This limited competition FOA is to continue The LIFE Study. The LIFE Study was designed to determine whether a long-term structured physical activity (PA) program, as compared with a successful aging (SA) health education program, reduces the risk of major mobility disability, defined as incapacity to walk 400 meters. The LIFE Study extension will determine effects of a long-term structured PA program on other important for older adults diseases and conditions, including mild cognitive impairment, dementia, cardiovascular disease, persistent major mobility disability, and other.