{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,5,23]],"date-time":"2025-05-23T04:34:44Z","timestamp":1747974884920,"version":"3.41.0"},"reference-count":26,"publisher":"Human Kinetics","issue":"6","license":[{"start":{"date-parts":[[2025,6,1]],"date-time":"2025-06-01T00:00:00Z","timestamp":1748736000000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,6,1]]},"abstract":"<jats:p><jats:italic><jats:bold>Purpose<\/jats:bold>:<\/jats:italic> Although it is anecdotally believed that fluctuating running speed during competition has a negative impact on running performance, its influence on physiological strain remains unclear. Therefore, the purpose of the present study was to determine the effect of fluctuating running speed during 10-km running on physiological strain compared with constant running speed. <jats:italic><jats:bold>Methods<\/jats:bold>:<\/jats:italic> Ten male endurance runners completed 2 trials on different days, consisting of either fluctuating (FLU) or constant (CON) running speed during 10-km running on a treadmill. In the CON trial, running speed was constant at 80% of maximal oxygen uptake (<jats:inline-formula\/>), while running speed fluctuated between 75% and 85% of <jats:inline-formula\/> in the FLU trial. Blood lactate levels were evaluated before and after running. Moreover, oxygen uptake (<jats:inline-formula\/>) and expired minute ventilation (<jats:inline-formula\/>) were measured with running. <jats:italic><jats:bold>Results<\/jats:bold>:<\/jats:italic> The time to complete 10-km running was the same between the 2 trials (FLU 38.6 [5.1]\u00a0min, CON 38.6 [5.1]\u00a0min). The FLU trial showed greater exercise-induced blood lactate elevation compared with the CON trial (FLU 4.5 [1.5]\u00a0mmol\/L, CON 2.9 [1.4]\u00a0mmol\/L). The mean values of <jats:inline-formula\/> (FLU 48.6 [3.5]\u00a0mL\u00b7kg<jats:sup>\u22121<\/jats:sup>\u00b7min<jats:sup>\u22121<\/jats:sup>, CON 47.1 [3.6]\u00a0mL\u00b7kg<jats:sup>\u22121<\/jats:sup>\u00b7min<jats:sup>\u22121<\/jats:sup>) and <jats:inline-formula\/> (FLU 95 [14]\u00a0L\/min, CON 87 [11]\u00a0L\/min) during running were significantly higher in the FLU trial than in the CON trial. <jats:italic><jats:bold>Conclusion<\/jats:bold>:<\/jats:italic> Fluctuating running speed elevated physiological strain compared with constant running speed during 10-km running, even if the time to complete 10-km running was the same.<\/jats:p>","DOI":"10.1123\/ijspp.2024-0445","type":"journal-article","created":{"date-parts":[[2025,2,26]],"date-time":"2025-02-26T10:31:07Z","timestamp":1740565867000},"page":"764-769","source":"Crossref","is-referenced-by-count":0,"title":["Fluctuating Running Speed During 10-km Running Elevates Physiological Strain"],"prefix":"10.1123","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5022-2005","authenticated-orcid":true,"given":"Daichi","family":"Sumi","sequence":"first","affiliation":[{"name":"Institute of Sport Science, ASICS Corporation, Kobe, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yasuho","family":"Takii","sequence":"additional","affiliation":[{"name":"Institute of Sport Science, ASICS Corporation, Kobe, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Satoru","family":"Abe","sequence":"additional","affiliation":[{"name":"Institute of Sport Science, ASICS Corporation, Kobe, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Masanori","family":"Sakaguchi","sequence":"additional","affiliation":[{"name":"Institute of Sport Science, ASICS Corporation, Kobe, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"100","reference":[{"issue":"5","key":"r1","series-title":"J Sport Health Sci","doi-asserted-by":"publisher","first-page":"537","DOI":"10.1016\/j.jshs.2020.06.011","article-title":"Pacing profiles and tactical behaviors of elite runners","volume":"10","author":"Casado A","year":"2021","unstructured":"Casado A, Hanley B, Jim\u00e9nez-Reyes P, Renfree A. 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