Gynecomastia after one year will usually no go away.Gym and weight loss may help to some degree.Unfortunately most of the time it won't remove it completely.
if you can do that with exercise please let me know.this is usually treated with surgery and it can be minimally invasive done through a tiny incision in the armpit. Get a few opinions from qualified plastic surgeons in your area and I think you will be happy with what you hear