Originally Posted by
Rowan
I know the powermeter is an easy, almost glib, answer these days, but some people can't afford, don't want or don't need a powermeter, especially when their aspirations do not include racing.
I only use the powermeter as an example of why you don't need hills to train for a hilly century or road ride. I'm not saying the OP needs to rely on a powermeter to train for hills.
Heck, while I do most of my training with virtualpower on a trainer (since all my weekday rides are indoors), I still rely on good ol' HR and average speed on known segments for my outdoor pacing both for training and racing. HR alone should get you close for keeping your intensity on flats enough for a similar HR effort on hills.