We belong to a gym which is close to our apartment and fiance's office. Sometimes he leaves work after dinner, goes to the gym, showers, and returns to the office. So it's perfect!
I joined this gym recently and today I got in the lap pool and took part in an "aquafit" class. It was totally strange but a refreshing change up to running on a treadmill or elliptical. It's cardio, strength training and balance/flexibility. Of course I felt like I could have been 80 years old, and I probably should go to the evening class with all of the young people but when you're free at 10:30 in the morning, it doesn't matter if you're in a pool with all ages. Plus...a pool in manhattan? to die for!