{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T17:30:14Z","timestamp":1790011814314,"version":"4.0.1"},"reference-count":28,"publisher":"Human Kinetics","issue":"11","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2024,11,1]]},"abstract":"<jats:p><jats:italic><jats:bold>Purpose<\/jats:bold>:<\/jats:italic> Continuous glucose monitors (CGMs) are becoming increasingly popular among endurance athletes despite unconfirmed accuracy. We assessed the concurrent validity of the FreeStyle Libre 2 worn on 2 different sites at rest, during steady-state running, and postprandial. <jats:italic><jats:bold>Methods<\/jats:bold>:<\/jats:italic> Thirteen nondiabetic, well-trained recreational runners (age\u2009=\u200940 [8]\u00a0y, maximal aerobic oxygen consumption\u2009=\u200946.1 [6.4]\u00a0mL\u00b7kg<jats:sup>\u20131<\/jats:sup>\u00b7min<jats:sup>\u20131<\/jats:sup>) wore a CGM on the upper arm and chest while treadmill running for 30, 60, and 90\u00a0minutes at intensities corresponding to 50%, 60%, and 70% of maximal aerobic oxygen consumption, respectively. Glucose was measured by manually scanning CGMs and obtaining a finger-prick capillary blood glucose sample. Mean absolute relative difference, time in range, and continuous glucose Clarke error grid analysis were used to compare paired CGM and blood glucose readings. <jats:italic><jats:bold>Results<\/jats:bold>:<\/jats:italic> Across all intensities of steady-state running, we found a mean absolute relative difference of 13.8 (10.9) for the arm and 11.4 (9.0) for the chest. The coefficient of variation exceeded 70%. Approximately 47% of arm and 50% of chest paired glucose measurements had an absolute difference \u226410%. Continuous glucose Clarke error grid analysis indicated 99.8% (arm) and 99.6% (chest) CGM data fell in clinically acceptable zones A and B. Time-in-range analysis showed reduced accuracy at lower glucose levels. However, CGMs accurately detected trends in mean glucose readings over time. <jats:italic><jats:bold>Conclusions<\/jats:bold>:<\/jats:italic> CGMs are not valid for point glucose monitoring but appear to be valid for monitoring glucose trends during steady-state exercise. Accuracy is similar for arm and chest. Further research is needed to determine whether CGMs can detect important events such as hypoglycemia during exercise.<\/jats:p>","DOI":"10.1123\/ijspp.2024-0102","type":"journal-article","created":{"date-parts":[[2024,9,9]],"date-time":"2024-09-09T11:29:15Z","timestamp":1725881355000},"page":"1307-1313","source":"Crossref","is-referenced-by-count":5,"title":["Validating the Use of Continuous Glucose Monitors With Nondiabetic Recreational Runners"],"prefix":"10.1123","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-0877-9556","authenticated-orcid":true,"given":"Lesley J.","family":"Mason","sequence":"first","affiliation":[{"name":"Faculty of Health Sciences, Australian Catholic University, Strathfield, NSW, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8018-4038","authenticated-orcid":true,"given":"Timothy","family":"Hartwig","sequence":"additional","affiliation":[{"name":"School of Exercise Science, Australian Catholic University, Strathfield, NSW, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9574-3656","authenticated-orcid":true,"given":"David","family":"Greene","sequence":"additional","affiliation":[{"name":"School of Exercise Science, Australian Catholic University, Strathfield, NSW, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"100","reference":[{"issue":"9","key":"r1","series-title":"Int J Environ Res Public Health","doi-asserted-by":"publisher","DOI":"10.3390\/ijerph18094963","article-title":"Regulation of energy substrate metabolism in endurance exercise","volume":"18","author":"Alghannam AF","year":"2021","unstructured":"Alghannam AF, Ghaith MM, Alhussain MH. 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