Max HR is what you can do for _seconds_ -- not minutes. Like "I will die, or die of puking" effort. Painful, wish you could die, effort...

Never had a stress test. 38yo, fit-ish and doing 10 mile/1000 vertical ft commutes each way (but slowly) twice a week, lots of 2-3 hr evening trail rides, 100k MTB races now and then -- and I've never had a resting pulse under 80. Maybe I don't want to know what the test will tell...