The loss of strength and power in old age has important implications for health. Even with healthy elderly people, cross-sectional comparisons imply a loss of strength at some 1.5% per year and of power at some 3.5% per year (averaged across the age range 65 to 84). On the other hand, healthy, very elderly people are at least as responsive to strength-training as younger adults. It is important to establish whether elderly people derive functional benefit from training-induced improvements in strength and whether laboratory measurements of strength and power might be used to identify those elderly people most at risk of losing important, everyday functional abilities.