Frontiers in Physiology最新文献

{"title":"A study on the effects of modified sprint interval trainingon physical fitness test scores and the quantitative and dose-response relationships among Chinese male university students.","authors":"Guoyuan Huang, Yang Chen, ByungChan Lee, Yipeng Qiu, Aqiang Mao, Maolong Liang, Maojie Liu","doi":"10.3389/fphys.2025.1555019","DOIUrl":"10.3389/fphys.2025.1555019","url":null,"abstract":"<p><strong>Introduction: </strong>This study primarily investigates the impact of a 6-week Sprint Interval Training (SIT) intervention on the physical fitness test results of male university students, as well as the dose-response relationship in adjusting the experimental protocol.</p><p><strong>Methods: </strong>A total of 26 male university students (aged 20 ± 2 years; height 174 ± 7 cm; weight 70 ± 14 kg; mean ± SD) with no systematic training in the past 3 months, no physiological diseases, and healthy physical condition voluntarily participated in the experiment. The SIT protocol was designed based on a classic Wingate sprint protocol (4-6 x 30 s sprints with 4 m of recovery), and adjustments were made based on the participants' actual adaptation. The final intervention consisted of 6 weeks of training, three times per week, with 2-3 repetitions of 30-s Wingate sprints (Cd = 0.075, resistance on the ergometer = weight/kg x Cd) and 4-5 m of recovery.</p><p><strong>Results: </strong>The results showed significant improvements in key anaerobic capacity indicators after the 6-week intervention: Average Power (AP) increased from 77.4 ± 10.1 to 132.6 ± 21.1 (p < 0.01, Adjusted p < 0.03 ment, with a maximum effect size of 3.344), Peak Power (PP) increased from 102.9 ± 14.5 to 189.5 ± 28.8 (p < 0.01, Adjusted p < 0.02, maximum effect 3.790), and Time to Peak Power (TTP) decreased from 12.3 ± 3.3 to 9.5 ± 2.6 (p < 0.01), confirming that the intervention enhanced the participants' anaerobic capacity. Additionally, The results of the physical fitness test showed significant improvements: standing long jump (SLJ) increased from 2.31 ± 0.15 m to 2.45 ± 0.18 m (significance level p < 0.01), 50 m sprint time decreased from 7.32 ± 0.42 s to 6.98 ± 0.38 s (significance level p < 0.01), and 1,000 m from 235.6 ± 18.4 s to 220.3 ± 16.8 s (significance level p < 0.01). Other metrics such as Body mass, BMI, Vital capacity, and Pull-ups also showed minor increases. Interestingly, Sit forward in a sitting position scores showed a noticeable improvement (from 12.9 ± 6.8 to 15.8 ± 6.2, p = 0.091).</p><p><strong>Discussion: </strong>Furthermore, The adjustment of the training programme has achieved good results, as evidenced by the fact that participants have achieved a training completion rate of over 95%, maintained a moderate subjective fatigue rating (RPE score of 13-15), and no one has withdrawn from the training due to discomfort.</p><p><strong>Conclusion: </strong>The modified SIT protocol proves to be an efficient and practical training method for improving college students' physical fitness.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1555019"},"PeriodicalIF":3.2,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11893556/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143604492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of aerobic, resistance, and combined training on cardiometabolic health-related indicators in inactive middle-aged men with excess body weight and obesity.","authors":"Friew Amare Mengistu, Yehualaw Alemu Lake, Molalign Enchalew Andualem, Yalemsew Demlie Miherete, Solomon Adamu Zewdie","doi":"10.3389/fphys.2025.1519180","DOIUrl":"10.3389/fphys.2025.1519180","url":null,"abstract":"<p><strong>Methods: </strong>Twenty physically inactive men (49.15 ± 2.581 years) and BMI with 27.66 ± 0.91, participated in an 8-month training programme involving concurrent exercise (CT), resistance training (RT), and aerobic training (AT) program to determine the effects on fasting blood glucose (FBG), insulin resistance (IR), blood pressure (BP) and waist-to-hip ratio (WHR) in overweight and obese adult persons. This study was used a randomized repeated measures parallel experimental design.</p><p><strong>Results: </strong>Pre-to-post mean values of FBG, IR, SBP, DBP and WHR significantly decreased. Exercise modality had a significant effect on FBG (F (2, 26) = 10.656, p = 0.001, η² = 0.571), with RT and CT showing greater reductions than AT. IR decreased more in RT than in AT (MD = 0.410 ± 0.101, p = 0.03). SBP also varied significantly between modalities (F (2, 26) = 13.103, p = 0.02, η² = 0.528), with CT and RT showing larger reductions than AT. WHR differed significantly (F (2, 16) = 18.175, p = 0.001, η² = 0.694), with AT and CT showing more reductions than RT. Diastolic blood pressure (DBP) showed no significant effect from exercise modality.</p><p><strong>Conclusion: </strong>These findings highlight the importance of tailored exercise interventions, with short rest RT and CT emerging as the most effective method for inactive overweight and obese individuals.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1519180"},"PeriodicalIF":3.2,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11893990/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143604514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing poultry health and productivity through the liver-gut axis with integrated nutritional and immunological approaches: a mini-review.","authors":"Felix Kwame Amevor, Victoria Anthony Uyanga, Liuting Wu, Dan Xu, Gang Shu, Yingjie Wang, Xiaoling Zhao","doi":"10.3389/fphys.2025.1537099","DOIUrl":"10.3389/fphys.2025.1537099","url":null,"abstract":"<p><p>The liver-gut axis plays a central role in maintaining the health and productivity of poultry. In addition, the liver-gut axis serves as a key regulator of digestion, metabolism, immunity, and detoxification. The gut, with its diverse microbiota, is the primary site for nutrient absorption and immune modulation, while the liver metabolizes nutrients, detoxifies harmful substances, and acts as a frontline defense against pathogens translocated from the gut. Disruptions in this interconnected system, including gut dysbiosis or liver inflammation, can lead to compromised immunity and reduced productivity. This mini-review explores integrated nutritional and immunological strategies aimed at optimizing the liver-gut axis to enhance poultry performance. Nutritional interventions, such as the use of flavonoids, vitamins, amino acids, micronutrients, probiotics, prebiotics, and synbiotics, have demonstrated their potential to support liver and gut health. Dietary components such as phytogenic additives, fiber, and fatty acids further contribute to immune modulation and systemic health. Immunological approaches, such as beta-glucans and <i>in ovo</i> stimulation, and molecular approaches, including advanced genetic techniques, offer additional avenues for improving disease resistance and organ function. Despite notable advancements, challenges including antibiotic resistance, environmental stressors, and implementation costs persist. Emerging technologies like metagenomics, metabolomics, and precision breeding offer innovative solutions to enhance liver-gut interactions. This review underscores recent advancements in understanding the liver-gut axis and calls for holistic strategies to improve sustainable poultry production. Future research should integrate these approaches to enhance resilience, productivity, and sustainability in the poultry industry.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1537099"},"PeriodicalIF":3.2,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11893858/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143604513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>In silico</i> oncology: a mechanistic multiscale model of clinical prostate cancer response to external radiation therapy as the core of a digital (virtual) twin. Sensitivity analysis and a clinical adaptation approach.","authors":"Georgios Stamatakos, Eleni Kolokotroni, Foteini Panagiotidou, Stamatia Tsampa, Christos Kyroudis, Simon Spohn, Anca-Ligia Grosu, Dimos Baltas, Constantinos Zamboglou, Ilias Sachpazidis","doi":"10.3389/fphys.2025.1434739","DOIUrl":"10.3389/fphys.2025.1434739","url":null,"abstract":"<p><strong>Introduction: </strong>Prostate cancer (PCa) is the most frequent diagnosed malignancy in male patients in Europe and radiation therapy (RT) is a main treatment option. However, current RT concepts for PCa have an imminent need to be rectified in order to modify the radiotherapeutic strategy by considering (i) the personal PCa biology in terms of radio resistance and (ii) the individual preferences of each patient.</p><p><strong>Methods: </strong>To this end, a mechanistic multiscale model of prostate tumor response to external radiotherapeutic schemes, based on a discrete entity and discrete event simulation approach has been developed. Following technical verification, an adaptation to clinical data approach is delineated. Multiscale data has been provided by the University of Freiburg. Additionally, a sensitivity analysis has been performed.</p><p><strong>Results: </strong>The impact of model parameters such as cell cycle duration, dormant phase duration, apoptosis rate of living and progenitor cells, fraction of dormant stem and progenitor cells that reenter cell cycle, number of mitoses performed by progenitor cells before becoming differentiated, fraction of stem cells that perform symmetric division, fraction of cells entering the dormant phase following mitosis, alpha and beta parameters of the linear-quadratic model and oxygen enhancement ratio has been studied. The model has been shown to be particularly sensitive to the apoptosis rate of living stem and progenitor cells, the fraction of dormant stem and progenitor cells that reenter cell cycle, the fraction of stem cells that perform symmetric division and the fraction of cells entering the dormant phase following mitosis. A qualitative agreement of the model behavior with experimental and clinical knowledge has set the basis for the next steps towards its thorough clinical validation and its eventual certification and clinical translation. The paper showcases the feasibility, the fundamental design and the qualitative behavior of the model in the context of <i>in silico</i> experimentation.</p><p><strong>Discussion: </strong>Further data is being collected in order to enhance the model parametrization and conduct extensive clinical validation. The envisaged digital twin or OncoSimulator, a concept and technologically integrated system that our team has previously developed for other cancer types, is expected to support both patient personalized treatment and <i>in silico</i> clinical trials.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1434739"},"PeriodicalIF":3.2,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11891158/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143596591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Size and site matter: the influence of corpus callosum subregional lesions on the magnitude of cross-education of strength.","authors":"Marco Morrone, Gianluca Martinez, Antonio Achene, Mariano Scaglione, Salvatore Masala, Andrea Manca, Franca Deriu","doi":"10.3389/fphys.2025.1554742","DOIUrl":"10.3389/fphys.2025.1554742","url":null,"abstract":"<p><strong>Introduction: </strong>Cross-education is an established yet not fully understood phenomenon involving interhemispheric processes within the corpus callosum (CC) that result in strength gains in the untraining limb following training of the contralateral homologous muscles. There is a substantial lack of cross-education studies employing lesional models. This study employed the model of multiple sclerosis, a condition typically featuring demyelinating callosal lesions, to pinpoint CC subregions that mediate cross-education, potentially fostering the mechanistic understanding of the interlimb transfer.</p><p><strong>Methods: </strong>Nine individuals with relapsing-remitting multiple sclerosis (median Expanded Disability Status Scale: 3.5) and focal CC lesions underwent a 6-week, high-intensity isokinetic training program (≥80% maximal effort at 10°/s) targeting their stronger ankle dorsiflexors. Sagittal FLAIR MRI scans were segmented into five CC subregions (CC1-CC5), with lesion volumes quantified for each subregion. Strength (peak concentric torque at 10°/s) was measured bilaterally before (PRE) and after (POST) training to determine cross-education, defined as the percentage increase in torque of the untrained, weaker limb. Correlations between lesion volumes in CC subregions and cross-education were analyzed.</p><p><strong>Results: </strong>Both the trained (+21.5 ± 15.8%, p = 0.002) and untrained (+35.2 ± 24.9%, p = 0.003) limbs demonstrated post-training strength gains, reducing but not eliminating inter-limb asymmetry. Lesions specifically in the rostral body (CC2) correlated with reduced cross-education magnitude (rs = -0.670, p = 0.048) and smaller improvements in strength asymmetry (rs = 0.809, p = 0.008). No associations were detected in other CC subregions.</p><p><strong>Conclusion: </strong>These findings highlight the pivotal role of specific CC subregions, particularly the rostral body, in mediating cross-education of strength. These findings advance our understanding of CC role in the interhemispheric dynamics underpinning cross-education. Routine MRI can identify patients without CC2 lesions who may benefit from cross-education, providing a practical approach to improving muscle strength when weaker muscles cannot be directly trained.</p><p><strong>Clinical trial registration: </strong>ClinicaTrials.Gov, identifier NCT02010398.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1554742"},"PeriodicalIF":3.2,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11891228/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143596603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Connexin hemichannels and early atrophic signaling in muscle during sepsis.","authors":"Elisa Balboa, Fujiko Saavedra, Luis A Cea, Aníbal A Vargas, Tomás Regueira, Juan C Sáez","doi":"10.3389/fphys.2025.1514769","DOIUrl":"10.3389/fphys.2025.1514769","url":null,"abstract":"<p><p>Sepsis pathogenesis is complex, and effective treatments are limited, leading to high mortality rates between 20% and 55%. Early identification of factors contributing to sepsis-related muscle dysfunction is critical for risk stratification and potential therapeutic development. The immune response during sepsis affects skeletal muscles, contributing to organ dysfunction and worsening prognosis. In this study, we explore the role of connexin hemichannels (Cx HCs) in the early changes in muscle homeostasis during sepsis. Using a cecal ligature and puncture (CLP)-induced sepsis model, we assessed IL-6 levels, weight loss, myofiber cross-sectional area, resting membrane potential, and connexin expression in control and Cx43/Cx45-deficient mice. CLP induced IL-6 elevation, sarcolemma permeabilization, reduced membrane potential, and activation of the ubiquitin-proteasome pathway in control mice, while Cx43/45-deficient mice exhibited reduced all CLP-induced muscle alterations. These findings suggest that Cx43 and Cx45 are involved in the early development of muscle alterations during sepsis.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1514769"},"PeriodicalIF":3.2,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11891358/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143596598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effects of training intervention on the prevention of knee joint injuries: a systematic review and meta-analysis.","authors":"Gangbin Zheng, Sai Zeng, Tiangeng Li, Liang Guo, Ling Li","doi":"10.3389/fphys.2025.1455055","DOIUrl":"10.3389/fphys.2025.1455055","url":null,"abstract":"<p><strong>Objective: </strong>To evaluate the impact of neuromuscular, core strength, balance, and proprioceptive training on preventing knee injuries in young athletes, to identify optimal intervention characteristics.</p><p><strong>Methods: </strong>This review followed the 2020 guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A systematic search of English and Chinese literature in databases included PubMed, Web of Science, EBSCO, CNKI, and Wanfang, covering studies published from January 1, 2000, to 12 April 2024. Inclusion criteria targeted randomized controlled trials (RCTs) on training interventions aimed at knee injury prevention among young athletes. The analysis used a random-effects model to pool data from studies meeting our criteria, ensuring a comprehensive evaluation of intervention effectiveness.</p><p><strong>Results: </strong>A total of 19 randomized controlled trials (RCTs) involving 28,176 subjects were included. The meta-analysis showed that training intervention programs reduced the risk of lower extremity knee injuries by 25% (RR = 0.75, 95% CI: 0.65-0.85). The most notable effects were observed in intervention with exercise duration of 5-15 min, frequencies of 4-5 times per week, and program lengths exceeding 26 weeks.</p><p><strong>Conclusion: </strong>The findings highlight the effectiveness of specific training interventions in reducing knee injury risk among athletes. These insights provide a clear framework for designing training routines that effectively prevent knee injuries.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1455055"},"PeriodicalIF":3.2,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11891182/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143596607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acute effects of caffeine and paracetamol on velocity and power in resistance exercise.","authors":"Bela Scapec, Jozo Grgic, Dorian Varovic, Pavle Mikulic","doi":"10.3389/fphys.2025.1536591","DOIUrl":"10.3389/fphys.2025.1536591","url":null,"abstract":"<p><p>This study aimed to explore the isolated and combined effects of caffeine and paracetamol (acetaminophen) on velocity and power in resistance exercise. Twenty-eight resistance-trained men and women participated in this randomized, double-blind, placebo-controlled, crossover study. The participants performed three sets of the bench press with 75% of one-repetition maximum to momentary muscular failure after ingesting a placebo, caffeine (3 mg/kg), paracetamol (1,500 mg), or caffeine + paracetamol 45 min before exercise. Velocity and power of the repetitions in each set were analysed. Compared to placebo, only isolated caffeine ingestion increased mean velocity (<i>d</i> = 0.34), and mean power (<i>d</i> = 0.17) in the first set. No significant differences between the conditions were observed for any of the analysed outcomes in the second and third sets. Our results indicate that only isolated caffeine ingestion improves velocity and power in resistance exercise, even though these effects are not consistent across all sets. Paracetamol ingestion was not ergogenic, even when combined with caffeine. These results highlight that analgesics may be ineffective in improving resistance exercise performance.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1536591"},"PeriodicalIF":3.2,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11891366/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143596594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The relationship and agreement between systemic and local breakpoints in locomotor and non-locomotor muscles during single-leg cycling.","authors":"Markus Tilp, Nina Mosser, Gudrun Schappacher-Tilp, Annika Kruse, Philipp Birnbaumer, Gerhard Tschakert","doi":"10.3389/fphys.2025.1465344","DOIUrl":"10.3389/fphys.2025.1465344","url":null,"abstract":"<p><strong>Introduction: </strong>There is a well-established relationship between the respiratory compensation point (RCP) and local muscular breakpoints determined from near-infrared spectroscopy (NIRS) and electromyography (EMG). However, these breakpoints have not yet been compared both in locomotor and non-locomotor muscles simultaneously in single-leg cycling exercise. Therefore, the aim of the study was to investigate the relationship and agreement between systemic and local breakpoints in locomotor and non-locomotor muscles.</p><p><strong>Method: </strong>Data from twelve physically-active participants (25.5 ± 3.9 years, 176.1 ± 11.6 cm, 71.2 ± 9.4 kg, 4 females) who completed a continuous single-leg step incremental cycling test (10 W min^-1) with their right leg were included in the analysis. Ventilation and gas exchange were recorded to determine RCP. Surface EMG (sEMG) and NIRS signals were measured from both vasti lateralis muscles and breakpoints were determined from root mean Q square sEMG and deoxygenated hemo- and myoglobin signal m[HHb].</p><p><strong>Results: </strong>There was no significant difference in the power output at RCP (127.3 ± 21.8 W) and local muscular breakpoints both from the locomotor (m[HHb]: 119.7 ± 23.6 W, sEMG: 126.6 ± 26.0 W) and non-locomotor (m[HHb]: 117.5 ± 17.9 W, sEMG: 126.1 ± 28.4 W) muscles. Breakpoints also showed significant (p < 0.01) correlations (r = 0.67-0.90, ICC = 0.80-0.94) to each other with weaker correlations in the non-locomotor muscle (r = 0.66-0.86, ICC = 0.74-0.90). Despite the strong correlations, high individual variability and weak limits of agreement (up to -32.5-46.5 W) and substantial absolute differences (10.2-16.7 W) were observed which indicates that these breakpoints cannot be used interchangeably.</p><p><strong>Discussion: </strong>These findings offer further insights into the mechanistic relationship between local and systemic physiological response to exercise with increasing workload. We conclude that, despite strong correlations, local muscular breakpoints do not have to coincide with systemic boundaries of physiological domains.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1465344"},"PeriodicalIF":3.2,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11891192/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143596612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical countermeasures for spaceflight-associated neuro-ocular syndrome during 30-days of head down tilt bed rest: design, implementation, and tolerability.","authors":"Stefan Moestl, Laura De Boni, Jan-Niklas Hoenemann, Tilmann Kramer, Jan Schmitz, Dominik Pesta, Timo Frett, Maria Bohmeier, Petra Frings-Meuthen, Ann Charlotte Ewald, Andrea Nitsche, Patricia Loehr, Alexandra Noppe, Nicolas Klischies, Alex S Huang, Steven S Laurie, Karina Marshall-Goebel, Brandon R Macias, Jens Tank, Jens Jordan, Edwin Mulder","doi":"10.3389/fphys.2025.1530783","DOIUrl":"10.3389/fphys.2025.1530783","url":null,"abstract":"<p><p>After longer duration space missions, some astronauts experience structural and functional changes in the eye and structural changes in the brain, termed Spaceflight-Associated Neuro-Ocular Syndrome (SANS). Countermeasures against SANS are required to minimize potential operation impacts and negative long-term health consequences. Headward fluid shifts, which appear to promote SANS, provide a target for countermeasures. The SANS countermeasures study, a 30 days strict head down tilt bed rest (HDTBR) study, tested two mechanical countermeasures aimed at reversing cephalad fluid overload. This work presents design and methodology of the study with a focus on countermeasure implementation and tolerability. Following baseline evaluations, participants were randomized to four groups and HDTBR commenced: Daily application of 25 mmHg lower body negative pressure for 6 h, six-hour bilateral venous constrictive thigh cuffs following moderate cycling exercise on 6 days per week, a negative control group without countermeasures, and a positive control group with HDTBR interruption for 6 h per day by sitting upright. The potential of these countermeasures for future space applications was examined in 86 different experiments, which will be reported elsewhere. Comfort ratings ranging from 1 (very uncomfortable) to 5 (very comfortable) were used to asses tolerability. Overall, 47 participants (20 women) completed the study. Out of 4,032 h scheduled for both countermeasures, 10.5 h were not performed due to medical issues unrelated to the countermeasures. Mean comfort ratings were 3.9 in men and 4.4 in women in the lower body negative pressure group (p = 0.1356) and 4.2 in men and 3.9 in women in the thigh cuff group (p = 0.1604). We conclude that both countermeasures were well tolerated and applied under well controlled conditions, thus, allowing for meaningful analyses of efficacy in attenuating HDTBR effects.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1530783"},"PeriodicalIF":3.2,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11891356/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143596601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}