Immune function in marathon runners versus sedentary controls.
Marathon runners (N = 22) who had completed at least seven marathons (X +/- SEM = 23.6 +/- 5.7) and had been training for marathon race events for at least 4 yr (12.3 +/- 1.3) were compared with sedentary controls (N = 18). Although the two groups were of similar age (38.7 +/- 1.5 and 43.9 +/- 2.2 yr, respectively) and height, the marathon runners were significantly leaner and possessed a VO2max 60% higher than that of the controls. Neutrophil counts tended to be lower in the group of marathoners, while other leukocyte and lymphocyte subsets were similar to controls. Mitogen-induced lymphocyte proliferation did not differ between groups. Natural killer cell cytotoxic activity (NKCA) was significantly higher in the marathoners versus controls (373 +/- 38 vs 237 +/- 41 total lytic units, respectively, a 57% difference, P = 0.02). For all subjects combined (N = 40) and within the group of marathon runners (N = 22), percent body fat was negatively correlated with NKCA (r = -0.48, P = 0.002; r = -0.49, P = 0.019, respectively), and age was negatively correlated with Con A-induced lymphocyte proliferation (r = -0.41, P = 0.009; r = -0.53, P = 0.011, respectively). These data indicate that NKCA but not mitogen-induced lymphocyte proliferation is higher in marathon runners relative to sedentary controls.
Nieman
D C
DC
Department of Health, Leisure, and Exercise Science, Applachian State University, Boone, NC, USA.
Buckley
K S
KS
Henson
D A
DA
Warren
B J
BJ
Suttles
J
J
Ahle
J C
JC
Simandle
S
S
Fagoaga
O R
OR
Nehlsen-Cannarella
S L
SL
D000328:Adult; D016022:Case-Control Studies; D003602:Cytotoxicity, Immunologic / Q000502:physiology; D006801:Humans; D007111:Immunity, Cellular; D007694:Killer Cells, Natural / Q000276:immunology; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000502:physiology*; D012420:Running / Q000502:physiology*