I used to get more outbreaks when I was in a worse physical shape (overweight, little exercise). Then it was maybe one every 2 months. Now I'm in the normal BMI range and I exercise regularly (albeit not to a high level) and my outbreaks are 2 times a year.

Valaciclovir definitely helps, but one's own immune system plays a huge role. After all, most people in the world have that virus, few actually get outbreaks.