Yeah, but doing a 1000 means getting to start of 1000 then starting and finishing a 1000.
That's quite different to getting to start of 400, completing the 400, getting to other 400 start and finishing second 400, getting home then getting to start of 100 or 200 and doing that.
I've been doing his DIYs a bit this year though so it's not all bad news :)
I mentioned this to the missus last night but if I do the 2x400s on the Sat and Sun I'll be too fucked to ride the Chilterns on the Mon.