I was reading an article about high intensity training in the winter at pezcyclingnews.com and it got me thinking about the right way to train over the winter.
The vast majority of cyclists and many coaches believe that the old way is the best way: Lots of base miles in the off-season. Of course, if you live in a warm or moderate climate, than this is a great way to work toward the next season. If you live in a cold climate, the thought of putting in long base miles on the trainer can be a hard pill to swallow. Also, if you are short on time, putting in high intensity work can be a good alternative.
There have been many studies, but the one I found most interesting was the follow up study done by Gibala in 2006. He tested a high intensity training regimen of only 2.5 hours with a more traditional endurance based training of 10.5 hours at 60-65% VO2peak. The result was that both training regimens produced similar results. They determined this by measuring muscle glycogen levels and the concentration of key enzymes in the aerobic metabolic pathway.
More work is required in order to adapt these results into real-life training plans, but it does indicate that using high intensity workouts in the off-season can provide some of the same benefits that base building does. The key is to use the high intensity workouts in moderation.
You can find the article here: High Intensity Training 2007: Latest Evidence
Good luck in your off season training!!