What about horseback riding? Two of my kids did it for years, including my non-sporty kid. Besides teaching good posture that strenghtens back muscles, it also increasingly works the legs. Best, however, is that it just really focuses on an awareness of your body and your horse's body as you move, and both of these, in turn, stengthen your core.

IME you can find riding schools both in cities and in rural areas.

Of course, you also get the fun and relaxation of being with beautiful, amazing animals!

She thought she could, so she did.