European Journal of Applied Physiology最新文献

{"title":"Effects of normobaric hypoxia and hyperthermia on ventilatory responses to high-intensity interval training bouts.","authors":"Michele Girardi, Andrea Nicolò, Samuele M Marcora, Ilenia Bazzucchi, Francesco Felici, John Dickinson, Massimo Sacchetti","doi":"10.1007/s00421-026-06334-2","DOIUrl":"10.1007/s00421-026-06334-2","url":null,"abstract":"<p><strong>Purpose: </strong>Respiratory frequency (f_R) and tidal volume (V_T) show distinct responses during high-intensity interval training (HIIT) bouts, yet the underlying mechanisms remain unclear. We investigated the effects of hypoxia and hyperthermia on ventilatory responses to HIIT bouts.</p><p><strong>Methods: </strong>Ten recreationally trained males (mean ± SD: peak oxygen uptake: 3.98 ± 0.62 L/min, age: 28 ± 6 years) performed the same HIIT protocol to exhaustion in three randomized conditions: normobaric hypoxia (HYP, 15% O₂), hyperthermia (HOT, 35 °C, 40% humidity), and control (CON, 18 °C and 40% humidity). Work-recovery phases (30-30 s) were performed at 109% of peak power output from a prior incremental test and 50 W, respectively.</p><p><strong>Results: </strong>Time-to-exhaustion (TTE) differed (P < 0.05) across CON (18.0 ± 4.4 min), HYP (9.4 ± 2.8 min), and HOT (12.6 ± 3.1 min) conditions. Iso-time f_R was associated with changes in TTE and positively correlated with perceived exertion (P < 0.001; r = 0.85) and aural temperature (P < 0.001; r = 0.58). On average, f_R increased during the work phase and decreased during recovery, primarily driving pulmonary ventilation ([Formula: see text]) during work-recovery alternations. Conversely, V_T showed a smaller and opposite response, with higher values during recovery. V_T plateaued in all conditions, but higher values were observed in HYP versus CON and HOT, accompanied by higher capillary blood lactate levels and lower blood oxygen saturation.</p><p><strong>Conclusions: </strong>f_R is associated with changes in exercise tolerance irrespective of the environmental conditions tested and is more closely related to perceived exertion than to aural temperature. f_R primarily drives the [Formula: see text] response to high-intensity work-recovery alternations, while V_T appears fine-tuned on f_R levels and the magnitude of metabolic inputs.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5379-5396"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148367609","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":"Low-intensity exercise reduces negative affect via circulating endocannabinoid dynamics in healthy young adults.","authors":"Tetsuya Yabe, Daisuke Ando, Katsuhiro Koyama","doi":"10.1007/s00421-026-06364-w","DOIUrl":"10.1007/s00421-026-06364-w","url":null,"abstract":"<p><strong>Purpose: </strong>Mental health disorders represent a critical challenge in modern society, necessitating the establishment of effective management strategies. Low-intensity exercise is thought to improve mood by activating endocannabinoids (eCBs), but the underlying mechanisms remain unclear. This study aimed to test the hypothesis that an increase in circulating eCB levels during low-intensity exercise contributes to a reduction in negative affect.</p><p><strong>Methods: </strong>In a randomized crossover trial, 30 healthy participants completed two 60-min cycling exercise sessions at two intensities: low (30% heart rate reserve [HRR]) and moderate (50% HRR). Plasma concentrations of N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG) were measured at four points: pre-exercise (baseline), during exercise (10 and 30 min), and immediately post-exercise (60 min). Mood was assessed before and after each session using the Physical Activity Affect Scale.</p><p><strong>Results: </strong>Plasma eCB concentrations did not change uniformly and showed substantial inter-individual variability in both conditions. Although low-intensity exercise significantly reduced negative affect, this change was not significantly correlated with the cumulative plasma AEA and 2-AG during the exercise. Notably, a repeated-measures correlation (rmcorr) revealed a significant negative correlation between plasma AEA concentrations and negative affect across pre- and post-exercise time points in the low-intensity condition.</p><p><strong>Conclusion: </strong>Low-intensity exercise improved negative affect despite inconsistent aggregate changes in eCBs, specifically AEA and 2-AG. Dynamic intra-individual changes in plasma AEA, rather than cumulative concentrations, appear to drive this mental health benefit. These findings suggest a novel mechanism implicating exercise-induced AEA dynamics in mental health improvement.</p><p><strong>Clinical trial registration: </strong>UMIN-CTR UMIN000060566, registered 4 February 2026, retrospectively registered.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5655-5663"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148561075","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 electrical stimulation with blood flow restriction shows preliminary effects on abductor hallucis muscle size and toe flexor strength: a pilot randomized controlled trial.","authors":"Kazunori Okamura, Shoma Uehara, Naotaka Nagamune, Shusaku Kanai","doi":"10.1007/s00421-026-06326-2","DOIUrl":"10.1007/s00421-026-06326-2","url":null,"abstract":"<p><strong>Purpose: </strong>To examine the effects of neuromuscular electrical stimulation (NMES) combined with blood flow restriction (BFR) on abductor hallucis (ABH) cross-sectional area (CSA) compared with NMES alone in a pilot randomized controlled trial. Toe flexor strength (TFS) and foot posture were also examined as secondary and exploratory outcomes, respectively.</p><p><strong>Methods: </strong>Thirty participants were randomly allocated to either an NMES + BFR group or an NMES-alone group. Both groups received 15 min of ABH NMES three times weekly for 6 weeks, while the NMES + BFR group additionally received BFR. ABH CSA, TFS, and Foot Posture Index-6 (FPI-6) scores were assessed pre- and post-intervention by a blinded assessor. Post-intervention between-group differences were analyzed using baseline-adjusted analysis of covariance.</p><p><strong>Results: </strong>The NMES + BFR group showed greater post-intervention ABH CSA than the NMES group (adjusted mean difference [95% confidence interval] = 0.19 [0.08-0.30] cm², p = 0.001). The between-group difference in TFS favored the NMES + BFR group but was not statistically significant (1.83 [- 0.09-3.75] kg, p = 0.061). Exploratory analysis showed lower post-intervention FPI-6 scores in the NMES + BFR group than in the NMES group (- 1.59 [- 2.46--0.72] points, p = 0.001). No adverse events or intolerance leading to discontinuation occurred.</p><p><strong>Conclusion: </strong>Six weeks of NMES combined with BFR showed preliminary favorable effects on ABH CSA compared with NMES alone, whereas evidence for superior improvement in TFS was inconclusive. All findings, including the exploratory foot posture results, require confirmation in larger studies with more complete intervention-dose reporting.</p><p><strong>Trial registration: </strong>Registration number (date): UMIN000054853 (August 1, 2024).</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5293-5301"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148344346","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":"Acute hemoglobin responses during bench press exercise across relative loads and sport backgrounds: a cross-sectional functional near-infrared spectroscopy study.","authors":"Toru Kosuge, Tadamitsu Matsuda, Susumu Yoshida, Kodai Sugawara, Hiroku Mitsuya, Takayoshi Hakkaku, Shogo Okamura, Toshihiko Hashimoto, Takashi Okada","doi":"10.1007/s00421-026-06333-3","DOIUrl":"10.1007/s00421-026-06333-3","url":null,"abstract":"<p><strong>Purpose: </strong>To compare acute hemoglobin responses during bench press (BP) exercise among bodybuilders (BB), powerlifters (PL), Paralympic powerlifters (PP), and untrained controls (CON), with emphasis on relative load and sport background.</p><p><strong>Methods: </strong>Thirty-eight participants (BB, n = 10; PL, n = 10; PP, n = 8; CON, n = 10) performed ten BP repetitions at 20%, 40%, and 60% of one-repetition maximum (1RM). Multichannel functional near-infrared spectroscopy (fNIRS) was used to assess oxygenated hemoglobin (O₂Hb), deoxygenated hemoglobin (HHb), and total hemoglobin (tHb) responses over the C3-Cz-C4 region. Linear mixed models were used to test the effects of group, condition, and their interactions.</p><p><strong>Results: </strong>The main effect of condition was significant for ΔO₂Hb in nine of ten channels and for ΔtHb in one channel (p_FDR_channel < 0.05). No group effects or group × condition interactions were observed for ΔO₂Hb, ΔHHb, or ΔtHb. Within-group post hoc analyses showed that ΔO₂Hb differences were observed mainly between 20 and 40% of 1RM (p_FDR_slice < 0.05), with fewer additional differences involving 60% of 1RM.</p><p><strong>Conclusion: </strong>Acute hemoglobin responses during BP were expressed primarily as ΔO₂Hb changes and were associated with relative load under the present low-to-moderate load conditions. Because group effects and group × condition interactions were not supported, these findings should be regarded as preliminary and descriptive rather than evidence of sport-specific adaptation or between-group differences in response magnitude. Observed O₂Hb changes represent regional hemodynamic responses, not direct measures of cortical activation or motor control processes.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5499-5519"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148351222","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 influence of mouth pressure on the cardiovascular response during inspiratory muscle loading at a constant transdiaphragmatic pressure.","authors":"Megan L Lance, Scott F Thrall, Benjamin P Thompson, Leah M Mann, Jou-Chung Chang, Katherine M Taylor, Nadia M Navarro Solano, Madison J Gorsline, Richard J A Wilson, Trevor A Day, Paolo B Dominelli, Glen E Foster","doi":"10.1007/s00421-026-06304-8","DOIUrl":"10.1007/s00421-026-06304-8","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate whether the cardiovascular response during inspiratory pressure-threshold loading (ITL) is augmented by higher mouth pressure (P_m) when transdiaphragmatic pressure is maintained, and whether greater negative intrathoracic pressure increases intra-breath fluctuations in mean arterial pressure (MAP).</p><p><strong>Methods: </strong>Sixteen healthy participants (6 females) completed two, 5-min ITL tasks while targeting a transdiaphragmatic pressure of 65 cmH₂O, breathing rate of 15 breaths/min, and duty cycle of 0.7. In one task, absolute P_m was low (20-30 cmH₂O; low P_m task), while in the other task it was higher (40-50 cmH₂O; high P_m task).</p><p><strong>Results: </strong>Both tasks resulted in an increase in heart rate (HR; low P_m: + 13 [95% Confidence Interval: 7,19] beats/min; high P_m: + 15 [9,21] beats/min; P < 0.0001] and MAP (low P_m: + 12 [5,19] mmHg; high P_m: + 11 [4,18] mmHg; P < 0.0001). For the high P_m task, the HR response was greater (+ 3 [2,5] beats/min; P < 0.0001), the MAP response was lower (-2 [-4,0] mmHg; P = 0.0209), and there was a greater inspiratory-expiratory MAP difference (P = 0.0009), compared to the low P_m task.</p><p><strong>Conclusion: </strong>Increasing P_m during ITL elicited a greater HR response and a blunted MAP response. The smaller changes in MAP during inspiration compared to expiration during the high compared to low P_m task may suggest an influence of negative intrathoracic pressure on cardiac loading. Future studies are required to determine how cardiac output changes with increases in P_m.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5155-5167"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148276554","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":"Linking the dietary inflammation index to sarcopenia in diabetes: mediation by body roundness index and evidence from complementary analyses.","authors":"Yang Yang, Ren-Hua Lv, Peng-Min Liu, Yan-Qiu Sun, Lu-Ping Wang, Yu Yu, Li-Mei Zhang, Xin-Yang Zhang","doi":"10.1007/s00421-026-06342-2","DOIUrl":"10.1007/s00421-026-06342-2","url":null,"abstract":"<p><strong>Background: </strong>This study investigates whether dietary inflammatory index (DII) is associated with sarcopenia risk in diabetes and the mediating role of body roundness index (BRI). Two-sample Mendelian randomization (MR) was additionally employed to provide genetic evidence complementing these relationships.</p><p><strong>Methods: </strong>Data from 2252 participants were sourced from the National Health and Nutrition Examination Survey. The DII was evaluated using a 24-hour dietary recall, whereas data for the sarcopenia index were acquired through dual-energy X-ray absorptiometry. Multivariate regression and mediation analysis examined associations. In parallel, these results were indirectly supported through two-sample MR analyses and animal experiments.</p><p><strong>Results: </strong>Adjusted logistic regression analysis indicates that a higher DII is significantly linked to an increased prevalence of sarcopenia as opposed to the lowest DII category (odds ratio [OR] = 1.97, 95% confidence interval [CI]: 1.37 to 2.82). A restricted cubic spline model revealed a positive linear relationship between DII and sarcopenia incidence in diabetics. BRI significantly mediated this association (P = 0.038), while BMI showed no significant mediation (P = 0.314). MR suggests anti-inflammatory foods (fruits, vegetables, vitamin C) protect against muscle loss, while saturated fatty acids accelerate it. Simultaneously, studies on animals demonstrated that a diet high in inflammatory foods leads to muscle deterioration.</p><p><strong>Conclusions: </strong>Higher DII scores correlated with increased sarcopenia risk in diabetes, a link partially mediated by BRI. Anti-inflammatory dietary components were protective; saturated fatty acids were associated with muscle loss. DII may help identify at-risk patients.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5553-5564"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148445177","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":"Intensity matters: high-intensity interval resistance exercise induces greater immune activation than low-intensity resistance exercise 45 min post-workout.","authors":"Fabian Fabritius, Matthias Rißmayer, Miriam Ringleb, Niklas Joisten, Wilhelm Bloch, Finn Dreisigacker, Florian Javelle","doi":"10.1007/s00421-026-06337-z","DOIUrl":"10.1007/s00421-026-06337-z","url":null,"abstract":"<p><strong>Purpose: </strong>Acute physical exercise triggers a transient immune response. For endurance exercise, these effects are intensity-dependent. In contrast, the role of exercise intensity in resistance exercise (RE) and its contribution to immune modulation remains less understood. This randomised crossover trial aims to compare the acute effects of High-Intensity Interval Resistance Exercise (HIIRE) versus Low-Intensity Resistance Exercise (LIRE) on routine clinical cellular inflammatory markers-neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII)-in 24 healthy, RE-trained young men.</p><p><strong>Methods: </strong>Measurements were taken at baseline (T₀), immediately post-exercise (T₁), and 45 min post-exercise (T₂). It was hypothesised that HIIRE would elicit a significantly greater increase in NLR, PLR, and SII from baseline (T₀) to post-exercise (T₁ and T₂) compared to LIRE.</p><p><strong>Results: </strong>Baseline-adjusted ANCOVAs revealed significant interactions for cellular inflammatory markers (η²_p = .072; NLR: p < .001, η²_p = .217; PLR: p < .001, η²_p = .147; SII: p < .001, η²_p = .204). Post hoc analyses locate this difference for NLR, PLR, and SII 45 min post-exercise, with greater increases of HIIRE.</p><p><strong>Conclusion: </strong>The results suggest a complex immune response involving pro-inflammatory signalling and immune cell redistribution induced by acute RE, with intensity being a main driver. This underscores the pivotal role of intensity in modulating acute immune responses to RE, with potential implications for exercise prescription targeting inflammatory processes.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5579-5594"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13633966/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148469709","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":"Maximal aerobic speed: methodological implications and unintended consequences.","authors":"Fernando Gabe Beltrami, Øyvind Støren, Jan Helgerud","doi":"10.1007/s00421-026-06331-5","DOIUrl":"10.1007/s00421-026-06331-5","url":null,"abstract":"<p><p>Maximal aerobic speed (MAS) represents the minimal speed where a further increase in speed will not result in a further increase in oxygen consumption (V̇O₂). MAS is determined from the relationship between maximal V̇O₂ (V̇O_2max) and running economy, the latter also expressed as the O₂ cost of running. There is no standardized method for determination of MAS in the literature, but three approaches are more dominant: the first approach consists of determining a loss of linearity between V̇O₂ and speed. The second approach performs a linear extrapolation from the relationship between submaximal V̇O₂ and speed towards V̇O_2max. The third approach divides V̇O_2max by the O₂ cost of running measured over one or more speeds. We explore the assumptions and flaws of the different approaches. We show that the first approach lacks sufficient objectivity. The second approach, based on linear extrapolation, is prone to significant error, particularly when changes in O₂ cost happen at the lower or higher speeds tested, to the extent that higher sub-maximal V̇O₂ for a given speed results in improved MAS and vice-versa. We suggest that MAS should be assessed using a simple division of V̇O_2max by the O₂ cost of running determined from a race-relevant speed, which can be easily integrated into a single testing session.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5101-5106"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13633949/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148618991","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":"Interval eccentric cycling : a promising training modality for sedentary people.","authors":"Benoît Vandenbroeck, Jean-François Kaux, Florence Schleich, Justine Monseur, Stéphanie Hody","doi":"10.1007/s00421-026-06345-z","DOIUrl":"10.1007/s00421-026-06345-z","url":null,"abstract":"<p><strong>Introduction: </strong>Older adults are prone to deconditioning. High intensity interval training (HIIT) effectively generates functional improvements, but at a high metabolic demand. Eccentric training (ET) is emerging as an efficient method because of its capacity to develop high forces at low metabolic cost. We compared the effects of eccentric HIIT (EI), concentric HIIT (CI) and eccentric continuous (EC) cycling training.</p><p><strong>Methods: </strong>43 sedentary adults (61yo) performed EI (n=15), EC (n=15) or CI (n=13) training twice-a-week for 12 weeks. Training intensities ranged from 120 to 135% (EI) and 80 to 90% (CI, EC) of maximal aerobic power (MAP). Maximal oxygen consumption (VO₂ max), MAP, quadriceps maximal isometric torque (MIT) and functional abilities were evaluated before and after training. Rate of perceived exertion (RPE), heart rate (HR), cognitive demand and muscle soreness were monitored during training.</p><p><strong>Results: </strong>EI and EC showed lower mean HR and RPE than CI (HR: 63%; 65%; 85% and RPE: 12; 11; 14, respectively), without onset of soreness. Improvements in MIT (+14%; +17; +24%), 6-minute walking distance (+6%; +6%; +4%) and ten-times sit-to-stand test(+14%; +17%; +11%) were observed in EI, EC and CI. However, only CI provided aerobic improvements (MAP: +4%;+1%; +18% and VO₂ max: +1%; -1%; +14%, for EI, EC and CI, respectively).</p><p><strong>Conclusion: </strong>ET can be safely integrated in rehabilitation to improve muscular function and exercise capacity in patients unable to tolerate conventional concentric exercise intensities. EI appears as a promising method in both preventive and rehabilitative settings, but with limited effects on aerobic capacity.</p><p><strong>Trial registry: </strong>The trial was registered on ClinicalTrial.gov, the 24th September 2025, NCT07189975.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5345-5361"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148445132","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":"Impact of total creatine and accessible phosphate pool on endurance exercise: implications for muscle fibers bioenergetic specificity and creatine supplementation.","authors":"Bernard Korzeniewski","doi":"10.1007/s00421-026-06365-9","DOIUrl":"10.1007/s00421-026-06365-9","url":null,"abstract":"<p><strong>Purpose: </strong>To determine the effect of the total creatine (tCr) and accessible phosphate (aP) pool (tCaP) on the kinetic variables (maximal muscle oxygen consumption, V̇O_2max, transition time of the muscle V̇O₂ on-kinetics, t_0.63, time to exhaustion, t_lim, critical power, CP and work over CP in the power-duration relationship, W') of intense moderate-term endurance exercise.</p><p><strong>Methods: </strong>A dynamic computer model of the skeletal muscle bioenergetic system, involving the each-step-activation mechanism of system stimulation during work transitions and P_i-double-threshold mechanism of muscle fatigue is used.</p><p><strong>Results: </strong>A decrease in tCaP significantly increases V̇O_2max, t_lim and CP, moderately increases W' and shortens t_0.63. Significantly enough decrease in tCaP moves the system (at a determined power output) from the severe to heavy (and further to moderate) exercise intensity domain. An increase in tCr alone has an insignificant effect on the system.</p><p><strong>Conclusions: </strong>A decrease in tCaP, especially in aP, increases fatigue resistance of muscle during endurance exercise through attenuation of P_i increase during exercise. An increase in tCr alone has little impact on fatigue resistance. In the sequence of muscle cell types: glycolytic fast-twitch type II skeletal muscle fibers → oxidative slow-twitch type I skeletal muscle fibers → heart muscle fibers the tCaP, especially aP, pool size decreases, which can contribute to the increasing fatigue-resistance in this sequence. While Cr supplementation, elevating tCr, increases the strength and force of acute maximal-intensity very-short-term exercise, it has no significant effect on endurance exercise, at least through the creatine kinase system.</p>","PeriodicalId":12005,"journal":{"name":"European Journal of Applied Physiology","volume":" ","pages":"5691-5702"},"PeriodicalIF":2.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148591263","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}