Pacific Athletic Club
The Pacific Athletic Club in Carmel Valley is an option if you’re willing to pay the steep membership fees to have access to a great health club, heated pools (open longer hours than the local rec center), and children’s classes/activities with child care. Its nice, there’s no question, but you pay for it. General membership is one fee, when children reach a certain age they must be added to the membership and tennis/raquet membership is extra.
http://www.pacsandiego.com/ has all the info and some photos. The childcare here is great if you want to get a work out in, limited to 2 hour time-frames, but they offer a lot of good children’s classes (from sports, to art, to drama, etc.), camps during summer and vacations from school and for adults there are a ton of great Yoga, Personal Trainer, and Spin type classes too.
The facility is new and offers a full Spa as well. There is a healthy food area too for families and several pools for the kids that are heated. One pool is no more than 3 feet deep the whole length and offers a waterfall to cool the little ones off. There are two other large pools - one adult only - the other for families.
Swim lessons are offered here and I’ve heard good things about them. Personal swim lessons are available too.

