I need someone to help me clearly understand this portion of the video.
How I understand it is Max velocity (for example) should only be trained for 12 weeks per…???what???. Is this out of the year? then what? How long until you address it again?
More questions to come?
Help 
I think it is more that after 12 weeks of maximum speed you will probably have improved as much as you are going to without overdoing it… it also tells you about how long it takes to really train these qualities. But how long will you have in reality? The longest I ever have before a competition hits me is 11 weeks.
If you are training and not competing (for whatever reason) I would suggest putting in 2 weeks of rest and test and then going back to GPP again.