I agree, Goldfinch.
I can only take about 45 minutes on the trainer. Most of the Cyclo-Core programs I've done over the past 4 years are about that long. Of course, there's no video, just a list of the drills. I use my own music. A few are an hour. I also have a really good interval workout that is 30 minutes long, that I got, from all places, Runner's World magazine. That's my favorite. I sweat more than anything else and it's over with quickly. During the winter, I tend to do one trainer workout and one spin class a week. Any other aerobic stuff I do depends on my schedule and if there is snow for nordic skiing/snowshoeing. I feel as if I work as much in 45 minutes on the trainer than in an hour ride outside, maybe even more. I'm not doing drills outside, just riding up hills. Since, I maintain my weight this way, I think intensity trumps time for me. And i am working out 5-6 days a week.