{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,27]],"date-time":"2026-09-27T10:15:59Z","timestamp":1790504159933,"version":"4.1.0"},"reference-count":46,"publisher":"Wiley","issue":"5","license":[{"start":{"date-parts":[[2015,5,6]],"date-time":"2015-05-06T00:00:00Z","timestamp":1430870400000},"content-version":"vor","delay-in-days":5,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Experimental Physiology"],"published-print":{"date-parts":[[2015,5]]},"abstract":"<jats:sec><jats:title>New Findings<\/jats:title><jats:p><jats:list list-type=\"bullet\">\n<jats:list-item>\n<jats:p><jats:bold>What is the central question of this study?<\/jats:bold><\/jats:p>\n<jats:p>Does metabolic alkalosis affect central and peripheral mechanisms associated with exercise\u2010induced muscle fatigue in humans?<\/jats:p>\n<\/jats:list-item>\n<jats:list-item>\n<jats:p><jats:bold>What is the main finding and its importance?<\/jats:bold><\/jats:p>\n<jats:p>Inducing metabolic alkalosis before exercise preserved voluntary activation, but not muscle excitation, after a 2\u00a0min maximal voluntary contraction (MVC) followed by ischaemia. An effect of pH was also observed in maximal rates of torque development, where alkalosis mitigated the reduction in maximal rates of torque development after the initial 2\u00a0min MVC. For the first time, these results demonstrate a differential effect of pH on voluntary activation as well as maximal rates of torque development after sustained, maximal voluntary knee extension in humans.<\/jats:p>\n<\/jats:list-item>\n<\/jats:list><\/jats:p><\/jats:sec><jats:sec><jats:label\/><jats:p>The increased concentration of protons during fatiguing exercise may contribute to increased activation of group III and IV afferents and subsequently reduced central drive, but this has yet to be confirmed in exercising humans. Here, we determined whether inducing metabolic alkalosis differentially affects descending central drive after fatiguing exercise and whether this effect may, in part, be explained by attenuating group III and IV afferent firing. Eleven men performed a maximal 2\u00a0min voluntary knee extension (MVC) followed by a 2\u00a0min rest and subsequent 1\u00a0min MVC with an occlusive cuff either in placebo [PLA; 0.3\u00a0g\u00a0(kg body weight)<jats:sup>\u22121<\/jats:sup> calcium carbonate] or alkalosis conditions [ALK; 0.3\u00a0g\u00a0(kg body weight)<jats:sup>\u22121<\/jats:sup> sodium bicarbonate]. Femoral nerve stimulation was applied before exercise, after the 2\u00a0min MVC and at 40\u201360\u00a0s intervals throughout the remainder of the protocol to explore central and peripheral mechanisms associated with reductions in maximal force and rate of torque development. Although voluntary activation declined to a similar extent after the 2\u00a0min MVC, during the ischaemic period voluntary activation was higher during ALK (PLA, 57\u00a0\u00b1\u00a08%; ALK, 76\u00a0\u00b1\u00a05%). Maximal voluntary torque declined at similar rates during the task (203\u00a0\u00b1\u00a019\u00a0N\u00a0m), but maximal rate of torque development was significantly higher in the ALK conditions after the 2\u00a0min MVC (mean difference of 177\u00a0\u00b1\u00a060\u00a0N\u00a0m\u00a0s<jats:sup>\u22121<\/jats:sup>). These results demonstrate the effect of pH on voluntary activation as well as maximal rates of torque development after sustained, maximal voluntary knee extension in humans.<\/jats:p><\/jats:sec>","DOI":"10.1113\/ep085054","type":"journal-article","created":{"date-parts":[[2015,2,26]],"date-time":"2015-02-26T04:19:01Z","timestamp":1424924341000},"page":"519-530","source":"Crossref","is-referenced-by-count":31,"title":["The effect of metabolic alkalosis on central and peripheral mechanisms associated with exercise\u2010induced muscle fatigue in humans"],"prefix":"10.1113","volume":"100","author":[{"given":"Jason C.","family":"Siegler","sequence":"first","affiliation":[{"name":"Sport and Exercise Science School of Science and Health University of Western Sydney  Sydney NSW Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paul","family":"Marshall","sequence":"additional","affiliation":[{"name":"Sport and Exercise Science School of Science and Health University 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