To maintain basic fitness it does not matter so much what form of exercise is chosen, as long as it is not damaging to the skeletal system or connective tissues. Many people are unable to run due to foot, knee, hip, or back problems, but almost everyone can walk. Walking outside is better than inside on a treadmill, and walking hills is better than walking on flat ground. Exercise machines such as stationary bikes, cross country ski machines, and stair steppers work well for a lot of people who live in the city, especially in the winter, or for those who hate exercise. Whatever you choose to do, it is important to at least double the resting pulse for 30 minutes no less than four days a week. This is the absolute minimum required to maintain the health and function of the cardiovascular-pulmonary system. If your resting pulse is 70, you must walk, jog, ski, bike, swim or what have you, fast enough to keep the pulse at 140 beats per minute for at least 30 minutes. I have a strong preference to exercising outside in isolated places where there is only me and the forest, or only me and the river. Running along logging roads in the hilly back country, or swimming in the green unpolluted water of a forest river is a spiritual experience for me. It is a time to meditate, to commune with nature, and to clear my mind and create new solutions. The repetitive action of running or walking or swimming, along with the regular deep breathing in clean air, with no distractions except what nature provides is truly health promoting. Sharing these activities with friends or family can also be great fun and some of the best in social interactions. It is one of my favorite ways of visiting with people. I don't expect other people to be as enthusiastic about exercise as I am, but I do hope that everyone will make an effort to be minimally fit as an ongoing part of their health program into old age. Diet For A Long, Long Life Some people not only want to be healthy, but they want to live in good health long past the normal life span projected by statistical tables for Homo Sapiens. Dr. Roy Walford, a well-respected medical research gerontologist who has been actively studying longevity for many years, is one of those. He has scientifically demonstrated with accepted studies that a qualitative life span up to at least 115 years of age is reasonably attainable by the average person if they start working on it no later than about 50 years of age, though earlier is much better.