There are many different components to long distance training. Learn how to train with good running form and overcome mental hurdles.
Running alone does not strengthen and tone. Learn strength training exercises to work the individual muscles that support you on your run.
Don't become fatigued or plateau with the same running routine. Learn various cross training exercises that will keep your body engaged.
Your core muscles function with each motion. Learn core strengthening exercises that will support your body in everything you do.