{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,25]],"date-time":"2026-07-25T17:39:15Z","timestamp":1785001155540,"version":"3.55.0"},"reference-count":0,"publisher":"American Physiological Society","funder":[{"DOI":"10.13039\/501100001700","name":"Ministry of Education, Culture, Sports, Science and Technology","doi-asserted-by":"publisher","award":["22H00499"],"award-info":[{"award-number":["22H00499"]}],"id":[{"id":"10.13039\/501100001700","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002241","name":"MEXT | Japan Science and Technology Agency","doi-asserted-by":"publisher","award":["JPMJSP2124"],"award-info":[{"award-number":["JPMJSP2124"]}],"id":[{"id":"10.13039\/501100002241","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["journals.physiology.org"],"crossmark-restriction":true},"short-container-title":["American Journal of Physiology-Regulatory, Integrative and Comparative Physiology"],"abstract":"<jats:p> Hyperthermia stimulates ventilation (hyperthermia-induced hyperventilation). In exercising humans, once the core temperature reaches ~37\u00b0C, minute ventilation (V<jats:sub>E<\/jats:sub>) increases linearly with rising core temperature, and the slope of the relation between V<jats:sub>E<\/jats:sub> and core temperature reflects the sensitivity of the response. We previously reported that sodium bicarbonate ingestion reduces V<jats:sub>E<\/jats:sub> during prolonged exercise in the heat without affecting the sensitivity of hyperthermia-induced hyperventilation. Here, we hypothesized that reductions in V<jats:sub>E<\/jats:sub> associated with sodium bicarbonate ingestion reflect elevation of the core temperature threshold for hyperthermia-induced hyperventilation. Thirteen healthy young males ingested sodium bicarbonate (0.3 g\/kg body weight) (NaHCO<jats:sub>3<\/jats:sub> trial) or sodium chloride (0.208 g\/kg body weight) (NaCl trial), after which they performed a cycle exercise at 50% of peak oxygen uptake in the heat (35\u00b0C and 50% relative humidity) following a pre-cooling. The pre-cooling enabled detection of an esophageal temperature ( T<jats:sub>es<\/jats:sub>: an index of core temperature) threshold for hyperthermia-induced hyperventilation. The T<jats:sub>es<\/jats:sub> thresholds for increases in V<jats:sub>E<\/jats:sub> were similar between the two trials (P = 0.514). The slopes relating V<jats:sub>E<\/jats:sub> to T<jats:sub>es<\/jats:sub> also did not differ between trials (P = 0.131). However, V<jats:sub>E<\/jats:sub> was lower in the NaHCO<jats:sub>3<\/jats:sub> than the NaCl trial in the range of T<jats:sub>es<\/jats:sub> = 36.8-38.4\u00b0C (P &lt; 0.007, main effect of trial). These results suggest that sodium bicarbonate ingestion does not alter the core temperature threshold or sensitivity of hyperthermia-induced hyperventilation during prolonged exercise in the heat; instead, it downshifts the exercise hyperpnea. <\/jats:p>","DOI":"10.1152\/ajpregu.00282.2022","type":"journal-article","created":{"date-parts":[[2023,5,15]],"date-time":"2023-05-15T12:53:05Z","timestamp":1684155185000},"update-policy":"https:\/\/doi.org\/10.1152\/aps-crossmark-policy","source":"Crossref","is-referenced-by-count":4,"title":["Sodium bicarbonate reduces ventilation without altering core temperature threshold or sensitivity of hyperthermia-induced hyperventilation in exercising humans"],"prefix":"10.1152","author":[{"given":"Akira","family":"Katagiri","sequence":"first","affiliation":[{"name":"Institute of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Naoto","family":"Fujii","sequence":"additional","affiliation":[{"name":"Institute of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan"},{"name":"Advanced Research Initiative for Human High Performance (ARIHHP), University of Tsukuba, Ibaraki, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kohei","family":"Dobashi","sequence":"additional","affiliation":[{"name":"Faculty of Education, Hokkaido University of Education, Hokkaido, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yin-Feng","family":"Lai","sequence":"additional","affiliation":[{"name":"Institute of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bun","family":"Tsuji","sequence":"additional","affiliation":[{"name":"Department of Health Sciences, Prefectural University of Hiroshima, Hiroshima, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takeshi","family":"Nishiyasu","sequence":"additional","affiliation":[{"name":"Institute of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan"},{"name":"Advanced Research Initiative for Human High Performance (ARIHHP), University of Tsukuba, Ibaraki, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"24","published-online":{"date-parts":[[2023,5,15]]},"container-title":["American Journal of Physiology-Regulatory, Integrative and Comparative Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.physiology.org\/doi\/pdf\/10.1152\/ajpregu.00282.2022","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,5,15]],"date-time":"2023-05-15T12:53:08Z","timestamp":1684155188000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.physiology.org\/doi\/10.1152\/ajpregu.00282.2022"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,5,15]]},"references-count":0,"alternative-id":["10.1152\/ajpregu.00282.2022"],"URL":"https:\/\/doi.org\/10.1152\/ajpregu.00282.2022","relation":{},"ISSN":["0363-6119","1522-1490"],"issn-type":[{"value":"0363-6119","type":"print"},{"value":"1522-1490","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,5,15]]},"assertion":[{"value":"2022-11-04","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2023-05-10","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2023-05-15","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"ajpregu.00282.2022"}}