Walking is good for all of your body, mind and spirit. For localizing exercise on certain parts of your body, there are good suggestions everywhere. For arms and upper body, use at least a 5 pound weight to lift out and straight up from your body. Repeat this 10-20 times each session dependent on being a beginner or a regular exerciser. Even if you walk, this is good for your upper body if you have excess weight there. If you are under 50, you should be able to do push-ups. Over 50 you get torso results with a floor exercise. Sit flat on the floor and raise both legs so that toes are same height as your head and stretch your arms straight out and hold for 5 seconds. Repeat 5-10 times. Add a forward type plank lying flat on floor raise your full body until your knees are straight up above your heels; clasp your hands underneath your body and stretch your arms out straight. Hold for 5-10 seconds at least 10 times. For arms, legs and central body balance, place knees and hands on floor and lift right arm and left leg at the same time. Do the same with left arm and right leg at least 5 times each session. These are the exercises you can do at home on rainy or cold days. Do not skip days that you cannot go out to walk or run.
The above exercises help with balance besides the circulation from brain to toes. You can find other helpful advice at my website: http://www.weightlift-off.com/.
To your good health, joyduf