Physical Exercise Increases Natural Cellular-Mediated Tumor Cytotoxicity in Elderly Women

Abstract
The influence of acute treadmill exercise on natural killer (NK) cell tumor cytotoxicity in vitro was studied in elderly women after participation in a program of physical exercise training (PET) (n = 7) or after participation in a paralleling nonexercise control (NEC) condition (n = 7). The two study groups were equated (p > 0.05) according to age, percent total body fat, functional status as measured by multi-inventory ranking, and exercise capacity. After the experimental period, the PET subjects had a greater basal level of NK activity than the NEC subjects (PET 38.2 percent specific lysis, %SL, vs. NEC 28.8% SL; p < 0.05). Both groups experienced an increase in NK activity after acute treadmill exercise (PET 38.2–57.4% SL, p < 0.01; NEC 28.8–37.8% SL, p < 0.05), but the increase in the PET subjects was significantly (p < 0.05) grater than that observed in the NEC subjects. We conclude that natural cellular-mediated tumor cytotoxicity is increased in response to acute exercise and long-term PET in elderly women.