2) a sport, wherein people run as a form of athletic activity as opposed to merely another action that a person can take. In other words, they run for the sake of running (or in order to compete with other individuals in an event called a "race.") Some people totally dedicate themselves to this sport, to the point where it is a major part of their lives. Others do it on a fairly regular basis in order to stay in shape, or as part of a training/workout regimen.
Still others run occasionally, when they feel like it.
In order to run well, it helps to have good form (running incorrectly can put stress on your joints and be even more painful), good endurance, patience, and commitment (you don't just give up after 5 seconds, or you'll never get anywhere).
2) The cross country kids went running after school. Everyone else stared at them funny because it was 25 degrees out and snowing.
"Running has given me the courage to start, the determination to keep trying, and the childlike spirit to have fun along the way. Run often and run long, but never outrun your joy of running." -Julie Isphording, Marathon winner
"Oh idk, probably 8miles."
"Come on lets do 10"
"Ok, I'm feeling pretty good anyways"