Athens80

Yeah, I've frequently gone 10bpm higher than the highest max heart rate calculated by those formulas, and I don't think I've ever gone remotely close to all out while wearing a heart rate monitor. I can ride for an hour at what the lower formulas calculate as my max heart rate. The ranges indicated by the aerobic threshold test put my true max heart rate 28 bpm higher than any of those formulas indicate. So they may be right for the middle of the bell curve of a population, but I don't know that they are useful for an individual.

So perceived exertion is a good way to start, and then doing the threshold test at an appropriate point will fine-tune the numbers for those who love numbers. And a laboratory test will get even more precise figures but at a cost.