Journal of applied physiology最新文献

{"title":"How much energy does overcoming air resistance cost at 4-min-mile pace?","authors":"Edson Soares da Silva, Wouter Hoogkamer, Shalaya Kipp, Rodger Kram","doi":"10.1152/japplphysiol.00456.2025","DOIUrl":"https://doi.org/10.1152/japplphysiol.00456.2025","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":"139 1","pages":"260-261"},"PeriodicalIF":3.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144608420","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":"The 4-minute mile mom.","authors":"Normand A Richard, Anita T Coté","doi":"10.1152/japplphysiol.00439.2025","DOIUrl":"https://doi.org/10.1152/japplphysiol.00439.2025","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":"139 1","pages":"256"},"PeriodicalIF":3.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144608425","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":"Role of overweight and obesity on vascular responses to the cold pressor test and hypoxia in women.","authors":"Natasha G Boyes, Dain W Jacob, Brian Shariffi, Anna M Gonsalves, Jennifer L Harper, Brian P Bostick, Jacqueline K Limberg","doi":"10.1152/japplphysiol.00162.2025","DOIUrl":"10.1152/japplphysiol.00162.2025","url":null,"abstract":"<p><p>Sympathetic-mediated vasoconstriction is attenuated during hypoxia in young women with normal weight (NW) (i.e., hypoxic sympatholysis). Obesity is associated with exaggerated sympathetic nervous system activity that may augment sympathetic vasoconstriction and impair hypoxic sympatholysis. We hypothesized that hypoxic sympatholysis would be attenuated in women with overweight (OW) and obesity compared with women with normal weight. Forearm blood flow (FBF, venous occlusion plethysmography), muscle sympathetic nerve activity (MSNA, peroneal microneurography), blood pressure (finger plethysmography), and arterial oxygen saturation ([Formula: see text], pulse oximetry) were measured in women with normal weight (NW; <i>n</i> = 15; 24 ± 7 yr; 22 ± 2 kg/m²) and women with overweight/obesity (OW; <i>n</i> = 9; 27 ± 7 yr; 33 ± 5 kg/m²). Participants completed a cold pressor test (CPT) during normoxia (98 ± 1% [Formula: see text]) and hypoxia (82 ± 2% [Formula: see text]). Hypoxia increased MSNA burst frequency in NW but not in OW (<i>P</i> = 0.030). Sympathetic vasoconstriction (<i>P</i> = 0.909) and hypoxic vasodilation (<i>P</i> = 0.295) did not differ between groups. In contrast, hypoxic sympatholysis was lower in OW than NW (<i>P</i> = 0.029). Measures of adiposity were negatively associated with hypoxic sympatholysis: percent body fat (<i>r</i> = -0.406, <i>P</i> = 0.049), android fat (<i>r</i> = -0.443, <i>P</i> = 0.030), gynoid fat (<i>r</i> = -0.447, <i>P</i> = 0.029), and waist circumference (<i>r</i> = -0.458, <i>P</i> = 0.024). Hypoxic sympatholysis is attenuated in women with increased adiposity, despite preserved sympathetic vasoconstriction and hypoxic vasodilation compared with women with normal weight. These findings have implications for vascular control of blood flow in conditions associated with obesity and hypoxia (e.g., sleep apnea).<b>NEW & NOTEWORTHY</b> Sympathetic-mediated vasoconstriction is attenuated during hypoxia in young women with normal weight, demonstrating the expected hypoxic sympatholysis. Conversely, hypoxic sympatholysis is attenuated in women with increased adiposity, despite preserved sympathetic vasoconstriction and hypoxic vasodilation compared with women with normal weight. These data advance our understanding of the impact of obesity on neurovascular control of blood flow and have implications for individuals with obesity and conditions associated with hypoxia (e.g., sleep apnea).</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"239-248"},"PeriodicalIF":3.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12278904/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144496779","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":"Association of Physical Activity, Sedentary Time and Sleep with Maternal Vascular Function in Women with a History of Preeclampsia.","authors":"Virginia R Nuckols, Kristen G Davis, Meaghan N Smith, Mariah L Carey, Blair Bell, Mark K Santillan, Donna A Santillan, Gary L Pierce","doi":"10.1152/japplphysiol.00928.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00928.2024","url":null,"abstract":"<p><p><b>Background:</b> A history of preeclampsia (hxPE) is associated with persistent vascular dysfunction and elevated risk of chronic hypertension. Twenty-four-hour activity behaviors, including physical activity, sedentary time (SED), and sleep are modifiable factors that may promote favorable vascular function and blood pressure in women with a hxPE. The primary objective of this study was to investigate the cross-sectional relations between habitual physical activity, SED and sleep with aortic stiffness and twenty-four-hour blood pressure patterns in young women with a hxPE and healthy pregnancy controls. <b>Methods:</b> Participants (n=68; aged 21-42 years, 1-5 years after delivery) wore a thigh-mounted activity monitor (activPAL) for seven days and maintained a sleep log to assess habitual physical activity, SED, sleep duration. Participants underwent measures of aortic stiffness(measured by carotid-femoral pulse wave velocity, CFPWV), and twenty-hour ambulatory blood pressure monitoring (ABPM). <b>Results:</b> Women with a hxPE (N=33) did not differ in physical activity, SED or sleep compared with healthy pregnancy controls (N=35). SED (β = 0.214, 95CI [0.004, 0.416]) and light-intensity physical activity (β = -0.204, 95CI [-0.397, -0.004]) were independently related to CFPWV. Frequency of sleep disturbances, but not shorter sleep duration, was associated with higher 24-hour diastolic blood pressure (β = 0.258, 95CI [0.009, 0.525]). Select perceived benefits and barriers to exercise were more pronounced among women with hxPE and benefits were associated with higher moderate-vigorous physical activity (ρ=0.43, P=0.003). <b>Conclusions:</b> Our findings link habitual activity, pregnancy history, and perceived exercise benefits with aortic stiffness and identify population and behavioral targets to improve cardiovascular health in young parous women.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144528120","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":"Robustness of hamstring muscle activation strategies following selective hypertrophy induced by Nordic hamstring curl and stiff-leg deadlift exercises.","authors":"Titouan Morin, Arnault Hubert Caillet, Antoine Nordez, Valentin Doguet, Lilian Lacourpaille","doi":"10.1152/japplphysiol.00237.2025","DOIUrl":"https://doi.org/10.1152/japplphysiol.00237.2025","url":null,"abstract":"<p><p>This study aims to determine whether muscle activation distribution between hamstrings is modified after nine weeks of two resistance training programs that induce a selective muscle hypertrophy. Using a blinded randomized controlled design, thirty-six resistance-untrained individuals were assigned to one of three groups: control (CON), Nordic hamstring exercise (NHE), and stiff-leg deadlift (SDL) groups. Strength gain was measured as changes in one-repetition maximum (1RM). Changes in semimembranosus (SM), semitendinosus (ST), and biceps femoris (BF) muscle volume were measured using 3D freehand ultrasound. Activation of each hamstring muscle head was assessed using surface electromyography during the trained exercise (or both for CON) performed at 80% of 1RM. We found a significant increase in 1RM after nine weeks for the NHE (37.4 ± 13.8%) and SDL (34.0 ± 21.2%) groups compared to CON. This strength gain was accompanied by selective hypertrophy of ST (24.3 ± 10.8%) and SM (11.2 ± 12.7%), for the NHE and SDL groups, respectively. However, statistical parametric mapping analyses revealed that the muscle activation was not altered over the time, between the groups, or by their interactions (all <i>p ≥ 0.05</i>). Our findings demonstrate a robustness of muscle activation strategies over time despite training-induced selective hypertrophy. These results provide a deeper understanding of the complex interplay between neural drive and muscle mechanical characteristics. This provides additional impetus to study long term effect of activation strategies (e.g., on the development of musculoskeletal disorders), as they seem to represent a trait-like characteristic rather than a transient state.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144528124","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":"The Role of Adipose Tissue in Critical Illness-Induced Skeletal Muscle Wasting - New Considerations for Treatment Approaches.","authors":"Casey L Sexton, Selene Meza-Perez, Konstantinos Papanikolaou, Tomasz M Kaminski M Kaminski, Marta Nowacka-Chmielewska, Piotr Rodak, Yi Lin, Thomas W Buford, Peter E Morris, Davis A Englund, Robert T Mankowski","doi":"10.1152/japplphysiol.00203.2025","DOIUrl":"https://doi.org/10.1152/japplphysiol.00203.2025","url":null,"abstract":"<p><p>Critical illness-induced muscle wasting is associated with poor in-hospital and long-term outcomes, but prevention strategies are lacking. Critical illness elicits muscle wasting through upregulation of protein degradation and down-regulation of protein synthesis via primary (i.e., modulation of ubiquitin-proteasome, autophagy-lysosome, calpain, and caspase-3 pathways) and secondary (i.e., bed rest/disuse, nutritional modulation, and accumulation of cellular damage) mechanisms. However, therapeutic targeting of these skeletal muscle mechanisms has not advanced the prevention of critical illness-induced muscle wasting, which may require exploring the roles of other peripheral organs. For example, recent research has demonstrated positive associations between whole-body adipose tissue mass, maintenance of muscle mass, and lower mortality rates in critically ill patients. However, having excess adiposity is often associated with impaired skeletal muscle remodeling due to blunted anabolic signaling, which has been tied to insulin resistance, lipid accumulation, and inflammation. Thus, the positive association between adiposity and beneficial outcomes in critical illness is paradoxical. This may be explained, at least partially, by an incomplete understanding of the processes by which adipose tissue influences skeletal muscle health and function in the context of critical illness. This review highlights the current evidence and key questions that warrant further investigations to improve understanding of the relationship between adipose tissue and skeletal muscle health. This knowledge may then be leveraged to facilitate new therapeutic approaches aimed at improving skeletal muscle health and functional outcomes in patients with critical illness.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144528125","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":"Ultrasound detection of lymphatic bubbles in a porcine dive model.","authors":"Joshua Currens, Richard E Moon, Matthew S Makowski, Michael J Natoli, Jayne Leypoldt, Jean C Woolard, David Brown, Arian Azarang, Robert H Brown, Eric A Schinazi, Zach Ransom, Virginie Papadopoulou, Rachel Lance","doi":"10.1152/japplphysiol.00171.2025","DOIUrl":"https://doi.org/10.1152/japplphysiol.00171.2025","url":null,"abstract":"<p><p>Ultrasound is currently the optimal imaging modality in the decompression research field for assessing intracorporeal gas. Decompression sickness (DCS) is triggered by excess gas bubble presence in the body; however, the relationship is not well understood. Presently, the decompression physiology field does not have a strong predictive DCS biomarker. In this study, we explore the presence of lymph node decompression bubbles in a porcine model after a provocative hyperbaric exposure. Porcine test subjects (n=37) underwent an aggressive decompression profile as part of a larger study and a subsequent investigation of the left inguinal lymph node was conducted with ultrasound. Ultrasound images were assessed by three trained sonographers for lymph node bubbles. Regional brightness was analyzed after <i>post-hoc</i> phantom calibrated standardization of ultrasound depth and gain settings. Of the 37 animals that we examined for lymph node bubbles, 17 were diagnosed with severe DCS and 14 were identified to have lymph node bubbles. A post mortem dissection was conducted for a few animals, and bubbles could be found streaming from the lymph node corresponding with a severe DCS subject. The brightness assessment of the standardized ultrasound images indicated that DCS cases typically had a decrease in region intensity after the dive with a potential peak sensitivity of 94.1% and specificity of 55% based on receiver operating curve analysis. This study is the first non-invasive detection of lymph node decompression bubbles with confirmation of bubbles by post mortem dissection. A positive correlation between lymph node bubbles and DCS severity was found.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144528126","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":"Central Command Activation During Exercise is an Essential Mechanism to Sustain Diving Bradycardia.","authors":"Marcela S Araujo, Adamor S Lima, Rosa V D Guerrero, Lauro C Vianna","doi":"10.1152/japplphysiol.00274.2025","DOIUrl":"https://doi.org/10.1152/japplphysiol.00274.2025","url":null,"abstract":"<p><p>Previous studies have shown that the bradycardic response to diving is maintained or enhanced during exercise. However, the integrative mechanism by which diving-induced bradycardia supersedes exercise-induced tachycardia remains unclear. This study aimed to elucidate the contributions of central and peripheral afferent mechanisms to the diving response in humans under controlled laboratory conditions. Thirty-two healthy participants (17 males, 15 females; mean age 22±3 years; BMI 24±4 kg/m²) were exposed to simulated diving via trigeminal nerve stimulation (TGS) under three experimental conditions: (1) voluntary light (LEx) and moderate (MEx) leg cycling exercise, (2) passive exercise and the cold pressor test (CPT), and (3) a combination of voluntary exercise and CPT. Continuous beat-to-beat heart rate (HR) and arterial blood pressure were measured, with surface electromyography confirming the absence of voluntary muscle contractions during passive cycling. TGS elicited significant bradycardia at rest, and this response was increased during voluntary LEx, and preserved during voluntary MEx when compared to rest. In contrast, compared to rest, the HR response to TGS during passive exercise was significantly attenuated, while CPT completely abolished the bradycardic response to TGS. However, during LEx combined with CPT, TGS elicited a significant bradycardic response when compared to the CPT alone. Overall, these findings suggest that 1) central command activation is an essential mechanism for sustaining the diving bradycardia; 2) isolated peripheral afferent reflexes exert inhibitory feedback to regulate diving-induced bradycardia; 3) central and peripheral afferent feedback are important mechanisms by which volitional skeletal muscle contractions modulate the cardiovascular adjustments to \"diving\".</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144528121","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":"Cerebrovascular variability interactions after acute ischemic stroke: insights from directionality analysis based on transfer entropy.","authors":"Francesca Gelpi, Beatrice Cairo, Vlasta Bari, Beatrice De Maria, Angela Sm Salinet, Man Y Lam, Osian Llwyd, Jonathan Ince, Jatinder S Minhas, Ronney B Panerai, Alberto Porta","doi":"10.1152/japplphysiol.00250.2025","DOIUrl":"https://doi.org/10.1152/japplphysiol.00250.2025","url":null,"abstract":"<p><p>Dynamic cerebral autoregulation (CA) limits fluctuations of mean cerebral blood flow, approximated as mean cerebral blood velocity (MCBv) measured via transcranial Doppler ultrasound, in the presence of variations of mean arterial pressure (MAP). This mechanism is impaired after acute ischemic stroke (AIS). CA impairment is usually assessed by hypothesizing that MAP variations are completely responsible for MCBv changes, while disregarding the MCBv contributions to MAP variability. We exploited transfer entropy (TE) and conditional TE (CTE) to assess the strength of the directional interactions from MAP to MCBv and <i>vice versa</i> accounting for partial pressure of end-tidal carbon dioxide. Traditional markers were computed for comparison. We analyzed recordings from 34 control individuals (CTRL, age: 66 ± 7 yrs) and 48 AIS patients (age: 66 ± 13 yrs) acquired within 48 hours of stroke symptom onset. MCBv was recorded in both hemispheres including affected and unaffected hemispheres in AIS patients. AIS patients exhibited hypertension and hypocapnia. After AIS MCBv diminished, especially in the affected hemisphere. TE and CTE decreased along the pressure-to-flow pathway as well. Both directional markers tended to increase along the flow-to-pressure arm irrespective of the hemisphere. Traditional indexes could not detect any difference. Our analysis suggests that the CA impairment was characterized by an imbalance of information transfer within the MCBv-MAP closed loop with a reduced importance of the pressure-to-flow and increased relevance of the flow-to-pressure arm. The study stresses the relevance of assessing MCBv-MAP relationship in closed loop especially when variability of MAP and MCBv are considered.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144528122","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":"Heterozygous <i>MYH7</i> R403Q mutation impairs left atrial mitochondrial function in a Yucatan mini-pig model of genetic non-obstructive hypertrophic cardiomyopathy.","authors":"Alexa Krause, Taylor J Kelty, Grace M Meers, Alan J Russell, Marc J Evanchik, Ben Barthel, Craig A Emter, R Scott Rector","doi":"10.1152/japplphysiol.00339.2025","DOIUrl":"https://doi.org/10.1152/japplphysiol.00339.2025","url":null,"abstract":"<p><p>Hypertrophic cardiomyopathy (HCM) can be caused by a <i>MYH7</i> R403Q gene mutation, which drives pathological cardiac remodeling and may ultimately lead to heart failure. Here we sought to examine the effects of this mutation on cardiac mitochondrial function in a Yucatan mini-pig model of genetic HCM. Activity of key mitochondrial enzymes, citrate synthase and β-HAD, were significantly reduced in the left atria of HCM animals compared to the control group. However, left atrial mitochondrial respiration was significantly greater in HCM pigs vs controls in the following states: basal (42%, p=0.001), state 2 (47%, p=0.02) and uncoupled (p=0.003), potentiating a compensatory mechanism. Surprisingly, left ventricular mitochondrial respiration and mitochondrial enzymatic activity did not differ between the HCM model vs healthy control pigs. However, proteomic profiling revealed parallel mitochondrial dysfunction and impairment to energy metabolism processes in both chambers, such as inhibited fatty acid metabolism and mitogenesis in the left atria and increased mitochondrial dysfunction and concentration of fatty acids in the left ventricle. Collectively, the <i>MYH7</i> R403Q mutation may contribute to HCM through chamber-specific mechanisms that promote mitochondrial dysfunction and impaired energy homeostasis. Further, these findings demonstrate the utility of this preclinical large animal model for identifying novel mechanisms underlying genetic heart failure with translational impact for individuals affected with HCM.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144528123","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}