Can keeping a phal in constant bloom stress it out?

[carykeshen]

I have a few "on id" phals that I forced into second blooms. On a couple of them, the older, lower leaves seem limp. New growth seems okay. Can trying to keep these plants in perpetual bloom stress them out? Also, the flowers on my second blooms don't seem to last nearly as long as on the first blooms. Is that normal?