Working out while watching bad 4 o'clock TV is not the only reason I love my gym membership.
Once a week I use it for a "swim date" with Claire -- Evan stays in the nursery while we play in the indoor pool. It's really fun one-on-one time and we both look forward to it every week.
Several months ago when I had a sinus infection that knocked me flat, I dropped the kids off in the gym nursery and read books and magazines while dangling my feet in the hot tub and pool.
At least once I used the gym solely to take a shower with the kids nowhere in sight. Literally, I left them in the nursery and headed straight to the locker room for a long hot shower. I shaved my legs -- even above the knees (luxury). I skipped the two-in-one for separate shampoo and conditioner (luxury). I blowdried my hair, applied my makeup and got dressed in peace (luxury, luxury, luxury).
Occasionally I also use the gym for doing work. This afternoon I had some late editing come in and I wanted to knock it out before tomorrow so my morning's free for some running around that will be 100 times easier if I can do it while the kids are at school. I traded the treadmill for my laptop and got it done. I even brought as-yet-unfinished "Jane Eyre" along, but that turned out to be overly optimistic. What did people do before free WiFi?