Weak muscles and back pain
Weak muscles equal back pain. Your spinal support will be weak if your core muscles are weak. A spine surrounded by weak, under developed muscles will lead to postural problems and back pain.

A well balanced and functional weight training routine will alleviate back pain, improve your posture and strengthen the muscles which support the spine.

Should you use a weight lifting belt?
Weight lifting belts promote bad form and give a false sense of security. Because of this avoid them at all cost. Your aim should be to strengthen your core, not rely on a belt. The Transverse Abdominis (TVA) is our weight lifting belt; it wraps around the spine and protects it.
Exercises that will help to strengthen your TVA and other core muscles include: squats, deadlifts, rows, press ups, overhead press and bench press.

Raise your metabolic rate
Weight training will also help you lose fat by burning calories and rasing your metabolic rate, thus you will be burning more calories when you are out of the gym. Excess weight will place undue stress on the spine; losing weight will therefore relieve pressure from the spine.

Conclusion
Back pain need not be something you have to live with all your life. With a carefully constructed weight programme you can improve and even elevate your condition.