Max strength training vs. Endurance
Research conducted over a decade has shown some interesting benefits for cyclists and other aerobic athletes. It appears as though very high resistance and low repetitions (3-4 reps, 4 sets) conducted 3-4 times a week greatly improves Max V02 and work economy without increasing the size of the muscle mass. In other words, it's a win-win scenario for cyclists.
There are, however, some things to keep in mind when performing the training. The motions have to be slow and deliberate, no jumpy, jerky or explosive motion. You are not focusing on explosiveness or speed, but rather trying to improve your body's ability to rally and effectively use the existing muscle mass. Lets take a well used exercise, such as leg press; slowly lower the weights to the lowest point and stop, hold for a few seconds before pushing away. This will improve the connections between muscle tissue and nerve-endings, resulting in increased efficiency. In other words, your muscles can do more with the same amount of energy spent (02 and glycogen). For more on this very interesting topic, take a look at this old, but very interesting article: http://www.ntnu.no/gemini/1996-04/35.html Enjoy!