Experimental Physiology最新文献

{"title":"Fatiguing exercise reduces cellular passive Young's modulus in human vastus lateralis muscle","authors":"Grace E. Privett, Austin W. Ricci, Larry L. David, Karen Wiedenfeld Needham, Yong How Tan, Karina H. Nakayama, Damien M. Callahan","doi":"10.1113/EP092072","DOIUrl":"10.1113/EP092072","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 \u0000 <p>Previous studies demonstrated that acute fatiguing exercise transiently reduces whole-muscle stiffness, which might contribute to increased risk of injury and impaired contractile performance. We sought to elucidate potential intracellular mechanisms underlying these reductions. To that end, the cellular passive Young's modulus was measured in muscle fibres from healthy, young males and females. Eight volunteers (four male and four female) completed unilateral, repeated maximal voluntary knee extensions until task failure, immediately followed by bilateral percutaneous needle muscle biopsy of the post-fatigued followed by the non-fatigued control vastus lateralis. Muscle samples were processed for mechanical assessment and separately for imaging and phosphoproteomics. Fibres were passively (pCa 8.0) stretched incrementally to 156% of initial sarcomere length to assess Young's modulus, calculated as the slope of the resulting stress–strain curve at short (sarcomere length = 2.4–3.0 µm) and long (sarcomere length = 3.2–3.8 µm) lengths. Titin phosphorylation was assessed by liquid chromatography followed by high-resolution mass spectrometry. The passive modulus was significantly reduced in post-fatigued versus control fibres from male, but not female, participants. Post-fatigued samples showed altered phosphorylation of five serine residues (four located within the elastic region of titin) but did not exhibit altered active tension or sarcomere ultrastructure. Collectively, these results suggest that acute fatigue is sufficient to alter phosphorylation of skeletal titin in multiple locations. We also found reductions in the passive modulus, consistent with prior reports in the literature investigating striated muscle stiffness. These results provide mechanistic insight contributing to the understanding of dynamic regulation of whole-muscle tissue mechanics in vivo.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Highlights</h3>\u0000 \u0000 <div>\u0000 <ul>\u0000 \u0000 <li>\u0000 <p><b>What is the central question of this study?</b></p>\u0000 \u0000 <p>Previous studies have shown that skeletal muscle stiffness is reduced following a single bout of fatiguing exercise in whole muscle, but it is not known whether these changes manifest at the cellular level, and their potential mechanisms remain unexplored.</p>\u0000 </li>\u0000 \u0000 <li>\u0000 <p><b>What is the main finding and its importance?</b></p>\u0000 \u0000 <p>Fatiguing exercise reduces cellular stiffness in skeletal muscle from males but not females, suggesting that fatigue alters tissue compliance in a sex-dependent manner. The phosphor","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":"109 11","pages":"1922-1937"},"PeriodicalIF":2.6,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1113/EP092072","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142008535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interference with glutamate antiporter system xc− enables post-hypoxic long-term potentiation in hippocampus","authors":"Bradley S. Heit,&nbsp;Alex Chu,&nbsp;Alyssa McRay,&nbsp;Janet E. Richmond,&nbsp;Charles J. Heckman,&nbsp;John Larson","doi":"10.1113/EP092045","DOIUrl":"10.1113/EP092045","url":null,"abstract":"<p>Our group previously showed that genetic or pharmacological inhibition of the cystine/glutamate antiporter, system x_c⁻, mitigates excitotoxicity after anoxia by increasing latency to anoxic depolarization, thus attenuating the ischaemic core. Hypoxia, however, which prevails in the ischaemic penumbra, is a condition where neurotransmission is altered, but excitotoxicity is not triggered. The present study employed mild hypoxia to further probe ischaemia-induced changes in neuronal responsiveness from wild-type and xCT KO (xCT^−/−) mice. Synaptic transmission was monitored in hippocampal slices from both genotypes before, during and after a hypoxic episode. Although wild-type and xCT^−/− slices showed equal suppression of synaptic transmission during hypoxia, mutant slices exhibited a persistent potentiation upon re-oxygenation, an effect we termed ‘post-hypoxic long-term potentiation (LTP)’. Blocking synaptic suppression during hypoxia by antagonizing adenosine A₁ receptors did not preclude post-hypoxic LTP. Further examination of the induction and expression mechanisms of this plasticity revealed that post-hypoxic LTP was driven by NMDA receptor activation, as well as increased calcium influx, with no change in paired-pulse facilitation. Hence, the observed phenomenon engaged similar mechanisms as classical LTP. This was a remarkable finding as theta-burst stimulation-induced LTP was equivalent between genotypes. Importantly, post-hypoxic LTP was generated in wild-type slices pretreated with system x_c⁻ inhibitor, <i>S</i>-4-carboxyphenylglycine, thereby confirming the antiporter's role in this phenomenon. Collectively, these data indicate that system x_c⁻ interference enables neuroplasticity in response to mild hypoxia, and, together with its regulation of cellular damage in the ischaemic core, suggest a role for the antiporter in post-ischaemic recovery of the penumbra.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":"109 9","pages":"1572-1592"},"PeriodicalIF":2.6,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11363115/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141995563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Blood flow restriction: The acute effects of body tilting and reduced gravity analogues on limb occlusion pressure.","authors":"Patrick Swain, Nick Caplan, Luke Hughes","doi":"10.1113/EP091874","DOIUrl":"https://doi.org/10.1113/EP091874","url":null,"abstract":"<p><p>Blood flow restriction (BFR) has been identified as a potential countermeasure to mitigate physiological deconditioning during spaceflight. Guidelines recommend that tourniquet pressure be prescribed relative to limb occlusion pressure (LOP); however, it is unclear whether body tilting or reduced gravity analogues influence LOP. We examined LOP at the leg and arm during supine bedrest and bodyweight suspension (BWS) at 6° head-down tilt (HDT), horizontal (0°), and 9.5° head-up tilt (HUT) positions. Twenty-seven adults (age, 26 ± 5 years; height, 1.75 ± 0.08 m; body mass, 73 ± 12 kg) completed all tilts during bedrest. A subgroup (n = 15) additionally completed the tilts during BWS. In each position, LOP was measured twice in the leg and arm using the Delfi Personalized Tourniquet System after 5 min of rest and again after a further 5 min. The LOP at the leg increased significantly from 6° HDT to 9.5° HUT in bedrest and BWS by 9-15 mmHg (Cohen's d = 0.7-1.0). Leg LOP was significantly higher during BWS at horizontal and 9.5° HUT postures relative to the same angles during bedrest by 8 mmHg (Cohen's d = 0.6). Arm LOP remained unchanged between body tilts and analogues. Intraclass correlation coefficients for LOP measurements taken after an initial and subsequent 5 min rest period in all conditions ranged between 0.91-0.95 (leg) and 0.83-0.96 (arm). It is advised that LOP be measured before the application of a vascular occlusion in the same body tilt/setting to which it is applied to minimize discrepancies between the actual and prescribed tourniquet pressure.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141995562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy expenditure, intake and availability in female soccer players via doubly labelled water: Are we misrepresenting low energy availability?","authors":"Samuel J McHaffie, Carl Langan-Evans, Juliette A Strauss, José L Areta, Christopher Rosimus, Martin Evans, Ruth Waghorn, James Grant, Matthew Cuthbert, Catherine Hambly, John R Speakman, James P Morton","doi":"10.1113/EP091589","DOIUrl":"https://doi.org/10.1113/EP091589","url":null,"abstract":"<p><p>Female soccer players have been identified as presenting with low energy availability (LEA), though the prevalence of LEA may be overestimated given inaccuracies associated with self-reporting dietary intakes. Accordingly, we aimed to quantify total daily energy expenditure (TDEE) via the doubly labelled water (DLW) method, energy intake (EI) and energy availability (EA). Adolescent female soccer players (n = 45; 16 ± 1 years) completed a 9-10 day 'training camp' representing their national team. Absolute and relative TDEE was 2683 ± 324 and 60 ± 7 kcal kg^-1 fat free mass (FFM), respectively. Mean daily EI was lower (P < 0.01) when players self-reported using the remote food photography method (RFPM) (2047 ± 383 kcal day^-1) over a 3-day period versus DLW derived EI estimates accounting for body mass (BM) changes (2545 ± 518 kcal day^-1) over 7-8 days, representing a mean daily Δ of 499 ± 526 kcal day^-1 and 22% error when using the RFPM. Estimated EA was different (P < 0.01) between methods (DLW: 48 ± 14 kcal kg^-1 FFM, range: 22-82; RFPM: 37 ± 8 kcal kg^-1 FFM, range: 22-54), such that prevalence of LEA (<30 kcal kg^-1 FFM) was lower in DLW compared with RFPM (5% vs. 15%, respectively). Data demonstrate the potential to significantly underestimate EI when using self-report methods. This approach can therefore cause a misrepresentation and an over-prevalence of LEA, which is the underlying aetiology of 'relative energy deficiency in sport' (REDs). HIGHLIGHTS: What is the central question of this study? Do self-reported dietary intakes (via remote food photography method, RFPM) overestimate low energy availability (LEA) prevalence in female soccer players compared with energy intake evaluation from the doubly labelled water (DLW) method? What is the main finding and its importance? Estimated energy availability is greater with the DLW method compared with RFPM, such that the prevalence of LEA is greater when self-reporting dietary intakes. Accordingly, data demonstrate the potential to misrepresent the prevalence of LEA, an underlying factor in the aetiology of 'relative energy deficiency in sport' (REDs).</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141982050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acute exposure to carbon monoxide inhalation and/or hot water immersion transiently increases erythropoietin in females but not in males","authors":"Kaitlyn G. DiMarco,&nbsp;Christopher L. Chapman,&nbsp;Natasha E. Weiser,&nbsp;Emma R. Matsell,&nbsp;Kathryn M. Lucernoni,&nbsp;Samantha Chacon,&nbsp;Margaret M. B. Grivette,&nbsp;John R. Halliwill,&nbsp;Andrew T. Lovering,&nbsp;Christopher T. Minson","doi":"10.1113/EP091923","DOIUrl":"10.1113/EP091923","url":null,"abstract":"<p>The use of acute carbon monoxide inhalation (COi) and hot water immersion (HWI) are of growing interest as interventions to stimulate erythropoietin (EPO) production. However, whether EPO production is further augmented when combining these stressors and whether there are sex differences in this response are poorly understood. Therefore, we measured circulating EPO concentration in response to acute COi and HWI independently and in combination and determined whether the responses were altered by sex. Participants completed three study visits—COi, HWI, and combined COi and HWI—separated by 1 week in a randomized, balanced, crossover design. Renal blood velocity was measured during all interventions, and carboxyhaemoglobin was measured during and after COi. Serum samples were analysed every hour for 6 h post-intervention for EPO concentration. HWI decreased renal blood velocity (46.2 cm/s to 36.2 cm/s) (<i>P </i>&lt; 0.0001), and COi increased carboxyhaemoglobin (1.5%–12.8%) (<i>P </i>&lt; 0.0001) without changing renal blood velocity (46.4–45.2 cm/s) (<i>P</i> = 0.4456). All three interventions increased peak EPO concentration from baseline (COi: 6.02–9.74 mIU/mL; HWI: 6.80–11.10 mIU/mL; COi + HWI: 6.71–10.91 mIU/mL) (<i>P</i> = 0.0048) and to the same extent (<i>P</i> = 0.3505). On average, females increased EPO while males did not in response to COi (females: 6.17 mIU/mL; males: 1.27 mIU/mL) (<i>P</i> = 0.0010), HWI (females: 6.47 mIU/mL; males: 2.14 mIU/mL) (<i>P</i> = 0.0104), and COi and HWI (females: 6.65 mIU/mL; males: 1.76 mIU/mL) (<i>P</i> = 0.0256). These data emphasize that combining these interventions does not augment EPO secretion and that these interventions may work better in females.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":"109 10","pages":"1782-1795"},"PeriodicalIF":2.6,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11442759/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141982049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Peer review: the imprimatur of scientific publication","authors":"Ronan M. G. Berg,&nbsp;Karyn L. Hamilton,&nbsp;Joanne Fiona Murray,&nbsp;Peying Fong","doi":"10.1113/EP092108","DOIUrl":"10.1113/EP092108","url":null,"abstract":"&lt;p&gt;At &lt;i&gt;The Journal of Physiology&lt;/i&gt; and &lt;i&gt;Experimental Physiology&lt;/i&gt;, we continually rely on the keen support from expert referees to provide external peer review of submitted manuscripts (Forsythe, &lt;span&gt;2017&lt;/span&gt;). This is a mandatory step in the publication process, as it is in all other established journals within the biomedical and allied sciences. Indeed, even with the digitalization of scientific communication over the past three decades, the peer-reviewed scientific article remains the primary outlet for disseminating research (Nicholas et al., &lt;span&gt;2015&lt;/span&gt;). As physicist John Ziman noted in his widely cited book, &lt;i&gt;Public Knowledge&lt;/i&gt;, ‘the referee is the lynchpin about which the whole business of Science is pivoted’ (Ziman, &lt;span&gt;1968&lt;/span&gt;).&lt;/p&gt;&lt;p&gt;Recent significant changes in the publication landscape have posed challenges to conventional academic publishing models, challenges of which we, as editors of &lt;i&gt;The Journal of Physiology&lt;/i&gt; and &lt;i&gt;Experimental Physiology&lt;/i&gt;, are acutely aware. These changes include the open access model of publishing and the use of preprint servers. Over the last two decades there has been a move from the traditional publishing model to the open access publishing model; the major difference between the two models being that the reader has been replaced by the author as the primary source of income for the publisher. Both the scientific community and the public benefit from this more equitable approach to disseminating science. The use of preprint servers allows researchers to upload manuscripts to disseminate findings before undergoing formalized peer review, in an effort to accelerate the accessibility of research and its wider availability to the public. Both these changes align with policies from &lt;i&gt;UK Research and Innovation&lt;/i&gt;, the &lt;i&gt;European Commission&lt;/i&gt; and the &lt;i&gt;US White House Office of Science and Technology Policy&lt;/i&gt;, which all encourage making publicly funded research results freely and immediately available to both the wider scientific community and the public.&lt;/p&gt;&lt;p&gt;In light of these developments, some suggest that the peer review process, and perhaps even the classical scientific journals themselves, will become obsolete (DeMaria, &lt;span&gt;2023&lt;/span&gt;; Lu et al., &lt;span&gt;2024&lt;/span&gt;). Starting in 2025, the Bill &amp; Melinda Gates Foundation, one of the major funding sources of biomedical research programmes, will require its grant holders to make their research publicly available as preprints while, at the same time, all financial support to pay for open access fees to peer-reviewed journals will cease (Lenharo, &lt;span&gt;2024&lt;/span&gt;); these two actions by this influential Foundation will expectedly further advance the move away from the peer review process and classical scientific journals. We suspect that misuse of the open access process as a business model by some publishing companies, which creates an economic incentive to accept more or less anything for publication in so-","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":"109 9","pages":"1407-1411"},"PeriodicalIF":2.6,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11363102/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141982052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ingesting carbonated water post-exercise in the heat transiently ameliorates hypotension and enhances mood state","authors":"Masanobu Kajiki,&nbsp;Akira Katagiri,&nbsp;Ryoko Matsutake,&nbsp;Yin-Feng Lai,&nbsp;Hideki Hashimoto,&nbsp;Takeshi Nishiyasu,&nbsp;Naoto Fujii","doi":"10.1113/EP091925","DOIUrl":"10.1113/EP091925","url":null,"abstract":"<p>The objective was to assess if post-exercise ingestion of carbonated water in a hot environment ameliorates hypotension, enhances cerebral blood flow and heat loss responses, and positively modulates perceptions and mood states. Twelve healthy, habitually active young adults (five women) performed 60 min of cycling at 45% peak oxygen uptake in a hot climate (35°C). Subsequently, participants consumed 4°C carbonated or non-carbonated (control) water (150 and 100 mL for males and females regardless of drink type) at 20 and 40 min into post-exercise periods. Mean arterial pressure decreased post-exercise at 20 min only (<i>P</i> = 0.032) compared to the pre-exercise baseline. Both beverages transiently (∼1 min) increased mean arterial pressure and middle cerebral artery mean blood velocity (cerebral blood flow index) regardless of post-exercise periods (all <i>P</i> ≤ 0.015). Notably, carbonated water ingestion led to greater increases in mean arterial pressure (2.3 ± 2.8 mmHg vs. 6.6 ± 4.4 mmHg, <i>P </i>&lt; 0.001) and middle cerebral artery mean blood velocity (1.6 ± 2.5 cm/s vs. 3.8 ± 4.1 cm/s, <i>P</i> = 0.046) at 20 min post-exercise period compared to non-carbonated water ingestion. Both beverages increased mouth exhilaration and reduced sleepiness regardless of post-exercise periods, but these responses were more pronounced with carbonated water ingestion at 40 min post-exercise (mouth exhilaration: 3.1 ± 1.4 vs. 4.7 ± 1.7, <i>P</i> = 0.001; sleepiness: −0.7 ± 0.91 vs. −1.9 ± 1.6, <i>P</i> = 0.014). Heat loss responses and other perceptions were similar between the two conditions throughout (all <i>P</i> ≥ 0.054). We show that carbonated water ingestion temporarily ameliorates hypotension and increases the cerebral blood flow index during the early post-exercise phase in a hot environment, whereas it enhances mouth exhilaration and reduces sleepiness during the late post-exercise phase.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":"109 10","pages":"1683-1697"},"PeriodicalIF":2.6,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11442846/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141982051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The independent and combined effects of aerobic exercise intensity and dose differentially increase post-exercise cerebral shear stress and blood flow","authors":"M. Erin Moir,&nbsp;Adam T. Corkery,&nbsp;Kathleen B. Miller,&nbsp;Andrew G. Pearson,&nbsp;Nicole A. Loggie,&nbsp;Avery A. Apfelbeck,&nbsp;Anna J. Howery,&nbsp;Jill N. Barnes","doi":"10.1113/EP091856","DOIUrl":"10.1113/EP091856","url":null,"abstract":"&lt;p&gt;This research examined the impact of aerobic exercise intensity and dose on acute post-exercise cerebral shear stress and blood flow. Fourteen young adults (27 ± 5 years of age, eight females) completed a maximal oxygen uptake (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mover&gt;\u0000 &lt;mi&gt;V&lt;/mi&gt;\u0000 &lt;mo&gt;̇&lt;/mo&gt;\u0000 &lt;/mover&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;O&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mi&gt;max&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${{dot{V}}_{{{{mathrm{O}}}_2}max }}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) treadmill test followed by three randomized study visits: treadmill exercise at 30% of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mover&gt;\u0000 &lt;mi&gt;V&lt;/mi&gt;\u0000 &lt;mo&gt;̇&lt;/mo&gt;\u0000 &lt;/mover&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;O&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mi&gt;max&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${{dot{V}}_{{{{mathrm{O}}}_2}max }}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; for 30 min, 70% of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mover&gt;\u0000 &lt;mi&gt;V&lt;/mi&gt;\u0000 &lt;mo&gt;̇&lt;/mo&gt;\u0000 &lt;/mover&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;O&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mi&gt;max&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${{dot{V}}_{{{{mathrm{O}}}_2}max }}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; for 30 min and 70% of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mover&gt;\u0000 &lt;mi&gt;V&lt;/mi&gt;\u0000 &lt;mo&gt;̇&lt;/mo&gt;\u0000 &lt;/mover&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;O&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mi&gt;max&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${{dot{V}}_{{{{mathrm{O}}}_2}max }}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; for a duration that resulted in caloric expenditure equal to that in the 30% &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mover&gt;\u0000 &lt;mi&gt;V&lt;/mi&gt;\u0000 &lt;mo&gt;̇&lt;/mo&gt;\u0000 &lt;/mover&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 ","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":"109 10","pages":"1796-1805"},"PeriodicalIF":2.6,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11442852/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141982053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sex differences in cervical disc height and neck muscle activation during manipulation of external load from helmets","authors":"Nai-Hao Yin,&nbsp;Irene Di Giulio,&nbsp;Peter D. Hodkinson,&nbsp;Federico Formenti,&nbsp;Ross D. Pollock","doi":"10.1113/EP091996","DOIUrl":"10.1113/EP091996","url":null,"abstract":"<p>Neck pain associated with helmet-wear is an occupational health problem often observed in helicopter pilots and aircrew. Whether aircrew helmet wearing is associated with physiological and biomechanical differences between sexes is currently unknown. This study investigated neuromuscular activation patterns during different helmet-wearing conditions. The helmet load was manipulated through a novel Helmet Balancing System (HBS) in healthy, non-pilot male and female participants (<i>n</i> = 10 each, age 19–45 years) in two phases. Phase A assessed the acute effects of helmet-wear on neck muscles activation during head movements. Phase B examined changes in muscle activity and cervical disc height after wearing a helmet for 45 min. In Phase A, muscle activity was similar between sexes in many movements, but it was higher in female participants when wearing a helmet than in males. The HBS reduced muscle activity in both sexes. In Phase B, female participants exhibited a greater level of muscular fatigue, and male participants’ cervical disc height was significantly decreased [5.7 (1.4) vs. 4.4 (1.5) mm, <i>P</i> &lt; 0.001] after continuous wearing. Both sexes showed no significant change in muscle fatigue and disc height [male: 5.0 (1.3) vs. 5.2 (1.4) mm, <i>P</i> = 0.604] after applying HBS. These findings demonstrate sex-specific physiological and biomechanical responses to wearing a helmet. They may indicate different postural and motor control strategies, associated with different neck pain aetiologies in male and female aircrew, the knowledge of which is important to reduce or prevent musculoskeletal injuries associated with helmet wearing.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":"109 10","pages":"1728-1738"},"PeriodicalIF":2.6,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11442774/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141906299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How to spot the truth","authors":"G. Drummond,&nbsp;M. J. Tipton","doi":"10.1113/EP092160","DOIUrl":"10.1113/EP092160","url":null,"abstract":"&lt;p&gt;‘Truth’ is under attack, more so now than ever before, and for many reasons one of which is social media. We hear and read remarkable, often preposterous claims from many sources. This may be in political debate, the presentation of new products, or new health-enhancing exercises ranging from hot water pools to cold water swimming. These frequently claim to be ‘scientific findings’ often reporting ‘new studies have shown’ stories, underpinned by ‘expert’opinion. They are amplified in the media until the next fad comes along.&lt;/p&gt;&lt;p&gt;This pervasive form of persuasion is a war of beliefs, which in many cases may contradict accepted knowledge. It is always possible, in fact likely, that some of the more absurd claims may not involve, or even be properly aware of, current scientific understanding, in which case these claims may be logical, but based on incorrect assumptions or understanding. Flat earthers have a consistent world view, which is probably logical to them; it just is not compatible with other known facts. But truth is the first casualty of war, and now more than ever, we must equip ourselves and others with the skills needed to judge how valid the information we are presented with is.&lt;/p&gt;&lt;p&gt;This is not as simple as it might appear. The context is all-important. Interestingly, there are far fewer exact rules, firm guidelines and exact cut-off levels than people might imagine for establishing the truth. Most scientific knowledge is rarely expressed in terms of utter validity, but rather expressed as ‘fits’ or ‘is not inconsistent with’ what we know already, or ‘suitable for predicting performance’. For example, we now know that gravity can be bent; but Newton's simple straight-line approximation has taken astronauts to the moon and back (sorry, flat earthers). In addition, although statisticians use words consistently and exactly, they do not use words such as ‘population’ and ‘sample’ in the way they are used in general parlance. Nor is the logic of statistics straightforward. For example, the most commonly used tests of likelihood assume ‘if, and only if, these random samples were drawn from a single population, then…’ Logical and consistent, yes, but not well understood, even by some scientists. For example, in one study, trainee doctors, who should be reading this sort of stuff all the time, were given a simple statement using this test. When asked to choose the correct conclusion out of four possibilities, almost half made a wrong choice (Windish et al., &lt;span&gt;2007&lt;/span&gt;).&lt;/p&gt;&lt;p&gt;The truth helps you make ‘adequately correct’ decisions and act accordingly. Such decisions depend on the situation, and the risks of making a correct or incorrect decision. Uncertainty doesn't mean we know nothing, or that anything could be true: it just means you don't bet your house on an outsider.&lt;/p&gt;&lt;p&gt;Some years ago, a district court decided that a particular vaccine was responsible for an adverse outcome (which was scientifically doubtful). This trigg","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":"109 11","pages":"1811-1814"},"PeriodicalIF":2.6,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1113/EP092160","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141897217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}