Several recent important studies have clearly shown that a low physical fitness represents a potent risk factor and even a predictor of both cardiovascular and all-causes morbidity and mortality. As a consequence, physical fitness assessment should be performed at the clinical level since, when properly assessed, it is a highly valuable health and life expectancy indicator. Based on the results of fitness assessment in a particular person and knowing his/her life style and daily physical activity, an individually adapted training program can be prescribed. This training program will allow that person to develop his/her maximal physical potential while improving his/her physical and mental health and attenuating the deleterious consequences of aging. In fact, physical exercise is today proposed as a highly effective means to treat and prevent major morbidity and mortality causes in industrialized countries. Most of these causes are associated with the aging process. In order to be effective, this type of intervention should be directed to improve the aerobic capacity and strength. In addition, it should be complemented with work directed to improve the general coordination and flexibility. Finally, diet optimization and use of nutritional supplements and legal ergogenic aids are key elements to improve the functional capacity and health, all of which is synonymous of anti-aging interventions.