Telomeres, Aging and Exercise: Guilty by Association? Author: Chilton W1, O'Brien B2, Charchar F3,4,5 Affiliation: <sup>1</sup>Faculty of Health Sciences and Faculty of Science and Technology, Federation University Australia, Ballarat, VIC 3350, Australia. w.chilton@federation.edu.au. <sup>2</sup>Faculty of Health Sciences and Faculty of Science and Technology, Federation University Australia, Ballarat, VIC 3350, Australia. b.obrien@federation.edu.au. <sup>3</sup>Faculty of Health Sciences and Faculty of Science and Technology, Federation University Australia, Ballarat, VIC 3350, Australia. f.charchar@federation.edu.au. <sup>4</sup>Department of Physiology, University of Melbourne, Melbourne, VIC 3010, Australia. f.charchar@federation.edu.au. <sup>5</sup>Department of Cardiovascular Sciences, University of Leicester, Leicester LE1 7RH, UK. f.charchar@federation.edu.au. Conference/Journal: Int J Mol Sci. Date published: 2017 Nov 29 Other: Volume ID: 18 , Issue ID: 12 , Special Notes: doi: 10.3390/ijms18122573. , Word Count: 155 Telomeres are repetitive tandem DNA sequences that cap chromosomal ends protecting genomic DNA from enzymatic degradation. Telomeres progressively shorten with cellular replication and are therefore assumed to correlate with biological and chronological age. An expanding body of evidence suggests (i) a predictable inverse association between telomere length, aging and age-related diseases and (ii) a positive association between physical activity and telomere length. Both hypotheses have garnered tremendous research attention and broad consensus; however, the evidence for each proposition is inconsistent and equivocal at best. Telomere length does not meet the basic criteria for an aging biomarker and at least 50% of key studies fail to find associations with physical activity. In this review, we address the evidence in support and refutation of the putative associations between telomere length, aging and physical activity. We finish with a brief review of plausible mechanisms and potential future research directions. KEYWORDS: aging; association; biomarker; physical activity; telomeres PMID: 29186077 DOI: 10.3390/ijms18122573