"Elite marathon runner" != "average joe"

There is a reason why he's an elite at distance running. It's because he is not normal and it shouldn't surprise anyone that he is outside the norm for HR ranges.

This gets me thinking. Perhaps the OP is working too hard. If he's failing after a minute on the interval set; that's not even enough time to elevate the HR to steady state. Perhaps he is putting the resistance on very high and working very hard to try to hit the HR number too quickly. Have to ease into things and reach your target HR after a couple minutes at effort -- it's not going to happen in a couple seconds unless you want to way overshoot the target. It's really easy to go too hard on a stationary resistance trainer.