Train for a hard cycle...by not cycling.
This sounds impractical, and flies in the face of the "specificity" notion of athletic training (i.e., if you are training for a sprint, then do lots of sprints of that distance in training). But it worked for me yesterday, and is another example that the high-intensity training (HIT) promoted by informative sites such as Mark's Daily Apple, and good books like Body By Science, works.
I rode the Appalachian Gap out of the Mad River Valley yesterday, which is one of the hard bike climbs you can do in Vermont. I rarely do anything like this any more; a few times per year.
I didn't exactly smoke it, but I did it competently, 28 minutes and change for about 2.76 miles at an average elevation gain of 9 percent (1,306 vertical for 2.76 miles). A nine percent climb is hard (comparable to some of the mountainbike climbs I've done in Switzerland). This is one of the climbs that serious local cyclists like to do. I did it without any specific bike training whatsoever, and it was hard but not a sufferfest (I rode my road bike exactly once this year, and have done a few easy mountainbikes).
I'm not trying to brag or diminish the efforts of good New England climbers (they probably would smoke my time). However, I am pointing out that I have remained pretty strong for endurance efforts by using only "paleolithic" style training -- high-intensity weight lifting and sprinting. I train about 25 percent of the time I used to train when I did endurance sports, yet I can do the App Gap almost as fast (or even as fast) as I could have done back when I was putting in excess bike miles. Not to mention the fact that I'm 52.
A 30 minute HIT session, done correctly, *will* prepare you for any necessary endurance efforts, but without the dangerous oxidative stress and damage that endless endurance training will generate.
Now that I've done the App Gap, today I'm returning to my typical routine of pull-ups, squats, and other productive strength exercises. Read Body By Science; it really works!