Thanks very much for the podcast with Phil Maffetone. I might be wrong, but most of his clinical work seemed to be with male athletes, and I haven't heard him speak on whether the formula is as applicable to women, so would be interested to hear your thoughts on this. I'd also be interested to know whether you use a heart rate formula to determine your zone 2 target.
How have the age based Maximum Aerobic Function formulas been validated? Neither the 220-age or Maffetone's 180-age make any sense to me. They seem to be based on a theoretical maximum heart rate. If my maximum heart rate at age 68 is 186--why am I subtracted my age from 180? Why is it assumed that my heart rate is lower than 180 or 220? by an amount based on my age? Should I be compared to an average 68 year old female who doesn't exercise when considering what is healthy or normal for me?