I have used intervals on the bike in a hit and miss way over the past year.

I have made a committment to myself to get into serious and specific training to improve my time trialling...

So I am getting up early on Tuesdays and Thursdays to make sure i get specific rides in and don't flag them at the end of the day when i am tired from work.

I am doing "power" intervals on Tuesdays - 3 minutes at my lactate threshold and then let my heart rate drop, and then another 3 minutes. I am slowly increasing the length of the interval and the number of intervals.

On Thursdays I am doing hill intervals... climbing a hill on my aeros in the big chain ring...

I have a TT in two weeks - I'll let you know if they have worked at all...