Flicking back on the last few pages of this thread, I'm struck by this modern day notion that mothers must sacrifice their every need to devote themselves entirely to their child during all waking hours.
Basically how utterly daft this thinking is.
In becoming mothers, we don't cease to become humans. We still have our own fundamental human needs, which often include things like exercising or engaging our brains. The idea that the OP feels the need to seek permission to leave her baby (with a qualified, trusted minder) while she takes a few hours out to keep herself healthy & sane is actually staggering. The fact that some of you are refusing to give her that permission is just awful.
Previous generations didn't have to engage with this bollocks. The vast majority of mothers simply had too much to do, keeping a family clean, safe, warm, fed. More primitive (or indeed enlightened) societies had support systems in place to give new mothers a break (Naomi Woolf has some great material on this). Aristocratic mothers often farmed out their babies to local wet nurses for years, not taking them back to the family home until 4/5. Not saying we should go back to this practice by the way but it makes the following point ...
We've turned out generations and generations of predominately happy, well adjusted human beings. Short periods of separation from mummy at 7 months do not have catastrophic consequences.
I think we need to give ourselves a break - and our asses down to the gym for those who are so inclined.