PHYSICAL-ACTIVITY AND IMMUNE FUNCTION IN ELDERLY WOMEN

The relationship between cardiorespiratory exercise, immune function, and upper respiratory tract infection (URTI) was studied in elderly wo men utilizing a randomized controlled experimental design with a follo w-up of 12 wk. Thirty-two sedentary. elderly Caucasian women, 67-85 vr of age, who met specific selection criteria, were randomized to eithe r a walking or calisthenic group: 30 completed the study. Twelve highl y conditioned elderly women. 65-84 yr of age. who were active in endur ance competitions, were recruited at baseline for cross-sectional comp arisons. Intervention groups exercised 30-40 min, 5 d.wk-1, for 12 wk, with the walking group training at 60% heart rate reserve and the cal isthenic group engaging in mild range-of-motion and flexibility moveme nts that kept their heart rates close to resting levels. At baseline, the highly conditioned subjects exhibited superior NK (119 +/- 13 vs 7 7 +/- 8 lytic units, P < 0.01) and T (33.3 +/- 4.9 vs 21.4 +/- 2.1 cpm x 10(-3) using PHA. P < 0.05) cell function. despite no differences i n circulating levels of lymphocyte subpopulations. Twelve weeks of mod erate cardiorespiratory exercise improved the VO2max of the sedentary subjects 12.6%, but did not result in any improvement in NK cell activ ity or T cell function. Incidence of URTI was lowest in the highly con ditioned group and highest in the calisthenic control group during the 12-wk study, with the walkers in an intermediate position (chi-square = 6.36, P = 0.042). In conclusion, the highly conditioned elderly wom en in this study had superior NK and T cell function when compared wit h their sedentary counterparts. Twelve weeks of moderate cardiorespira tory exercise. however, was not associated with an improvement in immu ne function in previously sedentary elderly women.