Swimming Endurance Research Articles

Nutritional Preparation for an Ultra-Endurance Swimmer: A Case Report

Introduction: Nutritional considerations and metabolic determinates for ultra-endurance events continue to evolve with the increasing popularity of events. This case study assessed the nutritional requirements required of 30-year-old male ultra-endurance athlete to successfully complete an endurance open-water swim. Methods: Dietary intake in preparation for the event was assessed, estimated caloric needs, and a nutritional analysis was performed on the athlete to determine nutritional intake that was required to successfully complete the endurance swim event. The athlete was monitored for 24.3 miles (Ontario, Canada to Northeast, Pennsylvania, United States). Day of nutritional changes were observed, and body composition was assessed pre- and post-event. Results: The swimmer was monitored for 11 hours, 28 minutes and 5 seconds. Determination of athletes’ potential metabolic energy would shape the energy cost to complete the endurance event. Modifications prior to the ultra-endurance swim event met the athlete’s energy requirement for training and the energy reserve needed for the endurance swim event. Conclusions: The addition of calories and nutritional modifications prior to the ultra-endurance swim event met the athlete’s energy requirement for training and the energy reserve needed for the endurance swim event. This case study highlights the importance of providing nutritional support for ultra-endurance athletes and the difficulty in predicting energy expenditure for such an event.

Assessment of blood biochemical parameters in endurance swimming: Hematological biomarkers and their implications

Assessment of blood biochemical parameters in endurance swimming: Hematological biomarkers and their implications

The Consumption of Beeswax Alcohol (BWA, Raydel®) Improved Zebrafish Motion and Swimming Endurance by Protecting the Brain and Liver from Oxidative Stress Induced by 24 Weeks of Supplementation with High-Cholesterol and D-Galactose Diets: A Comparative Analysis Between BWA and Coenzyme Q10.

The prolonged consumption of D-galactose (Gal) has been associated with severe damage in the liver and brain via exacerbation of oxidative stress, non-enzymatic glycation, and the aging process. The current study was initiated for a comparative assessment of beeswax alcohol (BWA, final 0.5% and 1.0% w/w) and coenzyme Q10 (CoQ10, final 0.5% and 1.0% w/w) against high-cholesterol (HC, final 4%, w/w) and -galactose (Gal, final 30%, w/w)-induced adverse events in zebrafish during 24 weeks of consumption. The survivability of zebrafish decreased to 82.1% due to HC+Gal exposure, but this was substantially improved (91.0%) with the consumption of 0.5% and 1.0% BWA. In contrast, no protective effect of CoQ10 consumption (1.0%) was observed on the survivability of zebrafish. Nevertheless, both BWA and CoQ10 displayed a significant (p < 0.001) preventive effect against HC+Gal-induced body weight enhancement. The HC+Gal-induced cognitive changes, marked by staggered and confused swimming behavior, and retarded swimming speed and motion patterns (restricted to the bottom of the tank), were efficiently restored by BWA. A significantly higher residence time in the upper half of the tank, 3.1-and 4.5-fold reduced latency time along with 3.5-fold and 4.1-fold higher swimming distance, was logged in the 0.5% and 1.0% BWA groups, respectively, than the zebrafish that consumed HC+Gal. In addition, BWA effectively enhanced plasma ferric ion reduction (FRA) and paraoxonase (PON) activity and alleviated the total cholesterol (TC), triglyceride (TG), and blood glucose levels disrupted by the consumption of HC+Gal. Also, the HC+Gal-alleviated plasma high-density lipoprotein-cholesterol (HDL-C) was 2.6-fold (p < 0.001) enhanced in the group that consumed 1.0% BWA, which was significantly 1.5-fold (p < 0.001) better than the effect of 1.0% CoQ10. Similarly, BWA displayed a superior impact over CoQ10 to mitigate HC+Gal-induced plasma AST and ALT levels, hepatic IL-6 production, generation of oxidized species, cellular senescence, and fatty liver changes. Moreover, BWA protects the brain against HC+Gal-induced oxidative stress, apoptosis, and myelin sheath degeneration. Conclusively, compared to CoQ10, BWA efficiently can the HC+Gal-impaired brain and liver functionality to subside and improves the dyslipidemia and cognitive behavior of zebrafish.

Exercise-induced methylation of the Serhl2 promoter and implication for lipid metabolism in rat skeletal muscle.

Environmental factors such as physical activity induce epigenetic modification, with exercise-responsive DNA methylation changes occurring in skeletal muscle. To determine the skeletal muscle DNA methylation signature to endurance swim training we used whole-genome methylated DNA immunoprecipitation (MeDIP) sequencing. Gene set expression analysis (GSEA) of differentially methylated promoter regions (DMRs) an enrichment of four gene sets, including those annotated to lipid metabolic process, with differentially hypermethylated or hypomethylated promoter regions in skeletal muscle of exercise-trained rats. Single base resolution bisulfite sequencing confirmed that neighboring CpGs in the transcription start site of Serhl2 (Serine Hydrolase Like 2) were hypomethylated in exercise-trained rats. Serhl2 gene expression was upregulated in exercise-trained rats, as well as in an exercise-in-a-dish model of L6 myotubes subjected to electrical pulse stimulation (EPS). Serhl2 promoter activity was regulated by methylation, and in response to EPS. We identified a Nr4a binding motif in the Serhl2 promoter region, which upon deletion, reduced Serhl2 promoter activity and abolished sensitivity to methylation in L6 myotubes. Gene silencing of Serhl2 in L6 myotubes reduced both intracellular lipid oxidation and triacylglycerol synthesis in response to EPS. Exercise training promotes intracellular lipid metabolism and phenotypic changes in skeletal muscle through epigenomic modifications on Serine Hydrolase Like 2. Hypomethylation of Serhl2 promoter affects transcription factor binding of Nr4a, Serhl2 promoter activity, and Serhl2 mRNA expression in skeletal muscle. Our data link exercise-induced epigenomic regulation Serhl2 with lipid oxidation and triacylglycerol synthesis in skeletal muscle.

Evaluation of effect of Nerium oleanderagainst STZ induced diabetic neuropathy rat model by reducing NF-κB pathway

Diabetic neuropathy (DN) is a chronic diabetic complication, which is difficult to manage. The current investigation evaluates the effect of Nerium oleander(NO) in the management of diabetic neuropathy (DN). Diabetic neuropathy was induced by streptozotocin (STZ) [60 mg/kg, i.p.] and treated with NO 150 mg/kg and 300 mg/kg, per oral (p.o.) for two week. Blood glucose level, analgesic response, muscle coordination, and intestinal transit were estimated in DN rats. Oxidative stress and inflammation were estimated in DN rats. Loss of muscle coordination, swim Endurance and analgesic response were attenuated by NO treatment in DN rats. Mediators of inflammation and oxidative stress parameters were ameliorated in NO treated DN rats. The given study concluded that NO has beneficial for the management of DN by regulating oxidative stress and inflammatory mediators.

Anti-fatigue effect of an enzymatically derived deer velvet extract through muscle damage recovery and improvement of antioxidant levels

Ethnopharmacological relevanceDeer velvet (DV) has been extensively used in traditional Oriental medicine to treat various diseases. Its pharmacological spectrum encompasses tonicity, longitudinal bone growth of adolescence, blood retention, hemopoiesis facilitation, enhancement of organ function, physical function improvement, and augmentation of physical vitality. Among its myriad effects, DV notably exhibits anti-fatigue properties; however, its specific mode of action is yet to be fully elucidated. Aim of the studyThis study was undertaken to investigate the anti-fatigue and exercise performance-enhancing effects of YC-1101(HENKIV®), an enzymatically derived DV extract, in C2C12 cell lines and forced swimming mouse models. Materials and methodsThe effect of YC-1101 on increasing cell growth and lowering lactate dehydrogenase (LDH) activity was assessed in C2C12. The antioxidative effects of YC-1101 and its mechanistic underpinnings were also evaluated in C2C12 cells. Moreover, mice were subjected to an exhaustive swimming test subsequent to 3 weeks of YC-1101 extract administration. Fatigue-associated biochemical parameters, such as LDH activity and lactate, superoxide dismutase, glutathione peroxidase, and malondialdehyde levels, were measured in serum and muscle tissues. ResultsYC-1101 significantly promoted myoblast growth and reduced LDH activity, indicative of a cell-proliferative effect. Notably, free radical scavenging assays and analysis of reactive oxygen species production and antioxidant-related mRNA expression corroborated the significant involvement of YC-1101 in antioxidation, an important mechanism in anti-fatigue processes. Furthermore, animal experiments demonstrated prolonged swimming endurance and inhibition of muscle LDH accumulation in forced swimming mouse models. Serum biochemical analysis further revealed significant modulation of the expression of anti-fatigue-related biomarkers. Various bioactive low-molecular-weight DV peptides were enriched in YC-1101 compared to YHC-BE-2038 (a DV extract without enzymatic digestion). The anti-fatigue effect of YC-1101 was significantly stronger than that of YHC-BE-2038. ConclusionsThese findings suggest the potential of YC-1101 as a nutraceutical adjunct in ameliorating fatigue, concurrently facilitating muscle damage recovery, and exerting antioxidant effects via the nuclear factor E2-related factor 2-Kelch-like ECH-associated protein-1 pathway. It can be assumed that the complex action of low-molecular-weight DV peptides produced during the enzymatic degradation process was effective, and the further research is needed.

Changes in aerobic metabolism associated with the settlement transition for the leopard coral grouper (Plectropomus leopardus)

Metamorphosis is a critical aspect of coral reef fish ecology. This developmental milestone marks changes in form and function that permit successful transition of pelagic larvae to the demersal lifestyle on coral reefs. However, we know very little about the physiological changes that occur during this period, specifically potential changes in energetics associated with swimming. This is critical, as swimming is the mechanism by which pelagic larvae find a suitable reef on which to settle. Coral grouper larvae (Serranidae: Plectropomas leopardus) were collected at night as they came into the vicinity of a fringing reef to settle, and their physiological metamorphosis was characterized. Larvae and 24 h-settled juveniles were exposed to an endurance swimming test at ecologically relevant swimming speeds, and oxygen uptake rates were measured during activity. To describe how aerobic and anaerobic properties of tissues change during metamorphosis, we also measured whole body citrate synthase and lactate dehydrogenase activity, respectively, as well as mitochondrial density in the trunk and pectoral fins. Our approach accurately measures the oxygen uptake rates these life stages need during the recruitment process, with larvae having a 74% higher mass-specific oxygen uptake rate (ṀO2) than settled juveniles despite swimming at speeds that are only 1.5 body-lengths per second (BLs−1) faster. Citrate synthase activity significantly decreased upon settlement; as larvae had 3.7 times higher activities than juveniles, suggesting that rapid changes in aerobic metabolism of tissues may be an important process during metamorphosis in this species. In contrast, lactate dehydrogenase did not significantly differ upon settlement. These findings highlight some physiological modifications that pelagic coral grouper larvae undertake within 24 h that contribute to successfully settling onto a coral reef.

Cardiac parasympathetic reactivation after a high-intensity intermittent effort in water polo players: impact of swimming endurance performance status

Cardiac parasympathetic reactivation after a high-intensity intermittent effort in water polo players: impact of swimming endurance performance status

Research on the Anti-Fatigue Effects and Mechanisms of Arecoline in Sleep-Deprived Mice.

This research aims to estimate the anti-fatigue effects of arecoline and explore its underlying mechanisms using a murine model of central fatigue precipitated by sleep deprivation (SD). Seventy-two male C57BL/6 mice were randomly assigned to six groups: a control group, an SD-induced fatigue model group, a group that received Rhodiola Rosea capsules (2.5 mg/kg), and three arecoline groups, which were administered at low, medium, and high doses (10, 20, and 40 mg/kg, respectively). Following 28 days of continuous administrations, the effects of arecoline on mouse fatigue-related behaviors were assessed by behavioral tests, including grip strength, rotarod performance, and weight-bearing swimming endurance. The release levels of the related biochemical markers were measured by enzyme-linked immunosorbent assays (ELISAs). Western blotting was employed to quantify the expression levels of nuclear factor erythroid 2-related factor (Nrf2), Kelch-like ECH-associated protein 1 (Keap1), heme oxygenase 1 (HO-1), sequestosome-1 (p62), and NADPH quinone oxidoreductase 1 (NQO1) in the gastrocnemius muscle. Arecoline administration notably enhanced grip strength, delayed the onset of fatigue as evidenced by extended latencies in rotarod tests, and increased the duration of weight-bearing swimming in mice. In the elevated plus maze, arecoline obviously decreased both the number of entries and the total distance traveled in the open arms. Arecoline markedly decreased the contents of creatine kinase, blood urea nitrogen, lactate dehydrogenase, triglycerides, and cholesterol in the serum, while it elevated the levels of total testosterone, lactate dehydrogenase, and immunoglobulin G. Furthermore, it significantly increased the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase in the gastrocnemius muscle, reduced malondialdehyde levels, augmented hippocampal SOD and CAT activity, and elevated glycogen stores in both liver and muscle tissues. Neurotransmitter levels showed significant increases, cytokine levels were markedly reduced, and the expressions of Nrf2, Keap1, NQO1, p62, and HO-1 in brain tissues were significantly upregulated. This study demonstrates that arecoline has anti-fatigue activity, and the specific mechanisms are associated with elevating glucose and lipid metabolism levels, relieving oxidative stress damage, inhibiting neuroinflammatory response, and regulating neurotransmitter levels and the Keap1/Nrf2/HO-1 signaling pathway. The research provides a new direction for arecoline's potential in preventing and improving fatigue.

Anti-fatigue activity on male mice of 70% ethanol and aqueous extract of Rusa unicolor antler from East Kalimantan

Energy supply issues, ATP+PC, anaerobic glycolysis, product accumulation, lactic acid, mechanical failure of muscles to contractions and nervous system changes contribute to fatigue. The goal of this study was to determine whether 70% ethanol and aqueous extracts of Rusa unicolor antler from East Kalimantan, Indonesia, can reduce fatigue in male mice. A total of sixty-four male mice aged 2-3 months (20-30 g) were randomly assigned to eight groups (negative control, positive control and 3 doses of treatments for each extract). After that, the swimming endurance time was assessed, and blood glucose levels were measured before and after the test. Mice's tiredness is demonstrated by their head remaining submerged for 4-7 s while their tails and legs are stretched. One-way ANOVA was used to statistically analyze the data. The results showed that there were significant differences between all treatments with the negative control group (p&lt;0.05). At a dose of 1.3 mg/kg BW of 70% ethanol and aqueous extract of Rusa unicolor antlers were able to maintain the stamina of male mice in swimming for 2 hrs 37 mins. Both extracts improve endurance training, delay tiredness, and promote recovery after exercise. Hence, Rusa unicolor antler extract can significantly improve athletic ability and facilitate recovery after exercise in male mice by increasing endurance training capacity and delaying tiredness.

S-1-Propenylcysteine Enhances Endurance Capacity of Mice by Stimulating Fatty Acid Metabolism via Muscle Isoform of Carnitine Acyltransferase-1

BackgroundEndurance 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. ObjectivesThis 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. MethodsMale 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. ResultsThe 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. ConclusionsS1PC 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.

Systematical Investigation on Anti-Fatigue Function and Underlying Mechanism of High Fischer Ratio Oligopeptides from Antarctic Krill on Exercise-Induced Fatigue in Mice.

High Fischer ratio oligopeptides (HFOs) have a variety of biological activities, but their mechanisms of action for anti-fatigue are less systematically studied at present. This study aimed to systematically evaluate the anti-fatigue efficacy of HFOs from Antarctic krill (HFOs-AK) and explore its mechanism of action through establishing the fatigue model of endurance swimming in mice. Therefore, according to the comparison with the endurance swimming model group, HFOs-AK were able to dose-dependently prolong the endurance swimming time, reduce the levels of the metabolites (lactic acid, blood urea nitrogen, and blood ammonia), increase the content of blood glucose, muscle glycogen, and liver glycogen, reduce lactate dehydrogenase and creatine kinase extravasation, and protect muscle tissue from damage in the endurance swimming mice. HFOs-AK were shown to enhance Na+-K+-ATPase and Ca2+-Mg2+-ATPase activities and increase ATP content in muscle tissue. Meanwhile, HFOs-AK also showed significantly antioxidant ability by increasing the activities of superoxide dismutase and glutathione peroxidase in the liver and decreasing the level of malondialdehyde. Further studies showed that HFOs-AK could regulate the body's energy metabolism and thus exert its anti-fatigue effects by activating the AMPK signaling pathway and up-regulating the expression of p-AMPK and PGC-α proteins. Therefore, HFOs-AK can be used as an auxiliary functional dietary molecules to exert its good anti-fatigue activity and be applied to anti-fatigue functional foods.

Effects of Chlorich®EnergyBoost on Enhancing Physical Performance and Anti-Fatigue Properties in Mice.

Chlorich®EnergyBoost, a water extract obtained from Chlorella sorokiniana, has been proposed to enhance physical performance and provide anti-fatigue effects. This study assessed the impact of Chlorich®EnergyBoost supplementation on physical performance and its anti-fatigue properties. Twenty-four mice were allocated into four groups: (1) the control group receiving only water,;(2) the 1X group (49.2 mg/kg/day); (3) the 2X group (98.4 g/kg/day); and (4) the 5X group (246 g/kg/day). All groups were orally administered the supplements for four consecutive weeks. The evaluation included grip strength, swimming endurance, an exhaustion test, and serum biochemistry analysis. Additionally, the study examined the bioactive peptides through matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) and conducted bacterial reverse mutation and acute oral toxicity tests for safety assessment. The findings indicated that Chlorich®EnergyBoost supplementation led to a significant reduction in serum lactate levels by 14.08% to 22.54% and blood urea nitrogen levels by 12.23% to 16.76%, an increase in the lactate clearance rate by 0.28 to 0.35, an enhancement of muscle glycogen storage by 1.10 to 1.44-fold, and hepatic glycogen storage by 1.41 to 1.47-fold. These results demonstrated dose-dependent effects. MALDI-TOF analysis revealed the expression of dihydrolipoamide dehydrogenase and superoxide dismutase. Both the bacterial reverse mutation and acute oral toxicity tests showed no adverse effects.

The interactive effects of different exercises and hawthorn consumption on the pain threshold of TMT-induced Alzheimer male rats

Exercise increases the pain threshold in healthy people. However, the pain threshold modulation effect of exercise and hawthorn is unclear because of its potential benefits in people with persistent pain, including those with Alzheimer's disease. Accordingly, after the induction of Alzheimer's disease by trimethyl chloride, male rats with Alzheimer's disease were subjected to a 12-week training regimen consisting of resistance training, swimming endurance exercises, and combined exercises. In addition, hawthorn extract was orally administered to the rats. Then, their pain threshold was evaluated using three Tail-flick, Hot-plate, and Formalin tests. Our results showed that Alzheimer's decreased the pain threshold in all three behavioral tests. Combined exercise with hawthorn consumption had the most statistically significant effect on Alzheimer's male rats' pain threshold in all three experiments. A combination of swimming endurance and resistance exercises with hawthorn consumption may modulate hyperalgesia in Alzheimer's rats. Future studies need to determine the effects of these factors on the treatment and/or management of painful conditions.Graphical

Fish in the fast lane: the stressful consequences of speeding through a flume

Understanding the swimming ability of different fish species is essential for assessing their ecological niche, behaviour and overall fitness. Changes in swimming ability can relate to the overall health of aquatic ecosystems, as it can be affected by water quality, temperature or habitat quality changes. Our study investigated the effects of stress on swimming performance in wild vairone (Telestes muticellus) in an experimental flume. The obtained data was analysed using k-means clustering to identify stress response patterns. Our findings demonstrate that k-means clustering effectively identified distinct subgroups of fish with similar stress responses in groups with physiological stress responses with high individual variability. We found that short-term exposure to a stress source such as high-velocity running water can increase swimming endurance in this species concerning the velocity in the setup, which was mainly seen in the cortisol and MDA levels in the muscle tissue of the fish. The velocity of the water showed limitations on swimming ability tests and highlighted that fish have a specific range of swimming speeds that they can sustain.

Impact of chronic muscle use and disuse on innate immune signaling in skeletal muscle

Mitochondria exhibit high levels of adaptability to various stimuli such as chronic muscle use (i.e. exercise) or disuse, such as immobilization or denervation. These changes in the mitochondrial network ultimately affect the health and functioning of skeletal muscle, which contributes to whole-body metabolism, locomotion, and postural stability. It is now acknowledged that mitochondrial dysfunction can activate inflammatory pathways through the recognition of damage-associated molecular patterns (DAMPs). The objective of this study was to examine how changes in mitochondria brought about by either chronic muscle inactivity or chronic exercise training affect innate immune system activation. We hypothesized that an inverse relationship between mitochondrial content and innate immune signaling would be evident in skeletal muscle. To investigate this, skeletal muscle from the hindlimbs of mice was collected after 7 days of sciatic muscle denervation, or after 4.5 weeks of endurance swim training involving 240 minutes of daily exercise. We analyzed the expression of the NLRP3 inflammasome, innate immune system signaling proteins, mitochondrial markers, and mitochondrial DNA (mtDNA) content using western blotting, cytochrome C oxidase (COX) activity, ELISA and qPCR. Following 7 days of denervation, there was a significant decrease in both COX-IV protein and COX activity, indicating a reduction in mitochondrial content. This was accompanied by an increase (p&lt;0.05) in NLRP3, procaspase-1, gasdermin-D (GSDMD) and its active N-terminal fragment, GSDMD-N, as well as a notable increase in IL-1β. In addition, other possible converging pathways were also upregulated including cGAS-STING, and gasdermin-E. In comparison, following exercise training, there was a significant increase in mitochondrial content, apparent through increases in COX-IV protein, COX activity and mitochondrial RNA content. This was associated with decreases in procaspase-1 and caspase-1 protein expression alongside reduced STING activation. These findings highlight an inverse relationship between mitochondrial content and the activation of several inflammatory pathways that possibly converge upon NLRP3 inflammasome activation and pyroptotic cell death, leading to detriments in skeletal muscle health. This work aims to further the understanding of innate immune signaling pathways within muscle which can potentially highlight therapeutic targets to regulate its activation under divergent metabolic conditions. This work was supported by funds from the Natural Science and Engineering Research Council (NSERC). Priyanka Khemraj is the holder of an Ontario Graduate Scholarship. David A. Hood is the holder of a Canadian Research Chair in Cell Physiology. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Endurance Training Provokes Arrhythmogenic Right Ventricular Cardiomyopathy Phenotype in Heterozygous Desmoglein-2 Mutants: Alleviation by Preload Reduction.

Desmoglein-2 mutations are detected in 5-10% of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). Endurance training accelerates the development of the ARVC phenotype, leading to earlier arrhythmic events. Homozygous Dsg2 mutant mice develop a severe ARVC-like phenotype. The phenotype of heterozygous mutant (Dsg2mt/wt) or haploinsufficient (Dsg20/wt) mice is still not well understood. To assess the effects of age and endurance swim training, we studied cardiac morphology and function in sedentary one-year-old Dsg2mt/wt and Dsg20/wt mice and in young Dsg2mt/wt mice exposed to endurance swim training. Cardiac structure was only occasionally affected in aged Dsg20/wt and Dsg2mt/wt mice manifesting as small fibrotic foci and displacement of Connexin 43. Endurance swim training increased the right ventricular (RV) diameter and decreased RV function in Dsg2mt/wt mice but not in wild types. Dsg2mt/wt hearts showed increased ventricular activation times and pacing-induced ventricular arrhythmia without obvious fibrosis or inflammation. Preload-reducing therapy during training prevented RV enlargement and alleviated the electrophysiological phenotype. Taken together, endurance swim training induced features of ARVC in young adult Dsg2mt/wt mice. Prolonged ventricular activation times in the hearts of trained Dsg2mt/wt mice are therefore a potential mechanism for increased arrhythmia risk. Preload-reducing therapy prevented training-induced ARVC phenotype pointing to beneficial treatment options in human patients.

Injury Incidence and Injury Period Prevalence in Underwater Hockey: A Retrospective Study

Abstract Purpose Underwater Hockey (UWH) is an upcoming sport involving limited contact between players. To date there are no published estimates of injuries in UWH. The aim of this study was to provide estimate on overall injury incidence and injury period prevalence in a sample of UWH players. Methods A cross-sectional study design with a convenience sample of UWH players recorded injuries sustained over the previous 12-month period. A total of 441 UWH players completed the study online questionnaire. Descriptive statistics with confidence intervals, alongside a one variable Chi squared test (χ2) or independent sample t-test. Results The overall injury incidence was 2.33/1000 h. Wrist, hand, and finger injuries combined (31.8%) were the most frequently injured regions followed by isolated shoulder injuries (16.8%). Contact with another player was the most frequent injury mechanism (43.5%) attributed, whilst the most common injury duration was between 8 and 28 days (35.9%). Conclusion This is the first study to report injury data in a sample of UWH players. Incidence rates were similar to other water-based sports such as endurance swimming. The high prevalence of wrist, hand and finger and shoulder injuries suggest that future injury prevention programmes should look to include upper limb-focussed risk reduction strategies.

Evaluation of adaptogenic and antidepressant activity of hydroalcoholic leaves extract of Salacia chinensis in mice

Study was carried out to evaluate the Adaptogenic and Antidepressant effect of Salacia chinensis leaf extract in animal model.Salacia chinensis is a plant species belonging to the family Celastraceae. This study was carried out to evaluate the Adaptogenic and Antidepressant effect of Salacia chinensis leaf extract in animal model. Swimming Endurance Test was used to evaluate the Adaptogenic activity in albino mice while Tail Suspension Test and Elevated Plus Maze test was used to evaluate the Antidepressant activity in albino mice. In Swimming Endurance model various biochemical parameters like blood glucose, cholesterol, triglycerides were estimated, weight of organs like liver, spleen and adrenal gland was measured in stress control and extract treated animals. Immobility as behavioural parameter was assessed in Tail Suspension Test and Elevated Plus Maze model of depression after treatment with hydroalcoholic extract of Salacia chinensis leaf at selected dose of 200 mg/kg and 400 mg/kg. Results of the study have showed significant Adaptogenic and Antidepressant activity of Salacia chinensis.Preliminary Phytochemical Analysis (15) Salacia chinensis leaves extract was subjected to chemical tests for the identification of their active constituents. The results have indicated the presence of flavonoid, alkaloids, terpenoids, saponins, glycosides, carbohydrates.The biochemical estimation results obtained showed decrease in blood glucose, triglyceride, and slight increase in cholesterol level when compared to control which support the adaptogenic activity of the title plant as shown in table no: 02,03,04 and fig no: 03,04,05,06,07. The duration of immobility was reduced after treated with hydroalcoholic extract of Salacia chinensis and results are significant on both high dose 400 mg/kg, p.o. (P&amp;#60;0.001) and low dose 200 mg/kg, p.o. (P&amp;#60;0.01) with that of standard Imipramine (10 mg/kg, p.o.) indicating that the extract possess significant antidepressant activity. Results depicted in table no: 05 and fig no: 08,09.The hydroalcoholic extract of Salacia chinensis at high dose (400 mg/kg, p.o) (P˂0.05) significantly increased the number of entries in to open arm and total time spent in open arm as compared to control.It shows increase in the mobility of the mice in open arm which suggest the antidepressant activity shown in table no:06 and fig no: 10,11.Based on the results obtained from this study it can be concluded that the hydroalcoholic extract of Salacia chinensis leaves possess Adaptogenic and Antidepressant activity. This beneficial effect of Salacia chinensis leaf might be due to presence of flavonoids, alkaloids and its derivatives.

Trimethylamine N-Oxide Improves Exercise Performance by Reducing Oxidative Stress through Activation of the Nrf2 Signaling Pathway.

Trimethylamine N-oxide (TMAO) has attracted interest because of its association with cardiovascular disease and diabetes, and evidence for the beneficial effects of TMAO is accumulating. This study investigates the role of TMAO in improving exercise performance and elucidates the underlying molecular mechanisms. Using C2C12 cells, we established an oxidative stress model and administered TMAO treatment. Our results indicate that TMAO significantly protects myoblasts from oxidative stress-induced damage by increasing the expression of Nrf2, heme oxygenase-1 (HO-1), NAD(P)H dehydrogenase (NQO1), and catalase (CAT). In particular, suppression of Nrf2 resulted in a loss of the protective effects of TMAO and a significant decrease in the expression levels of Nrf2, HO-1, and NQO1. In addition, we evaluated the effects of TMAO in an exhaustive swimming test in mice. TMAO treatment significantly prolonged swimming endurance, increased glutathione and taurine levels, enhanced glutathione peroxidase activity, and increased the expression of Nrf2 and its downstream antioxidant genes, including HO-1, NQO1, and CAT, in skeletal muscle. These findings underscore the potential of TMAO to counteract exercise-induced oxidative stress. This research provides new insights into the ability of TMAO to alleviate exercise-induced oxidative stress via the Nrf2 signaling pathway, providing a valuable framework for the development of sports nutrition supplements aimed at mitigating oxidative stress.