We need to have three goals for aging. The first two are clear; survival and avoiding disease. Equally important is a third goal, to maintain fitness and a high level of four reserve factors. These reserve factors allow us to successfully respond to the challenges we face as we age. Cognitive reserve is the capacity to maintain effective cognitive function despite age-related changes in the brain. Maintaining high cognitive reserve is not our only goal. We must also maintain high physical, psychological, and social reserves. Physical reserve reflects the capacity of all our body systems. Psychological reserve is our ability to maintain healthy mental function, and social reserve describes our interpersonal network and supports. With aging, our ability to function is dependent upon the interaction of these four reserve factors. Our capacity to respond well to adversity is called resilience and is a fundamental goal of aging. It is important to realize the critical nature of these four reserve factors because through our actions we can enhance our capacity for resilience and enhanced fitness with aging.