Well, most sources online would say that you would have to take the stuff (both of it) at least for a week or so (if I'm correct), but in my experience, just taking bigger doses for two days works as well if one wants to have a quick fix. Of course it would be the most beneficial if you take it continually for some weeks at a time.
I do between 6-10 and usually get a pretty good pump, which does not cause problems. feels rather cool though. I run the "straight" parts of the tracks and walk the curved parts as rest periods.