Originally Posted by
generalkdi
I just use the maximum heartrate rule of thumb (220 - age) . He is 36 year old, it does 184 so I rounded it down and said "over 180" it could be dangerous. Of course, it depend of people condition... If you start to feel dizzy at 160bpm stop pushing it!
What you're basing that on is 30+ year old theory. Do a search and find up to date data. Lots of fit people ride at 200 bpm; lots of fit people can't sustain 160 bpm at the same age.
You need to do a test to see what your personal max is