title: Chronic resistance exercise training improves natural killer cell activity in older women.
abstract: BACKGROUND
  Regular exercise has been reported to slow the age-associated declines in natural killer cell activity (NKCA). To evaluate this response, we recruited older, postmenopausal women (65-85 years old) to fill one of two groups: training (10 weeks of resistance exercise; TR) or control.
  
  
  METHODS
  Blood samples were collected from an arm vein in the TR group at rest (PRE), immediately following (POST), and 2 hours (2H) following an acute bout of resistance exercise both before (BEFORE) and after (AFTER) training. Leukocytes and NKCA were determined by flow cytometry and a whole blood (51)Cr release assay, respectively.
  
  
  RESULTS
  Acute exercise increased total leukocyte (p < .05), CD8 (p < .05), CD4 (p < .05), and CD56 counts (p < .05), but there was no effect of training. NKCA was greater TR-AFTER-PRE (136%), -POST (80%), and -2H (127%) compared to similar values from TR-BEFORE (p < .05).
  
  
  CONCLUSIONS
  Increased resting NKCA after chronic resistance training suggests that immunity has been improved.
authors.affiliation: Department of Health and Human Performance, University of Houston, Texas 77204-6015, USA. bmcfarlin@uh.edu
authors.forename: Brian K
authors.initials: BK
authors.lastname: McFarlin
authors.forename: Michael G
authors.initials: MG
authors.lastname: Flynn
authors.forename: Melody D
authors.initials: MD
authors.lastname: Phillips
authors.forename: Laura K
authors.initials: LK
authors.lastname: Stewart
authors.forename: Kyle L
authors.initials: KL
authors.lastname: Timmerman
mesh_terms: D000368:Aged; D015444:Exercise / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007694:Killer Cells, Natural / Q000502:physiology*; D007958:Leukocyte Count