A hernia is a physical problem so supplements, food and drugs can do nothing to heal it.
Strenuous exercise also puts pressure on the abdomen so risks a re-herniation if its corrected itself, or making the hernia larger.
That said, I've never heard anyone ban strenuous activity because of a hiatus hernia, unless yours was incredibly large and your stomach was at risk of going completely into your chest.
There are some things you can do to help a hernia. First is to massage the stomach down. /www.youtube.com/watch?v=qofS1iVuwoQ
Second is to drink some warm water, then go on tip toes and come down hard onto your heals. This can pull your stomach down. I went from a large hiatus hernia to none/small by doing these tricks over a few months.
GERD, Anxiety, Depression, Rolling Hiatus Hernia, Esophageal Hypersensitivity