Exercise-induced oxidative stress: cellular mechanisms and impact on muscle force production

Effects of 8-week Theracurmin Super (TS-P1; Curcumin) supplementation on exercise-induced oxidative stress: A randomised, double-blind, placebo-controlled parallel clinical trial

Background

Given curcumin's antioxidant properties, this study aimed to determine the effectiveness and safety of Theracurmin Super supplementation in mitigating exercise-induced oxidative stress in healthy adults.

Methods

Seventy-one healthy adults participated in this study, which was conducted at Seoul National University from April 2022 to March 2023. Eligibility was determined during visit 1 through maximum oxygen consumption assessed using the Bruce Treadmill protocol. In visit 2, participants were randomly allocated to either the Theracurmin Super supplement group (TG, n = 36) or Placebo supplement group (PG, n = 35). Over 8 weeks, participants consumed Theracurmin Super (curcumin, 120 mg/day) or Placebo (curcumin, 0 mg/day) twice daily and visited the laboratory four times. Various parameters, including body composition, vital signs, nutrition quotient for adults, cardiorespiratory endurance, blood biomarkers, and adverse events, were assessed at each visit. Statistical analyses included per-protocol analysis, t-tests for group and within-group differences, and two-way ANOVA.

Results

In week 8, blood biomarkers linked to oxidative stress, including TBARs, MDA, 8-OHdG, SOD, TOS, and OSI, showed significant group- and week-related interactions (total oxidant status: resting state P = 0.021; oxidative stress index, resting state P = 0.020, end of exercise, P = 0.013). Notably, the TG showed a significant decrease in total oxidant status (resting state P = 0.041) and oxidative stress index (resting state P = 0.018 and end of exercise P = 0.008) between weeks 0 and 8. However, MDA and 8-OHdG levels did not show statistically significant changes.

Conclusion

Theracurmin Super effectively reduced oxidative stress before and after exercise, highlighting curcumin's promising role in managing oxidative stress. Significant improvements in TOS and OSI were observed, although changes in MDA and 8-OHdG levels were not statistically significant. Further research could provide insights into these mixed results across different oxidative biomarkers.

Trial registration

Clinical Research Information Service (CRIS): KCT0008731.

What are the potential mechanisms of fatigue-induced skeletal muscle hypertrophy with low-load resistance exercise training?

High-load resistance exercise (>60% of 1-repetition maximum) is a well-known stimulus to enhance skeletal muscle hypertrophy with chronic training. However, studies have intriguingly shown that low-load resistance exercise training (RET) (≤60% of 1-repetition maximum) can lead to similar increases in skeletal muscle hypertrophy as compared with high-load RET. This has raised questions about the underlying mechanisms for eliciting the hypertrophic response with low-load RET. A key characteristic of low-load RET is performing resistance exercise to, or close to, task failure, thereby inducing muscle fatigue. The primary aim of this evidence-based narrative review is to explore whether muscle fatigue may act as an indirect or direct mechanism contributing to skeletal muscle hypertrophy during low-load RET. It has been proposed that muscle fatigue could indirectly stimulate muscle hypertrophy through increased muscle fiber recruitment, mechanical tension, ultrastructural muscle damage, the secretion of anabolic hormones, and/or alterations in the expression of specific proteins involved in muscle mass regulation (e.g., myostatin). Alternatively, it has been proposed that fatigue could directly stimulate muscle hypertrophy through the accumulation of metabolic by-products (e.g., lactate), and/or inflammation and oxidative stress. This review summarizes the existing literature eluding to the role of muscle fatigue as a stimulus for low-load RET-induced muscle hypertrophy and provides suggested avenues for future research to elucidate how muscle fatigue could mediate skeletal muscle hypertrophy.

The Effect of one-week spinach and NBS superfood supplementation on interleukin-6, superoxide dismutase, and malondialdehyde levels after repeated bouts of wingate test in trained men

BACKGROUND

Consuming nutritional supplements for improving athletic performance has always been considered an ergogenic aid. However, there is limited information on the efficacy of this strategy for enhancing antioxidant capacity in response to strenuous exercise with repeated nature. Therefore, this study investigated the effect of one week of spinach and NBS superfood supplementation on superoxide dismutase, malondialdehyde, and interleukin-6 in response to repeated bouts of Wingate test.

METHODS

Fifteen trained men voluntarily participated in this within- participants and counter-balanced study. Participants were exposed to three different conditions including (1) seven days of raw spinach supplementation (daily dose of 70 g); (2) seven days of NBS superfood supplementation (daily dose of 10 g); and (3) the control condition. One day after the supplementation period, participants came to the lab and performed 3 bouts of 30-second Wingate test with 4-minute rest intervals. Before the supplementation and 24 h after performing the Wingate, test blood samples were taken in each condition to measure serum levels of superoxide dismutase, malondialdehyde, and interleukin-6. One week of wash-out was applied between the conditions. Two-way repeated measures ANOVA were used for statistical analysis.

RESULTS

The results showed that at post-test measurement the serum level of interleukin-6 was significantly lower under the spinach and superfood conditions (p = 0.001,p = 0.003, respectively) compared to the control. The serum level of superoxide dismutase under the spinach (p = 0.035) and superfood (p = 0.01) conditions was significantly higher compared to the control at post-test measurement. Also, at post-test measurement, the serum level of malondialdehyde was significantly lower under the spinach (p = 0.001) and superfood (p = 0.017) conditions compared to the control.

CONCLUSION

According to the results of the present study, it seems that seven days' supplementation of either raw spinach or NBS superfood could positively affect the inflammatory responses to repeated anaerobic all-out activities. Therefore, these supplementation strategies might be considered ergogenic aids and used by athletes before participating in repeated strenuous activities.

Effects of a single dose of a betalain-rich concentrate on determinants of running performance and recovery muscle blood flow: a randomized, triple-blind, placebo-controlled, crossover trial

PURPOSE

This study aimed to examine the effects of a single dose of a betalain-rich concentrate (BRC) on determinants of running performance and recovery lactate clearance.

METHODS

In this a randomized, triple-blind, placebo-controlled, crossover trial, 17 male recreational runners (Age: 19.0 ± 1.0 years; Height: 176.8 ± 6.2 cm; Weight: 70.62 ± 8.1 kg; Body fat: 12.8 ± 0.03%; VO2max: 58.9 ± 8.6 ml/kg/min) consumed an acute dose of a BRC (100 mg) or a placebo (100 mg of dextrose; CON) and performed a running economy protocol (RE) at velocities corresponding to 60% and 80% of maximal oxygen consumption (VO2max) followed by a VO2max test. Both exercise and recovery skeletal muscle oxygenation (SmO2) were assessed via near-infrared spectroscopy (NIRS), and recovery lactate was obtained.

RESULTS

BRC resulted in lower heart rate (HR) at velocities corresponding to 80% of VO2max (p = 0.05) and maximum HR (HRmax; p = 0.01), and a lower rating of perceived exertion (RPE) at velocities corresponding to 60% of VO2max (p = 0.02) when compared to CON. BRC also improved post-exercise SmO2 at 3 (p = 0.05), 4 (p = 0.02), and 5 min (p = 0.01) but not lactate clearance (p > 0.05). BRC did not significantly improve RE or VO2max (p > 0.05).

CONCLUSIONS

A single dose of BRC did not enhance RE or VO2max. However, the observed improvements in exercise HR, RPE, and SmO₂ suggest that BRC may confer cardiovascular benefits for exercise and recovery.

Exerkines: Potential regulators of ferroptosis

Ferroptosis is a programmed cell death, and its mechanism involves multiple metabolic pathways, such as iron and lipid metabolism, and redox homeostasis. Exerkines are important mediators that optimize cellular homeostasis and maintain physiological health during exercise stimulation. This article comprehensively examines the mechanisms and regulatory networks for governing ferroptosis and summarizes the impact of exercise and exerkines on ferroptosis under varying load intensities and disease contexts. Notably, despite its significant efficacy and minimal side effects, the therapeutic and prognostic potential of exercise in ferroptosis-related diseases remains largely unexplored. This article, by summarizing recent progresses in the regulation of exerkines-mediated ferroptosis, could further uncover the preventive or alleviative mechanisms of some diseases upon exercise interventions, which will be beneficial to design exercise interventional strategies for alleviating disease progression through the regulation of ferroptosis.

Preliminary insights into the effects of spinal manipulation therapy of different force magnitudes on blood biomarkers of oxidative stress and pro-resolution of inflammation mediators

BACKGROUND

Evidence has been reported that spinal manipulation therapy (SMT) leads to spine segmental hypoalgesia through neurophysiological and peripheral mechanisms related to regulating inflammatory biomarker function. However, these studies also showed substantial inter-individual variability in the biomarker responses. Such variability may be due to the incomplete understanding of the fundamental effects of force-based manipulations (e.g., patient-specific force-time characteristics) on a person's physiology in health and disease. This study investigated the short-term effects of distinct SMT force-time characteristics on blood oxidative stress and pro-resolution of inflammation biomarkers.

METHODS

Nineteen healthy adults between 18 and 45 years old were recruited between February and March 2020 before the COVID-19 pandemic and clustered into three groups: control (preload only), target total peak force of 400 N, and 800 N. A validated force-sensing table technology (FSTT®) determined the SMT force-time characteristics. Blood samples were collected at pre-intervention, immediately after SMT, and 20 min post-intervention. Parameters of the oxidant system (total oxidant status, lipid peroxidation and lipid hydroperoxide), the antioxidant system (total antioxidant capacity and bilirubin), and lipid-derived resolvin D1 were evaluated in plasma and erythrocytes through enzyme-linked immunosorbent assay and colorimetric assays.

RESULTS

The COVID-19 global pandemic impacted recruitment, and our pre-established target sample size could not be reached. As a result, there was a small sample size, which decreased the robustness of the statistical analysis. Despite the limitations, we observed that 400 N seemed to decrease systemic total oxidant status and lipid peroxidation biomarkers. However, 800 N appeared to transitorily increase these pro-oxidant parameters with a further transitory reduction in plasma total antioxidant capacity and resolvin D1 mediator.

CONCLUSION

Despite the small sample size, which elevates the risk of type II error (false negatives), and the interruption of recruitment caused by the pandemic, our findings appeared to indicate that different single SMT force-time characteristics presented contrasting effects on the systemic redox signalling biomarkers and pro-resolution of inflammation mediators in healthy participants. The findings need to be confirmed by further research; however, they provide baseline information and guidance for future studies in a clinical population.

The Various Mechanisms by Which Exercise-Induced Fatigue (EIF) Affects Spermatogenesis Through Testosterone

Currently, a great number of researches have proven that the EIF triggered by inappropriate and excessive exercise will affect normal function of the male reproductive system, resulting in various disorders or increasing disease risks. Reproductive system and motor system are highly correlated. Now, it is mainly considered that the testicular cell is modulated via hypothalamus-hypophysis-gonad(HPG) axis in the process of exercise, which involves the whole male reproductive system and affects spermatogenesis. However, there are many mechanisms leading to EIF, including hormonal levels, lactic acid accumulation, oxidative stress, calcium ion disorder, and inflammatory responses. These mechanisms interact with each other and can directly or indirectly affect spermatogenesis through testosterone hormones in various ways, with the majority having a negative impact. This ultimately leads to dysfunction of spermatogenesis and decreased sperm quality in the male reproductive system under the state of EIF. Therefore, this article reviews various theoretical mechanisms leading to EIF and their intervention methods on spermatogenesis through testosterone hormones, explaining the correlation between EIF and spermatogenesis from the perspective of endocrine regulation, providing new directions for the prevention and treatment of related symptoms.

Protective effect of exercise on animals with sepsis: a systematic review of the existing literature

BACKGROUND

Sepsis often led to multiple organ dysfunction (MODS) and even death. Although a variety of medicine were used to treat sepsis in clinic, there was still no specific and effective clinical medicine treatment. Exercise had been shown to work on MODS. However, in preclinical studies, there was no systematic evidence to summarize the effects of exercise training on sepsis.

OBJECTIVES

To investigate the effects of exercise training on sepsis in preclinical studies and explore possible mechanisms to provide reliable preclinical evidence for the use of exercise training in sepsis.

METHOD

Preclinical studies were retrieved from electronic databases (Pubmed, Embase, Cochrane Library, Scopus, Medline, Web of science) as of June 25, 2024. Our review included in vivo English studies evaluating the radioprotective effects of exercise training on sepsis. The quality of each study was assessed using the Center for Systematic Evaluation of Experimental Animal Studies (SYCLE) Animal Research Bias Risk Tool. All results were described comprehensively.

RESULTS

17 in vivo studies were included. Our comprehensive descriptive analysis showed that exercise could improve the general condition, lung injury, liver injury, kidney injury, heart and aortic injury, spleen and thymus injury, and other injuries in animals with sepsis. And its possible mechanisms were involved improving the general condition of sepsis animals, pathological and cell number of organs, anti-inflammation, anti-oxidative stress, anti-DNA damage, and so on.

CONCLUSION

Exercise training could protect sepsis by anti-inflammatory, anti-oxidative stress, increased antibacterial ability, reduced cell death, improved metabolism, vital signs and MODS.

Peroxiredoxin 2 mediates redox-stimulated adaptations to oxidative phosphorylation induced by contractile activity in human skeletal muscle myotubes

Skeletal muscle generates superoxide during contractions, which is converted to hydrogen peroxide (H2O2). H2O2 has been proposed to activate signalling pathways and transcription factors that regulate adaptive responses to exercise, but the concentration required to oxidize and activate key redox-sensitive signalling proteins in vitro is much higher than the typical intracellular levels seen in muscle after exercise. We hypothesized that 2-Cys-peroxiredoxins (PRDX), which rapidly oxidize in the presence of physiological concentrations of H2O2, serve as intermediary signalling molecules and play a crucial role in activating adaptive pathways following muscle contractions. This study has examined the human muscle myotube responses to contractile activity, or exposure to low extracellular concentrations (2.5-5 μM) of H2O2 and whether knock down of muscle PRDX2 alters the differential gene expression (DEG) that results from these stresses. Exposure of human skeletal muscle myotubes to a 15 min period of aerobic electrically stimulated isometric contractions or 5 μM H2O2 induced substantial changes in DEG with modification of many genes associated with adaptations of skeletal muscle to contractile activity. Common DEG in these conditions included upregulation of genes associated with increased mitochondrial oxidative phosphorylation, including COX1, COX2, COX3 and ATP6. In myotubes with PRDX2 knock down (94 % decrease in PRDX2 mRNA), the upregulation of genes associated with increased mitochondrial oxidative phosphorylation was abolished following contractile activity or exposure to H2O2. These data indicate that a common effect of contractile activity and exposure to "physiological" levels of H2O2 in human myotubes is to increase the expression of multiple genes associated with increased mitochondrial oxidative phosphorylation. Furthermore, these effects were abolished in PRDX2 knock down myotubes indicating that adaptations to upregulate multiple genes related to increased mitochondrial capacity in human muscle myotubes in response to exercise is both redox regulated and requires PRDX2 as an essential mediator of the effects of H2O2.

The Effects of Pomegranate Supplementation on Markers of Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis

Background

Pomegranate supplementation has been shown to reduce oxidative stress and inflammation, with some evidence suggesting it may accelerate recovery from exercise-induced muscle damage (EIMD), including metabolic, mechanical, and neuromuscular recovery.

Objectives

This systematic review and meta-analysis aimed to investigate the effects of pomegranate supplementation on markers of EIMD.

Methods

A systematic search of Scopus, PubMed, and Web of Science up to January 2024 identified studies evaluating pomegranate supplementation and exercise recovery. Studies involving athletes and nonathletes aged 18-55 were included. Weighted mean differences (WMDs) were calculated for EIMD markers. Study quality was assessed using a modified physiotherapy evidence database scale. This review was registered with the International Prospective Register of Systematic Reviews (ID: CRD42024536905).

Results

Ten studies were included in the meta-analysis. Pomegranate supplementation did not significantly affect markers of metabolic recovery, including myoglobin (WMD: -1.344 ng/mL; 95% confidence interval (CI): -4.11, 1.42 ng/mL, P = 0.342) and creatine kinase (WMD: -11.990 U/L; 95% CI: -28.64, 4.66 U/L, P = 0.158), or neuromuscular recovery, as indicated by lactate concentrations (WMD: -0.093 mmol/L; 95% CI: -0.39, 0.21 mmol/L, P = 0.546). Muscle soreness also remained unchanged (WMD: 0.999; 95% CI: -0.18, 2.17, P = 0.097). However, a significant reduction in lactate dehydrogenase amounts (WMD: -21.152 U/L; 95% CI: -39.29, -3.01 U/L, P = 0.022) immediately postexercise suggests a short-term protective effect against mechanical muscle damage.

Conclusions

Pomegranate supplementation does not appear to enhance overall recovery markers for EIMD but may offer short-term benefits for mechanical muscle damage. Standardizing supplementation regimens, dosages, and exercise protocols is crucial to better understand the potential benefits of pomegranate supplementation in EIMD recovery.

Guben Kechuan granule attenuates bronchial asthma by inhibiting NF-κB/STAT3 signaling pathway-mediated apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Chronic asthma caused by allergies is a lung illness marked by airway remodeling and hyperresponsiveness. Guben Kechuan (GK) granule is a clinically proven formula for treating lung disease. It relieves cough and helps to clear phlegm, but the mechanisms underlying its treatment for asthma are not clear.

AIM OF THE STUDY

We aimed to elucidate the efficacy and potential mechanisms by which GK ameliorates allergic asthma.

MATERIALS AND METHODS

Ultra-performance liquid chromatography (UHPLC-LTQ-Orbitrap-MS) identified the main chemical components of GK. The efficacy of GK was studied in an ovalbumin/alum (OVA)/AL(OH)3-sensitized rat model of bronchial asthma by measuring cytokine concentrations in serum and alveolar lavage samples, examining tissue pathology, and performing leukocyte counts. The mechanisms underlying its effectiveness in asthma were investigated by both transcriptomic and proteomic analyses.

RESULTS

GK relieved asthma-induced airway inflammation and remodeling, reduced inflammatory cell infiltration, and decreased the levels of the inflammatory cytokines TNF-α, IL-4, IL-5, IL-6, and IL-10. Analysis of the transcriptomic and proteomic results found that asthma activated the transcription factors STAT3 and NF-κB and induced oxidative-stress damage and apoptosis. GK was found to reduce Bax and caspase-3 expression, increase Bcl-2 expression, and inhibit asthma-induced apoptosis. GK downregulated the expression of the transcription factors STAT3 and NF-kB, which decreased the inflammatory response. Decreases in CAT, SOD, and GSH reduced asthma-induced oxidative-stress damage.

CONCLUSIONS

Our findings provide evidence that GK alleviates bronchial asthma by inhibiting apoptosis and oxidative stress damage mediated by the NF-κB/STAT3 signaling pathway.

Increased exercise tolerance in humanized G6PD-deficient mice

ABSTRACT

Glucose-6-phosphate dehydrogenase (G6PD) deficiency affects 500 million people globally, affecting red blood cell (RBC) antioxidant pathways and increasing susceptibility to hemolysis under oxidative stress. Despite the systemic generation of reactive oxygen species during exercise, the effects of exercise on individuals with G6PD deficiency remain poorly understood This study used humanized mouse models expressing the G6PD Mediterranean variant (S188F, with 10% enzymatic activity) to investigate exercise performance and molecular outcomes. Surprisingly, despite decreased enzyme activity, G6PD-deficient mice have faster critical speed than mice expressing human canonical G6PD. After exercise, deficient mice did not exhibit differences in RBC morphology or hemolysis, but had improved cardiac function, including cardiac output, stroke volume, sarcomere length, and mitochondrial content. Proteomics analyses of cardiac and skeletal muscles (gastrocnemius, soleus) from G6PD-deficient compared with sufficient mice revealed improvements in mitochondrial function and increased protein turnover via ubiquitination, especially for mitochondrial and structural myofibrillar proteins. Mass spectrometry-based metabolomics revealed alterations in energy metabolism and fatty acid oxidation. These findings challenge the traditional assumptions regarding hemolytic risk during exercise in G6PD deficiency, suggesting a potential metabolic advantage in exercise performance for individuals carrying noncanonical G6PD variants.

Advances in Fluorescence Techniques for the Detection of Hydroxyl Radicals near DNA and Within Organelles and Membranes

Hydroxyl radicals (•OH), the most potent oxidants among reactive oxygen species (ROS), are a major contributor to oxidative damage of biomacromolecules, including DNA, lipids, and proteins. The overproduction of •OH is implicated in the pathogenesis of numerous diseases such as cancer, neurodegenerative disorders, and some cardiovascular pathologies. Given the localized nature of •OH-induced damage, detecting •OH, specifically near DNA and within organelles, is crucial for understanding their pathological roles. The major challenge of •OH detection results from their short half-life, high reactivity, and low concentrations within biological systems. As a result, there is a growing need for the development of highly sensitive and selective probes that can detect •OH in specific cellular regions. This review focuses on the advances in fluorescence probes designed to detect •OH near DNA and within cellular organelles and membranes. The key designs of the probes are highlighted, with emphasis on their strengths, applications, and limitations. Recommendations for future research directions are given to further enhance probe development and characterization.

Effect of Physical Exercise on Telomere Length: Umbrella Review and Meta-Analysis

Background

Telomere length (TL) is a marker of cellular health and aging. Physical exercise has been associated with longer telomeres and, therefore, healthier aging. However, results supporting such effects vary across studies. Our aim was to synthesize existing evidence on the effect of different modalities and durations of physical exercise on TL.

Objective

The aim of this study was to explore the needs and expectations of individuals with physical disabilities and their interventionists for the use of a virtual reality physical activity platform in a community organization.

Methods

We performed an umbrella review and meta-analysis. Data sources included PubMed, Embase, Web of Science, Cochrane Library, and Scopus. We selected systematic reviews and meta-analyses of randomized and nonrandomized controlled clinical trials evaluating the effect of physical exercise on TL.

Results

Our literature search retrieved 12 eligible systematic reviews, 5 of which included meta-analyses. We identified 22 distinct primary studies to estimate the overall effect size of physical exercise on TL. The overall effect size was 0.28 (95% CI 0.118-0.439), with a heterogeneity test value Q of 43.08 (P=.003) and I² coefficient of 51%. The number of weeks of intervention explained part of this heterogeneity (Q_B=8.25; P=.004), with higher effect sizes found in studies with an intervention of less than 30 weeks. Exercise modality explained additional heterogeneity within this subgroup (Q_B=10.28, P=.02). The effect sizes were small for aerobic exercise and endurance training, and moderate for high-intensity interval training.

Conclusions

Our umbrella review and meta-analysis detected a small-moderate positive effect of physical exercise on TL, which seems to be influenced by the duration and type of physical exercise. High quality studies looking into the impact of standardized, evidence-based physical exercise programs on TL are still warranted.

Effects of long-term Tai Chi vs. aerobic exercise on antioxidant activity and cognitive function in individuals with Parkinson's disease

An imbalance between the generation of reactive oxygen species and the body's antioxidant defense mechanisms is closely related to the development and progression of Parkinson's disease (PD). Considering that physical exercise is a potential therapeutic intervention for modulating oxidative stress markers and cognitive function in PD, the primary purpose of this study was to compare the effects of different long-term exercise modalities on antioxidants and cognitive performance in patients with PD. In addition, the secondary purpose was to explore whether changes in the levels of these biochemical markers are associated with alterations in cognitive performance pre- and post-intervention. In all, 61 participants were randomly divided into the aerobic exercise (AE, n=20), Tai Chi exercise (TCE, n=21), or control (n=20) group. Blood samples were collected before and after a 12-week intervention period for the analysis of antioxidant markers [leukocyte 8-hydroxydeoxyguanosine (8-OHdG), catalase (CAT), glutathione (GSH), glutathione peroxidase (GSH-Px), oxidized glutathione (GSSG), superoxide dismutase (SOD), and uric acid (UA)]. Cognitive function was evaluated using the Mini-Mental State Examination (MMSE). Although no significant changes were observed in the activity of 8-OhdG, GSH-Px, GSSG, GSH:GSSG ratio, SOD, and cognitive performance in the AE and TCE groups, the 12-week AE intervention led to a significant increase in CAT and GSH levels, along with a significantly decrease in UA levels among individuals with PD. Conversely, the TCE intervention resulted in a significant increase in GSH levels. However, SOD activity and MMSE scores were significantly decreased after 12 weeks in the control group. The correlations between changes in MMSE scores and changes in the levels of GSH and UA prior to and after the intervention reached significance in the AE group. Thus, long-term AE and TCE might serve as effective strategies for reducing oxidative damage and preserving cognitive function in PD, with AE exhibiting greater benefits compared with TCE. These findings hold potential clinical relevance as complementary measures to standard medical treatments and alternative therapies, such as antioxidant supplements and dietary adjustments, particularly for individuals in the early stages of PD.

Effects of Maca (Lepidium meyenii Walp.) on Physical Performance in Animals and Humans: A Systematic Review and Meta-Analysis

BACKGROUND

Lepidium meyenii Walp. (LmW), known as maca, has been shown to increase physical performance. However, the effect size (ES) of LmW on the different manifestations of physical performance has not yet been described.

OBJECTIVES

To examine and qualitatively describe the studies published up to 2024 that employed LmW supplementation to increase physical performance in animal and human experimentation. In addition, the ES associated with the different interventions was calculated.

METHODS

The research followed PRISMA® guidelines for systematic reviews and meta-analyses, using Web of Science, Scopus, SPORTDiscus, PubMed, and MEDLINE databases until 2024. Randomized controlled studies with a pre- and post-test design, conducted both in vitro and in vivo in animals and humans, were included. Methodological quality assessment was performed using the CAMARADES tool for animal studies and the Newcastle Ottawa Scale for human studies. The main variables were the forced swimming test (FST), the rota-rod test (RRT), the grip strength test (GST), blood lactic acid (BLA), and lactic acid (LA). The analysis was conducted with a pooled standardized mean difference (SMD) through Hedges' g test (95% CI).

RESULTS

Twenty-one studies were included in the systematic review and sixteen in the meta-analysis. They revealed a large effect for all outcomes (SMD: FST = 2.26, RRT = 6.26, GST = 5.23, LA = -1.01, and BLA = -1.70).

CONCLUSIONS

The phytochemical compounds of LmW, mainly macamides, increase physical performance, showing a greater effect at higher doses (dose-response effect).

The Potential of Targeting APE1/Ref-1 as a Therapeutic Intervention for Duchenne Muscular Dystrophy

Significance: Inflammation and oxidative stress play crucial roles in the development and progression of skeletal muscle diseases. This review aims to examine the existing evidence regarding the involvement and inhibition of APE1/Ref-1 (apurinic/apyrimidinic endonuclease 1/redox factor 1) in diseases, then extrapolate this evidence to the context of skeletal muscle and discuss the potential beneficial effects of APE1/Ref-1 inhibition in ameliorating myopathy with a particular focus on dystrophic pathology. Critical Issues: Currently, therapeutic interventions targeting pathways, such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and nuclear factor erythroid 2-related factor 2 (NRF2), have shown limited efficacy in both clinical and preclinical settings. Thus, there is a need for a more comprehensive treatment approach. Recent Advances: APE1/Ref-1 is a multifunctional protein that was initially identified as being involved in DNA repair. However, newer research has revealed its additional role as a redox-sensitive regulator of transcription factors, including NF-κB and NRF2. Numerous studies have reported increased expression of APE1/Ref-1 in various disorders and have demonstrated the beneficial effects of inhibiting its redox function using the small molecular inhibitor, APX3330. Although these pathways are similarly dysregulated in neuromuscular disorders, the specific role of APE1/Ref-1 in skeletal muscle remains unclear, with only a limited number of studies noting its presence in this tissue. Future Directions: Further studies investigating the role of APE1/Ref-1 in skeletal muscle and identifying whether APE1/Ref-1 is up- or downregulated in dystrophic skeletal muscle would be required to determine whether upregulating or inhibiting the redox function of APE1/Ref-1 will alleviate chronic inflammation and heightened oxidative stress. Antioxid. Redox Signal. 00, 000-000.

The Influence of Berry-Derived Polyphenol Supplementation on Exercise-Induced Oxidative Stress and Cardiovascular Health in Physically Active Individuals

Numerous studies have documented that high-intensity or prolonged exercise is associated with increased oxidative stress and modification of antioxidant status. Polyphenol-rich dietary supplements seem to be the compounds that can upregulate the endogenous antioxidant defense system and consequently prevent muscle damage, support recovery. As berry fruits are at the top of the list of the richest polyphenol food sources, supplements containing berries have become the subject of interest in the context of counteracting exercise-induced oxidative stress and the development of cardiovascular diseases. The purpose of this review is to summarize current knowledge on the effects of berry-derived polyphenol supplementation on exercise-induced oxidative stress and cardiovascular health in physically active individuals. Based on the available literature, blackcurrant supplementation, with its richest version being New Zealand blackcurrant extract, is the most commonly explored berry fruit, followed by chokeberries and blueberries. Although several studies have documented the significant and beneficial influence of berry-derived supplements on redox status and cardiovascular response, some inconsistencies remain. The presented findings should be interpreted with caution due the limited number of available studies, particularly with the participation of physically active individuals. Further research is needed to reveal more comprehensive and accurate data concerning the impact of berry-derived supplements on exercise-induced outcomes taking into account the type of supplement, time of administration, and dosage.

Plant polysaccharides and antioxidant benefits for exercise performance and gut health: from molecular pathways to clinic

In the last three decades, our understanding of how exercise induces oxidative stress has significantly advanced. Plant polysaccharides, such as dietary fibers and resistant starches, have been shown to enhance exercise performance by improving energy metabolism, reducing fatigue, increasing strength and stamina, mitigating oxidative stress post-exercise, facilitating muscle recovery, and aiding in detoxification. Moreover, antioxidants found in plant-based foods play a crucial role in protecting the body against oxidative stress induced by intense physical activity. By scavenging free radicals and reducing oxidative damage, antioxidants can improve exercise endurance, enhance recovery, and support immune function. Furthermore, the interaction between plant polysaccharides and antioxidants in the gut microbiota can lead to synergistic effects on overall health and performance. This review provides a comprehensive overview of the current research on plant polysaccharides and antioxidants in relation to exercise performance and gut health.

Hydrogen gas inhalation prior to high-intensity training reduces attenuation of nitric oxide bioavailability in male rugby players

Background

Inhalation of hydrogen gas (H2) as an antioxidant supplement may alleviate exercise-induced oxidative damage and protect post-exercise hydrogen peroxide signaling, which may help mediate beneficial exercise adaptation. The aims of this study were to determine the effects of H2 inhalation on plasma nitric oxide (NO) level and its synthesis precursor in professional athletes.

Methods

A randomized, placebo-controlled, double-blind, crossover trial was conducted with professional male rugby players for 3 weeks. Participants underwent 1 week of H2 supplementation and 1 week of placebo treatment prior to daily sessions of high-intensity exercise training, separated by 1 week of low-intensity training as a washout.

Results

Two-way (supplementation and time) repeated-measures analyses of variance showed that NO, L-arginine, and tetrahydrobiopterin levels in the H2 inhalation group were significantly higher than those in the placebo group after exercise (D6) and remained higher after 24 h of rest (D7). Levels of hydroxydeoxyguanosine and interleukin 6 were lower in the H2 inhalation week than in the placebo week on D6 and D7. In addition, total antioxidant levels were significantly higher with H2 inhalation than with placebo.

Significance

These results suggest that H2 inhalation helps to maintain NO signaling after exercise and to alleviate inflammation and oxidative stress induced by high-intensity exercise training in professional athletes.

Impact of combined exercise on blood DNA methylation and physical health in older women with obesity

This study examined the effects of a 14-week combined exercise program on blood DNA methylation (DNAm) and its potential biological pathways in normal-weight, overweight, and obese older women. A total of 41 participants were assessed at baseline, 7 weeks, and 14 weeks into the training. Their whole-blood DNAm profiles were measured using the Infinitum MethylationEPIC BeadChip, alongside physical and biochemical health evaluations. The results showed notable health improvements, with decreases in blood pressure and cholesterol levels in the overweight and obese groups. Blood triglycerides were reduced only in the overweight group. Physical performance also improved across all groups. At 14 weeks, 1,043 differentially methylated positions (DMPs) were identified, affecting 744 genes. The genes were linked to biological processes, such as cellular metabolism, with significant pathway enrichment related to oxidative phosphorylation and chemical carcinogenesis. Additionally, the overweight group experienced significant reductions in methylation levels at eight lipogenesis-related genes. Protein EpiScore analysis revealed decreased levels of CCL11, VEGFA, and NTRK3 proteins at 14 weeks compared to baseline. Despite these significant molecular changes, there was no observable difference in DNAm age after the intervention. This study highlights how combined exercise can modify DNAm patterns in older women, particularly in lipogenesis-related genes, but suggests that further research is needed to understand the full implications for biological ageing.

Acute treadmill exercise induces mitochondrial unfolded protein response in skeletal muscle of male rats

Mitochondria are often referred to as the energy centers of the cell and are recognized as key players in signal transduction, sensing, and responding to internal and external stimuli. Under stress conditions, the mitochondrial unfolded protein response (UPRmt), a conserved mitochondrial quality control mechanism, is activated to maintain mitochondrial and cellular homeostasis. As a physiological stimulus, exercise-induced mitochondrial perturbations trigger UPRmt, coordinating mitochondria-to-nucleus communication and initiating a transcriptional program to restore mitochondrial function. The aim of this study was to evaluate the UPRmt signaling response to acute exercise in skeletal muscle. Male rats were subjected to acute treadmill exercise at 25 m/min for 60 min on a 0 % grade. Plantaris muscles were collected from both sedentary and exercise groups at various times: immediately (0), and at 1, 3, 6, 12, and 24 h post-exercise. Reactive oxygen species (ROS) production was assessed using hydrogen peroxide assay and dihydroethidium staining. Additionally, the mRNA and protein expression of UPRmt markers were measured using ELISA and real-time PCR. Mitochondrial activity was assessed using succinate dehydrogenase (SDH) and cytochrome c oxidase (COX) staining. Our results demonstrated that acute exercise increased ROS production and upregulated UPRmt markers at both gene and protein levels. Moreover, skeletal muscle exhibited an increase in mitochondrial activity in response to exercise, as indicated by SDH and COX staining. These findings suggest that acute treadmill exercise is sufficient to induce ROS production, activate UPRmt signaling, and enhance mitochondrial activity in skeletal muscle, expanding our understanding of mitochondrial adaptations to exercise.

Biophysics of ACL Injuries

Anterior Cruciate Ligament (ACL) injuries rank among the most prevalent and severe types of injuries, significantly impacting both athletes and non-athletes alike. These injuries not only result in immediate physical impairment, such as intense pain, substantial swelling, and a marked loss of mobility, but also carry long-term health consequences that can alter a person's quality of life. Chronic pain, persistent instability, and an increased risk of developing osteoarthritis are among the lasting effects that can follow an ACL injury. An in-depth understanding of the biophysics behind ACL injuries is paramount for devising effective prevention and treatment protocols. Biophysics, which combines principles from physics with biological systems, provides crucial insights into the mechanical and structural integrity of the ACL and its susceptibility to injury under various conditions. This systematic review aims to collate and synthesize the current knowledge surrounding the biophysical mechanisms that underlie ACL injuries.

Dietary antioxidant capacity is inversely associated with F2- isoprostane and body fat percentage in elite soccer referees

Background Dietary antioxidant Capacity (DaC) has been used as a tool for predicting plasma and dietary antioxidant concentrations. However, the DaC association with oxidative stress (OS) and body composition parameters is an unexplored area, mainly in physically active individuals. Given the potential for increased OS in physically active individuals, it becomes crucial to investigate this association. The aim of this study was to analyze the association between DaC, OS biomarkers, and body composition in healthy and physically active individuals. Methods This Cross-sectional study included 20 male soccer referees. Body composition measurements (body mass, fat mass, lean mass, and waist circumference), OS biomarkers (F2-isoprostane, total antioxidant state, total oxidative status, reduced glutathione, oxidized glutathione, superoxide dismutase, glutathione peroxidase (GPx) and catalase), and DaC were evaluated. Linear regression models were used to determine the association between DaC and the dependent variables. The study was approved by the Human Research Ethics Committee of the Federal University of Santa Catarina (UFSC), CAAE 82584318.0.0000.0121, and file no. 2.572.301. Results DaC was inversely associated with F2-isoprostane (p = 0.044), GPx activity (p = 0.048), and body fat percentage (p = 0.025). Conclusions Increased DaC in physically active individuals may bring benefits related to biomarkers of OS, such as decreasing F2-isoprostane and increasing GPx activity. The increase in DaC also showed an improvement in body composition, demonstrated by the lower percentage of body fat in the study subjects.

The effect of taraxerol acetate extracted from dandelion on alleviating oxidative stress responses in vitro

Oxidative stress can be alleviated by antioxidants intakes. Taraxerol acetate (TA), a natural triterpenoid extracted from dandelions, may reduce the risk of metabolic disorders by regulating oxidative stress. In the study, we investigated the effects of TA in relieving oxidative stress in murine intestinal epithelial cells using multiomics techniques. Here, we found that TA activated the antioxidant defense system. Total antioxidant capacity (T-AOC) and Catalase (CAT) activity notably increased after TA treatment. Additionally, TA treatment effectively reduced the levels of lactate dehydrogenase (LDH) and malonaldehyde (MDA) and alleviated H2O2-induced oxidative stress. Furthermore, TA induced significant changes in the levels of 30 important metabolites. Specifically, it activated the complement and coagulation cascades, NF-κB and MAPK and glycerophospholipid pathways, resulting in altered transcript levels of related genes, such as Serpinb9e, SCD2, Hspa1b, and Hspa1a. Thus, the results demonstrated that TA potentially could promote health by alleviating H2O2-induced oxidative damage and provide valuable insights for its further development.

Inhalation of Hydrogen-rich Gas before Acute Exercise Alleviates Exercise Fatigue: A Randomized Crossover Study

Hydrogen, as an antioxidant, may have the potential to mitigate fatigue and improve selected oxidative stress markers induced by strenuous exercise. This study focused on a previously unexplored approach involving pre-exercise inhalation of hydrogen-rich gas (HRG). Twenty-four healthy adult men first completed pre-laboratories to determine maximum cycling power (Wmax) and maximum cycling time (Tmax). Then they were subjected to ride Tmax at 80% Wmax and 60-70 rpm on cycle ergometers after inhaled HRG or placebo gas (air) for 60-minute in a double-blind, counterbalanced, randomized, and crossover design. The cycling frequency in the fatigue modeling process and the rating of perceived exertion (RPE) at the beginning and end of the ride were recorded. Before gas inhalation and after fatigue modeling, visual analog scale (VAS) for fatigue and counter-movement jump (CMJ) were tested, and blood samples were obtained. The results showed that compared to a placebo, HRG inhalation induced significant improvement in VAS, RPE, the cycling frequency during the last 30 seconds in the fatigue modeling process, the ability to inhibit hydroxyl radicals, and serum lactate after exercise (p<0.028), but not in CMJ height and glutathione peroxidase activity. The cycling frequency during the last 30 seconds of all other segments in the fatigue modeling process was within the range of 60-70 rpm. In conclusion, HRG inhalation prior to acute exercise can alleviate exercise-induced fatigue, maintain functional performance, and improve hydroxyl radical and lactate levels.

Influence of short-term chronic oral cannabidiol application on muscle recovery and performance after an intensive training protocol - a randomized double-blind crossover study

BACKGROUND

Rapid regeneration after intense exercise is essential for competitive athletes. Based on this assumption, supplementation strategies, focusing on food supplements, are increasing to improve the recovery processes. One such supplement is cannabidiol (CBD) which is gaining more attention in competitive sports. However, the evidence is still lacking and there are no data available about the effect of a short-term chronic application.

METHODS

A three-arm double-blind cross-over study was conducted to determine the effects of two different CBD products on performance, muscle damage and inflammatory processes in well-trained athletes. In total 17 subjects took successfully part in this study. Each subject underwent the six-day, high-intensity training protocol three times. After each training session, each subject took either a placebo or a CBD product (60 mg of oil or solubilisate). Between the intervention phases, at least four weeks of washout period was conducted. Before and after the training protocols the performance capacity in countermovement jump (CMJ), back squat (BS), bench press (BP) and 1-mile run were measured and biomarkers for muscle damage (creatine kinase, myoglobin), inflammatory processes (interleukin 6 and 10) and immune cell activity (ratios of neutrophil granulocytes, lymphocytes and, platelets) were analyzed. For statistical analyses, the current version of R and a linear mixed model was used.

RESULTS

It could identify different effects of the training protocol depending on performance level (advanced or highly advanced athletes) (p < .05). Regardless of the performance level, muscle damage and a reduction in performance could be induced by the training protocol. Only CBD oil was associated with a reduction in myoglobin concentration (p < .05) in advanced athletes. Concerning immune activity, a significant decrease in platelets lymphocyte ratios was observed in advanced athletes after placebo treatment (p < .05). CBD oil application showed a slight inhibitory effect (p < .10). Moreover, the reduction in performance differs between the performance levels. A significant decrease in CMJ was observed in advanced athletes and a decreasing trend in BS was observed in highly advanced athletes after placebo treatment (p < 0.10). Both CBD products do not affect performance parameters. For inflammatory parameters, no effects were observed.

CONCLUSION

It was found that the performance level of the subjects was a decisive factor and that they responded differently to the training protocol and the CBD application. However, no clear effects of either CBD product were found and further research is needed to identify the long-term effects of CBD application.

The impact of N-acetylcysteine on lactate, biomarkers of oxidative stress, immune response, and muscle damage: A systematic review and meta-analysis

N-acetylcysteine (NAC) is a compound whose mechanism of action is intricately linked to the provision of cysteine for glutathione synthesis. It has been used in medicine and has also made significant inroads into sports, as it can modify the levels of several biomarkers, including those of oxidative processes, inflammation and muscle damage after exercise. Because the effectiveness of NAC supplementation is unclear, the primary objective of the present study was to perform a meta-analysis elucidating how NAC supplementation alters the concentrations of GSH (glutathione), GSSG (glutathione disulfide), TBARS (thiobarbituric acid reactive substances), IL-6 (interleukin 6), TNF-α (tumour necrosis factor alpha), CK (creatine kinase), lactate, and muscle soreness after physical exertion. Suitable studies were searched for from February to September 2023, and the results of those included (n = 20) indicate that NAC supplementation significantly diminishes both muscle soreness (p = 0.03; the mean difference (MD) of NAC's effect was -0.43 with a 95% confidence interval (CI), -0.81, -0.04) and lactate concentrations after exercise (p = 0.03; the MD -0.56 mmol/L; 95% CI, -1.07, -0.06). A substantial decrease was observed in concentrations of IL-6 (p = 0.03; the standardized MD (SMD) was -1.71; 95% CI, -3.26, -0.16) and TBARS (p = 0.02; SMD was -1.03, 95% CI, -1.90, -0.15). Furthermore, an elevation in GSH concentration was observed following supplementation. However, we saw no significant effect of NAC on TNF-α, CK or GSSG concentrations. NAC supplementation holds promise for attenuating muscle soreness, lactate, TBARS and IL-6 concentrations and increasing GSH level following physical exertion.

The Potential Interplay Between HIF-1α, Angiogenic, and Autophagic Signaling During Intermittent Hypoxic Exposure and Exercise

Berkemeier, Quint N., Michael R. Deyhle, James J. McCormick, Kurt A. Escobar, and Christine M. Mermier. The potential interplay between HIF-1α, angiogenic, and autophagic signaling during intermittent hypoxic exposure and exercise High Alt Med Biol. 25:326-336, 2024.-Environmental hypoxia as a result of decreased barometric pressure upon ascent to high altitudes (>2,500 m) presents increased physiological demands compared with low altitudes, or normoxic environments. Competitive athletes, mountaineers, wildland firefighters, military personnel, miners, and outdoor enthusiasts commonly participate in, or are exposed to, forms of exercise or physical labor at moderate to high altitudes. However, the majority of research on intermittent hypoxic exposure is centered around hematological markers, and the skeletal muscle cellular responses to exercise in hypoxic environments remain largely unknown. Two processes that may be integral for the maintenance of cellular health in skeletal muscle include angiogenesis, or the formation of new blood vessels from preexisting vasculature and autophagy, a process that removes and recycles damaged and dysfunctional cellular material in the lysosome. The purpose of this review is to is to examine the current body of literature and highlight the potential interplay between low-oxygen-sensing pathways, angiogenesis, and autophagy during acute and prolonged intermittent hypoxic exposure in conjunction with exercise. The views expressed in this paper are those of the authors and do not reflect the official policy of the Department of Army, DOD, DOE, ORAU/ORISE or U.S. Government.

Muscle aging and sarcopenia: The pathology, etiology, and most promising therapeutic targets

Sarcopenia is a progressive muscle wasting disorder that severely impacts the quality of life of elderly individuals. Although the natural aging process primarily causes sarcopenia, it can develop in response to other conditions. Because muscle function is influenced by numerous changes that occur with age, the etiology of sarcopenia remains unclear. However, recent characterizations of the aging muscle transcriptional landscape, signaling pathway disruptions, fiber and extracellular matrix compositions, systemic metabolomic and inflammatory responses, mitochondrial function, and neurological inputs offer insights and hope for future treatments. This review will discuss age-related changes in healthy muscle and our current understanding of how this can deteriorate into sarcopenia. As our elderly population continues to grow, we must understand sarcopenia and find treatments that allow individuals to maintain independence and dignity throughout an extended lifespan.

The Effect of Moringa oleifera Leaf Extract on C2C12 Myoblast Proliferation and Redox Status Under Oxidative Insult

Skeletal muscle tissue can regenerate after damage through the action of satellite cells, which proliferate as myoblasts when activated. Oxidative stress, marked by high rates of reactive oxygen species (e.g., hydrogen peroxide, H2O2), impairs this process by increasing myoblast cell death. Moringa oleifera leaf extract (MOLE), known for its antioxidant properties, was tested for its protective effects on C2C12 myoblasts under oxidative stress. We assessed MOLE's impact on total antioxidant capacity (TAC), glutathione homeostasis (GSH/GSSG), cell viability, and wound recovery. The metabolomic analysis of MOLE using an LC-MSMS ZenoTOF 7600 mass spectrometry system identified key compounds, including peculiar glucosinolates (42.1%) and flavonoids (18.8%), as well as phenolic acids (4.5%) and other significant metabolites (34.6%; among them, amino acids, vitamins, and fatty acids). H2O2 disrupted myoblast redox balance and caused cell death, but MOLE treatment restored the GSH/GSSG ratio, improved TAC, and increased cell viability. Additionally, MOLE promoted faster wound closure in myoblasts exposed to H2O2. These findings suggest that MOLE can protect C2C12 myoblasts by restoring redox balance and enhancing recovery under oxidative stress.

Physical Activity Reduces Metabolic Risk via Iron Metabolism: Cross-National Evidence Using the Triglyceride-Glucose Index

Purpose: Studies suggest that the triglyceride-glucose index (TyG) is a novel and comprehensive marker of metabolic health. While most research indicates that increased physical activity (PA) is linked to improved metabolic health, some studies argue that the previous markers may not fully capture this relationship. This study uses TyG as a marker of metabolic health to examine the association between PA and TyG. Methods: Data are from cross-sectional surveys in three large population studies in China and the United States: CHARLS, CHNS, and NHANES. Regression models were applied to analyze the relationship between PA and TyG, with covariates adjusted in a stepwise manner. Stratified analysis was used to explore this relationship among different population groups, and, since it has been suggested that iron metabolism plays an important role in metabolic health, it was used as a mediating variable to construct a mediation model for analysis and discussion. Results: Higher PA was significantly associated with lower TyG levels across all three databases (p < 0.001), and this relationship remained robust after full adjustment for covariates. This negative association was more pronounced in older males (over 45 years). Iron metabolism also mediated this relationship, with mediation proportions ranging from 10% to 12.5%. Conclusions: There is a significant inverse association between PA and TyG, suggesting a link between increased PA and metabolic health, with iron metabolism moderating this relationship, especially among older males.

Impact of Physical Activity on Cellular Metabolism Across Both Neurodegenerative and General Neurological Conditions: A Narrative Review

BACKGROUND

Regular physical activity plays a crucial role in modulating cellular metabolism and mitigating the progression of neurodegenerative diseases such as Alzheimer's, Parkinson's, and Multiple Sclerosis.

OBJECTIVE

The objective of this review is to evaluate the molecular mechanisms by which exercise influences cellular metabolism, with a focus on its potential as a therapeutic intervention for neurological disorders.

METHODS

A comprehensive literature review was conducted using peer-reviewed scientific articles, with a focus on the period between 2015 and 2024, to analyze the effects of exercise on mitochondrial function, oxidative stress, and metabolic health.

RESULTS

The findings indicate that exercise promotes mitochondrial biogenesis, enhances oxidative phosphorylation, and reduces reactive oxygen species, contributing to improved energy production and cellular resilience. These metabolic adaptations are associated with delayed disease progression and reduced symptoms in patients with neurodegenerative conditions. Additionally, integrating exercise with nutritional strategies may further enhance therapeutic outcomes by addressing metabolic disturbances comprehensively.

CONCLUSIONS

This review concludes that personalized exercise protocols should be developed to optimize metabolic benefits for patients with neurological diseases, while future research should focus on biomarker development for individualized treatment approaches. These findings highlight the importance of non-pharmacological interventions in managing neurodegenerative diseases.

Decreased Work Capability Related to High-Altitude Exposure

Background

The unique environment of high altitude can affect the work capacity of those not accustomed to it, and in some cases, it can even endanger their lives. Studying the effect of high-altitude exposure on work capacity is important. Still, there are few reviews on this topic. We aimed to summarize the parameters used to evaluate work capability in a high-altitude environment, the potential pathophysiological mechanisms, and the available pharmacological and non-pharmacological strategies for improvement.

Methods

We conducted searches on PubMed, Google Scholar, and China National Knowledge Infrastructure to explore the existing literature including basic and clinical studies from 1968 to 2023, using keywords such as "work capability/performance and high-altitude hypoxia" or "work/exercise at high altitude". Conference proceedings, notes, and case reports were excluded. The CiteSpace 6.1.R3 was used for de-duplication.

Results

A total of 727 papers were identified through search terms from the database. 486 papers were eliminated following the de-duplication process, lacking full text and deemed irrelevant to this article. Among the remaining 241 papers, 21 investigate the underlying mechanisms of reduced work capability due to altitude exposure, and 94 papers discuss measures to improve work capability when exposed to high altitudes.

Conclusion

In conclusion, this review summarizes the evaluation of indicators, pathomechanisms, and improvement measures for high-altitude exposure-related changes in work capability. More basic research on its mechanisms and large-sample, randomized controlled clinical studies to validate its effects are needed.

Effect of vitamin C injections on exercise muscular performance and biochemical parameters in Trichinella spiralis-infected mice

Background

Trichinella spiralis is a worldwide intestinal nematode that can parasitize the striated muscles of its hosts at the larval stage. This study aims to evaluate potential of vitamin C for treating trichinellosis-related pathological problems in the infected muscles of mice.

Materials and Methods

Thirty CD1 male Albino mice were divided into three groups (10 mice per group). Negative and positive control groups (0.9% NaCl) and the infected vitamin C group (10 mg/kg body weight). Two weeks post-infection, each group was intraperitoneally injected daily for two weeks with Vitamin C or saline. The performance of the muscles was assessed both before and after the treatment. After dissection, constant parts of striated muscles were removed for further assays. The scoring of the histological changes of infected muscles was carried out. In addition to muscle malondialdehyde levels, superoxide dismutase and catalase activities were measured for the oxidative and antioxidant states. Creatine kinase and aspartate aminotransferase were also measured in tissues to reflect the degree of muscular damage.

Results

Vitamin C enhances the weakness of the muscular performance resulting from the infection. Vitamin C was able to repair some of the histological lesions that resulted from the infection. Trichinellosis caused severe changes in the biochemical markers in positive control animals. Muscle damage biomarkers and, besides, oxidative and antioxidant conditions were greatly ameliorated in infected vitamin C animals. Summing up, vitamin C can be used as a complementary drug due to its efficiency in improving pathogenesis following a trichinellosis infection. The supplement also must be tested in the intestinal stage of infection after showing promising results in the muscular stage.

Reactive oxygen species in age-related musculoskeletal decline: implications for nutritional intervention

Musculoskeletal disorders and age-related musculoskeletal decline are major contributors to the burden of ill health seen in older subjects. Despite this increased burden, these chronic disorders of old age receive a relatively small proportion of national research funds. Much has been learned about fundamental processes involved in ageing from basic science research and this is leading to identification of key pathways that mediate ageing which may help the search for interventions to reduce age-related musculoskeletal decline. This short review will focus on the role of reactive oxygen species in age-related skeletal muscle decline and on the implications of this work for potential nutritional interventions in sarcopenia. The key physiological role of reactive oxygen species is now known to be in mediating redox signalling in muscle and other tissues and ageing leads to disruption of such pathways. In muscle, this is reflected in an age-related attenuation of specific adaptations and responses to contractile activity that impacts the ability of skeletal muscle from ageing individuals to respond to exercise. These pathways provides potential targets for identification of logical interventions that may help maintain muscle mass and function during ageing.

Antioxidant Activity of Anthocyanins and Anthocyanidins: A Critical Review

Anthocyanins are the main plant pigments responsible for the color of flowers, fruits, and vegetative organs of many plants, and are applied also as safe food colorants. They are efficient antioxidants. In this review, the reactivity of anthocyanins and their aglycones, anthocyanidins, in the main antioxidant assays, and their reactions with reactive oxygen and nitrogen species, effects of interactions with other compounds and metal ions on the antioxidant activity of anthocyanins and the electrochemical properties of anthocyanins are presented. Numerous cases of attenuation of oxidative stress at the cellular and organismal levels by anthocyanins are cited. The direct and indirect antioxidant action of anthocyanins, the question of the specificity of anthocyanin action in complex extracts, as well as limitations of cellular in vitro assays and biomarkers used for the detection of antioxidant effects of anthocyanins, are critically discussed.

The Effects of Antioxidant Supplementation on Soccer Performance and Recovery: A Critical Review of the Available Evidence

Background Soccer is linked to an acute inflammatory response and the release of reactive oxygen species (ROS). Antioxidant supplements have shown promising effects in reducing muscle damage and oxidative stress and enhancing the recovery process after eccentric exercise. This critical review highlights the influence of antioxidant supplements on performance and recovery following soccer-related activity, training, or competition. Methods: English-language publications from the main databases that examine how antioxidant-based nutrition and supplements affect the recovery process before, during, and after soccer practice or competition were used. Results:Coenzyme Q10 (CoQ10), astaxanthin (Asx), red orange juice (ROJS), L-carnitine (LC), N-acetyl cysteine (NAC), beetroot (BET), turmeric root, and tangeretin reduce muscle damage (creatine kinase, myoglobin, cortisol, lactate dehudrogenase, muscle soreness). Tangeretin, docosahexaenoic acid (DHA), turmeric root, and aronia melanocarpa restrict inflammation (leukocytes, prostalagdin E2, C-reactive protein, IL-6 and 10). Q10, DHA, Asx, tangeretin, lippia citriodora, quercetin, allopurinol, turmeric root, ROJS, aronia melanocarpa, vitamins C-E, green tea (GTE), and sour tea (STE) reduce oxidative stress (malondialdehude, glutathione, total antioxidant capacity, superoxide dismutases, protein carbonyls, ascorbate, glutathione peroxidase, and paraoxonase 1). BET and NAC reinforce performance (endurance, jump, speed, strength). Conclusions: Further research is needed to determine the main mechanism and the acute and long-term impacts of antioxidant supplements in soccer.

The sodium/ascorbic acid co-transporter SVCT2 distributes in a striated membrane-enriched domain at the M-band level in slow-twitch skeletal muscle fibers

BACKGROUND

Vitamin C plays key roles in cellular homeostasis, functioning as a potent antioxidant and a positive regulator of cell differentiation. In skeletal muscle, the vitamin C/sodium co-transporter SVCT2 is preferentially expressed in oxidative slow fibers. SVCT2 is up-regulated during the early fusion of primary myoblasts and decreases during initial myotube growth, indicating the relevance of vitamin C uptake via SVCT2 for early skeletal muscle differentiation and fiber-type definition. However, our understanding of SVCT2 expression and function in adult skeletal muscles is still limited.

RESULTS

In this study, we demonstrate that SVCT2 exhibits an intracellular distribution in chicken slow skeletal muscles, following a highly organized striated pattern. A similar distribution was observed in human muscle samples, chicken cultured myotubes, and isolated mouse myofibers. Immunohistochemical analyses, combined with biochemical cell fractionation experiments, reveal a strong co-localization of SVCT2 with intracellular detergent-soluble membrane fractions at the central sarcomeric M-band, where it co-solubilizes with sarcoplasmic reticulum proteins. Remarkably, electrical stimulation of cultured myofibers induces the redistribution of SVCT2 into a vesicular pattern.

CONCLUSIONS

Our results provide novel insights into the dynamic roles of SVCT2 in different intracellular compartments in response to functional demands.

Acute and prolonged effects of Bacillus amyloliquefaciens GF424-derived SOD on antioxidant defense in healthy individuals challenged with intense aerobic exercise

Reactive oxygen species (ROS) play a vital role in cellular functions but can lead to oxidative stress and contribute to degenerative diseases when produced in excess. Maintaining redox balance is essential and can be achieved through innate defense mechanisms or external antioxidants. Superoxide dismutase (SOD) is a key enzyme that mitigates intracellular oxidative stress by converting harmful free radicals into hydrogen peroxide, which is subsequently neutralized by catalase and glutathione peroxidase. Previous studies have demonstrated the antioxidant capabilities of SOD derived from Bacillus amyloquefaciens GF424 (BA-SOD) in murine models exposed to either irradiation or SOD1 gene deletion. In this study, a randomized clinical trial was conducted to evaluate the antioxidative benefits of BA-SOD in healthy individuals undergoing acute aerobic exercise (AAE). Eighty participants were randomly assigned to receive either BA-SOD or a placebo for 8 weeks. Antioxidant enzyme activities and glutathione levels were measured before, immediately after, and 30 min post-exercise. A single dose of BA-SOD significantly reduced ROS levels induced by AAE, primarily by enhancing SOD activity in erythrocytes and activating glutathione peroxidase. Continuous BA-SOD administration was associated with a sustained increase in catalase activity and elevated levels of reduced glutathione (GSH). Transcriptomic and metabolomic analyses revealed that a single BA-SOD dose facilitated GSH oxidation, as evidenced by decreased levels of serine, glutamine, and glycine, and increased pyroglutamate levels. Additionally, repeated dosing led to increased expression of genes encoding isocitrate dehydrogenase and malic enzyme, which are involved in NADPH synthesis, as well as nicotinamide phosphoribosyl transferase and NAD kinase, which are essential for NADP availability-critical for converting oxidized glutathione (GSSG) back to GSH. These molecular insights align with clinical observations, suggesting that both acute and long-term BA-SOD supplementation may effectively enhance antioxidant defenses and maintain redox balance under oxidative stress conditions.

Enhancing exercise performance and recovery through sodium bicarbonate supplementation: introducing the ingestion recovery framework

Sodium bicarbonate (SB) supplementation is an ergogenic strategy for athletes competing in high-intensity exercise, but the efficacy of SB for accelerating recovery from exercise and thus improving performance during repeated bouts of exercise is not fully understood. In a similar fashion to using SB as a pre-exercise buffer, it is possible accelerated restoration of blood pH and bicarbonate following an exercise bout mechanistically underpins the use of SB as a recovery aid. Physiological mechanisms contributing to beneficial effects for SB during repeated bout exercise could be more far-reaching however, as alterations in strong ion difference (SID) and attenuated cellular stress response might also contribute to accelerated recovery from exercise. From inspection of existing literature, ingestion of 0.3 g kg-1 body mass SB ~60-90 min pre-exercise seems to be the most common dosage strategy, but there is evidence emerging for the potential application of post-exercise supplementation timing, gradual SB doses throughout a competition day, or even ingestion during exercise. Based on this review of literature, an SB ingestion recovery framework is proposed to guide athletes and practitioners on the use of SB to enhance performance for multiple bouts of exercise.

Does acute dehydration affect the neuromuscular function in healthy adults?-a systematic review

The effects of acute dehydration on neuromuscular function have been studied. However, whether the mechanisms underpinning such function are central or peripheral is still being determined, and the results are inconsistent. This systematic review aims to elucidate the influence of acute dehydration on neuromuscular function, including a novel aspect of investigating the central and peripheral neuromuscular mechanisms. Three databases were used for the article search: PubMed, Web of Science, and Scopus. Studies were included if they had objective measurements of dehydration, muscle performance, and electromyography data or transcranial magnetic stimulation or peripheral nerve stimulation measurements with healthy individuals aged 18-65 years. Twenty-three articles met the eligibility criteria. The studies exhibited considerable heterogeneity in the methods used to induce and quantify dehydration. Despite being inconsistent, the literature shows some evidence that acute dehydration does not affect maximal strength during isometric or moderate-speed isokinetic contractions. Conversely, acute dehydration significantly reduces maximal strength during slow-speed isokinetic contractions and fatigue resistance in response to endurance tasks. The studies report that dehydration does not affect the motor cortical output or spinal circuity. The effects occur at the peripheral level within the muscle.

Unlocking peak performance: The role of Nrf2 in enhancing exercise outcomes and training adaptation in humans

Since the discovery of the nuclear factor erythroid-derived 2-like 2 (Nrf2) transcription factor thirty years ago, it has been shown that it regulates more than 250 genes involved in a multitude of biological processes, including redox balance, mitochondrial biogenesis, metabolism, detoxification, cytoprotection, inflammation, immunity, autophagy, cell differentiation, and xenobiotic metabolism. In skeletal muscle, Nrf2 signalling is primarily activated in response to perturbation of redox balance by reactive oxygen species or electrophiles. Initial investigations into human skeletal muscle Nrf2 responses to exercise, dating back roughly a decade, have consistently indicated that exercise-induced ROS production stimulates Nrf2 signalling. Notably, recent studies employing Nrf2 knockout mice have revealed impaired skeletal muscle contractile function characterised by reduced force output and increased fatigue susceptibility compared to wild-type counterparts. These deficiencies partially stem from diminished basal mitochondrial respiratory capacity and an impaired capacity to upregulate specific mitochondrial proteins in response to training, findings corroborated by inducible muscle-specific Nrf2 knockout models. In humans, baseline Nrf2 expression in skeletal muscle correlates with maximal oxygen uptake and high-intensity exercise performance. This manuscript delves into the mechanisms underpinning Nrf2 signalling in response to acute exercise in human skeletal muscle, highlighting the involvement of ROS, antioxidants and Keap1/Nrf2 signalling in exercise performance. Furthermore, it explores Nrf2's role in mediating adaptations to chronic exercise and its impact on overall exercise performance. Additionally, the influence of diet and certain supplements on basal Nrf2 expression and its role in modulating acute and chronic exercise responses are briefly addressed.

Reactive oxygen species promote endurance exercise-induced adaptations in skeletal muscles

The discovery that contracting skeletal muscle generates reactive oxygen species (ROS) was first reported over 40 years ago. The prevailing view in the 1980s was that exercise-induced ROS production promotes oxidation of proteins and lipids resulting in muscle damage. However, a paradigm shift occurred in the 1990s as growing research revealed that ROS are signaling molecules, capable of activating transcriptional activators/coactivators and promoting exercise-induced muscle adaptation. Growing evidence supports the notion that reduction-oxidation (redox) signaling pathways play an important role in the muscle remodeling that occurs in response to endurance exercise training. This review examines the specific role that redox signaling plays in this endurance exercise-induced skeletal muscle adaptation. We begin with a discussion of the primary sites of ROS production in contracting muscle fibers followed by a summary of the antioxidant enzymes involved in the regulation of ROS levels in the cell. We then discuss which redox-sensitive signaling pathways promote endurance exercise-induced muscle adaptation and debate the strength of the evidence supporting the notion that redox signaling plays an essential role in muscle adaptation to endurance exercise training. In hopes of stimulating future research, we highlight several important unanswered questions in this field.

Exercise-induced Nrf2 activation increases antioxidant defenses in skeletal muscles

Following the discovery that exercise increases the production of reactive oxygen species in contracting skeletal muscles, evidence quickly emerged that endurance exercise training increases the abundance of key antioxidant enzymes in the trained muscles. Since these early observations, knowledge about the impact that regular exercise has on skeletal muscle antioxidant capacity has increased significantly. Importantly, in recent years, our understanding of the cell signaling pathways responsible for this exercise-induced increase in antioxidant enzymes has expanded exponentially. Therefore, the goals of this review are: 1) summarize our knowledge about the influence that exercise training has on the abundance of key antioxidant enzymes in skeletal muscles; and 2) to provide a state-of-the-art review of the nuclear factor erythroid 2-related factor (Nrf2) signaling pathway that is responsible for many of the exercise-induced changes in muscle antioxidant capacity. We begin with a discussion of the sources of reactive oxygen species in contracting muscles and then examine the exercise-induced changes in the antioxidant enzymes that eliminate both superoxide radicals and hydrogen peroxide in muscle fibers. We conclude with a discussion of the advances in our understanding of the exercise-induced control of the Nrf2 signaling pathway that is responsible for the expression of numerous antioxidant proteins. In hopes of stimulating future research, we also identify gaps in our knowledge about the signaling pathways responsible for the exercise-induced increases in muscle antioxidant enzymes.

Effects of high-intensity interval training versus moderate-intensity continuous training on vascular function among individuals with overweight and obesity-a systematic review

BACKGROUND

The study aimed to investigate and systematically review the evidence relating to the effects of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) on vascular function such as arterial diameter, arterial stiffness, pulse wave velocity, blood flow, etc. in individuals with overweight and obesity.

METHODS

The entire content of PubMed (MEDLINE), Scopus, SPORT Discus® (via EBSCO host), CINAHL, and Web of Science were searched. Only experimental research studies conducted in adult participants aged ≥18 years, published in English before January 2023 were included.

RESULTS

A total of 5397 studies were reviewed for the title and abstract with 11 studies being included for data extraction. The review resulted in a total of 346 individuals with overweight and obesity with body mass index (BMI) ranging between 25-36 kg/m2. HIIT and MICT intensities resulted in 85%-95% and 60%-70% maximal heart rate (MHR) respectively. Seven out of 11 studies showed some concerns about the overall risk of bias. Six of 11 studies reported improving vascular function following HIIT than MICT.

CONCLUSION

HIIT is a more effective and time-efficient exercise for enhancing vascular functions in individuals with overweight and obesity, leading to improvements in flow-mediated dilation by 3.9% and arterial diameter by 4.8%, compared to MICT.

The Synergistic Effect of Intradialytic Concurrent Training and Melatonin Supplementation on Oxidative Stress and Inflammation in Hemodialysis Patients: A Double-Blind Randomized Controlled Trial

BACKGROUND

This study aimed to investigate the effects of intradialytic concurrent (resistance-endurance) training combined with melatonin (MEL) supplementation on oxidative stress, inflammation, and cellular damage in hemodialysis (HD) patients.

METHODS

Thirty-two HD patients were randomly assigned to three groups: Exercise (EX)-MEL, EX-Placebo (PLA), and Control (C)-PLA. Participants in the EX-MEL and EX-PLA groups underwent 12 weeks of concurrent training. Before nocturnal sleep, they ingested either 3 mg of MEL (EX-MEL) or a placebo (EX-PLA and C-PLA). Blood samples were collected at baseline and after 12 weeks of intervention to assess lipid peroxidation [malondialdehyde (MDA)], antioxidant biomarkers [ferric-reducing antioxidant power (FRAP), reduced glutathione (GSH), total thiol (THIOL)], total bilirubin (TBIL), uric acid (UA), biomarkers of muscle and liver damage [aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), creatine kinase (CK), lactate dehydrogenase (LDH), and Gamma-glutamyltransferase (Gamma-GT)], and inflammation [C-reactive protein (CRP)].

RESULTS

EX-MEL demonstrated a decrease in MDA (p < 0.05) and CRP (p < 0.05), and an increase in FRAP (p < 0.05) pre- and post-training. Both EX-MEL and EX-PLA showed an increase in GSH (p < 0.001, and p < 0.05, respectively) and THIOL (p < 0.01, and p < 0.05, respectively) pre- and post-training. No significant changes were observed in TBIL, UA, ASAT, ALAT, CK, LDH, or Gamma-GT pre- and post-training across all groups.

CONCLUSION

Concurrent training combined with MEL supplementation enhances oxidant-antioxidant balance and reduces inflammation in HD patients more effectively than intradialytic concurrent training alone.

Screening of hub genes for sepsis-induced myopathy by weighted gene co-expression network analysis and protein-protein interaction network construction

Sepsis-induced myopathy is one of the serious complications of sepsis, which severely affects the respiratory and peripheral motor systems of patients, reduces their quality of life, and jeopardizes their lives, as evidenced by muscle atrophy, loss of strength, and impaired regeneration after injury. The pathogenesis of sepsis-induced myopathy is complex, mainly including cytokine action, enhances free radical production in muscle, increases muscle protein hydrolysis, and decreases skeletal muscle protein synthesis, etc. The above mechanisms have been demonstrated in existing studies. However, it is still unclear how the overall pattern of gene co-expression affects the pathological process of sepsis-induced myopathy. Therefore, we intend to identify hub genes and signaling pathways. Weighted gene co-expression network analysis was our main approach to study gene expression profiles: skeletal muscle transcriptome in ICU patients with sepsis-induced multi-organ failure (GSE13205). After data pre-processing, about 15,181 genes were used to identify 13 co-expression modules. Then, 16 genes (FEM1B, KLHDC3, GPX3, NIFK, GNL2, EBNA1BP2, PES1, FBP2, PFKP, BYSL, HEATR1, WDR75, TBL3, and WDR43) were selected as the hub genes including 3 up-regulated genes and 13 down-regulated genes. Then, Gene Set Enrichment Analysis was performed to show that the hub genes were closely associated with skeletal muscle dysfunction, necrotic and apoptotic skeletal myoblasts, and apoptosis in sepsis-induced myopathy. Overall, 16 candidate biomarkers were certified as reliable features for more in-depth exploration of sepsis-induced myopathy in basic and clinical studies.

Physical activity combined with tea consumption could further reduce all-cause and cancer-specific mortality

The study aimed to comprehensively assess the separate and combined effects of physical activity (PA) and tea consumption on all-cause mortality and cancer-specific mortality among 21,350 participants from The National Health and Nutrition Examination Survey (NHANES) between 2009 and 2018. PA and tea consumption were evaluated through self-reported questionnaires and dietary recall interviews at baseline, with mortality data from the National Death Index. Cox regression analyses yielded hazard ratios (HR) and 95% confidence intervals (CI). Results indicated that both tea consumption and PA independently reduced all-cause mortality. In the physically active group, tea consumption further decreased mortality risk, while this effect was not significant in the inactive group. Jointly, the highest tea consumers who exercised the most exhibited the lowest mortality risk compared to non-tea drinkers who exercised the least. Tea consumption alone does not significantly impact cancer-specific mortality; it is only in physically active group that tea consumption significantly lowers the risk of cancer-specific mortality. These findings underscore the potential benefits of regular tea consumption and PA in promoting longevity and reducing premature death risks.

Effects of 8 days intake of hydrogen-rich water on muscular endurance performance and fatigue recovery during resistance training

Background

Exercise-induced oxidative stress and inflammation can impair muscular function in humans. The antioxidant and anti-inflammatory properties of molecular hydrogen (H2) highlight its potential to be as an effective nutritional supplement to support muscular function performance in healthy adults. However, the effects of H2 supplementation on muscular endurance performance in trained individuals have not been well characterized. This study aimed to assess the effects of intermittent hydrogen-rich water (HRW) supplementation before, during, and after resistance training on muscular endurance performance, neuromuscular status, and subjective perceptual responses after a 48-h recovery period.

Methods

This randomized, double-blinded, placebo-controlled cross-over study included 18 trained men aged 19.7 ± 0.9 years. Participants in this study were instructed to consume 1,920 mL of HRW or pure water (Placebo) daily for 7 days. Additionally, participants were required to supplement with HRW or pure water five times during the training day (1,260 mL total). This included drinking 210 mL 30 min and 1 min before training, 210 mL between training sets, 210 mL immediately after training, and 420 mL 30 min into the recovery period. Participants performed half-squat exercises with the load set at 70% of one repetition maximum for six sets (half-squat exercise performed to repetitions failure each set). We measured the power output and number of repetitions in the free barbell half-squat used to assess muscular endurance performance in participants. The countermovement jump (CMJ) height, total quality recovery scale (TQRS), and muscle soreness visual analog scale (VAS) scores were measured to assess fatigue recovery status after training, as well as at 24 and 48 h of recovery.

Results

The total power output (HRW: 50,866.7 ± 6,359.9W, Placebo: 46,431.0 ± 9,376.5W, p = 0.032) and the total number of repetitions (HRW:78.2 ± 9.5 repetitions, Placebo: 70.3 ± 9.5 repetitions, p = 0.019) in the H2 supplemented group were significantly higher than in the placebo group. However, there was no statistically significant difference (p< 0.05) between the H2 and placebo groups in CMJ, TQRS, and VAS.

Conclusion

Eight days of intermittent HRW intake could significantly improve muscular endurance performance in trained individuals, making it a promising strategy for athletes or fitness enthusiasts looking to boost muscular endurance during resistance training or competitions. However, it should be noted that HRW intake alone may not be adequate to accelerate recovery from muscle soreness or fatigue following high-intensity training.