I am near 70 years old. Of course, I have had surgeries and injuries. I will share my exercise routine and how I developed the same. Like most guys, I was doing weightlifting. Fine. Then one day, I go to the doctor and announce that I probably need a hip replacement. Off to the physical therapist at Kaiser. I had two physical therapists. They tested me on what I could do, make the written recommendations and I was onto being able to walk properly. (I had been injured in martial arts). Then I discovered two books that helped. One is entitled Backache, stress and Tension by Dr. Hans Krause, MD. John Kennedy's physician. Skyhorse Publishing. He came up with 7 movements to test for back problems. If you were not able to complete just one iteration on a movement, he identified a series of exercises, the order of the exercises and photographs of how to do the exercises. He predicted that 80% of the people could be helped by running the tests and doing the exercises. So, I incorporated the Kaiser physical therapist exercises into some recommended by the published doctor.. Then, I found Complete Idiot's Guide to Core Conditioning. Exercises could be done without equipment. The most challenging appeared to be the Superman exercise. You lay flat on your stomach with the arms stretched in front and the legs stretched behind. You lift the legs and arms and hold the position. I do the amalgamated exercises on a floor mat (although I have done them many times on grass in the yard). Takes me an hour. No pain whatsoever. Takes over an hour a day. I have a simple Pilates Machine. I don't do the arm exercises with it. I do simple leg exercises that take about five minutes and keep the legs toned. Yes, I feel it in the legs. I have an old cross country skiing machine. I use the arm portion because I seem to not be able to coordinate the leg and arm movements. Takes a few minutes a day - and I can feel it in the arms. So, you might wonder where the cardio comes in. I do Argentine tango. Pay for just one class on Saturday afternoon and help in two other classes in the afternoon. Then, schedule permitting, I can dance during the week. When you think dance is for sissys, I relate the following. I have danced tango with women in their 90s. I know dancers who are over 100 years old. The mortality table indicates that avid dancers live many years past the average and are in better health as they live.