Practice makes perfect?

I've belonged to a gym for over three years now, and I've been at my current gym for just over a year. I love the new place, which is affiliated with a hospital. I've become much more active as a result of going to the new gym. I especially love my aerobics class with a wonderful instructor. I try to make it three times a week, and I was lucky enough to be able to change my work schedule to accommodate that! Thanks to the aerobics, I was recently able to enjoy a great vacation with my kids in the mountains. I felt so healthy and fit the whole time, and that was thanks to my aerobics class almost exclusively.
I'd like to lose some weight in addition to being stronger, but that doesn't seem to be in the cards....at least not yet.