Speed endurance the key to *all* 11/12second sprinters?

Remember - he still does SE on the Wed - just limited recovery for shorter efforts.
instead of doing a 300m or 250m, you could break it up into 2 x 150’s (300) or 2 x 125’s (250) and have a limited recovery between efforts, Such as a walk back to the start.
And you can control how fast each is by controlling your ACC limit