This workout can be done on the road as well but is best completed on a trainer. After a longer warmup of almost 15 minutes, you will perform 5 sets of 4 minutes at your threshold pace or 100 RPM in your flat road gear. There are 2 minute recoveries between each of the sets. The key to this workout is to maintain your RPM and / or Power output from the first set all the way through to set number five. Longer cool down on this one as well to be sure the legs are receiving all of the benefit of the workout efforts.
This is another great, early season triathlon or time trial type workout to help determine your fitness level.