Thanks for the suggestions—all of them very helpful. Here’s what I’ve been doing:

All of my rides contain some climbing. On every ride I do a 5 km, 4% average (some sections about 6%) climb to get out of the city. I almost always mix additional hills in as well.

On my “interval days,” I do one of two types—both generally on the flats. The first are short ones: 12 second sprint, 12 sec recovery; repeat 3 times; then a longer recovery (about 5 min). Rinse, lather, repeat anywhere between 3 and 6 times, depending on the length of the ride and my mood. By the way, I have recently read that Eric Zabel prefers these.

The second type are “cascading” ones: 1 min. hard, 45 sec recovery; 45 s hard, 30 s recovery; 30 s hard, 15-20 s recovery; 15 hard; then a longer recovery. Repeat 3 times. I am slowly upping the lengths of the segments.

I don’t have a HRM, but I push myself to the point where I would keel over if I added another 12 second sprint to the set. I take my eyeballs popping out to be a sign of “perceived endurance”!

I like the idea of doing “hill intervals.” I’ve not done much of that in the past. And I notice that, Nathan, you are suggesting a very steep and very short hill. When I think climbing, I usually think in longer terms. But, you are right that for strength work, a short anaerobic burst is better.

I, too, like high cadence riding (105-115 flats/ 90 hills). I was never a masher, but after “converting” to true high cadence riding, I would never go back.

Cheers!