Journal of applied physiology最新文献

{"title":"Sub-4-min mile: best case scenario from female world records.","authors":"Michele Zanini, Andrew Shaw, Richard Ferguson","doi":"10.1152/japplphysiol.00440.2025","DOIUrl":"https://doi.org/10.1152/japplphysiol.00440.2025","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":"139 1","pages":"249-250"},"PeriodicalIF":3.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144608424","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":"Under four, on the brink.","authors":"Samuel N Cheuvront","doi":"10.1152/japplphysiol.00426.2025","DOIUrl":"https://doi.org/10.1152/japplphysiol.00426.2025","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":"139 1","pages":"259"},"PeriodicalIF":3.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144608426","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 relation between proprioceptive ability and physical function in people with stroke, Parkinson's disease, and multiple sclerosis: a systematic review.","authors":"Lucy S Robertson, Georgia Fisher, Joanna Diong, Annie A Butler, Simon C Gandevia, Martin E Héroux","doi":"10.1152/japplphysiol.00088.2025","DOIUrl":"10.1152/japplphysiol.00088.2025","url":null,"abstract":"<p><p>The relationship between proprioceptive ability and physical function is commonly assessed in people with stroke, Parkinson's disease, and multiple sclerosis to investigate the etiology of functional deficits. The primary aim of this systematic review was to evaluate the magnitude of this association. We also investigated whether the magnitude of these associations was influenced by <i>1</i>) study sample size, <i>2</i>) the pairing of body regions targeted by assessments of proprioceptive ability and physical function, <i>3</i>) the proprioceptive sense assessed, and <i>4</i>) the type of proprioceptive assessment (low-level proprioception; high-level proprioception). A total of 56 studies reporting 438 measures of association were included. The magnitude of the associations ranged from -0.31 to 0.93 (<i>r</i> and ρ), with 92% being positive (better proprioceptive ability associated with better physical function). Study sample size, pairing of assessments, and type of low-level proprioceptive assessment (detect, discriminate, match) did not systematically influence the direction or magnitude of the associations. Ninety-seven percent of assessments focused on low-level proprioception and kinesthesia (position and movement sense). When studies discussed their measures of association, 50% used language that implied causality. Despite a detailed breakdown of measures of association, no clear pattern emerged regarding the link between proprioceptive ability and physical function. Future studies in people with stroke, Parkinson's disease, and multiple sclerosis should <i>1</i>) move away from simple measures of association to infer causation given that several interrelated and potentially confounding deficits coexist, and <i>2</i>) assess various aspects of proprioception, including high-level proprioception, as they differentially contribute to physical function.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"167-184"},"PeriodicalIF":3.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144234229","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":"Corrigendum for Hogwood et al., volume 137, 2024, p. 1503-1511.","authors":"","doi":"10.1152/japplphysiol.00323.2024_COR","DOIUrl":"https://doi.org/10.1152/japplphysiol.00323.2024_COR","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":"139 1","pages":"162-163"},"PeriodicalIF":3.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144528127","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":"Effects of aging on the vasoconstrictor reactivity and potassium channel regulation of diaphragm arterioles from male and female Fischer-344 rats.","authors":"Andrew G Horn, Kristina H Morrison, Kiana M Schulze, Sarah A Fenn, Judy Muller-Delp, David C Poole, Brad J Behnke","doi":"10.1152/japplphysiol.00152.2025","DOIUrl":"10.1152/japplphysiol.00152.2025","url":null,"abstract":"<p><p>Regional diaphragm hemodynamics are compromised with advanced age. Evidence suggests that age-related alterations in diaphragm blood flow distribution may be related to a decline in the vasoconstrictor reactivity of the diaphragm resistance vasculature. In medial costal diaphragm first order (1A) arterioles, we hypothesized that aging would be associated with blunted myogenic vasoconstriction and increased potassium (K⁺) channel modulation of myogenic tone. In young (Y) and old (O) Fischer-344 rats (<i>n</i> = 71), medial costal diaphragm 1A arterioles (112-220 µm) were isolated, cannulated, and pressurized via hydrostatic fluid reservoirs. Vasoconstrictor responses to increased intraluminal pressure (myogenic), potassium chloride (KCl)-induced vasoconstriction and passive pressure-diameter responses were assessed. In a separate set of arterioles, myogenic responses were evaluated in the presence and absence of the BK_Ca channel blocker iberiotoxin (IBX; 30 nM) and IBX plus the K_V channel inhibitor 4-aminopyridine (4-AP; 5 mM). Myogenic constriction was blunted (<i>P</i> = 0.038), and K⁺-induced constriction was decreased in medial costal 1A arterioles from O vs. Y rats (44 ± 8% vs. 58 ± 7%; <i>P</i> < 0.001). BK_Ca channel inhibition increased myogenic constriction to the same extent in medial costal 1A arterioles from Y and O rats whereas combined BK_Ca and K_V channel blockade abolished the age-related differences in myogenic constriction. In medial costal diaphragm arterioles, aging is associated with: <i>1</i>) impaired myogenic and K⁺-induced vasoconstriction, and <i>2</i>) increased K_V channel modulation of myogenic tone. These alterations in vasoconstrictor function provide novel vascular mechanisms contributing to age-related diaphragm blood flow dysregulation.<b>NEW & NOTEWORTHY</b> This investigation demonstrates that old age blunts both the myogenic response and potassium (K⁺)-induced vasoconstriction of diaphragm arterioles from male and female rats. The age-related decline in myogenic constriction was due, in part, to increased voltage-gated K⁺ channel (K_V) modulation of myogenic tone. These findings provide one mechanistic basis for the impaired diaphragm blood flow distribution associated with old age and, potentially, increased fatigability.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"275-286"},"PeriodicalIF":3.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144496778","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":"Incorporating gravity into synergistic control of upper limb movements using phasic synergies with positive and negative weights.","authors":"Alessandro Scano, Cristina Brambilla, Marta Russo, Andrea d'Avella","doi":"10.1152/japplphysiol.00779.2024","DOIUrl":"10.1152/japplphysiol.00779.2024","url":null,"abstract":"<p><p>Two models have been proposed to describe how motor control is affected by gravity. According to the gravity-compensation model, accelerating and decelerating the limb through phasic muscle activations is independent of the control of gravity forces, with tonic muscle activations counteracting gravity force. The effort-optimization model, instead, hypothesizes that muscles exploit gravity, decreasing tonic activity to minimize effort using negative phasic EMG components. Muscle synergies have been used for assessing motor control in neurophysiological studies, but synergistic models so far have neglected explicit representations of gravity forces. Therefore, we aimed at incorporating the pervasive presence of gravity into muscle synergies by extracting synergies with negative weights to capture negative phasic EMG components. Muscle synergies with positive and negative weights were extracted using the mixed-matrix factorization (MMF) algorithm on a set of upper limb reaching movements performed by 15 healthy participants across targets in different planes designed to elicit positive and negative phasic activations. Movements were grouped depending on the tonic components at movement onset, needed for gravity exploitation, and identified as \"increasing tonic EMG\" (ITE) and \"decreasing tonic EMG\" (DTE). ITE showed better reconstruction accuracy than DTE when extracting five or fewer synergies. DTE exhibited more negative phasic activations and synergy weights showed more negative values. A bootstrap procedure showed that synergies extracted from ITE and DTE are different in structure, and cluster analysis found nine clusters for ITE and ten for DTE. These results indicate that compensation and effort minimization models can coexist within the muscle synergy framework.<b>NEW & NOTEWORTHY</b> For the first time, a novel approach based on muscle synergies with positive and negative weights allows to account for the exploitation of gravity into synergistic models. This is achieved by a synergistic controller that incorporates both simplicity, as a reduced set of synergies underlying movement and static gravity compensation (phasic and tonic synergies), and effort optimization, based on the exploitation of gravity through negative phasic components.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"112-126"},"PeriodicalIF":3.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144248000","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":"Combination of running and energy restriction impairs bone parameters but does not inhibit endurance adaptations in fast-twitch muscle in young female rats.","authors":"Yuki Aikawa, Yusuke Wakasugi, Tomoya Fukuyasu, Nobuaki Sasai, Takenori Yamashita, Makoto Ohtsuki, Amane Hori, Kazuki Kioka, Naomi Omi, Naoya Nakai, Kazuhiko Higashida","doi":"10.1152/japplphysiol.00978.2024","DOIUrl":"10.1152/japplphysiol.00978.2024","url":null,"abstract":"<p><p>Low energy availability refers to a state where the body cannot provide sufficient energy to maintain essential physiological functions due to excessive exercise and inadequate energy intake. In athletes, low energy availability impairs bone parameters but may assist muscle adaptation from endurance training. This study was conducted to explore the effect of the combination of running and energy restriction (ER) on bone parameters and muscular endurance adaptations in young female rats. Seven-week-old female rats were divided into four groups: <i>1</i>) sedentary and ad libitum feeding (AL); <i>2</i>) voluntary wheel running and AL; <i>3</i>) sedentary and ER; and <i>4</i>) voluntary wheel running and ER. The experimental period was 11.5 wk. The ER groups were fed a 28% restricted diet compared with the sedentary and AL group. Our results demonstrated that the combination of running and ER decreased the body weight, uterus weight, plantaris and soleus muscle weight, bone mineral density of femur, tibia, and lumbar, and trabecular number of tibia. However, running increased the cross-sectional area (CSA) of type I and IIA fibers and the mitochondrial proteins levels in plantaris muscle under both AL and ER conditions. In the soleus muscle, running exerted no significant main effects on the transition to the myofiber type. ER did not affect the transition to the myofiber type and the mitochondrial protein levels in plantaris and soleus muscles. Our study reveals that the combination of running and ER impairs bone parameters; however, running induces endurance adaptations of plantaris muscle under both AL and ER conditions in young female rats.<b>NEW & NOTEWORTHY</b> Low energy availability impairs bone parameters but may assist muscle adaptation from endurance training. Our study demonstrated that the combination of running and energy restriction (ER) impaired bone mineral density and bone microarchitecture in young female rats. However, running increased the cross-sectional area of type I and IIA fibers, and the levels of mitochondrial proteins in plantaris muscle under both ad libitum feeding and ER conditions in young female rats.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"14-26"},"PeriodicalIF":3.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144127739","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":"Sex-based differences in peak oxygen uptake among individuals with heart failure: systematic review and meta-analysis.","authors":"Rachel J Skow, Stephen J Foulkes, Jing Wang, Devyn Walesiak, Thomas McMurtry, Megan Kennedy, Martin Halle, Stephan Mueller, Isabel Fegers-Wustrow, Frank Edelmann, Corey R Tomczak, Mark J Haykowsky","doi":"10.1152/japplphysiol.00153.2025","DOIUrl":"10.1152/japplphysiol.00153.2025","url":null,"abstract":"<p><p>Heart failure (HF) studies examining peak oxygen uptake (V̇o₂) have largely focused on males, leaving a significant gap in the understanding of the magnitude and the mechanisms underpinning the impairment in females with HF. The objective of this systematic review and meta-analysis is to examine sex differences in peak V̇o₂ in HF. Studies were found through Medline, EMBASE, Scopus, CINAHL, and SPORTDiscus and included if they compared peak V̇o₂ in males and females with HF. Data extraction and methodological quality assessment were completed by two independent coders. Main outcomes and measures included peak V̇o₂ (mL/kg/min, primary outcome) and its Fick determinants (secondary outcome). The weighted mean difference (WMD) was calculated for each outcome between females and males. After screening 1,579 articles, 33 studies were included. Peak V̇o₂ was lower in females versus males (<i>n</i> = 20,115, WMD: -2.1 mL/kg/min, 95% CI: -2.4 to -1.8 mL/kg/min). In studies reporting the Fick determinants, peak exercise cardiac output (<i>n</i> = 1,219, WMD: -1.3 L/min, 95% CI: -1.7 to -1.0 L/min), stroke volume (<i>n</i> = 1,151, WMD: -15.2 mL, 95% CI: -18.8 to -11.7 mL), and arterial-venous oxygen difference (<i>n</i> = 1,131, WMD: -1.4 mL/dL, 95% CI: -2.3 to -0.5 mL/dL) were lower, whereas peak heart rate was higher compared with males (<i>n</i> = 10,103, WMD: 2.4 beats/min, 95% CI: 0.1-4.7 beats/min). The greater peak V̇o₂ impairment among females with HF is likely due to lower peak exercise cardiac output and arterial-venous oxygen difference. Future research should prioritize interventions aimed at addressing these physiological constraints in females with HF.<b>NEW & NOTEWORTHY</b> This meta-analysis revealed that peak exercise oxygen uptake is 2.1 mL/kg/min lower in females with heart failure compared with males, which may be due to having a lower peak cardiac output and arterial-venous O2 content difference. These findings highlight the importance of developing sex-specific therapeutic approaches to better address the added physiological challenges faced by females with heart failure to improve cardiovascular and skeletal muscle health outcomes.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"45-57"},"PeriodicalIF":3.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144225591","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":"Last Word on Viewpoint: Seven (.65) seconds away: the possibility and physiology of a women's sub-4 min mile.","authors":"Rebekah J Osborne, Brett S Kirby, Matthew I Black, Anni Vanhatalo, Andrew M Jones","doi":"10.1152/japplphysiol.00521.2025","DOIUrl":"https://doi.org/10.1152/japplphysiol.00521.2025","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":"139 1","pages":"263-264"},"PeriodicalIF":3.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144608421","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":"Normal variation in brain volumetrics, CSF dynamics, and ocular structures from magnetic resonance images of healthy participants over two years.","authors":"Katrina J Carter, Steven S Laurie, Katherine G Warthen, Stuart H Sater, Bryn A Martin, Ching Mei Feng, Millennia Young, Khader M Hasan, Larry A Kramer, Brandon R Macias","doi":"10.1152/japplphysiol.00596.2024","DOIUrl":"10.1152/japplphysiol.00596.2024","url":null,"abstract":"<p><p>Changes in ocular and brain structure and cerebral spinal fluid (CSF) dynamics from magnetic resonance imaging (MRI) data have been reported in astronauts following long-duration spaceflight. The purpose of this study was to quantify normal variation in these outcomes over a 2-year period in a healthy cohort similar in age to astronauts, but without spaceflight experience. Variation in MRI acquisition, observer measurement, or normal aging over a 2-year period was used to determine thresholds for interpreting measures following long-duration spaceflight. Ten healthy participants (5 male), aged 38 ± 8 yr (mean ± SD), underwent five MRI sessions at baseline, 2, 6, 12, and 24 mo to quantify intracranial volumetry, CSF dynamics, pituitary morphology, and ocular structures. Total within-person variation ([Formula: see text]), modeled as the sum of the variance components for each outcome measure, was used to define a sensitivity threshold of 2.00 × [Formula: see text]. Changes greater than these thresholds can be interpreted as a result of an intervention and have <5% probability of occurring due to expected variability. Thresholds for change due to all sources of variability were: 27 mL for gray matter volume, 16 mL for white matter volume, 0.9 mL for lateral ventricular volume, 26.0 µL for CSF aqueductal stroke volume, 3.2 cm/s for peak-to-peak aqueductal CSF velocity, 0.5 mm for pituitary height, 0.50 mm for optic nerve sheath diameter, and 10.2 mm³ for posterior optic globe volume displacement. Changes on brain MR images after an intervention need to exceed these thresholds to be attributable to that intervention.<b>NEW & NOTEWORTHY</b> We report estimated thresholds of normal variability from methodological and physiological sources in brain and ocular outcomes in healthy participants. Outcomes that exceed these thresholds have less than a 5% probability of occurring due to these sources of variation. One of the present findings suggests that about 50% of the spaceflight-induced increase in lateral ventricular volume exceeds contributions of expected sources of measurement variability.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1-13"},"PeriodicalIF":3.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144119753","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}