This session is designed to keep your LT & AT & VO2max sharp. It also helps the cyclist break away quickly and settle into a fast rhythm. I've based this on something I read in Simon Burneys CX book, I need to make sure I have a solid base. Otherwise top end work and performance will soon crumble mid season.

I've got little time sometimes, so I've been doing a 20minute trail run in the morning with 5x 20second sprints uphill (as per slipppy CX climb).
After work - Warm up ride to Regants Park (10mins) then 3x 8minutes 95-104% Threshold. Currently 177-180bpm.
The park is roughly a 7-8 minute lap (for me). I did 5 minutes recovery. It is good as if you just look up the road, rather than watch the clock you can concentrate on keeping the right tempo.