title: Markers of chronic inflammation with short-term changes in physical activity.
abstract: OBJECTIVE
  Regular exercise is inversely related to markers of chronic inflammation, but we do not know to what extent these changes are the product of recent exercise behavior. The aim of the present investigation was to examine the stability of markers of chronic inflammation in the face of short-term positive and negative changes in physical activity in middle-aged men.
  
  
  METHODS
  Two studies were conducted using a randomized counterbalanced design. In the first study (Study 1), eight highly active men (age = 56 ± 5 yr, body mass index (BMI) = 23.3 ± 3.2 kg·m(-2), VO(2max) = 50.7 ± 7.0 mL·kg(-1)·min(-1)) undertook two trials; withdrawal of exercise for 1 wk versus control (normal exercise behavior). In the second study (Study 2), 10 sedentary men (age = 57 ± 2 yr, BMI = 27.9 ± 3.6 kg·m(-2), VO(2max) = 30.4 ± 4.6 mL·kg(-1)·min(-1)) undertook 30 min of daily walking at 60% VO(2max) for 1 wk versus control (normal sedentary behavior).
  
  
  RESULTS
  The withdrawal of exercise for 1 wk in highly active men (Study 1) and the imposition of 1 wk of daily exercise in sedentary men (Study 2) did not elicit any substantial changes in the inflammatory proteins C-reactive protein (CRP), IL-6, and TNF-α and circulating leukocyte concentration. The differences in inflammatory proteins between active (Study 1) and sedentary (Study 2) men were marked; for example, baseline CRP was 0.85 ± 0.79 and 3.02 ± 2.30 mg·L(-1), respectively.
  
  
  CONCLUSIONS
  The inflammatory markers CRP, IL-6, and TNF-α are stable and not affected by large short-term positive or negative alterations in exercise behavior. This stability strengthens the use of these markers in clinical and research settings because differences and changes are not simply the product of recent exercise behavior.
authors.affiliation: Department for Health, University of Bath, Bath, United Kingdom.
authors.forename: Adam J S
authors.initials: AJ
authors.lastname: Lund
authors.forename: Tina L
authors.initials: TL
authors.lastname: Hurst
authors.forename: Rex M
authors.initials: RM
authors.lastname: Tyrrell
authors.forename: Dylan
authors.initials: D
authors.lastname: Thompson
mesh_terms: D000368:Aged; D000886:Anthropometry; D015415:Biomarkers; D002097:C-Reactive Protein / Q000032:analysis*; D002908:Chronic Disease; D016207:Cytokines / Q000097:blood*; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000209:etiology / Q000378:metabolism*; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*
chemical_list: D015415:Biomarkers; D016207:Cytokines; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein