painful effort vs damage

It's not necessarily a bad sign if work is a struggle, any more than it's a bad sign to be out of breath while running. It depends how fast you're running. So learn to distinguish good pain from bad. Good pain is a sign of effort; bad pain is a sign of damage. - Paul Graham

There is a fine line between good pain and bad pain. In sports, it is often difficult to decide whether to keep training through the pain or to take a few rest days. Over time, this line has become slightly more clear to me in running. Growth is dependent on this good pain. We cannot stay in our comfort zone all the time and expect to grow. That being said, we must know when to stop and rest. Recovery is also essential for our growth.

Running metaphors translate over to most areas of life. Long distance running taught me to listen to my body. When I did not listen, I had to pay the price of an injury. The key is to be disciplined enough to do the daily work, but flexible enough to know when to stop.

What is one area where you need to push through good pain? What is an area where you need to rest to avoid damage?