The best way to deal with back pain is to stay active and continue doing regular exercise.
If your back pain is mild, try to exercise as well as maintaining an active lifestyle. You can do any activity that gives your body a good workout.
When choosing an activity, pick something you enjoy - that way you are more likely to stick with it. Ideally, your choice of activities should involve elements of endurance, as well as stregth and flexibility.
Examples include walking, running or jogging, cycling, dancing, swimming, hydrotherapy (exercising in the water) and aquarobics. There is some evidence that regular Yoga and Pilates is benificial for people with lower back pain as well.
You could also se your GP about your back pain to ask for a referral to a group exercise programme.