[ExI] Maximum heart rate

[Kryonica]

Since this is the time of the year for good New Year's resolutions - that one hopes to keep beyond Jan 1st -  I am thinking about purchasing at last a heart rate monitor watch & strap to use on my exercise bike to monitor percentage of maximum heart rate at various stages of the exercise as well as calories burnt.  One formula for maximum heart rate that I found is the one proposed by Lund University:

MHR = 190.2/ (1 + exp (0.0453 x (age - 107.5))), which gave me (female, 52 in february 2012) a value of 175.9

Since people on this list seem to mind their health with knowledge and conscientiousness, I'd like your opinion on how to calculate this value as well as its hypothetical usefulness for life extending exercising.  I might buy a Polar heart rate watch and also use it during non-cycling aerobic (that is high and low impact) exercise such as dancing and kickboxing.  I have done these things for years now but never bothered to measure my heart rate.  But with all the pills I have been advised to take by f.i.  Stefano and Eugen maybe my maximum heart rate will change.