Warren brought up a good point. That is, one thing works for him that doesnt have the same results for others, that is why one coach might use different methods for two athletes under his tuition. There is not a journal article that i am aware of that shows similar results for 100% of the participants in the study. Try different things and see which works for you. Having said that, when an article states that a particular training method works, it is for a scientifically significant number within each group. In other words, in the majority of cases, Interval training WILL improve VO2max in MOST people [though i must admit this is conditional on things such as current VO2max, pervious training etc]. BUT that it is very dependent on currernt condition and compliance to a given routine.
Try and keep in mind that VO2max is a measure of oxygen carrying capacity only, NOT performance. It is used as an indicator of CAPABILITY. That is to say, while you can increase your VO2, that does not mean you will ride faster, or longer, but is is a good indicator of your physiological ability to provide oxygen to working muscles. Many factors are involved when considering performance. As many on the forum have stated, you need a portfolio of training exercises, which must be managed in the correct sequence and timing to maximise performance. If you focus too much on one training method, you do so at your peril!