I cycle quite a lot in the summer, usually between 80-90km in a single session. This past February I started doing Tabata intervals on a bicycle trainer in my basement three times a week. When I brought my bicycle out this past spring and cycled my normal 80km route with several medium sized hills along the way, I found I was able to cycle over the hills much quicker and with much less effort than I could without doing tabata intervals. Previously, I had to stand up on my pedals when going over the hills, but I found with my improved V02 max I was able to stay on my seat and maintain a consistent pedal stroke without my lungs giving out on me. I can attest to the effectiveness of tabatas for cardio purposes.