As a data point, I can sustain ~70% on a stationary bike more or less indefinitely, and I can certainly achieve ~85% in bursts. (This is approximating my max heart rate as 200 bpm; I am 27, so the standard estimator makes it 193, and 200 is slightly conservative. I do not know the actual value.)
It’s possible I’m not in the class of people you’re aiming at, but if so you may want to be more specific (i.e. “people who are substantially overweight and out of shape.”) I am definitely not a veteran of purposeful exercise; but I am a person without a car, so I certainly do a lot more incidental walking than the average American.
My personal experience is that you get the person to do it 2-4 times and after that the activation cost goes up from feeling like you’re dying at the end of a HIIT session and they never build the habit.
As a data point, I can sustain ~70% on a stationary bike more or less indefinitely, and I can certainly achieve ~85% in bursts. (This is approximating my max heart rate as 200 bpm; I am 27, so the standard estimator makes it 193, and 200 is slightly conservative. I do not know the actual value.)
It’s possible I’m not in the class of people you’re aiming at, but if so you may want to be more specific (i.e. “people who are substantially overweight and out of shape.”) I am definitely not a veteran of purposeful exercise; but I am a person without a car, so I certainly do a lot more incidental walking than the average American.
My personal experience is that you get the person to do it 2-4 times and after that the activation cost goes up from feeling like you’re dying at the end of a HIIT session and they never build the habit.