Chronic resistance exercise training improves natural killer cell activity in older women.
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.
McFarlin
Brian K
BK
Department of Health and Human Performance, University of Houston, Texas 77204-6015, USA. bmcfarlin@uh.edu
Flynn
Michael G
MG
Phillips
Melody D
MD
Stewart
Laura K
LK
Timmerman
Kyle L
KL
D000368:Aged; D015444:Exercise / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007694:Killer Cells, Natural / Q000502:physiology*; D007958:Leukocyte Count