European Journal of Applied Physiology最新文献

{"title":"Concurrent training effects on H reflex, V wave and contractile properties of the plantar flexors: insights into different resistance training types.","authors":"Miguel Gomes, André Gonçalves, Pedro Pezarat-Correia, Goncalo V Mendonca","doi":"10.1007/s00421-025-05775-5","DOIUrl":"https://doi.org/10.1007/s00421-025-05775-5","url":null,"abstract":"<p><strong>Purpose: </strong>This study explored neuromuscular adaptations following 11 weeks of concurrent training (CT) compared to resistance-only (R) and endurance-only (E) in trained men.</p><p><strong>Methods: </strong>Thirty participants were randomized into three groups (E, R, CT), training three times per week. Neuromuscular assessments involved plantar-flexion maximal voluntary isometric contraction (MVIC), rate of torque development (RTD), evoked potentials (H reflex and V wave) and contractile properties at baseline, mid-training (week 5), and post-training. Resistance training for R and CT groups involved two phases: weeks 1-5 (maximal strength development) and weeks 6-11 (explosive/reactive strength and muscle power development). Endurance training for the E and CT groups involved 30-min of running on the heavy-intensity domain.</p><p><strong>Results: </strong>MVIC increased similarly in the R and CT groups. The R group significantly improved peak and sequential RTD, soleus electromyographic (EMG) activity, V wave and contractile properties. Conversely, the CT group exhibited an interference effect during the first phase with no improvements in RTD or neuromuscular parameters. During the second phase, the CT group exhibited significant enhancements in sequential RTD, soleus EMG activity, H- and V-wave amplitude. The improvements in the E group were limited to H-reflex excitability.</p><p><strong>Conclusion: </strong>These findings suggest that the magnitude of CT interference is modulated by the focus of resistance training (maximal vs explosive strength) being performed. However, it is relevant to note that contractile impairments seem to persist, likely due to endurance training in the heavy-intensity domain.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143779455","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":"Complications of applying approximate entropy to heart rate variability to locate optimal complexity in children with attention deficit hyperactivity disorder.","authors":"David M Garner, Tatiana Dias de Carvalho, Rubens Wajnsztejn, Luiz Carlos Marques Vanderlei, Vitor Engracia Valenti, Luiz Carlos de Abreu, Rodrigo Daminello Raimundo","doi":"10.1007/s00421-025-05774-6","DOIUrl":"https://doi.org/10.1007/s00421-025-05774-6","url":null,"abstract":"<p><strong>Introduction: </strong>The aim is to scrutinize approximate entropy (ApEn) to distinguish optimal complexity of heart rate variability (HRV) in children diagnosed with attention deficit hyperactivity disorder (ADHD). This was accomplished by varying their embedding dimension m and tolerance r. Determination of optimal m and r is heuristic. ApEn was enforced in ADHD to assess its effects on the HRV chaotic response.</p><p><strong>Methods: </strong>We studied 56 children divided equally into two groups: ADHD and control. Autonomic modulation of the heart rate was monitored for 20 min in the supine position without any physical, sensory or pharmacological stimuli. ApEn initially had r: 0.1 → 1.0 in 0.1 intervals and m: 1 → 10 in intervals of 1. The statistical significances were measured by three effect sizes: Cohen's d, Hedges' g and Glass's Δ.</p><p><strong>Results: </strong>Those most statistically important were for r = 0.9334, and m = 1, 2 and 3. Cohen's d (1.1277; m = 2) and Hedges' g (1.1119; m = 2) are the most reliable effect sizes. Glass's Δ (1.3724; m = 1) is unfortunately less reliable. ROC curve analysis shows AUC > 0.77 for r = 0.9334 and m = 1, 2, and 3.</p><p><strong>Conclusion: </strong>ApEn recognized the increased chaotic response in ADHD. This was confirmed by three effect sizes, AUC and p value during ROC analysis. Still, ApEn is an unreliable mathematical marker. ADHD discrimination was only achieved by extending the surveillance ranges for r; 0.8 → 1.0 and m; 1 → 3 at intervals of 0.0167. This necessitates an 'a priori' study making it inapt for online analysis. Even so, it could be useful in 'post hoc' analysis.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143771640","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":"Inspiratory effort increases blood volume in the thoracic cavity and decreases end-expiratory lung impedance: a preliminary prospective study.","authors":"Kazuhiro Takahashi, Ayaka Koyama, Daisuke Irimada, Akihiro Kanaya, Daisuke Konno, Yu Kaiho, Yusuke Takei, Kazutomo Saito, Yutaka Ejima, Masanori Yamauchi","doi":"10.1007/s00421-025-05767-5","DOIUrl":"https://doi.org/10.1007/s00421-025-05767-5","url":null,"abstract":"<p><strong>Purpose: </strong>Passive leg raising (PLR) increases intrathoracic blood volume by redistributing blood from the lower to the upper body area. While inspiratory effort is hypothesized to have a similar effect due to pressure differences between the intrathoracic and extrathoracic cavities, direct evidence is scarce. Therefore, this study evaluated whether excessive inspiratory effort increases intrathoracic blood volume using end-expiratory lung impedance (EELI).</p><p><strong>Methods: </strong>Volunteers, fitted with electrical impedance tomography (EIT) belts, underwent a spontaneous breathing procedure in the supine position (control step). They breathed through a specialized face mask with separated inspiration and expiration routes (one-way valves) and their EELI was continuously recorded. First, PLR was performed. Subsequently, resistors (3-mm and 2-mm) were sequentially added to the mask's inspiration route, requiring volunteers to increase inspiratory effort. A reference EELI was established during spontaneous breathing, and changes in EELI (ΔEELI) were calculated for each step (control, PLR, 3-mm, and 2-mm). ΔEELI values were compared using the Friedman test and Wilcoxon signed-rank test with Holm's P value adjustment.</p><p><strong>Results: </strong>Across 11 participants, the mean ΔEELI decreased by 13, 18, and 19 units for PLR, 3-mm, and 2-mm resistors, respectively. The Friedman test and Wilcoxon signed-rank test revealed significant differences between the control and each aforementioned intervention.</p><p><strong>Conclusion: </strong>PLR and increased inspiratory effort augment thoracic blood volume, thereby reducing EELI.</p><p><strong>Registration: </strong>UMIN000054238. April/23/2024.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143779461","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 combined effects of artificial gravity, temperature, and hypoxia on haemodynamic responses and limb blood flow.","authors":"Jason T Fisher, Urša Ciuha, Pierre Denise, Adam C McDonnell, Hervé Normand, Igor B Mekjavic","doi":"10.1007/s00421-025-05773-7","DOIUrl":"https://doi.org/10.1007/s00421-025-05773-7","url":null,"abstract":"<p><p>Under simultaneous environmental and gravitational stressors, integrated vascular responses maintain homeostatic balance via coordinated baro- and thermo-regulatory action. The effect of temperature and hypoxia at an elevated gravitational vector on the interaction of these systems was examined. Ten male participants experienced either cool (18.4 °C) or warm (29.1 °C) ambient temperatures in normoxia (partial pressure of oxygen, P_IO₂ = 133 mmHg) or hypoxia (P_IO₂ = 92 mmHg). Cardiovascular (heart rate, HR; arterial pressure, MAP; cardiac output, CO; stroke volume, SV; skin blood flow, SkBF) and thermoregulatory (skin temperature; core temperature) responses were monitored during standing (NG), and supine centrifugation at ground reaction forces (GRF) measured with a force platform at 1GRF and 2GRF. At 2GRF, warm and hypoxic conditions reduced the test duration by 16%. No differences were observed between NG and 1GRF in any variable; however, 2GRF significantly raised HR by 29.3% and MAP by 12.6%, and lowered SV by 22.2%. Warm condition significantly increased HR, and significantly decreased MAP and SV compared to the cool condition, by 17.8%, 6.1%, and 5.8%, respectively. Hypoxia had no effect on any variable. Arm SkBF significantly decreased by 33.3% with increasing artificial gravity, whereas leg SkBF increased by 38.7%. Higher ambient temperatures had no effect on leg SkBF, but significantly increased arm SkBF by 38.7%. Human tolerance to passive centrifugation is significantly lower at 2GRF, and further affected by the ambient conditions. Haemodynamic and leg SkBF responses in higher temperature and Gz conditions were frequently unable to prevent pre-syncopal symptoms. Finally, arm SkBF was modulated by both baroreflex and thermoregulation, and the baroreflex alone in leg SkBF.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143763467","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":"Multidirectional effect of low-intensity neuromuscular electrical stimulation on gene expression and phenotype in thigh and calf muscles after one week of disuse.","authors":"Anna A Borzykh, Roman Y Zhedyaev, Ivan I Ponomarev, Tatiana F Vepkhvadze, Viktor G Zgoda, Mira A Orlova, Nikita E Vavilov, Nikita V Shishkin, Egor M Lednev, Pavel A Makhnovskii, Kristina A Sharlo, Anastasia R Babkova, Galina Yu Vassilieva, Rinat R Gimadiev, Boris S Shenkman, Ilya V Rukavishnikov, Oleg I Orlov, Elena S Tomilovskaya, Daniil V Popov","doi":"10.1007/s00421-025-05761-x","DOIUrl":"https://doi.org/10.1007/s00421-025-05761-x","url":null,"abstract":"<p><strong>Purpose: </strong>This study investigated the effects of a one-week disuse, both with and without low-intensity neuromuscular electrical stimulation-a safe (non-traumatic) approach to prevent the loss of muscle mass, on the functional capacities and gene expression in thigh and calf muscles.</p><p><strong>Methods: </strong>This study assessed the efficiency of low-intensity (~ 10% of maximal voluntary contraction) electrical stimulation in preventing the negative effects of 7-day disuse (dry immersion without and with daily stimulation) on the strength and aerobic performance of the ankle plantar flexors and knee extensors, mitochondrial function in permeabilized muscle fibers, and the proteomic (quantitative mass spectrometry-based analysis) and transcriptomic (RNA-sequencing) profiles of the soleus muscle and vastus lateralis muscle.</p><p><strong>Results: </strong>Application of electrical stimulation during dry immersion prevented a decrease in the maximal strength and a slight reduction in aerobic performance of the knee extensors, as well as a decrease in maximal (intrinsic) ADP-stimulated mitochondrial respiration and changes in the expression of genes encoding mitochondrial, extracellular matrix, and membrane proteins in the vastus lateralis muscle. In contrast, for the ankle plantar flexors/soleus muscle, electrical stimulation had a positive effect only on maximal mitochondrial respiration, but slightly accelerated the decline in the maximal strength and muscle fiber cross-sectional area, which appears to be related to the activation of inflammatory genes.</p><p><strong>Conclusion: </strong>The data obtained open up broad prospects for the use of low-intensity electrical stimulation to prevent the negative effects of disuse for \"mixed\" muscles, meanwhile, the optimization of the stimulation protocol is required for \"slow\" muscles.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143763419","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":"Neuromuscular fatigability is not affected by the contraction pattern of exercises with a similar mean torque.","authors":"Loïc Lebesque, Gil Scaglioni, Patrick Manckoundia, Alain Martin","doi":"10.1007/s00421-024-05660-7","DOIUrl":"10.1007/s00421-024-05660-7","url":null,"abstract":"<p><strong>Purpose: </strong>Neuromuscular fatigability is task-dependent, but the influence of the contraction pattern on neuromuscular fatigability is largely unknown. Therefore, the present study aims to investigate if neuromuscular fatigability is affected by the contraction pattern of exhausting isometric exercises.</p><p><strong>Methods: </strong>Thirteen participants sustained a plantar flexors MVC for 1 min (MVC_1-MIN) before and after exhausting exercises designed to produce a similar mean torque (30% MVC), and following a 10-min rest period. Exercises consisted of intermittent (INT), continuous (CON) or variable (continuous contraction alternating between moderate and low intensity, VAR) contractions performed until task failure.</p><p><strong>Results: </strong>The INT resulted in greater exercise duration and torque-time integral than CON and VAR. MVC similarly decreased after all exercises due to neural and muscular impairments. The torque loss during the MVC_1-MIN increased after all exercises to a similar extent, mainly because of neural alterations. Contrary to MVC, the torque loss during the MVC_1-MIN returned to baseline value after the recovery period.</p><p><strong>Conclusion: </strong>INT, CON and VAR exercises, performed with identical mean torque and until exhaustion, led to a similar neuromuscular fatigability. When the mean torque is matched among exercises, the contraction pattern does not influence the extent of neuromuscular fatigability, assessed through the maximal torque production and sustainability. The present findings are crucial to consider for the management of neuromuscular fatigability in physical conditioning in both athletes and patients.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"1115-1127"},"PeriodicalIF":2.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142715611","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":"Vigorous intensity heart rate-clamp exercise does not elicit recommended oxygen consumption rates.","authors":"Clara J Mitchinson, Djadmann Gustave, Pasquale J Succi, Brian Benitez, Minyoung Kwak, Haley C Bergstrom","doi":"10.1007/s00421-024-05665-2","DOIUrl":"10.1007/s00421-024-05665-2","url":null,"abstract":"<p><strong>Purpose: </strong>This study examined the power output adjustments and subsequent shifts in metabolic (V̇O₂) demands as well as minute ventilation ( <math> <msub><mover><mtext>V</mtext> <mo>˙</mo></mover> <mtext>E</mtext></msub> </math> ), respiratory rate (RR), and rating of perceived exertion (RPE) responses during vigorous intensity (77-95% HR_peak) heart rate (HR)-clamp cycle ergometry.</p><p><strong>Methods: </strong>Fifteen males (mean ± SD age = 25.9 ± 4.4 years) performed a graded exercise test to exhaustion to determine peak parameters and three, randomly ordered, HR-clamp trials to exhaustion, up to 60 min, at the lower (HR_L = 77% HR_peak), middle (HR_M = 86% HR_peak), and higher (HR_H = 95% HR_peak) end of the vigorous intensity range. Time course of changes were examined.</p><p><strong>Results: </strong>The times to exhaustion (T_lim) for the HR_L, HR_M, and HR_H trials were 56.05 ± 10.09, 44.22 ± 19.00, and 9.74 ± 7.54 min, respectively. There were significant decreases in power output, <math> <msub> <mrow><mover><mtext>V</mtext> <mo>˙</mo></mover> <mtext>O</mtext></mrow> <mn>2</mn></msub> </math> , and <math> <msub><mover><mtext>V</mtext> <mo>˙</mo></mover> <mtext>E</mtext></msub> </math> across time for each trial, but no changes in RR, and increases in RPE (p < 0.05). Responses were intensity specific for all variables such that mean values were lower for HR_L than HR_M, and HR_L and HR_M were lower than HR_H. The mean <math> <msub> <mrow><mover><mtext>V</mtext> <mo>˙</mo></mover> <mtext>O</mtext></mrow> <mn>2</mn></msub> </math> (HR_L = 56.7 ± 3.8, HR_M = 68.1 ± 4.3, and HR_H = 90.5 ± 3.3% <math> <msub> <mrow><mover><mtext>V</mtext> <mo>˙</mo></mover> <mtext>O</mtext></mrow> <mtext>2max</mtext></msub> </math> ) responses fell below the recommended <math> <msub> <mrow><mover><mtext>V</mtext> <mo>˙</mo></mover> <mtext>O</mtext></mrow> <mn>2</mn></msub> </math> range for vigorous exercise at 10%T_lim for HR_L, and at 90%T_lim for HR_M, but remained above the recommended V̇O₂ range for vigorous exercise until 70% of T_lim for HR_H.</p><p><strong>Conclusions: </strong>Only the HR_M trial met the current guidelines of a vigorous intensity <math> <msub> <mrow><mover><mtext>V</mtext> <mo>˙</mo></mover> <mtext>O</mtext></mrow> <mn>2</mn></msub> </math> sustained for at least 20 min. This study indicated that HR-clamp exercise cannot be consistently used to prescribe a desired metabolic stimulus for exercise performed in a single session.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"1205-1218"},"PeriodicalIF":2.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142767013","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":"Alterations in magnitude and spatial distribution of erector spinae muscle activity in cyclists with a recent history of low back pain.","authors":"Alessandro Sampieri, Giuseppe Marcolin, Federico Gennaro, Emanuele Magistrelli, Alessandro Del Vecchio, Tatiana Moro, Antonio Paoli, Andrea Casolo","doi":"10.1007/s00421-024-05628-7","DOIUrl":"10.1007/s00421-024-05628-7","url":null,"abstract":"<p><strong>Purpose: </strong>While cycling offers several health benefits, repetitive loading and maintenance of static postures for prolonged periods expose cyclists to low back pain (LBP). Despite high LBP prevalence in cyclists, underlying pathomechanics and specific lumbar region muscle activation patterns during cycling are unclear. Here, we compared lumbar erector spinae (ES) muscles activation and spatial distribution activity in cyclists with and without recent LBP history.</p><p><strong>Methods: </strong>Ten cyclists with recent LBP history (LBPG; Oswestry Disability Index score ~ 17.8%) and 11 healthy cyclists (CG) were recruited. After assessing the Functional Threshold Power (FTP), participants underwent an incremental cycling test with 4 × 3 min steps at 70%, 80%, 90%, and 100% of their FTP. High-density surface electromyography (HDsEMG) signals were recorded from both lumbar ES using two 64-channel grids. Information about ES activation levels (root-mean-square, RMS), degree of homogeneity (entropy), and cranio-caudal displacement of muscle activity (Y-axis coordinate of the barycenter of RMS maps) was extracted from each grid separately and then grand-averaged across both grids.</p><p><strong>Results: </strong>Repeated-measure 2-way ANOVAs showed a significant intensity by group interaction for RMS amplitude (p = 0.003), entropy (p = 0.038), and Y-bar displacement (p = 0.033). LBPG increased RMS amplitude between 70-100% (+ 19%, p = 0.010) and 80-100% FTP (+ 21%, p = 0.004) and decreased entropy between 70-100% FTP (- 8.4%, p = 0.003) and 80-100% FTP (- 8.5%, p = 0.002). Between-group differences emerged only at 100% FTP (+ 9.6%, p = 0.049) for RMS amplitude.</p><p><strong>Conclusion: </strong>Our findings suggest that cyclists with recent LBP history exhibit higher ES muscles activation and less homogeneous activity compared to healthy controls, suggesting potential inefficient muscle recruitment strategy.</p><p><strong>Trial registration number: </strong>HEC-DSB/09-2023.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"967-976"},"PeriodicalIF":2.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11950058/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142371360","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":"Enhancing endurance performance predictions: the role of movement velocity in metabolic simulations demonstrated by cycling cadence.","authors":"Anna Katharina Dunst, Clemens Hesse, Olaf Ueberschär","doi":"10.1007/s00421-024-05663-4","DOIUrl":"10.1007/s00421-024-05663-4","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Mader's mathematical model, widely employed for endurance performance prediction, aims to accurately represent metabolic response to exercise. However, it traditionally overlooks dynamic changes in metabolic processes at varying movement velocities.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;This narrative review examined the effect of cycling cadence on its key input parameters, including oxygen demand per Watt ( &lt;math&gt;&lt;msub&gt;&lt;mtext&gt;CE&lt;/mtext&gt; &lt;mrow&gt;&lt;mover&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mo&gt;˙&lt;/mo&gt;&lt;/mover&gt; &lt;mtext&gt;O2&lt;/mtext&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/math&gt; ), resting oxygen uptake ( &lt;math&gt; &lt;mrow&gt;&lt;mover&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mo&gt;˙&lt;/mo&gt;&lt;/mover&gt; &lt;msub&gt;&lt;mtext&gt;O&lt;/mtext&gt; &lt;mtext&gt;2Base&lt;/mtext&gt;&lt;/msub&gt; &lt;/mrow&gt; &lt;/math&gt; ), maximal oxygen uptake ( &lt;math&gt; &lt;mrow&gt;&lt;mover&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mo&gt;˙&lt;/mo&gt;&lt;/mover&gt; &lt;msub&gt;&lt;mtext&gt;O&lt;/mtext&gt; &lt;mtext&gt;2max&lt;/mtext&gt;&lt;/msub&gt; &lt;/mrow&gt; &lt;/math&gt; ), and maximal blood lactate accumulation rate (vLa&lt;sub&gt;max&lt;/sub&gt;). These findings were integrated into the model to assess cadence-induced variations in predicted power output at maximal aerobic power (MAP), maximal lactate steady state (MLSS), and peak fat oxidation (FAT&lt;sub&gt;max&lt;/sub&gt;).&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;A U-shaped relationship was found between cadence and both &lt;math&gt;&lt;msub&gt;&lt;mtext&gt;CE&lt;/mtext&gt; &lt;mrow&gt;&lt;mover&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mo&gt;˙&lt;/mo&gt;&lt;/mover&gt; &lt;mtext&gt;O2&lt;/mtext&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/math&gt; and &lt;math&gt; &lt;mrow&gt;&lt;mover&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mo&gt;˙&lt;/mo&gt;&lt;/mover&gt; &lt;msub&gt;&lt;mtext&gt;O&lt;/mtext&gt; &lt;mtext&gt;2Base&lt;/mtext&gt;&lt;/msub&gt; &lt;/mrow&gt; &lt;/math&gt; , while &lt;math&gt; &lt;mrow&gt;&lt;mover&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mo&gt;˙&lt;/mo&gt;&lt;/mover&gt; &lt;msub&gt;&lt;mtext&gt;O&lt;/mtext&gt; &lt;mtext&gt;2max&lt;/mtext&gt;&lt;/msub&gt; &lt;/mrow&gt; &lt;/math&gt; remained largely cadence-independent within typical cadences. vLa&lt;sub&gt;max&lt;/sub&gt; exhibited a polynomial increase with cadence, attributed to changes in lactate elimination, suggesting cadence-independent maximal glycolytic flux. Incorporating these findings into Mader's model considering various scenarios revealed significant cadence-induced variations, with power output differences of up to &gt; 100 W. Using cadence-dependent &lt;math&gt;&lt;msub&gt;&lt;mtext&gt;CE&lt;/mtext&gt; &lt;mrow&gt;&lt;mover&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mo&gt;˙&lt;/mo&gt;&lt;/mover&gt; &lt;mtext&gt;O2&lt;/mtext&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/math&gt; and &lt;math&gt; &lt;mrow&gt;&lt;mover&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mo&gt;˙&lt;/mo&gt;&lt;/mover&gt; &lt;msub&gt;&lt;mtext&gt;O&lt;/mtext&gt; &lt;mtext&gt;2Base&lt;/mtext&gt;&lt;/msub&gt; &lt;/mrow&gt; &lt;/math&gt; while maintaining constant &lt;math&gt; &lt;mrow&gt;&lt;mover&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mo&gt;˙&lt;/mo&gt;&lt;/mover&gt; &lt;msub&gt;&lt;mtext&gt;O&lt;/mtext&gt; &lt;mtext&gt;2max&lt;/mtext&gt;&lt;/msub&gt; &lt;/mrow&gt; &lt;/math&gt; and vLa&lt;sub&gt;max&lt;/sub&gt; yielded polynomial power output-cadence relationships, with optimal cadences of 84 rpm at MAP, 80 rpm at MLSS, and 70 rpm at FAT&lt;sub&gt;max&lt;/sub&gt;. Incorporating cadence-dependent vLa&lt;sub&gt;max&lt;/sub&gt; produced implausible results, supporting cadence-independent maximal glycolytic flux. A hypothesized cadence-dependent &lt;math&gt; &lt;mrow&gt;&lt;mover&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mo&gt;˙&lt;/mo&gt;&lt;/mover&gt; &lt;msub&gt;&lt;mtext&gt;O&lt;/mtext&gt; &lt;mtext&gt;2max&lt;/mtext&gt;&lt;/msub&gt; &lt;/mrow&gt; &lt;/math&gt; improved alignment between model predictions and empirical data.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;Negl","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"895-907"},"PeriodicalIF":2.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11950142/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143188867","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":"The impact of skinfold thickness and exercise intensity on the reliability of NIRS in the vastus lateralis.","authors":"Lena Stuer, Massimo Teso, Alessandro L Colosio, Maura Loi, Patrick Mucci, Silvia Pogliaghi, Jan Boone, Kevin Caen","doi":"10.1007/s00421-024-05654-5","DOIUrl":"10.1007/s00421-024-05654-5","url":null,"abstract":"<p><strong>Purpose: </strong>The aims of this study were (1) to assess the test-retest reliability of the primary near infrared spectroscopy (NIRS) variables (i.e., StO₂, T[Hb], [HbO₂] and [HHb]) during cycling and (2) to investigate potential influences of exercise intensity and adipose tissue thickness (ATT) on this reliability.</p><p><strong>Methods: </strong>21 men and 20 women completed twelve constant work rate tests (6 min) at six different exercise intensities with each intensity performed twice. NIRS variables were measured at the vastus lateralis. The coefficient of variance (CV%), the intraclass correlation coefficient (ICC), mean bias and limits of agreement (LoA) were determined for reliability purposes.</p><p><strong>Results: </strong>The reliability of baseline values were acceptable to very good (CV% range: 5.83 - 21.96%). The reliability of end-values (CV% range: 0.02 - 25.02%, ICC range: 0.0 - 0.935) and amplitudes (CV% range: 0.46 - 5099%, ICC range: 0.0 - 0.887) were more variable. In general, the mean biases of end-values and amplitudes showed wide limits of agreement. A homogeneous influence of exercise intensity on reliability could not be established but reliability measures appeared to be lower in people with a lower skinfold thickness. Moreover, the NIRS signals decreased with increasing ATT but stabilized upon reaching a cut-off of 8 mm ATT. In addition, ATT did have a significant influence on [HHb] amplitude. In participants with ATT < 8 mm, higher amplitudes were observed with increasing intensity whereas in participants with ATT > 8 mm, there were no differences between the intensities.</p><p><strong>Conclusion: </strong>The study reveals variable results with regards to reliability and there was no consistent influence of exercise intensity on reliability. Participants with a lower skinfold thickness showed stronger reliability. Moreover, NIRS signals decrease when ATT exceeds 8 mm. Careful consideration is necessary when interpreting NIRS signals in such cases.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"1061-1073"},"PeriodicalIF":2.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142686316","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}