Despite my post on Hints and Tips: Wet Weather Riding, sometimes enough is enough and the turbo (a.k.a. weapon of boredom) has to come out in the winter months.
Warm up for 20 minutes.
Select the big ring at the front, and a gear close to the top of the cassette at the back.
Pedal for one minute at 80 RPM followed by easy, relaxed pedalling for another minute.
Next pedal at 85 RPM followed by easy, relaxed pedalling for another minute. And so on, adding 5 RPM per minute.
Each Session extent the "on" interval so that is 1:20 mins, 1:40 mins etc.
You then progress this session week-on-week by increasing the duration of the intervals or using progressively harder gears and trying to match the cadence, thus producing more power. You could also vary the length of the intervals within the session in order to be more event specific. The duration of this kind of effort in a race is highly variable as other riders rarely telegraph how long they are going to go on the offensive.
Please note: I cannot claim these sessions as my own invention; they have come from someone else's little book of pain. Unfortunately, I've had them so long I don't know who! I know... worst reference ever...I would probably get thrown out of university for that...but I apologise sincerely to the original author.