LOW TO MODERATE INTENSITY ENDURANCE TRAINING IN HEALTHY OLDER ADULTS - PHYSIOLOGICAL-RESPONSES AFTER 4 MONTHS

Objective: To determine the physiological adaptations in previously sedentary healthy older men and women (mean age = 68) to a 16-week low-to-moderate-intensity exercise program. Design: Randomized, controlled trial. Setting: An exercise facility and testing laboratory in a gerontological research institute. Participants: Two-hundred forty-seven community-dwelling older persons free of significant cardiovascular, pulmonary, or uncontrolled metabolic disease, anemia, electrolyte abnormality, resting BP of 165/90 or greater, or chronic disease affecting the ability to exercise on a bicycle. Intervention: Subjects were randomly assigned to either an exercise (n = 166) or attention control group (n = 81). Exercisers trained thrice weekly for 40 minutes on a cycle ergometer (5-minute warm up , 30 minutes at training heart rate (THR), 5-minute cool down), THR was set at 70% of peak heart rate attained on a maximal exercise test (mean = 115 +/- 15). Control subjects attended weekly group talks. Testing took place before and after the program. Results: Peak attained oxygen uptake (VO2max) increased 8.5% in exercisers and decreased slightly in controls (p < .001) and oxygen uptake at ventilatory threshold (VeT VO2) increased by 3.5% in exercisers and decreased by 3% in controls (p < .001). This pattern of a greater increase in VO2max than VeT VO2 is different from that seen in young and middle-aged subjects. Conclusion: This study demonstrated that a large scale training program is feasible for healthy older people, that physiologic improvements can be measured after 16 weeks of low-to-moderate-intensity training, and that mechanisms of adaptation to exercise may be different in elderly subjects from those in younger ones.