Can leg claudication ever get better on its own?

With exercise: Claudication symptoms can be improved with exercise. With a regular program exercise endurance can improve. It is unlikely for symptoms ro go away on their own.

With exercise: Claudication can get better with exercise. Why? Because exercise improves the muscles ability to utilize oxygen efficiently. Athletes can run a marathon at high speeds because they trained their leg muscles. Similarly, although claudicants are unlikely to run a marathon, they can, with training, eventually walk long distances without pain. Not smoking, eating well, and medical treatment help too!