Journal of applied physiology最新文献

{"title":"Cerebral hemodynamic changes at high altitude in adults: a systematic review and meta-analysis of transcranial Doppler and duplex ultrasound studies.","authors":"J Pierre Zila-Velasque, Pamela Grados-Espinoza, Sebastian Abanto-Urbano, Mely Olarte-Durand, Martha I Vilca-Salas, Paula C Moran-Ballon, Carlos Quispe-Vicuña, Victor Velasquez-Rimachi, Joel Sequeiros, Kateriny Margot Regalado-Rodriguez, Patrick E Zila-Velasque, Sthefano E Zila-Velasque, Sheidy Clemente-Tueros, Fernando Terry, Carlos Alva-Diaz","doi":"10.1152/japplphysiol.00176.2026","DOIUrl":"10.1152/japplphysiol.00176.2026","url":null,"abstract":"<p><p>Exposure to intermediate and high altitude induces hypobaric hypoxia, which may alter cerebral hemodynamics through complex interactions involving hypoxia-driven vasodilation, hypocapnia, hematologic changes, and vascular remodeling; however, cerebrovascular responses vary substantially between native high-altitude populations and lowlander individuals. We conducted a systematic review and meta-analysis to quantify altitude-related changes in cerebral blood flow (CBF) and related hemodynamic parameters and to explore sources of heterogeneity. Major databases were searched through inception to November 2025 for observational studies evaluating cerebral hemodynamics at ≥1,500 m above sea level. Outcomes included mean velocity (MV), volumetric blood flow, arterial diameter, cerebrovascular conductance, cerebral oxygen saturation, autoregulation index, and global CBF. Random-effects models (Paule-Mandel) were used to pool mean differences, with subgroup and metaregression analyses performed; certainty of evidence was assessed with GRADE. Fifty-five studies including 1,935 participants were analyzed. Altitude exposure was associated with a reduction in mean cerebral artery velocity [mean difference (MD) -5.79 cm/s; 95% confidence interval (CI) -9.37 to -2.21; <i>I</i><sup>2</sup> = 96%], reduced volumetric blood flow (MD -32.99 mL/min; 95% CI -45.24 to -20.73; <i>I</i><sup>2</sup> = 98%), decreased arterial diameter (MD -0.27 mm; 95% CI -0.45 to -0.08; <i>I</i><sup>2</sup> = 91%), lower cerebrovascular conductance (MD -0.43 mL/min/mmHg; 95% CI -0.65 to -0.21; <i>I</i><sup>2</sup> = 24%), reduced cerebral oxygen saturation (MD -4.45%; 95% CI -6.77 to -2.14; <i>I</i><sup>2</sup> = 74%), and lower global cerebral blood flow (MD -155.00 mL/min; 95% CI -350.11 to 40.11; <i>I</i><sup>2</sup> = 95%), although heterogeneity was substantial across outcomes. Subgroup analyses suggested that native high-altitude populations and lowlander individuals exhibit distinct cerebrovascular responses, with population status, age, and altitude level explaining part of the observed variability. Overall certainty of evidence was very low. These findings indicate that exposure to altitude is associated with heterogeneous but consistent alterations in cerebral hemodynamic parameters, with marked differences between native and nonnative populations, underscoring the importance of population-specific physiological adaptation when interpreting cerebrovascular responses to hypoxia.<b>NEW & NOTEWORTHY</b> In this first global meta-analysis of ultrasound-based cerebral hemodynamics at ≥1,500 m, we show that altitude exposure is associated with lower cerebral blood flow velocity, volumetric flow, arterial diameter, and oxygen saturation in healthy adults. Native status, age, and altitude level partly explain marked heterogeneity. These findings highlight distinct adaptive patterns between native and nonnative populations and underscore the need for standardized, longitudinal s","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"717-730"},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148561935","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":"Reliability and validity of surface electromyography to identify contractile muscle fatigue during cycling in people with COPD.","authors":"Simone Pancera, Paulien Mellaerts, Daniel Langer, Mathieu Brancaleone, Mykyta Chunikhin, Luc Janssens, Bart Vanrumste, Wim Janssens, Stephanie Everaerts, Heleen Demeyer, Thierry Troosters","doi":"10.1152/japplphysiol.00541.2026","DOIUrl":"10.1152/japplphysiol.00541.2026","url":null,"abstract":"<p><p>Surface electromyography (sEMG) may provide reliable biomarkers of contractile muscle fatigue (CMF) during exercise in chronic obstructive pulmonary disease (COPD). This study aimed to: <i>1</i>) determine the test-retest reliability of amplitude- and frequency-based sEMG metrics recorded from the quadriceps muscle during a constant-work-rate cycling test (CWRT); <i>2</i>) assess their criterion validity for detecting CMF against potentiated twitch force (TWp); and <i>3</i>) explore associations between sEMG metrics and physiological outcomes. Adults with COPD referred for pulmonary rehabilitation performed two CWRTs to the limit of tolerance (<i>T</i>_lim) at 75%-80% of the individual peak workload, with physiological responses recorded. CMF was assessed by: <i>1</i>) amplitude- (root mean square, RMS) and frequency-based sEMG metrics recorded from the right quadriceps, analyzed per pedal stroke and expressed as <i>Z</i>-score changes at <i>T</i>_lim relative to a fatigue-free baseline; and <i>2</i>) the postexercise change in TWp of the right quadriceps. Relative and absolute test-retest reliability, and criterion validity of sEMG against TWp were assessed. Twenty-five participants completed the assessments. Among the sEMG metrics, only vastus lateralis RMS showed adequate relative reliability [intraclass correlation coefficient (95% CI) = 0.79 (0.74-0.85)] but a nonnegligible standard error of measurement of 0.58. Moreover, vastus lateralis RMS showed 86% sensitivity and specificity versus TWp in identifying CMF. An increase of ≥0.65 <i>Z</i>-scores identified the threshold for sEMG-based CMF. Changes in vastus lateralis RMS were moderately correlated with physiological responses at <i>T</i>_lim (<i>P</i> < 0.05). In conclusion, vastus lateralis RMS derived from sEMG can be used as a biomarker of CMF during cycling in individuals with COPD.<b>NEW & NOTEWORTHY</b> This study provides novel evidence that exercise-induced changes in the amplitude of the vastus lateralis surface electromyography signal during a standardized constant-work-rate cycling test can represent a reliable and valid biomarker of quadriceps contractile muscle fatigue in individuals with moderate-to-severe COPD.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"840-850"},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148724477","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":"Methods for analyzing acetylcholine-induced vasodilation in human skin.","authors":"Virginia G Content, Alexandria R McKenna, Auni C Williams, Jody L Greaney, Anna E Stanhewicz, Lacy M Alexander","doi":"10.1152/japplphysiol.00379.2026","DOIUrl":"10.1152/japplphysiol.00379.2026","url":null,"abstract":"<p><p>Intradermal microdialysis, combined with laser-Doppler flowmetry and local heating, is commonly used to investigate mechanisms of endothelial function and dysfunction in the cutaneous microcirculation. Local perfusion of acetylcholine (ACh), with and without <i>N</i>^G-nitro-l-arginine methyl ester [l-NAME; a nonselective nitric oxide (NO) synthase inhibitor], allows for direct assessment of pharmacologically induced endothelium- and NO-dependent vasodilation. However, variability in the analysis and reporting of cutaneous vascular conductance (CVC) responses to in vivo cholinergic stimulation limits reproducibility. The purpose of this investigation was to compare analytical approaches used to quantify in vivo cutaneous vasodilation by retrospectively analyzing ACh dose-response data and NO-dependent vasodilation using five methods. Curve-modeling approaches included nonlinear regression with: <i>1</i>) no constraints, <i>2</i>) Hill slope constraint, and <i>3</i>) top and bottom constraints. Point-by-point analysis and area under the dose-response curve (AUC) were also evaluated following graded ACh perfusion with and without l-NAME coperfusion. Nonlinear regression without constraints exhibited the highest rate of data exclusion due to poor model fit. Although all analysis methods detected the expected differences in CVC responses between ACh with and without l-NAME, each approach had distinct limitations. Nonlinear regression provides detailed pharmacodynamic parameters, including maximal and minimal vasodilator responses, logEC₅₀, and Hill slope, whereas point-by-point analysis and AUC offer straightforward quantitative assessments of NO-dependent vasodilation. Based on this retrospective analysis, we recommend the unconstrained model (<i>methods 1A/1B</i>) for characterizing the ACh dose-response relation, as the curves best reflect the visualized data. Point-by-point analysis, AUC, and l-NAME-sensitive component calculations may be more appropriate for quantifying NO-dependent vasodilation.<b>NEW & NOTEWORTHY</b> Although dose-response curves are commonly used to characterize in vivo cutaneous cholinergic vasodilator responses, modeling parameters and analytical approaches vary widely across studies. Here, we compare five methods applied to graded acetylcholine perfusion with and without <i>N</i>^G-nitro-l-arginine methyl ester [l-NAME; a nonselective nitric oxide (NO) synthase inhibitor] coperfusion to quantify NO-dependent vasodilation. We highlight key advantages and limitations of each method and provide practical recommendations for their implementation.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"933-944"},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13629242/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148813141","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":"Endurance training attenuates acute exercise-induced monocyte transcriptomic responses in adolescents: sex-specific molecular adaptations.","authors":"Abel Plaza-Florido, Fadia Haddad, Dan M Cooper, Shlomit Radom-Aizik","doi":"10.1152/japplphysiol.00282.2026","DOIUrl":"10.1152/japplphysiol.00282.2026","url":null,"abstract":"<p><p>Circulating monocytes contribute to atherogenesis and vascular dysfunction. Although clinical cardiovascular disease presents in adulthood, its biological origins often begin in youth and differ substantially between females and males. Twelve males and nine females (13-17 yr) completed an acute exercise protocol consisting of 10, 2-min cycling bouts at 70% of maximal work rate interspersed with 1-min rest intervals, performed before and after an 8-wk supervised endurance training intervention with brief supplementary strength work (60 min/session, 3 sessions/wk). Blood was collected before and immediately after each exercise challenge. Peripheral blood monocytes were isolated, and whole transcriptome RNA sequencing (RNA-seq) was performed. Before training, acute exercise induced a markedly greater monocyte transcriptomic response in females compared with males [5,135 vs. 567 differentially expressed transcripts, false discovery rate (FDR) < 0.1]. Pathway analyses identified vascular function-related pathways in males, whereas females showed enrichment of pathways related to adipose tissue cross talk and oxidative metabolism. Following training, the acute transcriptomic response was markedly attenuated in both sexes (165 transcripts in males and 94 in females, FDR < 0.1), representing an ∼98% reduction in females and a ∼70% reduction in males relative to pre-training responses. These findings reveal sex-specific monocyte responses to acute exercise in youth and suggest that endurance exercise alters immune transcriptional responsiveness in pathways relevant to vascular and cardiovascular health.<b>NEW & NOTEWORTHY</b> Acute exercise induced a markedly greater monocyte transcriptomic response in female adolescents than in males. Females showed activation of pathways related to adipose tissue signaling and oxidative metabolism, whereas males exhibited vascular-function pathways. Following exercise training, the monocyte transcriptomic response to acute exercise was substantially attenuated in both sexes. These findings identify sex-specific immune transcriptional responses to exercise during adolescence with potential implications for cardiovascular health.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"873-887"},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148669361","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":"Resistance training improves cardiovascular health in postmenopausal women: systematic review and meta-analysis.","authors":"Sonia L Rivera-Mejía, María Rúa-Alonso, Jessica Rial-Vázquez, Iván Nine, María Alejandra Camacho-Villa, María Gabriela Enríquez-González, Adrián Varela-Sanz, Juan Fariñas, Borja Revuelta-Lera, Enrique Fraga-Germade, Manuel Avelino Giráldez-García, Eliseo Iglesias-Soler","doi":"10.1152/japplphysiol.01180.2025","DOIUrl":"10.1152/japplphysiol.01180.2025","url":null,"abstract":"<p><p>Postmenopausal women (PW) experience hemodynamic and autonomic alterations that increase cardiovascular risk. Although aerobic exercise is widely recognized for its cardioprotective benefits, the chronic effects of resistance training (RT) on cardiovascular and autonomic function in this population remain less established. This systematic review aimed to evaluate the effects of RT on hemodynamic and vascular structure and function, cardiovascular autonomic control, and cardiac structural outcomes in PW. A comprehensive search of PubMed, Scopus, Web of Science, and SPORTDiscus was conducted up to February 2026. Randomized and nonrandomized controlled trials investigating RT interventions (≥4 wk) were included. Primary outcomes were resting heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean blood pressure (MBP). Secondary outcomes included vascular adaptations, heart rate variability (HRV), and cardiac structural characteristics. Meta-analyses were performed using a random-effects model, with pooled effects expressed as Hedges' <i>g</i>; heterogeneity was quantified using <i>I</i>². Risk of bias, reporting quality exercise parameters, and methodological consistency were assessed. Sixty studies met inclusion criteria. Meta-analyses showed statistically significant reductions in HR, SBP, DBP, and MBP after RT. The magnitude of the effects was small for HR (<i>g</i> = 0.30, 95% CI [0.02; 0.58], <i>I</i>² = 0.0%) and DBP (<i>g</i> = 0.37, 95% CI [0.11; 0.63], <i>I</i>² = 0.0%) and moderate effects for SBP (<i>g</i> = 0.68, 95% CI [0.40; 0.96], <i>I</i>² = 0.0%) and MBP (<i>g</i> = 0.68, 95% CI [0.37; 0.99], <i>I</i>² = 0.0%). Qualitative synthesis showed modest improvements in vascular adaptations and HRV, whereas echocardiographic studies reported no adverse structural cardiac adaptations. RT produces favorable cardiovascular and autonomic adaptations in PW, improving hemodynamic regulation without structural cardiac alterations.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"619-641"},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148470768","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":"Impact of acute mild and severe poikilocapnic hypoxia on dynamic cerebral autoregulation and its directional sensitivity in young healthy volunteers.","authors":"Shahrzad Soleimani Dehnavi, Marc-Antoine Roy, Mahmoudreza Taghizadeh, François Billaut, Patrice Brassard","doi":"10.1152/japplphysiol.00166.2026","DOIUrl":"10.1152/japplphysiol.00166.2026","url":null,"abstract":"<p><p>Dynamic cerebral autoregulation (dCA) stabilizes cerebral blood flow (CBF) during rapid mean arterial pressure (MAP) changes and exhibits directional sensitivity (i.e., attenuated CBF responses to transient MAP increases compared with MAP decreases). Hypoxia may impair this regulatory capacity and promote CBF instability. Whether the severity of poikilocapnic hypoxia differentially influences dCA and its hysteresis-like pattern remains unclear. This study examines the impact of acute mild [fraction of inspired oxygen ([Formula: see text]= 0.16)], and severe ([Formula: see text] = 0.10) hypoxia, compared with normoxia ([Formula: see text]= 0.21), on dCA and its directional sensitivity. Twenty participants completed 6-min oscillatory lower body negative pressure (OLBNP) trials at 0.05 and 0.10 Hz in three distinct sessions, where MAP and middle cerebral artery mean blood velocity (MCAv) were continuously recorded. dCA and its hysteresis-like pattern were quantified using transfer function analysis (TFA) and directional sensitivity analysis [with time-adjusted ratios of relative MCAv to MAP changes calculated for each transition during MAP increases (RelMCAv_T/RelMAP_T^INCREASE) and decreases (RelMCAv_T/RelMAP_T^DECREASE)], respectively. Severe hypoxia increased MAP (<i>P</i> = 0.042) and MCAv (<i>P</i> = 0.013) power and decreased TFA phase (<i>P</i> = 0.026) at 0.05 Hz OLBNP compared with normoxia. Mild hypoxia did not influence dCA. Regardless of hypoxia severity, RelMCAv_T/RelMAP_T^INCREASE was lower than RelMCAv_T/RelMAP_T^DECREASE at 0.05 Hz (<i>P</i> = 0.007) and 0.10 Hz (<i>P</i> = 0.008) OLBNP. These results suggest that acute severe, but not mild hypoxia, impairs dCA at 0.05 Hz OLBNP, reflecting reduced buffering capacity of the cerebral circulation. Nonetheless, the hysteresis-like pattern of dCA observed in normoxia remains unaffected by hypoxia severity, suggesting distinct regulatory mechanisms for dCA and its directional sensitivity under hypoxic stress.<b>NEW & NOTEWORTHY</b> Using a multimetric approach combining transfer function analysis with directional sensitivity metrics, we demonstrate that severe, but not mild, poikilocapnic hypoxia impairs dynamic cerebral autoregulation, whereas preserving its directional sensitivity across oxygen levels. These findings suggest that distinct mechanisms govern the dynamic and directional components of dynamic cerebral autoregulation.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"561-577"},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148470792","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":"Limb- and sex-specific determinants of vascular function assessed by flow-mediated dilation and passive limb movement.","authors":"Elisa Fioraso, Anna Pedrinolla, Jillian M Lang, Elena S Shostak, Stephen J Ives, Massimo Venturelli","doi":"10.1152/japplphysiol.00065.2026","DOIUrl":"10.1152/japplphysiol.00065.2026","url":null,"abstract":"<p><p>Assessing regional vascular function is crucial for understanding systemic cardiovascular health. This study primarily investigated whether flow-mediated dilation (FMD) and passive limb movement (PLM) yield congruent, interchangeable patterns across the upper limbs (ULs) and lower limbs (LLs). Secondarily, we evaluated sex-specific influences on these regional vascular relationships. Twenty healthy individuals (10 males and 10 females) underwent brachial and popliteal FMD, alongside axillary and femoral PLM, in a counterbalanced single session. Baseline diameters, FMD%, allometrically scaled FMD, and blood flow (BF) PLM parameters [peakBF, ΔpeakBF, area under the curve (AUC)] were analyzed. Regarding our primary aim, FMD% was significantly higher in UL than LL (7.7 ± 2.9% vs. 4.9 ± 1.8%; <i>P</i> = 0.002) and was not correlated between limbs (<i>r</i> = 0.11, <i>P</i> = 0.650). However, when analyzed using an allometric mixed model with baseline diameter as a covariate, this limb difference was no longer significant (<i>P</i> = 0.334). PLM ΔpeakBF was lower in UL than LL (ΔUL - LL = -68.3%; <i>P</i> < 0.001) but showed significant interlimb correlations (<i>r</i> = 0.50, <i>P</i> = 0.024). No limb × sex interaction was found for FMD% (<i>P</i> = 0.889) or allometric FMD% (<i>P</i> = 0.815). However, a significant limb × sex interaction emerged for PLM AUC (<i>P</i> < 0.001), driven by a higher absolute AUC in the LL for males (<i>P</i> < 0.001) and a higher volume-normalized AUC in the UL for females (<i>P</i> = 0.003). In conclusion, brachial and popliteal FMD are not interchangeable, providing complementary, region-specific information heavily influenced by vessel size, and FMD% is not affected by sex. PLM_UL and PLM_LL provide partially convergent but not equivalent information, warranting caution when comparing limbs, particularly when sex is a variable of interest.<b>NEW & NOTEWORTHY</b> This study directly compares flow-mediated dilation and passive limb movement across upper and lower limbs, providing novel insight into limb-specific vascular function. Flow-mediated dilation and passive limb movement are not interchangeable between limbs, impacting future experimental and clinical evaluation. Vascular function differs between sexes for passive limb movement, highlighting the need to consider sex-specific effects in study design.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"578-590"},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148436743","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":"Blood flow restriction in COPD: which implications for exertional dyspnea, contractile muscle fatigue, and rehabilitative exercise training?","authors":"Titouan Paul Perrin, Onésie Larrière, Laurent Razat, Hugo Randy, Marie Coudurier, Bruno Degano, Julien V Brugniaux, Mathieu Marillier","doi":"10.1152/japplphysiol.00448.2026","DOIUrl":"10.1152/japplphysiol.00448.2026","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"888-891"},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148793580","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":"Variability in cross-modal proprioceptive judgements impairs upper-limb function across the lifespan.","authors":"Lucy S Robertson, Joanna Diong, Annie A Butler, Peter Humburg, Simon C Gandevia, Martin E Héroux","doi":"10.1152/japplphysiol.00013.2026","DOIUrl":"10.1152/japplphysiol.00013.2026","url":null,"abstract":"<p><p>Proprioceptive deficits are thought to contribute to age-related decline in upper-limb function. We aimed to estimate the effect of proprioceptive ability on upper-limb function under an explicitly specified causal framework and to determine whether this effect varied with age. A causal graph was developed to outline plausible relationships among proprioceptive ability, upper-limb function, and related factors (e.g., age, tactile acuity, cognition, and muscle strength). A total of 184 healthy individuals (18-95 yr; 98 females and 86 males) completed a test battery. Proprioception was assessed using grasp-based measures of low-level proprioception (judgements within a single reference frame) and high-level proprioception (judgements across different frames of reference, involving transformations between visual and proprioceptive information). The causal graph identified the minimal adjustment set to reduce bias, and generalized linear models were used to estimate the effect of proprioceptive accuracy and precision on upper-limb function under the assumed causal structure. Poor high-level proprioception precision was linked with impaired performance on a functional task requiring participants to put on and button up a shirt, with the effect increasing with age. For example, at the median precision value, an 80-yr-old required on average 13 s longer than a 60-yr-old to complete the task. No evidence was found for an effect of low-level proprioception on functional performance. Although effect sizes were generally modest, the observed associations were consistent and demonstrated age-dependent effects. These findings are consistent with a role for high-level proprioception in upper-limb function and provide normative data across the lifespan, highlighting proprioception as a potential therapeutic target to mitigate age-related functional decline.<b>NEW & NOTEWORTHY</b> This is the first study to estimate the effect of proprioception on upper-limb function across the lifespan within an explicitly defined causal framework. Specifically, we investigated whether deficits in low-level proprioceptive judgements (made within a single frame of reference) or high-level proprioceptive judgements (made between frames of reference) impair upper-limb function across the lifespan. We provide novel evidence that imprecise high-level proprioceptive judgements impair an everyday upper-limb functional task, with this relationship strengthening with age.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"661-675"},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148470521","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":"Female-specific echocardiography-derived cardiac responses to the cold pressor test.","authors":"Emily K Van Berkel, Amélie Debray, Shannon I Delage, Brittany K Schwende, Sarah A Mackie, Rachel N Lord, Charlotte W Usselman","doi":"10.1152/japplphysiol.00942.2025","DOIUrl":"10.1152/japplphysiol.00942.2025","url":null,"abstract":"<p><p>We previously demonstrated heterogeneous vascular resistance (VR) responses to the cold pressor test (CPT) in females. Since cardiac output (CO) is a key determinant of the pressor response, we prospectively examined cardiac contributions to the CPT, hypothesizing that females would exhibit heterogeneous cardiac and vascular responses to the CPT. Nineteen healthy females (24 ± 3 yr, body mass index 22.9 ± 1.9 kg/m²) and a comparator group of nine males (23 ± 3 yr, 24.8 ± 1.6 kg/m²) completed a 3-min CPT including continuous measurements of mean arterial pressure (MAP; finger photoplethysmography), CO [stroke volume (SV) (echocardiogram) × heart rate (HR) (3-lead electrocardiogram)], and femoral VR [FVR; MAP/femoral blood flow (duplex ultrasound)]. The magnitudes of CPT-induced changes (Δ) in MAP (<i>P</i> = 0.96), HR (<i>P</i> = 0.59), CO (<i>P</i> = 0.09), and %FVR (<i>P</i> = 0.46) were not different between sexes; ΔSV was smaller in females (1.0 ± 5.0 vs. 5.0 ± 3.0 mL, <i>P</i> = 0.03). ΔSV responses were distinctly heterogeneous in female participants; females demonstrating positive ΔSV (SV_INC; <i>n</i> = 10) and negative ΔSV (SV_DEC; <i>n</i> = 9) were subdivided for subsequent analyses. SV_INC had higher ΔSV (5.0 ± 3.0 vs. -3.0 ± 2.0 mL; <i>P</i> < 0.001; by design) and ΔCO (1.11 ± 0.48 vs. 0.47 ± 0.43 L/min; <i>P</i> = 0.01) but lower Δtotal peripheral resistance (TPR) (median: -2 [interquartile range (IQR): 3] vs. 1 [2] mmHg/L/min; <i>P</i> = 0.008). %FVR (<i>P</i> = 0.87), ΔHR (<i>P</i> = 0.13), and ΔMAP (<i>P</i> = 0.85) did not differ between subgroups. Among all females, ΔSV was positively associated with ΔCO and negatively associated with ΔTPR but not ΔFVR, ΔHR, or ΔMAP, indicating that heterogeneous SV responses in females may be offset by systemic vascular resistance responses and do not impact the overall magnitude of the pressor response to the CPT.<b>NEW & NOTEWORTHY</b> Sex-specific cardiac and vascular cold pressor test (CPT) responses have not been well described. In females, we observed bidirectional CPT-induced, echocardiography-derived stroke volume (SV) responses that were negatively correlated with total peripheral resistance but not blood pressure, whereas males consistently increased SV. Pressor responses did not differ between sexes. These data support interindividual heterogeneity in the mechanisms by which females respond hemodynamically to the CPT, which do not appear to influence pressor responses.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"892-905"},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148760443","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}