Journal of applied physiology最新文献

{"title":"The academic tightrope: work-life balance in a fast-paced world.","authors":"Jéssica Maria Dantas Araújo Aragão, Aimée Obolari Durço","doi":"10.1152/japplphysiol.00716.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00716.2024","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142466254","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":"Balancing innovations and ethics: the evolving role of advanced technology in sports competitions.","authors":"Abdelmohsen Eldhma","doi":"10.1152/japplphysiol.00542.2024","DOIUrl":"10.1152/japplphysiol.00542.2024","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142307825","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":"Effect of diabetes on microvascular morphology and permeability of rat skeletal muscle: in vivo imaging using two-photon laser scanning microscopy.","authors":"Kazuki Hotta, Rie Shimotsu, Bradley J Behnke, Kazuto Masamoto, Kazuyoshi Yagishita, David C Poole, Yutaka Kano","doi":"10.1152/japplphysiol.00222.2024","DOIUrl":"10.1152/japplphysiol.00222.2024","url":null,"abstract":"<p><p>This investigation evaluated the microvascular permeability and ultrastructure of skeletal muscle capillaries in the skeletal muscle of diabetic (DIA) rats using two-photon laser scanning microscopy (TPLSM) and transmission electron microscopy (TEM). Microvascular permeability was assessed in the tibialis anterior muscle of control (CON) and DIA (streptozocin) male Wistar rats (<i>n</i> = 20, 10-14 wk) by in vivo imaging using TPLSM after fluorescent dye intravenous infusion. Fluorescent dye leakage was quantified to determine microvascular permeability. The ultrastructure was imaged by TEM ex vivo to calculate the size and number of intercellular clefts between capillary endothelial cells and also intracellular vesicles. Compared with control, the volumetrically determined interstitial fluorescent dye leakage, the endothelial cell thickness, and the number of intercellular clefts per capillary perimeter were significantly higher, and the cleft width was significantly narrower in tibialis anterior (TA) of DIA (interstitial fluorescent dye leakage, 2.88 ± 1.40 vs. 10.95 ± 1.41 µm³ × min × 10⁶; endothelial thickness, 0.28 ± 0.02 vs. 0.45 ± 0.03 µm; number of intercellular clefts per capillary perimeter, 6.3 ± 0.80 vs. 13.6 ± 1.7/100 µm; cleft width, 11.92 ± 0.95 vs. 8.40 ± 1.03 nm, CON vs. DIA, respectively, all <i>P</i> < 0.05). The size of intracellular vesicles in the vascular endothelium showed an increased proportion of large vesicles in the DIA group compared with the CON group (<i>P</i> < 0.05). Diabetes mellitus enhances the microvascular permeability of skeletal muscle microvessels due, in part, to a higher density and narrowing of the endothelial intercellular clefts, and larger intracellular vesicles.<b>NEW & NOTEWORTHY</b> Microvascular permeability in diabetic muscle was investigated using our original two-photon scanning laser microscopy method. Compared with controls, the leakage volume was increased in diabetic muscle, which was atrophic with smaller capillary diameter, endothelial cell thickening, and the appearance of more endothelial intercellular gaps or clefts, and large vesicles. Hyperpermeability was closely related to ultrafine structural changes of the capillary endothelial cell junctions.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141982301","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":"Neural and muscular contributions to the age-related differences in peak power of the knee extensors in men and women.","authors":"David J Wrucke, Andrew Kuplic, Mitchell D Adam, Sandra K Hunter, Christopher W Sundberg","doi":"10.1152/japplphysiol.00773.2023","DOIUrl":"10.1152/japplphysiol.00773.2023","url":null,"abstract":"<p><p>The mechanisms for the loss in limb muscle power output in old (60-79 yr) and very old (≥80 yr) adults and whether the mechanisms differ between men and women are not well understood. We compared maximal peak power of the knee extensor muscles between young, old, and very old men and women and identified the neural and muscular factors contributing to the age-related differences in power. Thirty-one young (22.9 ± 3.0 yr, 15 women), 82 old (70.3 ± 4.9 yr, 38 women), and 16 very old adults (85.8 ± 4.2 yr, 9 women) performed maximal isokinetic contractions at 14 different velocities (30-450°/s) to identify peak power. Voluntary activation (VA) and contractile properties were assessed with transcranial magnetic stimulation to the motor cortex and electrical stimulation of the femoral nerve. The age-related loss in peak power was ∼6.5 W·yr^-1 for men (<i>R</i>² = 0.62, <i>P</i> < 0.001), which was a greater rate of decline (<i>P</i> = 0.002) than the ∼4.2 W·yr^-1 for women (<i>R</i>² = 0.77, <i>P</i> < 0.001). Contractile properties were the most closely associated variables with peak power for both sexes, such as the rate of torque development of the potentiated twitch (men: <i>R</i>² = 0.69, <i>P</i> < 0.001; women: <i>R</i>² = 0.57, <i>P</i> < 0.001). VA was weakly associated with power in women (<i>R</i>² = 0.13, <i>P</i> = 0.012) but not in men (<i>P</i> = 0.191). Similarly, neuromuscular activation [rates of electromyography (EMG) rise] during the maximal power contraction was associated with power in women (<i>R</i>² = 0.07, <i>P</i> = 0.042) but not in men (<i>P</i> = 0.456). These data suggest that the age-related differences in maximal peak power of the knee extensor muscles are due primarily to factors within the muscle for both sexes, although neural factors may play a minor role in older women.<b>NEW & NOTEWORTHY</b> The greater age-related loss in power relative to the loss in muscle mass of the knee extensors was primarily due to factors altering the contractile properties of the muscle for both old and very old (≥80 yr) adults. The mechanisms for the decrements in power with aging appear largely similar for men and women, although neural factors may play more of a role in older women.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11486474/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142107789","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":"Last word on Viewpoint: Technological advances in elite sport: Should a line be drawn?","authors":"Brad W Wilkins, Michael J Joyner","doi":"10.1152/japplphysiol.00675.2024","DOIUrl":"10.1152/japplphysiol.00675.2024","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142307829","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":"Research trainees: Are we aiming for leaders or followers?","authors":"Ricardo J Fernandes","doi":"10.1152/japplphysiol.00728.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00728.2024","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142466252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of single- and bilateral limb immersion on systemic and cerebral hemodynamic responses to the cold pressor test.","authors":"Elric Y Allison, Yixue Mei, Geoff B Coombs, Vanessa Mizzi, Huseyn Ismayilov, Baraa K Al-Khazraji","doi":"10.1152/japplphysiol.00328.2024","DOIUrl":"10.1152/japplphysiol.00328.2024","url":null,"abstract":"&lt;p&gt;&lt;p&gt;The cold pressor test (CPT) involves cold water immersion of either the upper or lower limb(s) and elicits increases in sympathetic nervous activity (SNA), heart rate (HR), and mean arterial pressure (MAP) via stimulation of pain and cutaneous thermoreceptors. Greater pain perception during the CPT is associated with greater increases in SNA and more robust physiological responses. Due to potential differential sensitivity to both painful and thermal stimuli between upper and lower limbs, as well as potential effects of total exposure area, it is unclear whether the choice of limb(s) in CPT protocol design differentially affects systemic and cerebral hemodynamic responses. Our objective was to assess systemic and cerebral hemodynamic and ventilatory responses to different CPT protocols of the hand (CPT&lt;sub&gt;H&lt;/sub&gt;), foot (CPT&lt;sub&gt;F&lt;/sub&gt;), or bilateral feet (CPT&lt;sub&gt;BF&lt;/sub&gt;). We hypothesized CPT&lt;sub&gt;BF&lt;/sub&gt; would elicit greatest physiological responses due to increased exposure area to the cold stimulus. Twenty-eight (14 M, 14 F) healthy young adults [23.4 (SD: 2.4) yr] participated in three 3-min CPT protocols during a single visit. Blood pressure, HR, middle cerebral artery blood velocity (MCAv) and cerebrovascular conductance index, and end-tidal carbon dioxide ([Formula: see text]) were averaged over the final 30 s of each minute of the CPT for each protocol, and perceived pain was recorded at the end of each minute of the CPT. We found significant effects of the time-CPT protocol interaction on systolic blood pressure (&lt;i&gt;P&lt;/i&gt; = 0.02), diastolic blood pressure (&lt;i&gt;P&lt;/i&gt; &lt; 0.01), MAP (&lt;i&gt;P&lt;/i&gt; &lt; 0.01), and HR (&lt;i&gt;P&lt;/i&gt; &lt; 0.001). There were no differences between CPT protocols on either MCAv (&lt;i&gt;P&lt;/i&gt; = 0.4) or cerebrovascular conductance index (&lt;i&gt;P&lt;/i&gt; = 0.1). HR responses peaked in the first minute of the CPT, and changes from baseline were greater in CPT&lt;sub&gt;BF&lt;/sub&gt; [Δ14(16) beats/min] compared with CPT&lt;sub&gt;H&lt;/sub&gt; [Δ5(13) beats/min; &lt;i&gt;P&lt;/i&gt; = 0.01] and CPT&lt;sub&gt;F&lt;/sub&gt; [Δ4.04(13.3) beats/min; &lt;i&gt;P&lt;/i&gt; = 0.02]. MAP responses peaked in &lt;i&gt;minute 2&lt;/i&gt; of the CPT, and changes from baseline were greater in CPT&lt;sub&gt;H&lt;/sub&gt; [Δ12(8) mmHg) and CPT&lt;sub&gt;BF&lt;/sub&gt; (Δ13(9) mmHg] compared with CPT&lt;sub&gt;F&lt;/sub&gt; [Δ8(7) mmHg; &lt;i&gt;P&lt;/i&gt; &lt; 0.01]. Perceived pain was significantly greater in the CPT&lt;sub&gt;BF&lt;/sub&gt; [CPT1 7(2.3), CPT2 6.5(2.3), CPT3 6(3)] condition compared with CPT&lt;sub&gt;H&lt;/sub&gt; [CPT1 6(1.3), CPT2 6(2.3), CPT3 6(2.3)] and CPT&lt;sub&gt;F&lt;/sub&gt; [CPT1 6(3.0), CPT2 6(2.0), CPT3 5.5(3.0)] protocols at all three stages of the CPT (&lt;i&gt;P&lt;/i&gt; ≤ 0.01). Our findings suggest choice of limb(s) in CPT protocols may lead to differences in systemic hemodynamic responses, with pain perception potentially influencing these responses. Based on our results, we suggest that choice of limb should be considered in future design of CPT studies, with hand CPT providing the best balance between participant tolerability and robust physiological responses.&lt;b&gt;NEW & NOTEWOR","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141874954","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":"Muscle and tendon morphology of a world strongman and deadlift champion.","authors":"Thomas G Balshaw, Garry J Massey, Robert Miller, Emmet J McDermott, Thomas M Maden-Wilkinson, Jonathan P Folland","doi":"10.1152/japplphysiol.00342.2024","DOIUrl":"10.1152/japplphysiol.00342.2024","url":null,"abstract":"<p><p>This study compared the muscle and tendon morphology of an extraordinarily strong individual, a World's Strongest Man and deadlift champion (WSM), with that of various other athletic, trained, and untrained populations. The WSM completed the following: <i>1</i>) 3.0-T MRI scans, to determine the volume of 22 individual lower limb muscles, 5 functional muscle groups, patellar tendon (PT) cross-sectional area (CSA), and PT moment arm; and <i>2</i>) countermovement jumps (CMJ) and isometric midthigh pull (IMTP) contractions. The WSM was compared with previously assessed groups from our laboratory (muscle and tendon) and the wider research literature (CMJ and IMTP). The WSM's CMJ peak power (9,866 W) and gross (9,171 N) and net (7,480 N) IMTP peak forces were higher than any previously published values. The WSM's overall measured leg muscle volume was approximately twice that of untrained controls (+96%) but with pronounced anatomical variability in the extent of muscular development. The plantar flexor group (+120%) and the guy rope muscles (sartorius, gracilis, and semitendinosus: +140% to +202%), which stabilize the pelvis and femur, demonstrated the largest differences relative to that of untrained controls. The WSM's pronounced quadriceps size (greater than or equal to twofold vs. untrained) was accompanied by modest PT moment arm differences and, notably, was not matched by an equivalent difference in PT CSA (+30%). These results provide novel insight into the musculotendinous characteristics of an extraordinarily strong individual, which may be toward the upper limit of human variation, such that the WSM's very pronounced lower limb muscularity also exhibited distinct anatomical variability and with muscle size largely uncoupled from tendon size.<b>NEW & NOTEWORTHY</b> Lower-body muscle size of an extraordinarily strong individual, a World's Strongest Man and deadlift champion (WSM), was approximately twice that of controls but was underpinned by pronounced anatomical variability in the extent of muscular development (+23-202%): the plantar flexor group and guy rope muscles demonstrating the largest differences. The WSM's quadriceps size (more than or equal to twice that of controls) contrasted with modest differences in patella tendon moment arm (+18%) and was uncoupled from patellar tendon size (+30%).</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11486472/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141982302","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":"Technological equity in Elite sports: a matter of fairness and human evolution.","authors":"Rodrigo Zacca","doi":"10.1152/japplphysiol.00543.2024","DOIUrl":"10.1152/japplphysiol.00543.2024","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142307834","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":"Toxic trend: inhalation of the silent killer carbon monoxide by athletes to increase hemoglobin mass.","authors":"Carsten Lundby, Paul Robach","doi":"10.1152/japplphysiol.00491.2024","DOIUrl":"10.1152/japplphysiol.00491.2024","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142307837","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}