{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T01:47:05Z","timestamp":1760060825711,"version":"build-2065373602"},"reference-count":30,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2025,9,19]],"date-time":"2025-09-19T00:00:00Z","timestamp":1758240000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["82173575","2242023k30022"],"award-info":[{"award-number":["82173575","2242023k30022"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012226","name":"Fundamental Research Funds for the Central Universities","doi-asserted-by":"publisher","award":["82173575","2242023k30022"],"award-info":[{"award-number":["82173575","2242023k30022"]}],"id":[{"id":"10.13039\/501100012226","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Metabolites"],"abstract":"<jats:p>Purpose: To explore the potential relationship between salivary amino acid concentrations and 8 km running performance in male undergraduate students. Methods: Thirty male undergraduate students were recruited. Participants completed an 8 km run while wearing smart bracelets. Saliva samples were collected before, immediately after, and 24 h after the run. Ultra-High Performance Liquid Chromatography (UHPLC) was used to quantify salivary amino acids. Results: The fast group (average speed &gt; 12.80 km\/h) had a significantly shorter running time (35.66 \u00b1 1.30 min, p &lt; 0.001) and higher speed (13.59 \u00b1 0.46 km\/h, p &lt; 0.001) than the slow group. Before the run, salivary serine concentration (20.19 \u00b5g\/mL, p = 0.013) was higher in the fast group. After 24 h, salivary glutamine concentration (6.65 \u00b5g\/mL, p = 0.047) was lower in the fast group. Salivary threonine concentration was positively correlated with running speed. For every 1 \u00b5g\/mL increase in salivary threonine concentration, average running speed increased by 0.011 km\/h, and this correlation persisted after adjusting for age and heart rate. Conclusions: This study found a positive correlation between salivary threonine and 8 km running speed, along with differences in serine and glutamine concentrations among runners with different speeds. These findings provide preliminary evidence for the relationship between salivary amino acid concentrations and running performance, though further research with larger samples and diverse exercise types is needed.<\/jats:p>","DOI":"10.3390\/metabo15090625","type":"journal-article","created":{"date-parts":[[2025,9,19]],"date-time":"2025-09-19T10:08:58Z","timestamp":1758276538000},"page":"625","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Impact of Salivary Amino Acid Concentrations on 8 km Running Performance in Male Undergraduate Students: A Prospective Observational Study Based on HPLC"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-5144-0866","authenticated-orcid":false,"given":"Hai","family":"Zhao","sequence":"first","affiliation":[{"name":"Key Laboratory of Child Development and Learning Science (Ministry of Education), School of Biological Science and Medical Engineering, Southeast University, Nanjing 211189, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kangwei","family":"Shen","sequence":"additional","affiliation":[{"name":"Key Laboratory of Child Development and Learning Science (Ministry of Education), School of Biological Science and Medical Engineering, Southeast University, Nanjing 211189, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wei","family":"Fan","sequence":"additional","affiliation":[{"name":"Key Laboratory of Child Development and Learning Science (Ministry of Education), School of Biological Science and Medical Engineering, Southeast University, Nanjing 211189, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mengjie","family":"Li","sequence":"additional","affiliation":[{"name":"Key Laboratory of Child Development and Learning Science (Ministry of Education), School of Biological Science and Medical Engineering, Southeast University, Nanjing 211189, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8581-4446","authenticated-orcid":false,"given":"Xuejun","family":"Kang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Child Development and Learning Science (Ministry of Education), School of Biological Science and Medical Engineering, Southeast University, Nanjing 211189, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,9,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1117","DOI":"10.1007\/s40279-017-0835-7","article-title":"Effects of Strength Training on the Physiological Determinants of Middle- and Long-Distance Running Performance: A Systematic Review","volume":"48","author":"Blagrove","year":"2018","journal-title":"Sports Med."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"259","DOI":"10.1007\/BF02343797","article-title":"The energetics of endurance running","volume":"55","author":"Atchou","year":"1986","journal-title":"Eur. J. Appl. Physiol. Occup. Physiol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"683","DOI":"10.1152\/jappl.1991.70.2.683","article-title":"Modeling: Optimal marathon performance on the basis of physiological factors","volume":"70","author":"Joyner","year":"1991","journal-title":"J. Appl. Physiol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"991","DOI":"10.1249\/MSS.0b013e3181c0669d","article-title":"Test of the classic model for predicting endurance running performance","volume":"42","author":"McLaughlin","year":"2010","journal-title":"Med. Sci Sports Exerc."},{"key":"ref_5","first-page":"456","article-title":"Physiological aspects of running economy","volume":"24","author":"Morgan","year":"1992","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1615\/CritRevOncog.2018027598","article-title":"Current State of Knowledge on Salivary Gland Cancers","volume":"23","author":"Lin","year":"2018","journal-title":"Crit. Rev. Oncog."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1354936","DOI":"10.3389\/fmicb.2024.1354936","article-title":"Transcriptome analysis of salivary glands of rabies-virus-infected mice","volume":"15","author":"Guo","year":"2024","journal-title":"Front. Microbiol."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Sezanova, K., Gergulova, R., Shestakova, P., and Rabadjieva, D. (2024). Thermodynamic and Kinetic Studies of the Precipitation of Double-Doped Amorphous Calcium Phosphate and Its Behaviour in Artificial Saliva. Biomimetics, 9.","DOI":"10.3390\/biomimetics9080455"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"e30858","DOI":"10.1371\/journal.pone.0030858","article-title":"Expensive egos: Narcissistic males have higher cortisol","volume":"7","author":"Reinhard","year":"2012","journal-title":"PLoS ONE"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1189","DOI":"10.1007\/s00726-023-03308-y","article-title":"Common alterations in plasma free amino acid profiles and gut microbiota-derived tryptophan metabolites of five types of cancer patients","volume":"55","author":"Hussain","year":"2023","journal-title":"Amino Acids"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Zhao, H., and Kang, X. (2024). Associations of Depression Score with Dialkyl Phosphate Metabolites in Urine: A Cross-Sectional Study. Brain Sci., 14.","DOI":"10.3390\/brainsci14121290"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"e0153229","DOI":"10.1371\/journal.pone.0153229","article-title":"Intake of Protein Plus Carbohydrate during the First Two Hours after Exhaustive Cycling Improves Performance the following Day","volume":"11","author":"Rustad","year":"2016","journal-title":"PLoS ONE"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"409","DOI":"10.1146\/annurev.nu.04.070184.002205","article-title":"Branched-chain amino acid metabolism","volume":"4","author":"Harper","year":"1984","journal-title":"Annu. Rev. Nutr."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"E485","DOI":"10.1152\/ajpendo.00177.2014","article-title":"FOXO1 activates glutamine synthetase gene in mouse skeletal muscles through a region downstream of 3\u2032-UTR: Possible contribution to ammonia detoxification","volume":"307","author":"Kamei","year":"2014","journal-title":"Am. J. Physiol. Endocrinol. Metab."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Kamei, Y., Hatazawa, Y., Uchitomi, R., Yoshimura, R., and Miura, S. (2020). Regulation of Skeletal Muscle Function by Amino Acids. Nutrients, 12.","DOI":"10.3390\/nu12010261"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"e0129084","DOI":"10.1371\/journal.pone.0129084","article-title":"Metabolomic Analysis of the Skeletal Muscle of Mice Overexpressing PGC-1\u03b1","volume":"10","author":"Hatazawa","year":"2015","journal-title":"PLoS ONE"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2263409","DOI":"10.1080\/15502783.2023.2263409","article-title":"International Society of Sports Nutrition Position Stand: Effects of essential amino acid supplementation on exercise and performance","volume":"20","author":"Ferrando","year":"2023","journal-title":"J. Int. Soc. Sports Nutr."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"4351","DOI":"10.1210\/jc.2003-032159","article-title":"Essential amino acid and carbohydrate supplementation ameliorates muscle protein loss in humans during 28 days bedrest","volume":"89","author":"Urban","year":"2004","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1093\/ajcn\/78.2.250","article-title":"Essential amino acids are primarily responsible for the amino acid stimulation of muscle protein anabolism in healthy elderly adults","volume":"78","author":"Volpi","year":"2003","journal-title":"Am. J. Clin. Nutr."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"E488","DOI":"10.1152\/ajpendo.00094.2002","article-title":"Reduced amino acid availability inhibits muscle protein synthesis and decreases activity of initiation factor eIF2B","volume":"284","author":"Kobayashi","year":"2003","journal-title":"Am. J. Physiol. Endocrinol. Metab."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"586","DOI":"10.1016\/S0016-5085(19)32783-0","article-title":"Comparison of free amino acid and dipeptide absorption in the jejunum of sprue patients","volume":"67","author":"Adibi","year":"1974","journal-title":"Gastroenterology"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"E1011","DOI":"10.1152\/ajpendo.00690.2009","article-title":"An increase in essential amino acid availability upregulates amino acid transporter expression in human skeletal muscle","volume":"298","author":"Drummond","year":"2010","journal-title":"Am. J. Physiol. Endocrinol. Metab."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"315","DOI":"10.1113\/jphysiol.2003.050674","article-title":"Human muscle protein synthesis is modulated by extracellular, not intramuscular amino acid availability: A dose-response study","volume":"552","author":"Low","year":"2003","journal-title":"J. Physiol."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Church, D.D., Hirsch, K.R., Park, S., Kim, I.-Y., Gwin, J.A., Pasiakos, S.M., Wolfe, R.R., and Ferrando, A.A. (2020). Essential Amino Acids and Protein Synthesis: Insights into Maximizing the Muscle and Whole-Body Response to Feeding. Nutrients, 12.","DOI":"10.3390\/nu12123717"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1042\/bj2240355","article-title":"Gluconeogenesis from threonine in normal and diabetic rats","volume":"224","author":"Hetenyi","year":"1984","journal-title":"Biochem. J."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1007\/s00726-017-2490-6","article-title":"Roles of dietary glycine, proline, and hydroxyproline in collagen synthesis and animal growth","volume":"50","author":"Li","year":"2018","journal-title":"Amino Acids"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Hole\u010dek, M. (2022). Serine Metabolism in Health and Disease and as a Conditionally Essential Amino Acid. Nutrients, 14.","DOI":"10.3390\/nu14091987"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1186\/s13046-024-02994-0","article-title":"A glutamine tug-of-war between cancer and immune cells: Recent advances in unraveling the ongoing battle","volume":"43","author":"Wang","year":"2024","journal-title":"J. Exp. Clin. Cancer Res."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Cruzat, V., Macedo Rogero, M., Noel Keane, K., Curi, R., and Newsholme, P. (2018). Glutamine: Metabolism and Immune Function, Supplementation and Clinical Translation. Nutrients, 10.","DOI":"10.20944\/preprints201809.0459.v1"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Anderson, P.M., and Lalla, R.V. (2020). Glutamine for Amelioration of Radiation and Chemotherapy Associated Mucositis during Cancer Therapy. Nutrients, 12.","DOI":"10.3390\/nu12061675"}],"container-title":["Metabolites"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2218-1989\/15\/9\/625\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:48:52Z","timestamp":1760035732000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2218-1989\/15\/9\/625"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,9,19]]},"references-count":30,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2025,9]]}},"alternative-id":["metabo15090625"],"URL":"https:\/\/doi.org\/10.3390\/metabo15090625","relation":{},"ISSN":["2218-1989"],"issn-type":[{"type":"electronic","value":"2218-1989"}],"subject":[],"published":{"date-parts":[[2025,9,19]]}}}