European Journal of Applied Physiology最新文献

{"title":"A new approach to haemoglobin oxygen affinity research at high altitude: Determination of haemoglobin oxygen dissociation curves and 2,3-bisphosphoglycerate in an experimental human crossover hypoxic chamber study.","authors":"Simon Woyke, Herbert Oberacher, David Plunser, Christoph Siebenmann, Rachel Turner, Ivo B Regli, Maja Schlittler, Giacomo Strapazzon, Hermann Brugger, Mathias Ströhle, Thomas Haller, Hannes Gatterer","doi":"10.1007/s00421-025-05806-1","DOIUrl":"https://doi.org/10.1007/s00421-025-05806-1","url":null,"abstract":"<p><strong>Purpose: </strong>During rapid exposure to hypobaric hypoxia (HH), arterial oxygen tension and haemoglobin oxygen saturation decrease. The oxygen dissociation curve (ODC) describes the relationship of oxygen tension and haemoglobin oxygen saturation. Previous methods for ODC determination are mostly limited to standard conditions (40 mmHg PCO₂, 37 °C), and measurements of 2,3-bisphosphoglycerate (2,3-BPG) and adenosine triphosphate (ATP) are omitted. This study aimed to investigate hypoxia-induced changes on the ODC in a strictly controlled hypobaric chamber setting utilising a novel method for ODC determination, incorporating innovative 2,3-BPG and ATP measurements.</p><p><strong>Methods: </strong>In a randomised crossover design, ten healthy males completed two 4-day sojourns, one in HH (3,500 m) and one in normoxia (NX, 262 m). ODCs were determined from venous blood at 96 h using a highly customisable high-throughput microplate reader method. Haemoglobin half saturation pressure (P50) was measured for a standardised CO₂ tension of 40 mmHg (P50_st) and individual end-tidal CO₂ tensions (P_etCO₂) (P50_act). 2,3-BPG and ATP were determined by liquid chromatography-tandem mass spectrometry.</p><p><strong>Results: </strong>P50_st were increased in HH compared to NX but missed statistical significance (28.3 ± 2.0 mmHg vs. 26.8 ± 1.9 mmHg; p = 0.054), whilst P50_act was similar in HH and NX (26.4 ± 1.6 mmHg vs. 26.1 ± 2.7 mmHg; p = 0.360) despite reduced P_etCO₂ (31.0 ± 2.1 mmHg vs. 38.4 ± 2.5 mmHg; p < 0.001). 2,3-BPG and pH were significantly increased in HH compared to NX (16.8 ± 1.6 µmol/gHb and 20.5 ± 1.1 µmol/gHb, p < 0.001; 7.36 ± 0.01 versus 7.39 ± 0.02, p < 0.001).</p><p><strong>Conclusion: </strong>The 2,3-BPG increase after 96 h in HH compensates the effect of hypoxia-induced decrease in P_etCO₂/increase in pH on the ODC.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143993330","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":"Influence of local temperature on motor unit behavior during rapid contractions in humans.","authors":"Kazutaka Ota, Hikaru Yokoyama, Kazushige Sasaki","doi":"10.1007/s00421-025-05796-0","DOIUrl":"https://doi.org/10.1007/s00421-025-05796-0","url":null,"abstract":"<p><strong>Purpose: </strong>The rate of torque development (RTD) is temperature dependent, but the temperature effects on motor unit behavior during rapid contractions remain largely unknown. This study aimed to clarify the influence of local limb temperature on motor unit behavior and RTD during rapid contractions in humans.</p><p><strong>Methods: </strong>Ten healthy male participants rested in a sitting position while immersing their right lower leg in water at different temperatures (Hot: ~43 °C, Neutral: ~33 °C, and Cold: ~10 °C) for 20 min each. The participants then completed a series of voluntary isometric contractions of dorsiflexors while maintaining water immersion in each temperature condition. Specifically, they were instructed to perform two maximal voluntary contractions (MVC) followed by six rapid-hold contractions. High-density surface electromyography was recorded from the tibialis anterior muscle and decomposed into individual motor unit spike trains.</p><p><strong>Results: </strong>We found that the late RTD (from 0 to 150 ms after the torque onset) was significantly lower in Cold than in the other conditions even when normalized by MVC torque. The motor unit discharge rate at recruitment was significantly higher in Cold (51.4 ± 4.1 pps) than in Hot (42.0 ± 3.8 pps), while the recruitment threshold decreased with the temperature (Cold: 23.9 ± 2.7%, Neutral: 29.2 ± 2.5%, Hot: 36.2 ± 2.4% of MVC). The temperature-induced changes in the late RTD were significantly related to the changes in recruitment time and recruitment threshold.</p><p><strong>Conclusion: </strong>These findings suggest that local cooling induces earlier motor unit recruitment and higher discharge rate, mitigating the decrease in RTD.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143958028","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":"Football (soccer) match-derived hamstring muscles residual fatigue can be monitored using early rate of torque development.","authors":"Pedro L Cosio, Lia Moreno-Simonet, Daniel Fernández, Mario Lloret, Xavier Padulles, Josep M Padulles, Andreu Farran-Codina, Gil Rodas, Joan A Cadefau","doi":"10.1007/s00421-024-05694-x","DOIUrl":"10.1007/s00421-024-05694-x","url":null,"abstract":"<p><strong>Purpose: </strong>The aim of this study was to determine whether a soccer match affects the rapid force-generating capacity of the hamstring muscles, given their key role in both horizontal ground reaction force production during sprint biomechanics, and in the deceleration of the shank during the late swing phase, where rapid force production is essential owing to time constraints. Therefore, the research objective was to determine soccer match-induced hamstrings residual fatigue and recovery through rate of torque development (RTD) and associated biochemical parameters.</p><p><strong>Methods: </strong>The recovery kinetics of hamstrings RTD metrics by the 90°_hip:20°_knee test, together with serum biomarkers (creatine kinase, mitochondrial creatine kinase, transaminases, malondialdehyde, irisin), were assessed in 19 male, regional first-division soccer players (age = 20.9 ± 2.0 years, mass = 72.6 ± 11.9 kg, height = 175.9 ± 6.9 cm [mean ± SD]), before a soccer match (MD) and post-24 h (MD₊₁), post-48 h (MD₊₂) and post-72 h (MD₊₃), through a repeated measures design.</p><p><strong>Results: </strong>Early RTD to 50 ms (p < 0.001, g = -1.24) and 100 ms (p < 0.001, g = -1.06) remained unrecovered on MD₊₃ in both hamstring muscles. However, maximal voluntary isometric contraction (MVIC) torque of the dominant and non-dominant hamstrings was unrecovered on MD₊₂ (p = 0.004, g = -0.91; and p = 0.002, g = -0.98, respectively) and recovered on MD₊₃ (p = 0.057 and p = 0.070, respectively). Further, neuromuscular deficits were coupled with myocyte structural (p = 0.002, g = 1.11) and mitochondrial damage (p = 0.004, g = 0.92) biomarkers.</p><p><strong>Conclusion: </strong>Based in the findings, early RTD_0-50 and RTD_0-100 monitoring, through the 90°_hip:20°_knee IPC test, is a cost-effective method for assessing soccer match-induced hamstring muscles residual fatigue and recovery. Overall, soccer match-induced hamstring residual fatigue is not recovered within a 3-day recovery period. Practitioners can use rapid force production metrics through isometric assessments, providing a simple, non-exhaustive tool, for assessing residual fatigue status during congested competitive periods, to comprehensively balance muscle recovery with optimizing training.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"1449-1461"},"PeriodicalIF":2.8,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142893186","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 MDM2 SNP309 differentially impacts cardiorespiratory fitness in young healthy women and men.","authors":"Ghazal Haddadi, Brian Lam, Sokaina Akhtar, Loren Yavelberg, Veronica Jamnik, Emilie Roudier","doi":"10.1007/s00421-024-05682-1","DOIUrl":"10.1007/s00421-024-05682-1","url":null,"abstract":"<p><strong>Purpose: </strong>Maximal oxygen consumption (VO₂max), the predominant index of cardiorespiratory fitness (CRF), is a predictor of whole-body function and longevity in humans. The central cardiac function and the skeletal muscle's capacity to use oxygen are key determinants of VO₂max. Murine Double Minute 2 (MDM2), mainly known as an oncogene, could regulate myocardial hypertrophy, skeletal muscle angiogenesis, and oxidative phosphorylation. A prevalent single nucleotide polymorphism in the MDM2 promoter (SNP309) substitutes a T for a G, supporting a greater transcriptional activity. We aim to assess whether SNP309 impacts intrinsic CRF.</p><p><strong>Methods: </strong>82 young healthy nonathletic male and female adults aged 23 ± 2 years performed cardiorespiratory exercise testing to determine their VO₂max (mL kg^-1 min^-1). The genomic DNAs isolated from saliva were genotyped using Taqman-based qPCR.</p><p><strong>Results: </strong>A one-way ANOVA showed that SNP309 influenced relative VO₂max in the whole cohort (p = 0.044) and in men (p = 0.009), remaining non-significant in women (p = 0.133). VO₂max was higher in TT homozygotes than in GT heterozygotes (whole cohort, 47 ± 12 vs. 42 ± 6 mL kg^-1 min^-1, p = 0.030; men, 53 ± 8 vs. 45 ± 6 mL kg^-1 min^-1, p = 0.011). A contingency analysis revealed a positive association between SNP309 in men in which the TT genotype was more frequent in the high VO₂max group (p = 0.006). When considering G as the dominant allele, men bearing a G allele had lower relative VO₂max than TT homozygotes (47 ± 7 vs. 53 ± 8, GG/GT vs. TT, p = 0.010). Conversely, women bearing a G allele had a higher relative VO₂max than TT homozygotes (39 ± 5 vs. 34 ± 7, GG/GT vs. TT, p = 0.047).</p><p><strong>Conclusion: </strong>SNP309 impacts VO₂max in a sex-dependent manner in our cohort.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"1371-1383"},"PeriodicalIF":2.8,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142834705","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":"Is the cortisol awakening response truly a response to awakening? Replication and extension using overnight sampling.","authors":"Travis Anderson, Suzanne Vrshek-Schallhorn, Laurie Wideman","doi":"10.1007/s00421-024-05676-z","DOIUrl":"10.1007/s00421-024-05676-z","url":null,"abstract":"<p><p>The cortisol awakening response (CAR) is a discrete component of the circadian cortisol profile. Evidence suggests that the CAR is a deviation from the pre-awakening increase in cortisol concentration, although this has yet to be replicated. Therefore, the purpose of this study was to replicate this finding and to investigate further the extent to which the CAR is distinct from the circadian profile. Twelve participants completed 2 overnight visits in a sleep laboratory. An intravenous catheter was used to sample blood every 15 min. Participants were allowed to sleep ad libitum beginning at 2030 h, and blood sampling continued throughout the night until 1 h post-awakening, generating a total of 802 serum samples. Selected serum samples were assayed for cortisol, and piece-wise linear mixed-effect models tested the extent to which the increase in cortisol concentrations post-awakening deviated from the rise in cortisol concentrations from various pre-awakening periods. Results demonstrated that the CAR only significantly deviates from the pre-awakening rise when the pre-awakening linear rise is considered 4 (β = 1.79, 95% CI = 0.49-3.09, p = 0.007) or 5 (β = 1.79, 95% CI = 0.49-3.09, p = 0.007) h before waking. When including a non-linear change in cortisol during the 4-h pre-awakening period, the deviation from the diurnal profile for the CAR was no longer significant (β = 0.96, 95% CI = - 0.74-2.66, p = 0.266). These results partly agree and replicate previous evidence for the CAR being superimposed on the diurnal profile but continue to extend our teleological understanding of the functional role of the CAR.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"1475-1483"},"PeriodicalIF":2.8,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142921217","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":"Conceptualizing a load and volume autoregulation integrated velocity model to minimize neuromuscular fatigue and maximize neuromuscular adaptations in resistance training.","authors":"Landyn M Hickmott, Scotty J Butcher, Philip D Chilibeck","doi":"10.1007/s00421-025-05709-1","DOIUrl":"10.1007/s00421-025-05709-1","url":null,"abstract":"<p><p>Resistance training (RT) load and volume are considered crucial variables to appropriately prescribe and manage for eliciting the targeted acute responses (i.e., minimizing neuromuscular fatigue) and chronic adaptations (i.e., maximizing neuromuscular adaptations). In traditional RT contexts, load and volume are generally pre-prescribed; thereby, potentially yielding sub-optimal outcomes. A RT concept that individualizes programming is autoregulation: a systematic two-step feedback process involving, (1) monitoring performance and its constituents (fitness, fatigue, and readiness) across multiple time frames (short-, moderate-, and long-term); and (2) adjusting programming (i.e., load and volume) to elicit the targeted goals (i.e., responses and adaptations). A growing body of load and volume autoregulation research has accelerated recently, with several meta-analyses suggesting that autoregulation may provide a small advantage over traditional RT. Nonetheless, the existing literature has typically conceptualized these current autoregulation methods as standalone practices, which has limited their extensive utility in research and applied settings. The primary purpose of this review was three-fold. Initially, we synthesized the current methods of load and volume autoregulation, while disseminating each method's main advantages and limitations. Second, we conceptualized a theoretical Integrated Velocity Model (IVM) that integrates the current methods for a more holistic perspective of autoregulation that may potentially augment its benefits. Lastly, we illustrated how the IVM may be compared to the current methods for future directions and how it may be implemented for practical applications. We hope that this review assists to contextualize a novel autoregulation framework to help inform future investigations for researchers and practices for RT professionals.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"1221-1255"},"PeriodicalIF":2.8,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143037652","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":"Influence of body dimensions and sex on cold-induced vasodilation.","authors":"Rebecca S Weller, Jaro Govaerts, Rachel Akkermans, Douglas M Jones, Hein A Daanen","doi":"10.1007/s00421-024-05685-y","DOIUrl":"10.1007/s00421-024-05685-y","url":null,"abstract":"<p><p>Cold-induced vasodilation (CIVD) is a physiological response characterized by cyclic vasodilation occurring within 5-10 min of cold exposure, predominantly in the fingers and toes. This study aimed to determine the roles of body dimensions, specifically surface-to-mass (SM) ratio and sex in modulating CIVD responses. Thirty-nine participants (mean ± SD age: 24 ± 3 yr; height: 174 ± 28 cm; weight: 75.3 ± 15.2 kg; 20 males & 19 females) completed a 30-min immersion of the digits in ice water while sitting in a thermoneutral room (22 °C). Skin temperature was measured continuously on the anterior pads of the index, middle, ring, and little finger to assess CIVD parameters (onset time (t_onset), minimum finger temperature (T_min), maximum finger temperature (T_max), mean finger temperature (T_mean), and CIVD_waves). A negative relationship was observed between T_max and SM ratio (r =  - 0.39, p = 0.001) and T_mean and SM ratio (r =  - 0.32, p = 0.001), indicating that individuals with smaller SM ratios exhibited enhanced CIVD responses. A subgroup of 7 males and 7 females with identical anthropometrics from the original cohort showed no differences between any CIVD parameter: T_mean (Males: 8.0 ± 1.9 °C; Females: 8.9 ± 1.6 °C, p = 0.36), T_max (Males: 11.2 ± 3.1 °C; Females: 13.1 ± 1.2 °C, p = 0.16), T_min (Males: 5.9 ± 1.4 °C; Females: 5.0 ± 1.7 °C, p = 0.31), and t_onset (Males: 12.0 ± 4.4 min; Females: 9.6 ± 3.6 min, p = 0.28). Therefore, body dimensions seem to play a crucial role in modulating CIVD responses, whereas sex does not.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"1385-1393"},"PeriodicalIF":2.8,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142834702","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 effects, mechanisms and strategies of daytime napping on athletes: a narrative review.","authors":"Haitong Yu, Chengbo Yang, Chuanming Xu, Yan Zhuang","doi":"10.1007/s00421-025-05724-2","DOIUrl":"10.1007/s00421-025-05724-2","url":null,"abstract":"<p><p>Athletes generally suffer from insufficient sleep duration, lower sleep efficiency, and a high overall prevalence of insomnia. Daytime napping has been demonstrated to supplement nighttime sleep in athletes; however, recent controversial findings warrant further consideration. This review synthesized existing studies on the effects of daytime naps on athletes, explored potential mechanisms of daytime napping, and analyzed instances of ineffective interventions or negative outcomes. Daytime napping functions as a restorative strategy to counteract sleep deprivation or the post-lunch dip, assisting athletes in recovering anaerobic capacity, agility, reaction time, and alertness, with potential mechanisms including the reduction of sleepiness through adherence to circadian rhythms, decreased subjective soreness and fatigue attributed to autonomic functioning, and improved respiratory performance. The optimal nap period occurs between 13:00 and 15:00, with a 5-6 h interval between morning awakening and nap initiation. Depending on the athlete's nighttime sleep, opt for a 20 ~ 40 or 60 ~ 90 min nap with at least 60 min between the nap and subsequent exercise to reduce sleep inertia. The intervention efficacy of daytime napping was correlated with exercise intensity. A nap program must be developed based on the specific athletic demands of the sport in practical application.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"1257-1269"},"PeriodicalIF":2.8,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143373989","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":"<ArticleTitle xmlns:ns0=\"http://www.w3.org/1998/Math/MathML\">Exercise training-induced speeding of <ns0:math> <ns0:msub> <ns0:mrow><ns0:mover><ns0:mtext>V</ns0:mtext> <ns0:mo>˙</ns0:mo></ns0:mover> <ns0:mtext>O</ns0:mtext></ns0:mrow> <ns0:mn>2</ns0:mn></ns0:msub> </ns0:math> kinetics is not intensity domain-specific or correlated with indices of exercise performance.","authors":"Erin Calaine Inglis, Letizia Rasica, Danilo Iannetta, Kate M Sales, Daniel A Keir, Martin J MacInnis, Juan M Murias","doi":"10.1007/s00421-024-05674-1","DOIUrl":"10.1007/s00421-024-05674-1","url":null,"abstract":"<p><strong>Purpose: </strong>This study examined the effect of 3 and 6 weeks of intensity domain-based exercise training on <math> <msub> <mrow><mover><mtext>V</mtext> <mo>˙</mo></mover> <mtext>O</mtext></mrow> <mn>2</mn></msub> </math> kinetics changes and their relationship with indices of performance.</p><p><strong>Methods: </strong>Eighty-four young healthy participants (42 M, 42 F) were randomly assigned to six groups (14 participants each, age and sex-matched) consisting of: continuous cycling in the (1) moderate (MOD)-, (2) lower heavy (HVY1)-, and (3) upper heavy-intensity (HVY2)- domain; interval cycling in the (4) severe-intensity domain (i.e., high-intensity interval training (HIIT), or (5) extreme-intensity domain (i.e., sprint-interval training (SIT)); or (6) control (CON). Training participants completed two three-week phases of three supervised sessions per week, with physiological evaluations performed at PRE, MID and POST intervention. All training protocols, except SIT, were work-matched.</p><p><strong>Results: </strong>There was a significant time effect for the time constant ( <math><mrow><mi>τ</mi> <msub> <mrow><mover><mtext>V</mtext> <mo>˙</mo></mover> <mtext>O</mtext></mrow> <mn>2</mn></msub> </mrow> </math> ) between PRE (31.6 ± 10.4 s) and MID (22.6 ± 6.9 s) (p < 0.05) and PRE and POST (21.8 ± 6.3 s) (p < 0.05), but no difference between MID and POST (p > 0.05) and no group or interaction effects (p > 0.05). There were no PRE to POST differences for CON (p < 0.05) in any variables. Despite significant increases in maximal <math> <msub> <mrow><mover><mtext>V</mtext> <mo>˙</mo></mover> <mtext>O</mtext></mrow> <mn>2</mn></msub> </math> ( <math> <msub> <mrow><mover><mtext>V</mtext> <mo>˙</mo></mover> <mtext>O</mtext></mrow> <mtext>2max</mtext></msub> </math> ), estimated lactate threshold (θ_LT), maximal metabolic steady state (MMSS), and peak power output (PPO) for the intervention groups (p < 0.05), there were no significant correlations from PRE to MID or MID to POST between <math><mrow><mi>Δ</mi> <mi>τ</mi> <msub> <mrow><mover><mtext>V</mtext> <mo>˙</mo></mover> <mtext>O</mtext></mrow> <mn>2</mn></msub> </mrow> </math> and <math><mrow><mi>Δ</mi> <msub> <mrow><mover><mtext>V</mtext> <mo>˙</mo></mover> <mtext>O</mtext></mrow> <mtext>2max</mtext></msub> </mrow> </math> (r = - 0.221, r = 0.119), ΔPPO (r = - 0.112, r = - 0.017), Δθ_LT (r = 0.083, r = 0.142) and ΔMMSS (r = - 0.213, r = 0.049)(p > 0.05).</p><p><strong>Conclusion: </strong>This study demonstrated that (i) the rapid speeding of <math> <msub> <mrow><mover><mtext>V</mtext> <mo>˙</mo></mover> <mtext>O</mtext></mrow> <mn>2</mn></msub> </math> kinetics was not intensity-dependent; and (ii) changes in indices of performance were not significantly correlated with <math><mrow><mi>Δ</mi> <mi>τ</mi> <msub> <mrow><mover><mtext>V</mtext> <mo>˙</mo></mover> <mtext>O</mtext></mrow> <mn>2</mn></msub> </mrow> </math> .</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"1297-1310"},"PeriodicalIF":2.8,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12055666/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142784738","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":"Neuromuscular, cardiometabolic, and perceptual responses to a short sprint interval training session with different cycling torques.","authors":"José Riesco-Villar, Aarón Escribano-Pascual, Alejandro González-Fernández, Héctor Pascual-Redondo, Marina Gil-Calvo, Daniel Boullosa","doi":"10.1007/s00421-025-05794-2","DOIUrl":"https://doi.org/10.1007/s00421-025-05794-2","url":null,"abstract":"<p><strong>Purposes: </strong>Short sprint interval training (sSIT) can improve both aerobic and anaerobic indices through different protocol designs with sprinting bouts lasting ≤ 10 s. However, the limited available evidence does not allow the comprehensive understanding of the acute psycho-physiological effects of applying different torques during cycling sSIT protocols with very short, \"all out\" sprints. This study aims to evaluate the impact of high (HT) versus low (LT) torques on neuromuscular performance, cardiometabolic, and perceptual responses during a sSIT session of 5-s sprints.</p><p><strong>Methods: </strong>After familiarizations and determination of HT and LT with a graded sprinting test, 15 physically active individuals completed, in randomized order, 2 sSIT sessions (12, 5-s sprints on a cycle ergometer) with HT and LT. Mechanical (i.e., power, cadence, and rate of fatigue), physiological [i.e., surface electromyography (sEMG), oxygen consumption (VO₂), heart rate (HR), blood pressure (BP) and muscle oxygenation (SmO₂)], and perceptual parameters [i.e., rating of perceived exertion (RPE) and affective valence] were assessed during sessions and acute recovery.</p><p><strong>Results: </strong>Mean cadence and power, rate of fatigue, and RPE were higher in HT (p < 0.05), while time to peak power, sEMG amplitude, and affective valence were higher in LT (p < 0.05). Cardiometabolic parameters were similar during and after both protocols (p > 0.05).</p><p><strong>Conclusions: </strong>The manipulation of torque in a sSIT protocol with 5-s sprints promotes different neuromuscular and perceptual responses, but with no differences between conditions for cardiometabolic responses. These findings are relevant for designing sSIT protocols to adapt neuromuscular and perceptual loading based on targeted outcomes for specific populations.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143984561","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}