I don't know for sure since I am an after the A-plan hire, but I flew with a guy who kind of explained the whole thing to me. He seemed to indicate that after around age 62 and a couple of months it actually hurts a guy to work longer. (If that is the case, we have quite a few dumb pilots working past 62 here. Then again, many of them are scabs so we aren't talking intellectual giants, either.)

Can someone who understands all this better confirm and explain this?