PURPOSE: Physical activity training programs in older adults have recognized health benefits. Evidence suggests that training should include a combination of progressive resistance, balance, and functional training. Our aim was to assess the effects of a simple physical activity program working on strength, flexibility, cardiovascular fitness, and balance in older adults, as well as the effects of a detraining period, at various different ages. METHODS: This was longitudinal prospective study, including a convenience sample of 227 independent older adults (54 men, 173 women) who completed a simple 9-month training program and 3-month detraining follow-up. The subjects were categorized into two age groups (65-74 [n = 180], and >74 years [n = 47]). At the beginning of the study (baseline), the end of the training period, and 3 months later (postdetraining), body mass index, body fat percentage, triceps skinfold thickness, hand grip strength, lower limb and trunk flexibility, resting heart rate, heart rate after exercise, and balance were measured, while VO(2 max) was estimated using the Rockport fitness test and/or measured directly. RESULTS: Significant improvements in strength (p < .0001), flexibility (p < .0001), heart rate after exercise (p < .0001), and balance (p < .0001) were observed at the end of the training program. Flexibility and balance (p < .0001) improvements were maintained at the end of the detraining. CONCLUSION: A simple long-term physical activity training program increases strength in both sexes, improves flexibility in women, and improves balance in older adults. The results also indicate the importance of beginning early in old age and maintaining long-term training.