It may seem counterintuitive, but sometimes the most appropriate treatment for spondylolisthesis is no treatment at all. If your vertebra isn't slipping forward any further and if the spondylolisthesis isn't causing pain, you may not need any treatment.
If you have pain during certain activities, the most practical step is to stop doing those activities. Doctors generally recommend that people with spondylolisthesis avoid activities that put too much stress on the low back (lumbar spine). That would include sports like gymnastics, wrestling, and football. However, spondylolisthesis doesn't mean you can never participate in those activities again. You should discuss your activities with your doctor, and he or she will help you decide what you can and can't do.