Journal of applied physiology最新文献

{"title":"Improved muscle gearing in the medial gastrocnemius of pregnant and lactating rats.","authors":"Adrien A Arias, M Lauren Delargy, Nicole Danos","doi":"10.1152/japplphysiol.01083.2025","DOIUrl":"10.1152/japplphysiol.01083.2025","url":null,"abstract":"<p><p>Pennate muscles typically contract with complex three-dimensional shape changes that vary in magnitude across muscle force levels, allowing improved muscle fiber force-velocity dynamics across a whole muscle's range of forces (i.e., variable gearing ability). Previous work on the underlying mechanisms that dictate variable gearing suggests that the mechanical properties of intramuscular and extracellular connective tissue can act to constrain muscle bulging and gearing ability. However, it remains unclear whether increased muscle compliance can confer improved gearing ability. Recent work in pregnant and lactating rats suggests adaptations in the medial gastrocnemius (MG) muscle that may influence variable gearing ability and overall function. Here, we used in situ muscle preparations in rats to characterize the range of architectural gear ratios (AGR = muscle velocity/fascicle velocity), force-length properties, and force-velocity properties of isolated gastrocnemii to test the hypothesis that gearing ability improves during pregnancy and lactation. We found that pregnant and lactating rats exhibit a significantly wider range of AGRs and a steeper linear relationship between AGR and muscle force, suggesting an improved ability to fine-tune fiber contractile dynamics to force level during dynamic muscle contractions. This improved gearing ability is underpinned by longer muscle fascicles in pregnant and lactating rats, which have broader implications on in vivo force-velocity dynamics during locomotion. We conclude that young female rats are a viable biological system that naturally varies in gearing ability across different reproductive stages without differences in relative muscle stiffness.<b>NEW & NOTEWORTHY</b> Musculoskeletal remodeling in the medial gastrocnemius of pregnant and lactating rats suggests adaptations that may influence variable gearing ability. Here, we show improved gearing dynamics in pregnant and lactating rats compared with nonpregnant controls due, in part, to longer muscle fascicles. These findings add fascicle length to the list of mechanisms proposed to influence variable gearing in pennate muscle and has broader implications on in vivo force-length dynamics during locomotion in pregnant and lactating animals.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1208-1217"},"PeriodicalIF":3.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149074831","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 difference in orthostatic tolerance during simulated partial-gravity head-up tilts and efficacy of a lower body compression garment countermeasure.","authors":"Jason R Lytle, Katrina J Carter, Sarah K Pickering, Cambria S O'Grady, Stefan Moestl, Jens Tank, André Diedrich, Millennia Young, Brandon R Macias, Steven S Laurie, Stuart M C Lee","doi":"10.1152/japplphysiol.01130.2025","DOIUrl":"10.1152/japplphysiol.01130.2025","url":null,"abstract":"<p><p>After adaptation to weightlessness, astronauts will experience head-to-foot accelerations (G) during descent to and ascent from the lunar surface that may provoke symptoms of orthostatic intolerance (OI). There were no reports consistent with OI among Apollo astronauts who experienced up to 10 minutes of 0.4-0.6-G while standing without OI countermeasures during dynamic flight phases, although heart rate (HR) was elevated. The likelihood of developing OI in future Artemis crews, which will include females, may be greater given observations of increased postflight OI in females and potentially greater acceleration requirements. We assessed orthostatic tolerance and cardiovascular responses in 34 healthy individuals (16 females) during 20 minutes of 30, 50, and 80° head-up tilt (HUT), simulating sustained accelerations (0.50, 0.75, and 1.00-G) after pharmacologically induced hypovolemia (∼10% plasma volume loss) as a short-duration spaceflight model. On a separate day using the same model, we evaluated the efficacy of a lower body orthostatic intolerance garment (OIG) to prevent OI. Tilt tolerance time without OIG was 4.6 minutes greater in males than females during 80° HUT (<i>P</i> = 0.003). Without OIG, hypovolemic females demonstrated lower mean arterial pressures before and during HUT at 80° compared to males (<i>P</i> = 0.038). OIG use increased tolerance by 4.2 (<i>P</i> < 0.001) and 1.6 min (<i>P</i> = 0.007) for 80 and 50° HUT, respectively, and attenuated the increase in HR and decrease in stroke volume, which was greater in females (<i>P</i> < 0.001). Hypovolemic females demonstrated an increased cardiovascular response to HUT contributing to differences in OI throughout 20-min exposures, and the OIG demonstrates protection in all participants.<b>NEW & NOTEWORTHY</b> We report here that females were more likely to become presyncopal earlier than males during 20 min of 80° and 50° head-up tilt tests (HUT), representing 1.00-G and 0.75-G, respectively, but not during 30° HUT, representing 0.50-G. Additionally, wearing lower body compression garments protected against symptoms of orthostatic intolerance in both sexes. These results inform the spaceflight community for planning acceleration limits and countermeasure use during future exploration missions to the Moon and Mars.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1157-1170"},"PeriodicalIF":3.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149012377","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":"Longitudinal changes in competitive performance in elite 46,XY DSD runners during prolonged testosterone suppression.","authors":"Stéphane Bermon","doi":"10.1152/japplphysiol.90031.2026","DOIUrl":"10.1152/japplphysiol.90031.2026","url":null,"abstract":"<p><p>To assess longitudinal changes in the official competitive performance in elite runners with androgen-sensitive 46,XY differences of sex development (DSD) during prolonged testosterone suppression. This retrospective longitudinal study analyzed nine elite 46,XY DSD runners with 5α-reductase type 2 deficiency who maintained serum testosterone below 2.5 nmol/L after gonadectomy, gonadotropin-releasing hormone agonist treatment, or combined oral contraceptive use. Outdoor performances in sprint, middle-distance, and long-distance events were evaluated. Semester-best performances were compared with presuppression personal bests and expressed as percentage change and World Athletics World Ranking points. Before treatment, mean serum testosterone was 22.5 ± 6.5 nmol/L. Follow-up included 16 performance profiles and 44 semester-best observations over 0-1,258 days of suppression. Competitive performance declined after testosterone suppression, with mean decrements of 6.0, 7.1, 6.5, 7.2, 6.6, and 4.4% across successive semesters. Across the full observation period, the mean performance decrement was 6.5 ± 3.6%, and after 2 yr it remained approximately 6.0 ± 4.5%. No significant difference in percentage decrement was observed between sprint and middle-/long-distance groups, although substantial interindividual variability was present. Sustained testosterone suppression in elite androgen-sensitive 46,XY DSD runners was associated with a clear but heterogeneous reduction in competitive performance. In several athletes, the decrement remained smaller than the expected elite male-female performance gap, suggesting that previous male-range androgen exposure may confer advantages not uniformly abolished by current testosterone suppression.<b>NEW & NOTEWORTHY</b> First publication describing on the effect of testosterone suppression of androgen-sensitive differences of sex development (DSD) elite athlete and their competitive performance. Performance reduction is significant but heterogenous in magnitude and smaller than the expected and known performance gap between male and female elite athletes. Some DSD athletes showed performance reduction below 3% after 1,000 days of effective testosterone suppression. Performance reduction does not seem to be different in sprinters when compared with distance runners.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1116-1121"},"PeriodicalIF":3.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148891705","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":"Limited reproducibility of endurance training adaptations: could measurement error play a major role?","authors":"Pekka Matomäki, Timi Malinen","doi":"10.1152/japplphysiol.90156.2026","DOIUrl":"10.1152/japplphysiol.90156.2026","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1069-1072"},"PeriodicalIF":3.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148891713","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":"Home-based lower leg heat therapy in postmenopausal women with hypertension. I. Effects on blood pressure.","authors":"John D Akins, Rauchelle E Richey, Anna K Geib, Ryosuke Takeda, Bryon M Curtis, Monique A Roberts-Reeves, Amy M Moore, Yu-Lun Liu, Steven A Romero, Qi Fu","doi":"10.1152/japplphysiol.90170.2026","DOIUrl":"10.1152/japplphysiol.90170.2026","url":null,"abstract":"<p><p>Despite conventional drug treatment for hypertension, postmenopausal women in the United States maintain relatively poor blood pressure (BP) control rates. Alternatives, such as heat therapy, represent promising adjuvant treatments that may reduce BP. This study tested the hypothesis that 8 wk of home-based, lower leg heating would induce acute BP reductions that may contribute to sustained BP lowering in postmenopausal women with hypertension. Fifty-nine participants completed a randomized trial to receive either a thermoneutral sham (i.e., sham; 35°C; <i>n</i> = 30, 69 ± 5 yr) or heat therapy (42°C; <i>n</i> = 29, 69 ± 5 yr). Participants completed 8 wk of home-based, lower leg water immersion (≈4 sessions/wk; 45 min/session). Acute BP responses were assessed pre-to-postimmersion, whereas pre-to-postintervention BPs were assessed using 24-h ambulatory monitoring. The average acute reductions in BP and increases in heart rate pre-to-postimmersion were greater in heat therapy (sham, systolic: -2 ± 4 mmHg, diastolic: -2 ± 2 mmHg, heart rate: -3 ± 3 beats/min; heat therapy, systolic: -6 ± 6 mmHg, diastolic: -5 ± 3 mmHg, heart rate: 5 ± 4 beats/min; all <i>P</i> < 0.01). However, these acute responses did not translate into significant reductions in ambulatory BP, whereby ΔBP did not differ between groups (sham, systolic: 0 ± 8 mmHg, diastolic: 1 ± 5 mmHg; heat therapy, systolic: 2 ± 8 mmHg, diastolic: 1 ± 5 mmHg; all <i>P</i> ≥ 0.412). Our data demonstrate that 8 wk of home-based lower leg heat therapy reduces BP acutely, but was not associated with a chronic BP-lowering effect in postmenopausal women with hypertension. Therefore, these findings suggest that home-based, lower leg heat therapy is insufficient to elicit sustained BP reductions, despite consistent acute BP reductions, in postmenopausal women with either treated or untreated hypertension.<b>NEW & NOTEWORTHY</b> This study hypothesized that 8-wk of home-based lower leg heat therapy would reduce blood pressure from pre-to-postimmersion (i.e., acute) and pre-to-postintervention (i.e., chronic) in postmenopausal women with hypertension. Although this paradigm consistently reduced blood pressure acutely, there was no chronic blood pressure lowering effect. These findings highlight the need to better understand the appropriate frequency, temperature, duration, and modality of heat therapy and how certain conditions, like hypertension, modulate physiological adaptations.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1147-1156"},"PeriodicalIF":3.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149074792","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":"Partially countering the physiological effects of fentanyl with naloxone or d-cysteine ethyl ester in adult goats.","authors":"Reiauna Taylor, Suzanne E Neumueller, John DeSalvo, Grace Hilbert, Ilya R Bederman, Stephen J Lewis, Lawrence G Pan, Hubert V Forster, Matthew R Hodges","doi":"10.1152/japplphysiol.00116.2026","DOIUrl":"10.1152/japplphysiol.00116.2026","url":null,"abstract":"<p><p>Fentanyl is the leading contributor to opioid-involved overdose (OD) mortality in the United States. Despite the demonstrated efficacy, safety, and wide availability of naloxone (NAL), opioid-involved OD fatalities remain high. This suggests our understanding of the negative integrated physiological effects of fentanyl remains incomplete, and highlights the need to develop additional novel countermeasures. Here we tested whether the physiological and behavioral effects of intravenous fentanyl in adult female goats (<i>n</i> = 12) could be mitigated with NAL or the potential countermeasure d-cysteine ethyl ester (d-CYSee). As hypothesized, intravenous injections of high doses (HD) fentanyl caused immediate ventilatory suppression via reduced breathing frequency leading to hypoventilation and hypoxemia (≥10 min). HD fentanyl elicited immediate and sustained (≥90 min) increases in diaphragm, intercostal, abdominal, and laryngeal constrictor muscle activity along with an increased alveolar to arterial oxygen (A-a O₂) gradient and hypertension. Intravenous NAL administered immediately following HD fentanyl mitigated most of these effects except the increased activation of respiratory pump and airway muscles. In contrast, d-CYSee administration immediately following HD fentanyl countered the initial hypoventilation but did not mitigate the increases in muscle activation and persistent hypoxemia. Neither treatment prevented acute withdrawal-like behaviors emerging >90 min after fentanyl administration. The data suggest that there are physiological effects of HD fentanyl that are NAL-insensitive, and d-CYSee can transiently normalize blood gases and counter opioid-induced respiratory depression (OIRD) in adult goats.<b>NEW & NOTEWORTHY</b> Here we determined whether any of the deleterious physiological effects of high-dose fentanyl could be countered by naloxone and/or d-cysteine ethyl ester (d-CYSee) in adult goats. Fentanyl induced hypoventilation and sustained increases in respiratory and airway muscle activity and hypoxemia. Naloxone reversed all fentanyl effects except tonic muscle activation, and d-CYSee reversed fentanyl-induced hypoventilation. These data suggest some effects of fentanyl are naloxone-insensitive and that d-CYSee may be a valuable countermeasure for OIRD.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"689-701"},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13507957/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148561949","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":"Standing on the shoulders of giants: what have we learned about altitude training since the pre-1968 Olympic era?","authors":"Raphaël Faiss, Olivier Girard","doi":"10.1152/japplphysiol.00429.2026","DOIUrl":"10.1152/japplphysiol.00429.2026","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"927-932"},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148813098","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":"Are we addressing study limitations the right way? A conceptual framework to distinguish design constraints from methodological shortcomings.","authors":"Rhaí A Arriel, Moacir Marocolo, Jéssica Ferreira Rodrigues","doi":"10.1152/japplphysiol.00403.2026","DOIUrl":"10.1152/japplphysiol.00403.2026","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"591-594"},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148536209","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":"Dose- and time-dependent physiological effects of fentanyl in adult goats.","authors":"Reiauna Taylor, Suzanne E Neumueller, John DeSalvo, Grace Hilbert, Lawrence G Pan, Hubert V Forster, Matthew R Hodges","doi":"10.1152/japplphysiol.00115.2026","DOIUrl":"10.1152/japplphysiol.00115.2026","url":null,"abstract":"<p><p>Osverdoses (ODs) involving the synthetic opioid fentanyl annually contribute to thousands of deaths in the United States and are largely attributed to opioid-induced respiratory depression (OIRD). However, fentanyl OD negatively affect several aspects of cardiorespiratory function, including respiratory muscle rigidity and pulmonary gas exchange. Here, we tested the hypothesis that high doses of intravenous fentanyl (50-750 µg/kg) cause unique, time- and dose-dependent changes in physiologic functions and behaviors consistent with OIRD, muscle rigidity, impaired gas exchange, and acute withdrawal in a large animal model (adult female goats; <i>n</i> = 12). Within the first 15 min after injection, intravenous fentanyl dose-dependently reduced minute ventilation (V̇i; <i>P</i> < 0.0001), breathing frequency (Fb; <i>P</i> < 0.0001), swallowing (<i>P</i> < 0.001), and [Formula: see text] (<i>P</i> < 0.0001) but increased tidal volume (Vt; <i>P</i> = 0.0029), [Formula: see text] (<i>P</i> < 0.0001), the alveolar-arterial O₂ gradient (A-a; <i>P</i> = 0.0024), and respiratory pump and airway muscle electromyographic (EMG) activity. Thereafter (30-90 min postfentanyl), swallowing and [Formula: see text] remained reduced, whereas the A-a O₂ gradient and muscle EMG activity remained increased. Beginning 90 min postfentanyl, overall movement (cumulative vector magnitude, g; <i>P</i> < 0.0001) and the total behavioral response (sum of withdrawal behaviors; <i>P</i> < 0.001) were dose-dependently increased for 4 h. Thus, high-dose fentanyl caused significant and transient OIRD, sustained respiratory muscle activation, impaired gas exchange, and dose-dependent acute withdrawal-like behaviors. We conclude that fentanyl elicits dose- and time-dependent impairments of vital physiologic systems in adult goats similar to those reported in humans, suggesting that the goat is a unique and valuable model for translational hypothesis testing for future novel countermeasure development in vivo.<b>NEW & NOTEWORTHY</b> Here, we defined the time course of integrated physiologic effects of high doses of fentanyl in adult goats. High-dose fentanyl caused hypoventilation and sustained increases in tonic respiratory-related chest wall and airway muscle activity, increased the alveolar-to-arterial O₂ gradient, and caused dose-dependent increases in acute withdrawal-like behaviors. These data suggest that the integrated physiologic responses to fentanyl in adult goats closely resemble those in humans.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"642-652"},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13575953/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148536167","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":"Effects of 8-wk exercise snacks on muscle oxygenation and cardiometabolic, mitochondrial, and subclinical atherosclerosis markers in sedentary women.","authors":"Omar A Hernández-López, Alejandro Martínez-Lucas, Alberto Hermo-Argibay, Julia Cacace, Clara Luna-Marco, Rodrigo Yañez-Sepulveda, Pablo Fernández-Collazo, Laura Perea-Galera, Celia Bañuls, Carlos Morillas, Milagros Rocha, Víctor M Víctor, Susana Rovira-Llopis","doi":"10.1152/japplphysiol.00267.2026","DOIUrl":"10.1152/japplphysiol.00267.2026","url":null,"abstract":"<p><p>\"Exercise snacks\" (ExS) are brief, structured bouts of physical activity designed to counteract the metabolic effects of sedentary behavior. This pilot study examined whether ExS improves metabolic markers, body composition, fitness indicators, peripheral blood mononuclear cells (PBMC) mitochondrial dynamics, autophagy, and subclinical atherosclerosis. Twenty-two women [11 physically active (PA), 11 sedentary; International Physical Activity Questionnaire-classified] were enrolled. Sedentary participants completed daily 12-min ExS sessions for 8 wk. Assessments included body composition, blood biomarkers, muscle oxygenation, cardiorespiratory fitness, grip strength, PBMC mitochondrial dynamics/autophagy markers, and neutrophil-endothelial interactions. Age-adjusted comparisons revealed that sedentary women (34 ± 9 yr) had similar body composition to PA participants (26 ± 5 yr). Cholesterol, low-density lipoprotein, and antioxidant capacity were reduced in sedentary women (<i>P</i> < 0.05). ExS reduced insulin (<i>P</i> < 0.01). Sedentary women displayed higher resting and maximal heart rates, lower estimated [Formula: see text], and reduced muscle reoxygenation versus PA (<i>P</i> < 0.05), all of which improved after ExS, though resting heart rate remained elevated versus PA (<i>P</i> < 0.01). Grip-strength was comparable between sedentary and PA women and increased after ExS (<i>P</i> < 0.01). Neutrophil-rolling velocity was decreased in sedentary versus PA (<i>P</i> < 0.01) and restored by ExS (<i>P</i> < 0.05). Expression of mitochondrial dynamics-related genes (mitofusins, OPA1, and FIS1) was lower in sedentary versus PA (<i>P</i> < 0.05) without changes in protein levels. Autophagy and mitophagy-related genes (Beclin1, LC3b, p62, and Pink/Parkin) were downregulated in sedentary versus PA (<i>P</i> < 0.05), whereas only LC3b mRNA and BECLIN1 protein increased after ExS (<i>P</i> < 0.01). Our findings indicate that ExS can improve cardiometabolic health, functional fitness, PBMC mitochondrial markers, and neutrophil-rolling velocity in sedentary women.<b>NEW & NOTEWORTHY</b> Brief daily \"exercise snacks\" improved metabolic health, cardiorespiratory fitness, and muscle oxygenation in sedentary women. These changes were accompanied by modulation of PBMC mitochondrial dynamics, autophagy-related markers, and neutrophil-endothelial interactions. Our findings provide mechanistic support for time-efficient exercise as a feasible strategy to counteract sedentary-induced cardiometabolic dysfunction.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"676-688"},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148520618","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}