On one of my last conference calls before I retired, my replacement pointed out that it was my last call (yea!) A retired Judge from Florida offered advice, get a dog, walking the dog will force you to get out to walk everyday.
I didn't get a dog, but I am getting out for daily walkies. I walk at least an hour every day. If the weather is mild, I walk outside. If the weather is nasty, I walk on the treadmill at the gym here at the condo. If we are out of town, I walk more, much more.
Walking is simple, one foot in front of the other. If I couldn't walk, I would roll. Walking requires little - a good pair of shoes. I started wearing top of the line running shoes in my early 30's when I was running 1,000 miles a year. I replace my shoes 2 or 3 times a year, the padding breaks down in them. Most often I buy shoes that are on sale, and don't care what they look like. Sometimes I buy shoes because I like the look. A few years ago I spent months tracking down a pair of Nike that I saw in photos, they were released for the Japanese market and had to be special ordered.
Walking clears my mind. It gives me time to think. It gives me time to figure out the rambles in my mind. It gives me time to relax. It should be good for my body. A simple rule, if it hurts, change what you are doing. I vary speed, and surface to stay comfy.