Athletes are most often tuned into the saying, "No pain, no gain" for any and all injuries. But when it comes to acute injuries of the soft tissues anywhere in the body, the old adage "let pain be your guide" is more helpful. Further stressing or straining an already damaged area will only delay healing.
Chronic back pain is a different problem compared to an acute injury. With chronic back pain there is a tendency to avoid movements that hurt. This sets up a cycle of disuse, then pain, then more disability.
Increasing activity and movement might cause more pain as the body adjusts to the new movement or activity level. In such cases pain is not an alarm to signal more damage. The patient with chronic low back pain is advised to try to increase function even if pain increases.