I had my umbilical hernia operated on 29th Dec 2016. I had it since I was born, but training did cause it to gradually get worse.
you can buy a special belt off Amazon with a lump on it that pushes on the hernia to keep it in whilst training, they are only something like a tenner.
pretty sure they are simply called “umbilical hernia belt”
I still managed to place 4th in June 2017, the surgery us pretty straight forward and the recovery is fast.