Journal of applied physiology最新文献

{"title":"Hyperbaric oxygen increases mitochondrial biogenesis and function with oxidative stress in HL-1 cardiomyocytes.","authors":"Ha-Yeong Young, Sunchul Lee, Yeo-Eun Choi, Sang-Hoon Nam, Seung-Kuy Cha, Yangsik Jeong, Hyun Kim, Tae-Min Shin, Kyu-Sang Park","doi":"10.1152/japplphysiol.00428.2024","DOIUrl":"10.1152/japplphysiol.00428.2024","url":null,"abstract":"<p><p>Hyperbaric oxygen (HBO₂) therapy has been used to treat various pathological conditions, including carbon monoxide poisoning and ischemia-reperfusion injury. However, the molecular mechanisms underlying these therapeutic effects remain unclear. We investigated HBO₂-induced changes in mitochondrial function and biogenesis in a clonal cardiomyocyte cell line, HL-1. Cells were exposed to HBO₂ (3 atmospheres, 2,218 mmHg O₂, 39 mmHg CO₂) in a cell incubation chamber under controlled temperature and humidity conditions. Levels of reactive oxygen species (ROS), gene transcription and translation, mitochondrial membrane potential (ΔΨm), mitochondrial respiration, cellular ATP content, and spontaneous beating foci of HL-1 cells were measured. Exposure (2 or 6 h) to HBO₂ increased the cytosolic and mitochondrial ROS production, followed by upregulation of stress responses, including growth differentiation factor 15 and fibroblast growth factor 21. HBO₂ augmented antioxidant defense signaling through nuclear factor erythroid-2-related factor 2 and mitochondrial biogenesis through peroxisome proliferator-activated receptor-gamma coactivator-1α. HBO₂ exposure also elevated mitochondrial oxygen consumption, ΔΨm, and ATP production. To assess cardiomyocyte function, live cell imaging was performed, and the findings demonstrated an increase in the number of beating clusters in HL-1 cells following exposure to HBO₂. Notably, in HL-1 cells pre-treated with sublethal doses of mitochondrial electron transport chain inhibitors, further depolarization of ΔΨm was observed after HBO₂ exposure, implying exacerbation of mitochondrial dysfunction. Collectively, HBO₂-induced oxidative stress enhances mitochondrial biogenesis and function, possibly through a stress-mediated response. However, in the presence of defective mitochondrial function, cells may not be able to overcome the stress caused by HBO₂.<b>NEW & NOTEWORTHY</b> The molecular mechanisms underlying the beneficial effects of hyperbaric oxygen remain elusive. Here, we provide experimental evidence that hyperbaric oxygen induces oxidative stress in cardiac myocytes, triggering protective stress responses, enhancing antioxidant defense, and promoting mitochondrial biogenesis and function. However, hyperbaric oxygen can worsen mitochondrial function in cells with preexisting defects, suggesting an ambivalent consequence of hyperbaric oxygen on mitochondria that warrants consideration in therapeutic applications.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1490-1504"},"PeriodicalIF":3.3,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144127741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modulation of motor unit recruitment threshold and common synaptic inputs in triceps surae muscles: effects of ankle position.","authors":"Xin Sienna Yu, Jackson T Levine, José L Pons","doi":"10.1152/japplphysiol.00029.2025","DOIUrl":"10.1152/japplphysiol.00029.2025","url":null,"abstract":"<p><p>The objective of this study was to investigate how altering muscle length by changing ankle position affects force control, motor unit recruitment threshold, and motor unit coherence within and across triceps surae muscles. Sixteen healthy young adults performed isometric plantarflexion (PF) at three ankle positions with the ankle plantarflexed at 20° (PF20°), at the neural position (PF0°), and dorsiflexed at 20° (DF20°). High-density surface electromyography was used to record the medial and lateral heads of the gastrocnemius muscle (GM and GL) and the medial and lateral portions of the soleus muscle (SL and SM). Motor unit cumulative spike trains (MUCST) were used to calculate intramuscular, intermuscular, and Force-MUCST coherence in the delta (0-5 Hz), alpha (5-15 Hz), and beta (15-35 Hz) frequency bands. Recruitment thresholds of motor units matched across positions decreased when shifting the ankle from a shortened to lengthened position in GM, SL, and SM, while remaining unchanged and highest in GL. This change in ankle position also led to increased GM-SM coherence and intramuscular coherence in SM and SL in the delta band and improvements in force steadiness. In contrast, alpha band intramuscular coherence and Force-MUCST coherence decreased. Minimal changes were observed in beta band coherence across positions. This study reveals a neuromuscular control strategy that modulates motor unit recruitment and common synaptic inputs of triceps surae to maintain force output during isometric plantarflexions at varying muscle lengths.<b>NEW & NOTEWORTHY</b> This study demonstrates that changes in ankle position alter muscle length, impact force steadiness, motor unit recruitment thresholds, and oscillatory common inputs in the triceps surae. It highlights a neuromuscular control strategy that integrates afferent feedback, muscle mechanical properties, and descending inputs to synergistic plantarflexors. These findings provide a foundation for further investigation into muscle coordination during multijoint, dynamic movements.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1638-1650"},"PeriodicalIF":3.3,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144149452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inhibition of muscle sympathetic action potential firing and recruitment patterns following cannabis inhalation in humans.","authors":"Andrew W D'Souza, Johan S Thiessen, Christian P Cheung, Massimo Nardone, Jordan B Lee, Ryleigh E Baker, J Kevin Shoemaker, Jamie F Burr, Philip J Millar","doi":"10.1152/japplphysiol.00135.2025","DOIUrl":"10.1152/japplphysiol.00135.2025","url":null,"abstract":"<p><p>Cannabis is among the most widely used recreational substances, but the physiological consequences of acute and chronic use remain poorly studied. We recently demonstrated that acute cannabis use reduces muscle sympathetic nerve activity (MSNA). However, MSNA bursts comprise action potentials (APs) of varying size, which exhibit distinct firing and recruitment patterns that represent the communication between the sympathetic nervous system and the circulation. Applying a continuous wavelet transform to the microneurographic MSNA signal, we investigated the hypothesis that sympathetic AP firing patterns would be attenuated following cannabis inhalation at rest and during an end-expiratory apnea in young habitual cannabis users (<i>n</i> = 14; 7 females; 23 ± 3 yr). Following cannabis inhalation, MSNA burst occurrence and amplitude were reduced (all <i>P</i> < 0.001). Cannabis inhalation lowered the firing probability of medium-sized APs (normalized AP cluster 4: 78 ± 34 to 49 ± 31%; <i>P</i> = 0.03) and induced a derecruitment of larger AP clusters (22 ± 11 to 18 ± 9 clusters<b>;</b> <i>P</i> < 0.01). During an end-expiratory apnea following cannabis inhalation, there was an increase in MSNA burst frequency (8 ± 8 to 28 ± 10 bursts/min; <i>P</i> < 0.01), amplitude (51 ± 8 to 94 ± 34 AU; <i>P</i> < 0.01), AP frequency (74 ± 146 to 327 ± 387 spikes/min; <i>P</i> = 0.01), and the number of APs per burst (6 ± 5 to 10 ± 9 APs/burst; <i>P</i> = 0.03). However, the ability to recruit larger AP clusters (15 ± 11 to 16 ± 11 clusters; <i>P</i> = 0.57) and alter AP latency (1.23 ± 0.12 to 1.26 ± 0.17 s; <i>P</i> = 0.50) was absent. These data indicate that cannabis inhalation acutely decreases sympathetic AP firing and disrupts recruitment patterns in humans.<b>NEW & NOTEWORTHY</b> We examined the impact of cannabis inhalation on the firing and recruitment patterns of postganglionic muscle sympathetic action potentials (APs) in humans. We found that cannabis inhalation induced a derecruitment of larger, high-threshold APs, reduced the discharge probability and baroreflex control of medium-sized APs at rest, and impaired sympathetic AP recruitment during an end-expiratory apnea. Collectively, these data indicate that cannabis impairs the fundamental, homeostatic communication between the sympathetic nervous system and cardiovascular system.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1425-1434"},"PeriodicalIF":3.3,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144086134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"No effect of either heat therapy or aerobic exercise training on blood pressure in adults with untreated hypertension: a randomized clinical trial.","authors":"Brendan W Kaiser, Lindan N Comrada, Brandon M Gibson, Emma L Reed, Kieran S S Abbotts, Emily A Larson, Madison I Serrano, Karen Wiedenfeld Needham, Christopher L Chapman, John R Halliwill, Christopher T Minson","doi":"10.1152/japplphysiol.00959.2024","DOIUrl":"10.1152/japplphysiol.00959.2024","url":null,"abstract":"<p><p>Hypertension, a primary and preventable risk factor for cardiovascular and kidney disease, may be ameliorated by nonpharmacological lifestyle interventions such as aerobic exercise and heat therapy. Although both interventions have been demonstrated to reduce blood pressure in a variety of populations, there are no studies that have directly compared these methods for lowering blood pressure in adults with untreated hypertension. Forty-one adults (48 [35, 56] yr) were randomized to complete either 30 sessions of aerobic exercise training (<i>n</i> = 20) or heat therapy (<i>n</i> = 21) over 8-10 wk. Ambulatory and in-clinic blood pressure and markers of cardiorespiratory fitness, arterial stiffness, and renal function were measured at baseline (PRE) and after 30 heat therapy or exercise training sessions (POST). Twenty-four-hour ambulatory systolic blood pressure was not different following either aerobic exercise (PRE: 139 [134, 144] vs. POST: 140 [134, 145] mmHg; <i>P</i> = 0.65) or heat therapy (134 [128, 139] vs. 134 [128, 139]; <i>P</i> = 0.81) nor was 24-h ambulatory diastolic blood pressure after aerobic exercise (PRE: 85 [81, 89] vs. POST: 86 [83, 90] mmHg; <i>P</i> = 0.28) or heat therapy (81 [78, 85] vs. 81 [77, 85]; <i>P</i> = 0.44). In-clinic blood pressure was similarly unchanged following both aerobic exercise and heat therapy. These pressure responses, along with arterial stiffness and kidney function biomarkers, did not differ between treatment groups (all <i>P</i> > 0.05). These data suggest that, during an 8- to 10-wk intervention, exercise training and heat therapy have similar and limited impacts on blood pressure, arterial stiffness, and biomarkers of kidney function among adults with untreated hypertension.<b>NEW & NOTEWORTHY</b> Exercise training represents a crucial lifestyle intervention for improving blood pressure, yet many adults do not meet recommendations for physical activity. Heat therapy was tested against aerobic exercise training as a potential alternative lifestyle intervention. Neither heat therapy nor exercise training was effective for the treatment of hypertension.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1600-1614"},"PeriodicalIF":3.3,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12225054/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144127742","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":"Corrigendum for Claflin et al., volume 111, 2011, p. 1021-1030.","authors":"","doi":"10.1152/japplphysiol.01119.2010_COR","DOIUrl":"https://doi.org/10.1152/japplphysiol.01119.2010_COR","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":"138 6","pages":"1489"},"PeriodicalIF":3.3,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144266320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impaired neurovascular coupling in metabolic syndrome: an fNIRS study.","authors":"Jigar Gosalia, Jocelyn M Delgado Spicuzza, Christine K Bowlus, Andrew W Gardner, Nancy A Dennis, James A Pawelczyk, David N Proctor","doi":"10.1152/japplphysiol.00893.2024","DOIUrl":"10.1152/japplphysiol.00893.2024","url":null,"abstract":"<p><p>The mechanisms underpinning accelerated cognitive decline in metabolic syndrome (MetS) are poorly understood. Neurovascular coupling (NVC) is the coordinated matching of blood flow to neuronal activation and is dependent on endothelial function. NVC may drive blood flow dysregulation that contributes to neuronal damage and cognitive decline. The purpose was to assess NVC, peripheral endothelial function, and cognitive performance in older adults with MetS and healthy controls (CON), and the association of these factors. Older adults with and without MetS were recruited to complete a neurocognitive battery, assessment of NVC, and endothelial function. NVC was measured in the frontoparietal regions using functional near infrared spectroscopy (fNIRS) while participants completed the n-back task (0-, 1-, 2-back). Changes in oxyhemoglobin (HbO) and deoxyhemoglobin (HbR) signals reflected NVC during the n-back task. Endothelial function was measured using brachial ultrasound measurements of flow-mediated dilation (%FMD). MetS (<i>n</i> = 22; age: 66 ± 6 yr) demonstrated poorer NVC during higher cognitive loads, reflected by an attenuated increase in HbO in the premotor cortex during the 2-back task compared with CON (<i>n</i> = 26; age: 64 ± 5 yr) (<i>P</i> = 0.036). MetS also demonstrated poorer FMD (5.55 ± 1.35% vs. 4.42 ± 1.71%, <i>P</i> = 0.01) and 2-back accuracy compared with CON (MetS: 81.7 ± 6.4%; CON: 86.0 ± 6.1%, <i>P</i> = 0.027), with a significant positive association between these two factors (<i>r</i> = 0.37, <i>P</i> = 0.012). Impairments in NVC of the frontal cortex may be an early cerebrovascular mechanism underpinning cognitive decline in MetS and is discernible during higher cognitive loads. Peripheral endothelial dysfunction may be implicated in this mechanism.<b>NEW & NOTEWORTHY</b> Deficits in neurovascular coupling (NVC) precede neuronal damage and subsequent cognitive deficits, encompassing the vascular contributions to cognitive decline framework. Older adults with metabolic syndrome (MetS), a prevalent population, present with accelerated cognitive decline, however, changes to NVC in MetS had not been studied. We demonstrate that older adults with MetS exhibit reduced NVC during higher cognitive loads compared with healthy older adults, which corresponds with poorer working memory performance, and may involve endothelial dysfunction.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1651-1663"},"PeriodicalIF":3.3,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144093565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Arterial structure and function in the years after long-duration spaceflight.","authors":"Stuart M C Lee, L Christine Ribeiro, David S Martin, Steven S Laurie, Sara R Zwart, X Chen, Millennia Young, Brian Crucian, Scott M Smith, Brandon R Macias","doi":"10.1152/japplphysiol.00264.2024","DOIUrl":"10.1152/japplphysiol.00264.2024","url":null,"abstract":"<p><p>Spaceflight missions expose astronauts to an increased risk of oxidative stress and inflammatory damage that might accelerate the development or severity of cardiovascular disease. The purpose of this investigation was to determine whether long-duration spaceflight (>4 mo) results in structural and functional changes in the carotid and brachial arteries in the years after landing. Common carotid artery (CCA) intima-media thickness (cIMT), CCA distensibility and stiffness, and brachial artery endothelial-dependent and -independent vasodilation were measured in 13 International Space Station (ISS) astronauts (10 males and 3 females) approximately 180 and 60 days before launch, within 1 wk after landing, and up to 5 yr after landing. Additionally, we reviewed reports of cardiovascular-relevant parameters received from National Aeronautics and Space Administration (NASA) data archives within the Lifetime Surveillance of Astronaut Health obtained during flight certification and postflight annual physical examinations for eight of these astronauts. Postflight cIMT, CCA stiffness, distensibility, and brachial artery dependent- and -independent vasodilation were not different than preflight up to 5 yr after landing. Further, there were no records of newly diagnosed cardiovascular disease. Long-duration spaceflight missions on the ISS did not result in thickening of the carotid artery wall, increased CCA stiffness, endothelial dysfunction, or development of new symptoms or signs of cardiovascular disease in the first 5 years after long-duration spaceflight. Continued long-term surveillance of cardiovascular health in the larger astronaut cohort is necessary to characterize the lifetime risk of disease, particularly in astronauts who venture beyond low Earth orbit and are exposed to deep space radiation.<b>NEW & NOTEWORTHY</b> Previous investigations focused on in- and immediate postflight cardiovascular health indices. Here we report that in the 5 years after long-duration spaceflight in low Earth orbit, there was no evidence of increased carotid artery intima-media thickness or reduced brachial artery endothelium-dependent vasodilation in 13 middle-aged male and female astronauts. Additionally, biomarkers of oxidative stress and inflammation are dynamic in the days after landing and may not reflect the long-term health consequences of spaceflight.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1474-1488"},"PeriodicalIF":3.3,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143967229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Histamine is a molecular transducer of adaptation to endurance exercise training in humans.","authors":"Dylan C Sieck, Sydney H Kobak, Emily A Larson, Hans C Dreyer, Matthew J Fogarty, Gary C Sieck, Christopher T Minson, John R Halliwill","doi":"10.1152/japplphysiol.00687.2024","DOIUrl":"10.1152/japplphysiol.00687.2024","url":null,"abstract":"<p><p>Histamine is an apparent molecular transducer of physical activity responses and antihistamines modify transcription of many of the genes responding to exercise. The purpose of this study was to determine the role of histamine-receptor activation in adaptations to endurance exercise training. Sixteen healthy, nonsmoking individuals participated in a randomized double-blind placebo-controlled exercise training protocol with an experimental group receiving combined histamine H₁/H₂-receptor antagonists (blockade) and a control group receiving placebo capsules (placebo) before each exercise training session. Following 6 wk of endurance exercise training (21 training sessions), we determined the effect of blockade versus placebo on improvements in fitness and some of its determinants. The rate of improvement in peak power output over the period of exercise training intervention was 1.62 (0.85, 2.39)% per week in the blockade versus 3.05 (2.27, 3.82)% per week in the placebo group (<i>P</i> < 0.05 blockade vs. placebo). This was paralleled by blunted adaptations in vascular function and oxidative enzyme capacity but not by peak aerobic capacity (V̇o_2peak), which increased independent of blockade. Blocking histamine's actions during endurance exercise training via common over-the-counter antihistamines resulted in diminished gains in fitness, indicating that exercise-induced histamine release is important in generating many of the positive adaptations to exercise training that result in improvements in fitness.<b>NEW & NOTEWORTHY</b> Histamine appears to be intimately involved with skeletal muscle responses during and following exercise. Blocking histamine's actions during endurance exercise training by taking common over-the-counter antihistamines resulted in diminished gains in fitness. These results indicate that exercise-induced histamine release is important in generating many of the positive adaptations to exercise training.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1398-1410"},"PeriodicalIF":3.3,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12175747/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144078270","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 contribution of red blood cell desaturation to exercising skeletal muscle vasodilation heterogeneity.","authors":"Jacob L Schwartz, Adam N Di Salvo, Jonaline B Bernal, Sinan Osman, Robert F Bentley","doi":"10.1152/japplphysiol.00136.2025","DOIUrl":"10.1152/japplphysiol.00136.2025","url":null,"abstract":"<p><p>Experimentally challenging muscle blood flow during exercise requires cardiovascular compensation to protect the matching of oxygen delivery to oxygen demand; however, certain individuals may fail to protect this matching due to an absence of compensatory vasodilation at the local vasculature. We investigated whether red blood cell (RBC) desaturation explains the underlying presence of compensatory vasodilation. Furthermore, earlier studies were completed in males, and we sought to elucidate whether biological sex impacts this relationship. Forty healthy individuals (age: 23 ± 5 yr, 50% female) completed 4 min of submaximal forearm handgrip exercise at 30% maximum voluntary contraction both with and without brachial artery compression reducing forearm blood velocity by 30% and challenging muscle blood flow. Measures of forearm blood flow (mL/min), blood pressure (mmHg), and RBC desaturation (skeletal muscle oxygen saturation, %) were obtained throughout. Forearm vascular conductance (FVC, mL/min/100 mmHg), following challenged exercise, greater than 1.96 times the coefficient of variation of unchallenged exercise represented the presence of compensatory vasodilation. Data are Δ from rest (means ± SD). Twenty-six individuals responded with compensatory vasodilation, whereas 14 individuals did not (49 ± 20 vs. 0 ± 4%FVC, <i>P</i> < 0.001). RBC desaturation was greater in individuals responding with compensatory vasodilation (-22 ± 9 vs. -5 ± 4%oxygen, <i>P</i> < 0.001) and was negatively correlated with FVC (<i>r</i>_s = -0.819, <i>P</i> < 0.001). Sex had no effect on the presence of compensatory vasodilation (<i>P</i> = 0.507) nor on the extent (<i>P</i> = 0.506) or rate (<i>P</i> = 0.857) of RBC desaturation during the muscle blood flow challenge. The presence/absence of compensatory vasodilation following a muscle blood flow challenge appears to be proportional between sex and associated with local RBC desaturation.<b>NEW & NOTEWORTHY</b> When challenging muscle blood flow during small muscle mass exercise, compensatory vasodilation may protect the matching of oxygen delivery to the muscle's oxygen demand. The present study extended previous work by revealing an absence of compensatory vasodilation in 35% of individuals. Vasodilation was correlated with red blood cell (RBC) desaturation and sex did not influence the occurrence of experiencing compensatory vasodilation nor the relationship between vasodilation and RBC desaturation.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1435-1448"},"PeriodicalIF":3.3,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144016345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increasing the health span: unique role for exercise.","authors":"Glenn A Gaesser, Stephanie E Hall, Siddhartha S Angadi, David C Poole, Susan B Racette","doi":"10.1152/japplphysiol.00049.2025","DOIUrl":"10.1152/japplphysiol.00049.2025","url":null,"abstract":"<p><p>Health span, that period between birth and onset of major disease(s), when adequate physical and cognitive function permit those daily living activities essential to life quality, is lower in the United States than other developed countries. Physical inactivity and excessive calorie intake occupy dominant roles both in the problem, and by redressing them, in the solution. Consequently, this review focuses on evidence that appropriate exercise engagement and calorie restriction (CR) can improve physical and mental health with a view to extending the health span. Humanity, writ large, has grasped these underlying concepts for Millennia but has been largely intransigent to them. Thus, the final section proposes a novel Monty Python-esque approach that encompasses humanity's inimical sense of humor to increase physical fitness and mental health, restore energy balance, sustain better cognitive function, and extend the health span.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1285-1308"},"PeriodicalIF":3.3,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12182867/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144063946","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}