What are the general consensus on this? I am afraid to do weight training, or sit ups because i'm afraid it will mess up the band. Is this just a myth? What do you know about the topic?

Thanks!

As long as you're all healed up it wont hurt your band. Its important when you lift weights or do situps to breathe normally - banded or not, its not a great idea to increase your intraabdominal pressure by holding your breath and straining and its not the most efficient way to do the exercise either.