In my case it is simple. 5 years ago I Followed the formula and figured my Max HR was 163. But after a year or two a climbing sprint would push me to 172 so I figured that was my max HR. There are times today when I have pushed it to 181 and now consider that my max HR. But this time I am pretty sure 181-182 is my max HR because 183 causes me to get off the bike a hurl chunks. So my non medical opinion is your max HR is just below your have to stop and hurl point.