Effects of endurance training on selected parameters of immune function inelderly women

Background: Immune function decreases with age, rendering the elderly more susceptible to infection and tumor development. In addition, intense exerci se has been shown to decrease immune function in some populations. Few stud ies have examined the effects of exercise on immune function in the elderly and, to our knowledge, no studies have examined the effects of exercise on a population of active, but nonexercising elderly. Objective: The purpose of this study was to examine the effects of a 10-week endurance training pr ogram on selected parameters of immune function in active elderly women. Me thods: A total of 29 healthy, active women, aged 70-87, were randomly assig ned to either an exercise (76 +/- 5 years, n = 15) or control (77 +/- 6 yea rs, n = 14) group. The exercise group walked 3 days/week at 70% heart rate reserve (HRR). The duration on day 1 was 20 min and it was increased by 5 m in each day until subjects were walking for 50 min (week 3). It remained at 50 min for the duration of the study, while controls maintained normal act ivity. Blood samples were obtained from both groups at rest, and from the e xercise group after 20 min of walking at 70% HRR and after 2 h of recovery. Blood samples were collected prior to endurance training and again after 1 0 weeks of endurance training. Results: There was a significant decrease in 1-mile walk times as well as heart rate at completion of the walk in the e xercise group. Natural cell-mediated cytotoxicity (NCMC) was significantly higher post-exercise, compared to pre-exercise both before and after traini ng. After training it remained significantly elevated 2 h postexercise. The resting NCMC was significantly decreased in controls at week 10 but not in the exercise group. Conclusion: Ten weeks of endurance training resulted i n a significant decrease in both the 1-mile walk time and the post-walk hea rt rate in the exercisers but not the controls, without resulting in either an acute or chronic suppression of immune function. Further, endurance tra ining may lead to an attenuation of the decrease in cellular immune measure s which occurs during the winter, since the control group experienced a dec rease in NCMC and the exercisers did not. Copyright (C) 2000 S.Karger AG, B asel.