Running is one of those activities in which you improve the more you do it. While that may seem like common sense, you’d be surprised how many people expect to improve while running without consistent and dedicated exercise. This is especially important for any beginner running program or long distance running.
There are essentially two components to how far you can run:
Aerobic and anaerobic capacity, and muscle endurance (or stamina).
The first is how efficiently your body can move air through your system. The better your aerobic capabilities, the better you will be at maintaining a strenuous effort over a long period of time. The second is how well your muscles can hold up to the strain caused by a buildup of lactic acid in the muscle, among other things.