Having read some if the posts on here about Wk6, I already had an idea it might be tough this morning and it was.
I think after running 20 mins unbroken, putting the breaks in, starts the warm down process, and makes running again tougher. I'm sure this is part of the plan so that 25 mins unbroken on Friday will be a breeze by comparison.
That's what I'm telling myself any way.