Wow, I was just about to make a topic about this
I typically used to do sprints 2x/week (that was in 2008 ! )
So was disappointed when he said every 7-10 days; perhaps it's just for maintenance.
But this topic made me happy - I think I can stick to 2x/week (I go for 30 seconds, 90% intensity). I rarely do the 100%...