Not sure, Mullet said so....
To be brief, the HGH output from PowerFULL is significant, so in theory, the "Vacation" period tricks the receptors from desensitizing to the dopamine release and possibly create a rebound effect(more HGH release) after the 2 day "vacation" period.
It also allows you to dose higher on the 5 days(if money is an option) and stretches the life of the bottle out while possibly given a great effect.
I've used powerFULL for many years and really enjoy this protocol, but remember, supplementation can be designed to your needs so the label is not gospel, but what I feel works best in general.