I can't believe I have something substantive to add after Lisa has already replied to a thread.
The determination of your max HR is primarily genetic. You can work very close to or at it when you are in good shape. All other things being equal, someone with a smaller heart muscle will have a higher possible max HR (smaller = less capacity = more beats to get the volume of blood out) and, usually, a higher resting HR. A person with a huge heart muscle will have more chamber capacity, more volume per stroke, and a lower max (no need). They also can have some low resting HR.
Take 2 trained individuals the same age: me and my friend Beth. She has a resting HR of 39 when she is in good shape. My RHR never goes below 56 even when I am in the best shape. On the other hand, she has tested her max HR to be close to 170, whereas mine is 204. We're both in great cardiovascular shape, we can just infer she has a larger heart muscle (or, more technically accurate, larger volume per heart stroke) than I do. She'll never get her max HR up to where I can get mine and I'll never get my RHR down to where she gets it.
The freaks of the cardiovascular world, guys like Lance Armstrong, are blessed with a great low RHR, a huge max HR, and a high anaerobic threshhold and VO2max. But they are few and far between.
The formula (which I'm hearing is being revised to be 230-age for trained adults) is a rough guideline that won't fit everyone. Since you are already above that, you can guess it doesn't fit you.
Max Heart Rate = 220 - age?
Linear Mode
