I have mentioned in other posts that a yoga practice goes well with Structural Integration. Pilates is another good activity to help keep your structure in good shape. I am lucky enough to have an on-site class at my day job. A good Pilates class balances the work between the front and back body over time, and includes strengthening and stretching. Our instructor is now working at a new studio called Ekara in Woodbury, MN. They also have Yamuna body rolling, which I recommend as well.