Journal of applied physiology最新文献

{"title":"Evaluating the role of sex-related structure-function differences on airway aerosol transport and deposition.","authors":"Ge Jin, Haribalan Kumar, Alys R Clark, Kelly S Burrowes, Eric A Hoffman, Merryn H Tawhai","doi":"10.1152/japplphysiol.00898.2023","DOIUrl":"https://doi.org/10.1152/japplphysiol.00898.2023","url":null,"abstract":"<p><p>Several experimental studies have found that females have higher deposition of particles in the airways compared with males. This has implications for the delivery of aerosolized therapeutics and for understanding sex differences in respiratory system response to environmental exposures. This study evaluates several factors that potentially contribute to sex differences in particle deposition, using scale-specific structure-function models of 1D ventilation distribution, particle transport, and deposition. The impact of gravity, inhalation flow rate, and dead space are evaluated in 12 structure-based models (seven female; five male). Females were found to have significantly higher total, bronchial, and alveolar deposition than males across a particle size range from 0.01 to 10 . Results suggest that higher deposition fraction in females is due to higher alveolar deposition for smaller particle sizes, and higher bronchial deposition for larger particles. Females had higher alveolar deposition in the lower lobes, and slightly lower particle concentration in the left upper lobe. Males were found to be more sensitive to changes due to gravity, showing greater reduction in bronchial deposition fraction. Males were also more sensitive to change in inhalation flow rate, and to scaling of dead space due to the larger male baseline airway size. Predictions of sex differences in particle deposition - that are consistent with the literature - suggest that sex-based characteristics of lung and airway size interacting with particle size gives rise to differences in regional deposition.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142017535","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":"Skeletal muscle adaptations following eccentric contractions are not mediated by keratin 18.","authors":"Muni Swamy Ganjayi, Samuel W Frank, Thomas A Krauss, Michael L York, Robert J Bloch, Cory W Baumann","doi":"10.1152/japplphysiol.00496.2024","DOIUrl":"10.1152/japplphysiol.00496.2024","url":null,"abstract":"<p><p>The molecular mechanisms that drive muscle adaptations after eccentric exercise training are multifaceted and likely impacted by age. Previous studies have reported that many genes and proteins respond differently in young and older muscles following training. Keratin 18 (Krt18), a cytoskeletal protein involved in force transduction and organization, was found to be upregulated after muscles performed repeated bouts of eccentric contractions, with higher levels observed in young muscle compared to older muscle. Therefore, the purpose of this study was to determine if Krt18 mediates skeletal muscle adaptations following eccentric exercise training. The anterior crural muscles of Krt18 knockout (KO) and wild-type (WT) mice were subjected to either a single bout or repeated bouts of eccentric contractions, with isometric torque assessed across the initial and final bouts. Functionally, Krt18 KO and WT mice did not differ prior to performing any eccentric contractions (p≥0.100). Muscle strength (tetanic isometric torques) and the ability to adapt to eccentric exercise training were also consistent across strains at all time points (p≥0.169). Stated differently, immediate strength deficits and the recovery of strength following a single or multiple bouts of eccentric contractions were similar between Krt18 KO and WT mice. In summary, the absence of Krt18 does not impede the muscle's ability to adapt to repeated eccentric contractions, suggesting it is not essential for exercise-induced remodeling.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142017536","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":"Co-administration of PEGylated Apohemoglobin and Haptoglobin can Limit Vascular Dysfunction in the Microcirculation and Prevent Acute Inflammation.","authors":"Carlos J Munoz, Daniela Lucas, Cynthia R Muller, Jacinda Martinez, Quintin O'Boyle, Ivan S Pires, Andre F Palmer, Pedro Cabrales","doi":"10.1152/japplphysiol.00315.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00315.2024","url":null,"abstract":"<p><p>Unfortunately, during pathological conditions resulting in chronic hemolysis cell-free hemoglobin (Hb) is released into the circulation which releases free heme, resulting in several complications. One approach to prevent these toxicities is administration of supplemental scavenger proteins, haptoglobin (Hp) and hemopexin (Hpx). The goal of this body of work is to objectively measure levels of vascular reactivity and inflammatory profiles after an infusion of acellular hemoglobin in animals that were given a co-administration of PEGylated human apohemoglobin (PEG-apoHb), a hemopexin (Hpx)-mimetic that can scavenge free heme from hemoglobin, together with human plasma-derived Hp that can scavenge dimerized Hb. Utilizing intravital microscopy, Golden Syrian hamsters instrumented with a dorsal window chamber were used to evaluate the <i>in vivo</i> effects of 4 experimental groups that were then challenged with a hypovolemic injection (10% of the animal's blood volume) of human Hb (hHb, 5 g/dL). The four experimental groups consisted of: 1) lactated Ringer's (control), 2) PEG-apoHb only, 3) Hp only, and 4) PEG-apoHb + Hp. The microvascular hemodynamics (diameter and flow) in arterioles and venules were recorded at baseline, 20 minutes after treatment, and 20 minutes after hHb challenge. Systemic parameters (blood pressure and heart rate), blood gases (pH, pCO₂, and pO₂), blood parameters (Hb concentration and hematocrit), and multiorgan functionality/ inflammation were also measured. Our results suggest that co-administration of PEG-apoHb + Hp as a booster prior to the infusion of acellular hemoglobin significantly prevented vasoconstriction in the microcirculation, significantly increased the number of functional capillaries, and significantly reduced inflammation.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141982299","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":"Persistent physiological benefits from doping? Ethical implications for sports integrity.","authors":"Pedro L Valenzuela, Sebastian Sitko, Yannis Pitsiladis","doi":"10.1152/japplphysiol.00422.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00422.2024","url":null,"abstract":"<p><p>The effects of some widely abused doping substances such as anabolic androgenic steroids (AAS) on performance are well-documented, particularly in the short-term, and the use of these substances is banned by various sporting authorities, with athletes sanctioned from competing for up to 4 years. However, controversy exists on whether residual physiological effects of some doping practices could persist even years after discontinuation, granting unfair advantages to athletes long after sanctions have been served. Particularly, in support of the so-called muscle memory theory, growing evidence in both animals and humans suggest that AAS administration could exert long-term effects at the muscle level, notably a higher number of myonuclei. This effect could enhance retraining/muscle remodelling capacity long after AAS cessation, thus supposing an advantage for doped athletes even +4 years after doping practices have been discontinued. If confirmed, the persistence of physiological improvements resulting from past doping practices raises serious ethical concerns in the sports field and opens the door to lifelong sanctions.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141982303","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":"Androgen receptor markers do not differ between nonresponders and responders to resistance training-induced muscle hypertrophy.","authors":"João G A Bergamasco, Maíra C Scarpelli, Joshua S Godwin, Paulo H C Mesquita, Talisson S Chaves, Deivid G Silva, Diego Bittencourt, Nathalia F Dias, Ricardo A Medalha Junior, Paulo C Carello Filho, Vitor Angleri, Luiz A R Costa, J Max Michel, Felipe C Vechin, Andreas N Kavazis, Carlos Ugrinowitsch, Michael D Roberts, Cleiton A Libardi","doi":"10.1152/japplphysiol.00354.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00354.2024","url":null,"abstract":"<p><p>The aim of this study was to investigate whether baseline values and acute and chronic changes in androgen receptors (AR) markers, including total AR, cytoplasmic (cAR) and nuclear (nAR) fractions, as well as DNA-binding activity (AR-DNA), are involved in muscle hypertrophy responsiveness by comparing young nonresponder and responder individuals. After 10 weeks of resistance training (RT), participants were identified as nonresponders using two typical errors (TE) obtained through two muscle cross-sectional area (mCSA) ultrasound measurements (2×TE; 4.94%), and the highest responders within our sample were numerically matched. Muscle biopsies were performed at baseline, 24h after the first RT session (acute responses) and 96h after the last session (chronic responses). AR, cAR and nAR were analyzed using Western blotting, and AR-DNA using an ELISA-oligonucleotide assay. Twelve participants were identified as nonresponders (ΔmCSA: -1.32%), and twelve as responders (ΔmCSA: 21.35%). There were no baseline differences between groups in mCSA, AR, cAR, nAR or AR-DNA (<i>P</i> > 0.05). For acute responses, there was a significant difference between nonresponders (+19.5%) and responders (-14.4%) in AR-DNA (ES = -1.39; 95% CI: -2.53 to -0.16; <i>P</i> = 0.015). There were no acute between-group differences in any other AR markers (<i>P</i> > 0.05). No significant differences between groups were observed in chronic responses across any AR markers (<i>P</i> > 0.05). Nonresponders and responders presented similar baseline, acute and chronic results for the majority of the AR markers. Thus, our findings do not support the influence of AR markers on muscle hypertrophy responsiveness to RT in untrained individuals.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141982350","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 complexity of cerebral blood flow regulation: the interaction of posture and vasomotor reactivity.","authors":"Rebecca H Clough, Ronney B Panerai, Kannaphob Ladthavorlaphatt, Thompson G Robinson, Jatinder S Minhas","doi":"10.1152/japplphysiol.00851.2023","DOIUrl":"https://doi.org/10.1152/japplphysiol.00851.2023","url":null,"abstract":"<p><p>Arterial carbon dioxide (PaCO₂) and posture influence the middle (MCAv) and posterior (PCAv) cerebral artery blood velocitiesbut there is paucity of data about their interaction and need for an integrated model of their effects, including dynamic cerebral autoregulation (dCA). In 22 participants (11 male, age 30.2 ± 14.3 years), blood pressure (BP, Finometer), dominant MCAv and non-dominant PCAv (transcranial Doppler ultrasound), end-tidal CO₂ (EtCO₂, capnography) and heart rate (HR, ECG) were recorded continuously. Two recordings (R) were taken when the participant was supine (R1, R2), two taken when the participant was sitting (R3, R4), and two taken when the participant was standing (R5, R6). R1, R3 and R5 consisted of 3 minutes of 5% CO₂ through a mask and R2, R4 and R6 consisted of 3 minutes of paced hyperventilation. The effects of PaCO2 were expressed with a logistic curve model (LCM) for each parameter. dCA was expressed by the autoregulation index (ARI), dervived by transfer function analysis. Standing shifted LCM to the left for MCAv (p<0.001), PCAv (p<0.001), BP (p=0.03) and ARI (p=0.001); downwards for MCAv and PCAv (both p<0.001), and upwards for HR (p<0.001). For BP, LCM was shifted downwards by sitting and standing (p=0.024). For ARI, the hypercapnic range of LCM was shifted upwards during standing (p<0.001). A more complete mapping of the combined effects of posture and arterial CO₂ on the cerebral circulation and peripheral variables can be obtained with the LCM over a broad physiological range of EtCO₂ values.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141982304","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":"Effect of Diabetes on Microvascular Morphology and Permeability of Rat Skeletal Muscle: <i>In Vivo</i> Imaging Using Two-Photon Laser Scanning Microscopy.","authors":"Kazuki Hotta, Rie Shimotsu, Bradley J Behnke, Kazuto Masamoto, Kazuyoshi Yagishita, David C Poole, Yutaka Kano","doi":"10.1152/japplphysiol.00222.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00222.2024","url":null,"abstract":"<p><p>This investigation evaluated the microvascular permeability and ultrastructure of skeletal muscle capillaries in skeletal muscle of diabetic (DIA) rats using two-photon laser scanning microscopy (TPLSM) and transmission electron microscopy (TEM). Microvascular permeability was assessed in the tibialis anterior muscle of control (CON) and DIA (streptozocin) male Wistar rats (n = 20, 10-14 wk) by <i>in vivo</i> imaging using TPLSM after fluorescent dye intravenous infusion. Fluorescent dye leakage was quantified to determine microvascular permeability. The ultrastructure was imaged by TEM <i>ex vivo</i> to calculate the size and number of intercellular clefts between capillary endothelial cells and also intracellular vesicles. Compared with control, the volumetrically determined interstitial fluorescent dye leakage, the endothelial cell thickness, and the number of intercellular clefts per capillary perimeter were significantly higher, and the cleft width was significantly narrower in TA of DIA (interstitial fluorescent dye leakage, 2.88 ± 1.40 vs. 10.95 ± 1.41 µm³ x min x 10⁶; endothelial thickness 0.28 ± 0.02 vs. 0.45 ± 0.03 µm; number of intercellular clefts per capillary perimeter 6.3 ± 0.80 vs. 13.6 ± 1.7 /100 µm; cleft width 11.92 ± 0.95 vs. 8.40 ± 1.03 nm, CON vs. DIA respectively, all p <0.05). The size of intracellular vesicles in the vascular endothelium showed an increased proportion of large vesicles in the DIA group compared to the CON group (p < 0.05). Diabetes mellitus enhances the microvascular permeability of skeletal muscle microvessels, due, in part, to a higher density and narrowing of the endothelial intercellular clefts, and larger intracellular vesicles.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141982301","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":"Sexual dimorphisms in skeletal muscle: current concepts and research horizons.","authors":"Marianne E Emmert, Andrew S Emmert, Qingnian Goh, Roger Cornwall","doi":"10.1152/japplphysiol.00529.2023","DOIUrl":"10.1152/japplphysiol.00529.2023","url":null,"abstract":"<p><p>The complex compositional and functional nature of skeletal muscle makes this organ an essential topic of study for biomedical researchers and clinicians. An additional layer of complexity is added with the consideration of sex as a biological variable. Recent research advances have revealed sexual dimorphisms in developmental biology, muscle homeostasis, adaptive responses, and disorders relating to skeletal muscle. Many of the observed sex differences have hormonal and molecular mechanistic underpinnings, whereas others have yet to be elucidated. Future research is needed to investigate the mechanisms dictating sex-based differences in the various aspects of skeletal muscle. As such, it is necessary that skeletal muscle biologists ensure that both female and male subjects are represented in biomedical and clinical studies to facilitate the successful testing and development of therapeutics for all patients.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11343095/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141081679","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":"Mitochondrial function in lungs of rats with different susceptibilities to hyperoxia-induced acute lung injury.","authors":"Pardis Taheri, Devanshi D Dave, Ranjan K Dash, Guru P Sharma, Anne V Clough, Elizabeth R Jacobs, Said H Audi","doi":"10.1152/japplphysiol.00243.2024","DOIUrl":"10.1152/japplphysiol.00243.2024","url":null,"abstract":"<p><p>Adult rats exposed to hyperoxia (>95% O₂) die from respiratory failure in 60-72 h. However, rats preconditioned with >95% O₂ for 48 h followed by 24 h in room air acquire tolerance of hyperoxia (H-T), whereas rats preconditioned with 60% O₂ for 7 days become more susceptible (H-S). Our objective was to evaluate lung tissue mitochondrial bioenergetics in H-T and H-S rats. Bioenergetics was assessed in mitochondria isolated from lung tissue of H-T, H-S, and control rats. Expressions of complexes involved in oxidative phosphorylation (OxPhos) were measured in lung tissue homogenate. Pulmonary endothelial filtration coefficient (<i>K</i>_f) and tissue mitochondrial membrane potential (Δψ_m) were evaluated in isolated perfused lungs (IPLs). Results show that ADP-induced <i>state 3</i> OxPhos capacity (<i>V</i>_max) decreased in H-S mitochondria but increased in H-T. Δψ_m repolarization time following ADP-stimulated depolarization increased in H-S mitochondria. Complex I expression decreased in H-T (38%) and H-S (43%) lung homogenate, whereas complex V expression increased (70%) in H-T lung homogenate. Δψ_m is unchanged in H-S and H-T lungs, but complex II has a larger contribution to Δψ_m in H-S than H-T lungs. <i>K</i>_f increased in H-S, but not in H-T lungs. For H-T, increased complex V expression and <i>V</i>_max counter the effect of the decrease in complex I expression on Δψ_m. A larger complex II contribution to Δψ_m along with decreased <i>V</i>_max and increased <i>K</i>_f could make H-S rats more hyperoxia susceptible. Results are clinically relevant since ventilation with ≥60% O₂ is often required for extended periods in patients with acute respiratory distress syndrome (ARDS).<b>NEW & NOTEWORTHY</b> We assessed lung tissue mitochondrial bioenergetics in rats with tolerance (H-T) or susceptibility (H-S) to hyperoxia-induced ARDS. Results from studies in isolated mitochondria, tissue homogenate, and isolated perfused lungs show that mitochondrial bioenergetics are differentially altered in H-T and H-S lungs suggesting a potential role for mitochondrial bioenergetics in hyperoxia-induced ARDS. Results are clinically relevant since hyperoxia exposure is a primary therapy for patients with ARDS, and differential sensitivity to hyperoxia surely occurs in humans.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141310799","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 metabolic cost of breathing for exercise ventilations: effects of age and sex.","authors":"Shalaya Kipp, Sierra R Arn, Michael G Leahy, Jordan A Guenette, A William Sheel","doi":"10.1152/japplphysiol.00282.2023","DOIUrl":"10.1152/japplphysiol.00282.2023","url":null,"abstract":"<p><p>Given that there are both sex-based structural differences in the respiratory system and age-associated declines in pulmonary function, the purpose of this study was to assess the effects of age and sex on the metabolic cost of breathing (V̇o_2RM) for exercise ventilations in healthy younger and older males and females. Forty healthy participants (10 young males 24 ± 3 yr; 10 young females 24 ± 3 yr; 10 older males 63 ± 3 yr, 10 older females 63 ± 6 yr) mimicked their exercise breathing patterns (voluntary hyperpnea) in the absence of exercise across a range of exercise intensities. At peak exercise, V̇o_2RM represented a significantly greater fraction of peak oxygen consumption (V̇o_2peak) in young females, 12.7 ± 4.0%, compared with young males, 10.7 ± 3.0% (<i>P</i> = 0.027), whereas V̇o_2RM represented 13.5 ± 2.3% of V̇o_2peak in older females and 13.2 ± 3.3% in older males. At relative ventilations, there was a main effect of age, with older males consuming a significantly greater fraction of V̇o_2RM (6.6 ± 1.9%) than the younger males (4.4 ± 1.3%; <i>P</i> = 0.012), and older females consuming a significantly greater fraction of V̇o_2RM (6.9 ± 2.5%) than the younger females (5.1 ± 1.4%; <i>P</i> = 0.004) at 65% V̇e_max. Furthermore, both younger and older males had significantly better respiratory muscle efficiency than their female counterparts at peak exercise (<i>P</i> = 0.011; <i>P</i> = 0.015). Similarly, younger participants were significantly more efficient than older participants (6.5 ± 1.5% vs. 5.5 ± 2.0%; <i>P</i> = 0.001). Normal age-related changes in respiratory function, in addition to sex-based differences in airway anatomy, appear to influence the ventilatory responses and the cost incurred to breathe during exercise.<b>NEW & NOTEWORTHY</b> Here we show that at moderate and high-intensity exercise, older individuals incur a higher cost to breathe than their younger counterparts. However, as individuals age, the sex difference in the cost of breathing narrows. Collectively, our findings suggest that the normative age-related changes in respiratory structure and function, and sex differences in airway anatomy, appear to influence the ventilatory responses to exercise and the oxygen cost to breathe.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141261960","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}