Northug's secret sprint gears?

After Peter Northug blew out the WC circuit this year with so many
wins reached in the last 400 m by is now trademark strong finishes, I
am wondering if anybody knew about his secret gears he claimed to
have.
In watching carefully his "jump-skate", I found his technique is in
reality the double-push skate sprint technique that has been borrowed
from inline skating (for a discussion on the technique adapted to
cross-country skiing, see: http://forums.fasterskier.com/topic/...ush-technique).
A technique he seems to master quite sucessfully in skating.
But what about his other secret gear(s)?
Does such a technique may be easier to practice with rollerskis? I
would like to hear about any experience on that subject also.

Thanks,
An apprentice rollerskier