This is not directly answering the question, but it is related. The attached graph is my max HR for all the gym exercises (weights and spin) that I've done for the past 2 years. I'm 54, so the 220-54 predicts a 166 max, and my max is in the low 180's, while my resting HR is about 55. Some points:

Anything on this graph over 180 occurred when I was pushing really, really hard. Sometimes that just gets to 180, sometimes it has been as high as 188. I think max HR has daily variability. I don't feel equally good every day, so the idea that there is a uniform Max HR that never changes day-to-day is an approximation. I usually say that my max HR is about 182.

Max HR does not appear to be trainable. The average of all these sessions is essentially constant, and if anything, I've seen a very slight DECREASE (3-4 bpm) in max HR while going from untrained to capable (just barely) of a 5 hour century ride.

I have similar data, but less of it, from road rides with a Garmin; the gym data are from a Polar HRM.