European Journal of Applied Physiology最新文献

{"title":"Differential temporal responses of heel strike and toe off during split-belt locomotor adaptation.","authors":"Keisuke Hirata, Keisuke Kubota, Hiroki Hanawa, Taku Miyazawa, Naohiko Kanemura","doi":"10.1007/s00421-026-06315-5","DOIUrl":"10.1007/s00421-026-06315-5","url":null,"abstract":"<p><strong>Purpose: </strong>Human walking must maintain temporal coordination while adapting to perturbations. However, it remains unclear whether different gait events show similar or distinct temporal responses during adaptive walking. Using split-belt treadmill walking as a model of asymmetric temporal perturbation, we examined inter-event timing variability for heel strike (HS) and toe off (TO) in healthy young adult males.</p><p><strong>Methods: </strong>Variability was quantified as the coefficient of variation (CV) of inter-event intervals during baseline walking, early adaptation, and late adaptation. To assess perturbation-related temporal responses, we also calculated baseline-referenced changes in variability (ΔCV) and their magnitude (|ΔCV|).</p><p><strong>Results: </strong>HS exhibited higher absolute timing variability across walking phases and larger baseline-referenced changes during split-belt walking. In contrast, TO showed comparatively lower variability and smaller deviations from baseline in the present analysis. Double-support time symmetry was also altered during early adaptation and partially recovered later, indicating concurrent reorganization of whole-gait temporal coordination.</p><p><strong>Conclusion: </strong>These findings suggest that gait events do not contribute uniformly to temporal adjustment during split-belt walking. Event-specific analysis of baseline-referenced variability may therefore provide a useful perspective for describing temporal responses to locomotor perturbation.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5335-5344"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148344307","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 slow component of the [Formula: see text] response is associated with the increase in glycolytic contribution.","authors":"Austin B Shaw, Ethan J Hein, Jacob L McNary, Brady C McLain, Lydia K Caldwell, Sarah E Deemer, David W Hill","doi":"10.1007/s00421-026-06347-x","DOIUrl":"10.1007/s00421-026-06347-x","url":null,"abstract":"<p><strong>Purpose: </strong>After approximately 2 min of severe intensity exercise, there is a delayed increase in oxygen uptake (V̇O₂). It has been hypothesized that this slow component may be in response to an increase in glycolytic contribution, which causes a progressive recruitment of less-efficient Type II fibers. We examined whether the area under the curve of the V̇O₂ slow component (AUC_slow) is associated with glycolytic contribution during severe intensity constant-power cycling.</p><p><strong>Methods: </strong>Seven women and 13 men completed three constant-power cycle tests terminated at 3, 6, or 9 min in randomized order. The kinetics of the V̇O₂ response was modelled using iterative regression, and AUC_slow was calculated. Glycolysis contribution was estimated from peak post-exercise blood lactate. Pearson correlations assessed associations at each duration.</p><p><strong>Results: </strong>AUC_slow was 2 ± 1 mL·kg⁻¹ in 0-3 min of exercise; there was an additional 8 ± 3 mL·kg⁻¹ in min 3-6 and an additional 4 ± 3 mL·kg⁻¹ in min 6-9. Glycolysis contribution was 18 ± 7 mL·kg⁻¹ in min 0-3, an additional 6 ± 2 mL·kg⁻¹ in min 3-6, and an additional 2 ± 1 mL·kg⁻¹ in min 6-9. Correlation values for AUC_slow and glycolytic contribution were strong (r = 0.69, p < 0.01 for 3-6 min; and r = 0.75, p < 0.01 for 6-9 min).</p><p><strong>Conclusion: </strong>AUC_slow is related to glycolytic contribution after 3 min of severe intensity exercise. We speculate this is due to an increase in Type II fiber recruitment to compensate for fatiguing active fibers due to the accumulation of glycolytic metabolites.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5369-5377"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148419826","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 six weeks of hypoxia and hypoxic SIT on oxidative stress and myokine responses in skeletal muscle of high-fat-fed ApoE^-/- mice.","authors":"Yangwenjie Wang, Jessica Lavier, Linjia Wang, Weicheng Hua, Hao Wei, Changle Zhao, Maxime Pellegrin, Grégoire P Millet, Ying Zhang","doi":"10.1007/s00421-026-06350-2","DOIUrl":"10.1007/s00421-026-06350-2","url":null,"abstract":"<p><p>Atherosclerosis-induced oxidative stress drives skeletal muscle myopathy in peripheral artery disease, yet the combined effects of hypoxia and hypoxia sprint interval training (SIT) remain unclear. The present study was designed to evaluate how a six-week regimen of hypoxia exposure and SIT influences redox balance and myokine production in the skeletal muscle of high-fat diet (HFD) (21% fat, 1.5% (w/w) cholesterol; 43% (w/w) sucrose-free carbohydrate, 4.554 kcal/g)-fed atherosclerotic ApoE^-/- mice. Forty male ApoE^-/- mice fed a HFD were randomly assigned to four groups: Control-Normoxia, Control-Hypoxia, SIT-Normoxia, and SIT-Hypoxia. The hypoxia protocol involved exposures to 11.2% oxygen three times (40 min each) per week. Key assessment parameters included plasma lipid profiles, skeletal muscle reactive oxygen species (ROS), protein carbonyls, key components of the Nrf2 antioxidant pathway, glutathione metabolism, and myokine-related markers. Compared with the control group, both hypoxia and SIT-Normoxia significantly reduced levels of ROS, protein carbonyls, and Vegfa165 mRNA expression in the skeletal muscle. Hypoxia alone enhanced the levels of GSH-synthesizing enzymes and promoted myokine production. SIT-Normoxia improved plasma lipid profiles, activated the Nrf2 pathway, enhanced the GSH system, and upregulated myokines. SIT under hypoxia further reduced ROS and Vegfa165 while increasing plasma HDL-C and levels of SOD1 protein in the skeletal muscle, but failed to synergistically activate the Nrf2 pathway or enhance GSH production. Paradoxically, both intervention combinations suppressed the mRNA expression of myokine precursor Fndc5, BAIBA-synthesizing enzyme Hadh and Hadha. Overall, six weeks of isolated hypoxia exposure or SIT training independently reduced oxidative stress and promoted beneficial myokine responses in the skeletal muscle of ApoE^-/- mice fed a HFD. The wild-type (WT) mice fed a low-fat diet (LFD) was included to validate successful induction of hyperlipidemia, vascular remodeling, and skeletal muscle oxidative stress in ApoE^-/- mice after six weeks of HFD feeding.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5303-5318"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148535712","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 uncontrolled rise of performance peptides: reasons for concern and a call for scientific and regulatory action.","authors":"Marcel S B Arruda, Monique C Gonçalves, Marcus V S Campos, Rafael A Azevedo, Andresa R Casale, Jorge Hallak, Hamilton Roschel, Bruno Gualano","doi":"10.1007/s00421-026-06398-0","DOIUrl":"10.1007/s00421-026-06398-0","url":null,"abstract":"","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5107-5110"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148789881","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 central and cerebral hemodynamic responses to lower body negative pressure (LBNP): an experimental study.","authors":"F Tripoli, L Ridolfi, M Romanelli, R Rabbito, S Roatta, S Scarsoglio","doi":"10.1007/s00421-026-06313-7","DOIUrl":"10.1007/s00421-026-06313-7","url":null,"abstract":"<p><strong>Purpose: </strong>The effectiveness of lower body negative pressure (LBNP) as an in-flight countermeasure against cardiovascular deconditioning is still debated, with significant gaps in understanding cerebral hemodynamics and sex-related differences. This study investigates acute central, peripheral, and cerebral responses to graded LBNP during exposure to -6° head-down tilt posture (HDT) in 30 subjects (15 females, 15 males).</p><p><strong>Methods: </strong>Central and peripheral hemodynamic variables (heart rate, blood pressure, cardiac output, and total peripheral resistance) were continuously and non-invasively measured using finger photo-plethysmography along with NIRS parameters from the forearm and the forehead, and cerebral blood velocities within the middle and posterior cerebral arteries (MCA and PCA). The protocol included a 15-min baseline phase in -6° HDT followed by three 5-min levels of LBNP (from -20 to -40 mmHg).</p><p><strong>Results: </strong>LBNP primarily affected central and peripheral hemodynamics. At the cerebral level, significant changes in cerebral blood velocity and Beer-Lambert NIRS parameters were detected, while spatially resolved spectroscopy NIRS variables did not show significant changes. Sex differences were observed in blood pressure, total peripheral resistance, and forearm NIRS parameters, whereas at the cerebral level, sex had a significant effect only on the cerebrovascular conductance of the PCA (CVC_PCA).</p><p><strong>Conclusion: </strong>Our main findings highlight: (i) comparable anterior and posterior cerebral responses, as both blood velocities in the MCA and PCA exhibited a similar decreasing trend at higher LBNP values; and (ii) sex differences occurring primarily in systemic and peripheral cardiovascular responses.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5211-5224"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13633958/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148344357","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":"Rates of maximal blood lactate accumulation in the extreme intensity exercise domain: implications for training prescription.","authors":"Ozgur Ozkaya, Hakan As, Arda Peker, Mark Burnley, Andrew M Jones","doi":"10.1007/s00421-026-06290-x","DOIUrl":"10.1007/s00421-026-06290-x","url":null,"abstract":"<p><strong>Purpose: </strong>This study investigated the rate of blood lactate accumulation (vLa) across six maximal sprint efforts and identified a breakpoint (vLa_BP) in the vLa-power relationship.</p><p><strong>Methods: </strong>Twelve physically active males completed 5, 10, 15, 20, 25, and 30-s all-out sprints in randomised order on separate days, with resistances set at 10 to 12.5% of body mass. The vLa was calculated as the change in blood lactate between the resting and peak value (∆La) divided by the test duration. A piecewise linear regression was used to identify the vLa_BP and its corresponding power output (P-vLa_BP) in the vLa-power relationship. Pulmonary V̇O₂ responses were modelled using V̇O₂ data obtained from exercise and the subsequent 15-min recovery period.</p><p><strong>Results: </strong>A distinct P-vLa_BP was identified at 795 ± 135 W and 11.2 ± 1.5 W·kg^-1, corresponding to a vLa of 0.50 ± 0.10 mM·s^-1, ∆La of 6.50 ± 1.27 mM, and sprint duration of 13.3 ± 1.9 s. The vLa did not increase significantly during the 30, 25, 20, and 15-s all-out sprint tests (0.41 ± 0.04 to 0.48 ± 0.10 mM·s⁻¹; p > 0.05) but increased markedly in the 10 and 5-s tests (0.58 ± 0.14 mM·s⁻¹, p < 0.05; 0.7 ± 0.20 mM·s⁻¹, p < 0.01). V̇O₂ on-kinetics below the P-vLa_BP (30 and 15 s) was best described by linear function (R² ≥ 0.96; SEE ≤ 272 mL·min^-1; p < 0.001), while the V̇O₂ data could not be modelled for sprints performed above the P-vLa_BP (10 and 5 s).</p><p><strong>Conclusion: </strong>The present study demonstrated that the P-vLa_BP separates ranges of power outputs with discrete V̇O₂ kinetics which are characteristic of different subzones within the extreme intensity exercise domain.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5225-5234"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13633953/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148344372","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":"Correction to: Glycolysis and oxidative phosphorylation as a function of cytosolic phosphorylation state and power output of the muscle cell.","authors":"Alois Mader","doi":"10.1007/s00421-026-06316-4","DOIUrl":"10.1007/s00421-026-06316-4","url":null,"abstract":"","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5703"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148727717","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":"Moderate altitude-mimicking CO-induced inhibition of hemoglobin oxygen binding decreased middle-distance swimming speed in male national-level swimmers.","authors":"Tomas Venckunas, Justas Achramavicius, Hakan Westerblad, Viktorija Maconyte, Ilona Judita Zuoziene, Inga Pravdinskiene, Carsten Lundby, Arvydas Stasiulis","doi":"10.1007/s00421-026-06339-x","DOIUrl":"10.1007/s00421-026-06339-x","url":null,"abstract":"<p><strong>Purpose: </strong>Performance in endurance sports is generally linked to aerobic capacity, but this link is less clear in swimming due to its technical complexity and constricted breathing periods. Here, we studied the effect of a moderate acute reduction in blood oxygen transport capacity on middle-distance swimming performance.</p><p><strong>Methods: </strong>In a double-blind, randomized crossover design, national-level swimmers (6 men, 6 women; 20 ± 2 years; FINA score 604 ± 105) completed two 200 m front crawl swimming time-trials (TT) on average six days apart, either 30 min after rebreathing moderate (men: 1.5 ml·kg^- 1, women: 1.2 ml·kg^- 1; CO) or small (SHAM) CO dose. Capillary blood lactate and hemoglobin CO binding (%HbCO) were measured before and after the TT.</p><p><strong>Results: </strong>HbCO was ~ 9% in CO and ~ 3% in SHAM. Analysis at the group level showed 1.5 ± 1.6% longer TT times in CO than in SHAM in men (136.6 ± 6.5 vs. 134.5 ± 6.2 s; p = 0.018), whereas there was no significant difference in women. The average increase in blood lactate during TT (10.5-13.5 mmol·l^- 1) did not differ between conditions. Analysis at the individual level showed longer swimming TT times in the CO than in the SHAM condition (range: 1.1 to 5.0 s) in eight of the twelve participants.</p><p><strong>Conclusion: </strong>We observed a small negative effect of moderate acute hypoxemia on middle-distance swimming speed in male national-level swimmers, which will have a limited impact on a population basis but can be highly important for an individual competitive swimmer.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5533-5542"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148374953","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 differences in NIRS-derived reactive hyperemia across protocols and their association with muscle quality.","authors":"Olavo João Frederico Ramos, Natália Soares Veiga, Paola Quevedo da Costa, Maria Clara Ramos Souza Rodrigues, Paulo Cavalheiro Schenkel, Rogerio Nogueira Soares, Thiago Silveira Alvares","doi":"10.1007/s00421-026-06303-9","DOIUrl":"10.1007/s00421-026-06303-9","url":null,"abstract":"<p><strong>Introduction: </strong>Sex-related differences in microvascular reactivity may be influenced by the magnitude of muscle desaturation (ischemic stimulus) during the blood flow occlusion period. Thus, this study used near-infrared spectroscopy (NIRS) to assess skeletal muscle microvascular reactivity in three distinct metabolic and mechanical conditions.</p><p><strong>Methods: </strong>Nineteen participants (10 males, 9 females) completed a randomized parallel design including a vascular occlusion test (VOT), maximal voluntary isometric contraction (MVIC), and a dynamic fatigue exercise protocol (FEx) to elicit ischemic, mechanic and metabolic insults, respectively. Morphological muscle quality was also assessed using ultrasonography. NIRS-derived indices of tissue oxygenation and blood volume were continuously monitored.</p><p><strong>Results: </strong>Males exhibited a greater post-exercise total hemoglobin reperfusion slope ([tHb] slope) across protocols compared with females (p < 0.05). In males, higher morphological muscle quality was associated with a steeper reperfusion slope (p < 0.05), whereas no such relationships were observed in females.</p><p><strong>Conclusion: </strong>Sex differences in microvascular reactivity were evident across ischemic, isometric, and dynamic exercise conditions, with oxygen extraction only partially accounting for sex differences in microvascular reactivity in highly metabolic demand condition such as FEx. Our findings also suggest that the greater microvascular reactivity in males may be linked to better morphological muscle quality compared to females, thus providing novel insights into the mechanisms driving the accelerated reperfusion rates observed in males compared to females.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5253-5263"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148344387","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":"Surface electromyographic analysis of the rectus abdominis during trunk-flexed and sustained forced expirations.","authors":"Kentaro Chino, Toshiyuki Ohya","doi":"10.1007/s00421-026-06322-6","DOIUrl":"10.1007/s00421-026-06322-6","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate rectus abdominis (RA) activity during forced expiration under conditions where RA activity is assumed to be prominent, including trunk flexion and sustained expiration.</p><p><strong>Methods: </strong>Fourteen males performed maximal voluntary forced expirations sustained from total lung capacity (TLC) to residual volume with and without slow trunk flexion. Maximal voluntary forced expiration from TLC with rapid trunk flexion was also performed as a single effort. As a reflexive forced expiration, sneezing was performed. Submaximal sustained expirations at 20, 30, and 50% of maximal expiratory mouth pressure were also conducted. During voluntary expirations, mouth pressure was measured using a mouth pressure meter. During all tasks, EMG activity of the RA and internal oblique/transversus abdominis (IO/TrA) were measured using surface electromyography.</p><p><strong>Results: </strong>RA activity during maximal voluntary forced expiration did not change with slow trunk flexion but increased with rapid trunk flexion; however, neither condition increased expiratory mouth pressure. RA activity was significantly lower than IO/TrA activity during maximal voluntary forced expirations with and without trunk flexion, but did not differ significantly from IO/TrA activity during sneezing. During maximal voluntary sustained expiration, RA activity increased without trunk flexion but decreased with trunk flexion. RA activity increased during submaximal voluntary sustained expirations at all mouth pressure levels, but the magnitude of the increase was smaller than that of the OI/TrA.</p><p><strong>Conclusion: </strong>The RA was less active and less responsive during voluntary forced expiration than the other abdominal muscles, whereas it appeared to be similarly active and responsive during reflexive forced expiration.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5421-5436"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148344285","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}