many people do say after 50 years, my lower legs get skinner. Our body temperature's 40 percent is made by the muscles. And 70 percent of muscles are in the lower extremities. As long as we use muscles with exercises, we produce energy with exercise and the body termperature will go up.
This will help the prevention of skinning legs. I recommed you walk 10,000 steps everyday. With 60-100 meter/minute. Do for 20 minutes 3 times a week.