Originally Posted by euphoria

here are some good intervals to start with

2x20 (20 mins on, 10 mins. rest, 20 mins on)

5x5 (5 mins on, 5 mins rest, 5 mins on, etc. for a total of five work intervals)

and tabatas which are 7-8 repetitions of 20 sec on, 10 sec rest (doesn't sound like much but will hurt mucho grande if done correctly)

The pacing is the trickiest part but you want to hold the highest sustainable effort possible for each time period (start out a little slow but keep pedaling if you blow a fuse and lose your concentration)

oh, and don't do these everyday! start off with maybe two a week and see how your body reacts.