title: Cell-free plasma DNA as a novel marker of aseptic inflammation severity related to exercise overtraining.
abstract: BACKGROUND
  Circulating free plasma DNA is implicated in conditions associated with tissue injury, including exercise-induced inflammation, and thus is a potential marker for athletic overtraining.
  
  
  METHODS
  We measured free plasma DNA along with C-reactive protein (CRP), creatine kinase (CK), and uric acid (UA) in 17 recreationally trained men participating in a 12-week resistance training regimen (8 resistance multi-joint exercises selected to stress the entire musculature: bench press, squat, leg press, snatch, hang clean, dead lifts, barbell arm curls, and rowing), consisting of 4 training periods (t1, t2, t3, and t4).
  
  
  RESULTS
  Plasma DNA concentrations increased markedly after t1, t2, and t3 and returned to baseline after t4. There were substantial differences between t2 and t1 and between t3 and t2 plasma DNA concentrations. CRP increased by 300% after t2 and by 400% after t3 (there was no difference between t2 and t3 CRP values) compared with baseline (t0). CK increased only after t3. UA increased after t2 and t3, with a greater increase after t3.
  
  
  CONCLUSIONS
  This study demonstrates that, after chronic excessive resistance exercise, plasma DNA concentrations increase in proportion to training load, suggesting that plasma DNA may be a sensitive marker for overtraining-induced inflammation.
authors.affiliation: Department of Physical Education and Sports Science, Democritus University of Thrace, Komotini Greece.
authors.forename: Ioannis G
authors.initials: IG
authors.lastname: Fatouros
authors.forename: Aspasia
authors.initials: A
authors.lastname: Destouni
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Margonis
authors.forename: Athanasios Z
authors.initials: AZ
authors.lastname: Jamurtas
authors.forename: Christina
authors.initials: C
authors.lastname: Vrettou
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Kouretas
authors.forename: George
authors.initials: G
authors.lastname: Mastorakos
authors.forename: Asimina
authors.initials: A
authors.lastname: Mitrakou
authors.forename: Kiriakos
authors.initials: K
authors.lastname: Taxildaris
authors.forename: Emmanouel
authors.initials: E
authors.lastname: Kanavakis
authors.forename: Ioannis
authors.initials: I
authors.lastname: Papassotiriou
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D004247:DNA / Q000097:blood*; D015444:Exercise; D006801:Humans; D007249:Inflammation / Q000175:diagnosis*; D008297:Male; D010949:Plasma; D012016:Reference Values; D013177:Sports
chemical_list: D015415:Biomarkers; D004247:DNA