HI Bessy!!
I know that even now, when I go out for a hard ride, my lungs still will ache and I'll cough..I just figure it's a good cleaning out of my lungs! I know that I'm in good shape, so I just think when you work your lungs HARD that is how they respond. There was a thread about this awhile back.....I think this is it.

http://forums.teamestrogen.com/showthread.php?t=15160

Hope that helps!!