I've been amazed recently at the number of guys I've spoken to doing these really short intervals ( 1 min on 1 min off etc) on turbo trainers. At least 3 of the people I've spoken to seem to really struggle in the 17's group if the pace increases slightly or if things get even slightly hilly.
Guys, these ride to you drop efforts on the TTs are not very effective at training your aerobic system. The reason you can't keep up when the pace increases slightly or the road starts to go up is essentially because your 'thresholds' are too low. If you want to keep up with the Merek's of this world you need to raise your 'thresholds'. Those very short intervals are anerobic speed work outs. They are part of the persuit rider, kilo specialist or sprinters arsenal.
If you can't even stay with the pace when its moderately fast then, for you, they're an absolute waste of time! If you want to sustain a fast pace for anything longer than five minutes (thats all of us right! then twice weekly efforts close to or @ time trial pace (15mins-40mins) would be a much more effective way to raise your 'threshold'; and long term a lot less fatiguing - you could do them all year round - than the short hard stuff. As I said before the 30sec-2min intervals are essentially anerobic (no oxygen) workouts. Guess what? endurance cycling (90secs>) is an aerobic ( oxygen) sport . Cheers