I'll admit that I am a little hesitant about the future.
I am 37
I run marathons
I am nursing
I am not too afraid of how my maintenance needs will change when I stop nursing. Actually, the way timing may work out I may slide into maintenance as part of the weaning.
Its the other stuff. Aging. Marathons. I dont know that I will WANT to keep marathon training levels for the rest of my life. I'll run as long as I am physically able, then walk, then crawl, then shoot myself (j/k) .
But I do struggle a bit with HOW FAR would I be willing to cut calories to maintain a weight as aging catches up with me.