Originally Posted by terrymorse
Hmm. Maybe you're going out too hard on the first interval. I've read that you're supposed to slowly build the intensity, so that you're going hardest at the end of your last interval.
Possibly. But that's how it goes if I do my 2 x 20's by HR. I find it odd though that there can be as much as 10% difference on my averages between my first and second interval. I'm going to try what Skydive did sometime soon and that's doing considerably more warmup before doing any intense work. I'll see how that goes. As I said earlier, getting to 90% and maintaining it isn't really much of a problem. It just usually happens on the longer 2 - 3 hour rides.