Originally Posted by waterrockets
That's the kind of hills I use for repeats here in Austin. 14% for 1/2 mile or so. I do 6 repeats, and do them with negative splits (each climb is faster than the previous). Once you get good at pacing yourself, you can get a really tight group so there's only a 10-second spread on the 6 repeats. Great workout, and a great way to learn how to pace yourself.
I do a similar repeat on my fluid trainer. I start with 52x12 and sprint from 70% to 90% Max HR, once there, I wind down the HR slowly and then repeat in the next lowest gear. Keeps me in the aerobic zone and below the LT but with good results for strength.
Good for 45 minutes of high intensity.