Lance Armstrong said that and it's a great motto. Yet, with the return of my once ancient knee injury, I find myself asking "am I quitting or being smart?"
Recognizing injury and pain, and taking the necessary time to recover is difficult because we come face to face with the "no pain, no gain" mentality nearly everyday. People want to push through challenges, push through the pain and for what? A medal, a time, a good sweat? All of those things are worth it as long as the pain is "good pain" and not "bad pain". I use quotes because my yoga teachers refer to good vs bad pain a lot in class. Good pain is that dull pain or sometimes burning sensation you feel in your muscles when you push them too hard. This is the pain I feel while doing pushups or a lot of sit-ups. Bad pain is a nervy or sharp pain. When you feel bad pain - stop immediately!
That isn't quitting, that is being smart. However, many of us do not take the necessary time to recover and rehab the bad pain. It might mean sitting out a marathon you've been training for or not participating in your flag football season. The long term effect of properly resting and recovering is worth missing out on 1 event or 1 season. That's not quitting, that's listening to your body and knowing that running is forever; not a temporary part of your life.