highly relevant in the brain, where metabolism must be precisely regulated to maintain appropriate neuronal excitability and synaptic transmission. Direct evidence that microglia can impact on neuronal energy metabolism has been widely lacking, however. Combining molecular profiling, electrophysiology, oxygen microsensor recordings and mathematical modeling, we investigated microglia-mediated disturbances in brain energetics during neuroinflammation. Our results suggest that proinflammatory microglia showing enhanced nitric oxide release and decreased CX3CR1 expression transiently increase the tissue lactate/glucose ratio that depends on transcriptional reprogramming in microglia, not in neurons. In this condition, neuronal network activity such as gamma oscillations (30-70 Hz) can be fueled by increased ATP production in mitochondria, which is reflected by elevated oxygen consumption. During dysregulated inflammation, high energy demand and low glucose availability can be boundary conditions for neuronal metabolic fitness as revealed by kinetic modeling of single neuron energetics. Collectively, these findings indicate that metabolic flexibility protects neuronal network function against alterations in local substrate availability during moderate neuroinflammation.
Topics: Animals; Neurons; Energy Metabolism; Microglia; Mice; Neuroinflammatory Diseases; Glucose; Mitochondria; Nitric Oxide; Lactic Acid; Nerve Net; Brain; Oxygen Consumption; Adenosine Triphosphate; Inflammation; Male; Mice, Inbred C57BL
PubMed: 38909138
DOI: 10.1038/s41598-024-64872-1