I got the HR monitor for Christmas and have just started to work my training around it. As I've been reading about HR zones, resting, max HR, etc. I'm finding that to determine your max HR for the sport you are doing is the most beneficial. I've been using a calculated value based on my age, fitness level, resting HR, etc. For those of you who train using HR zones, what did you do to determine your max HR? It's winter and COLD where I am on the eastern US right now. I'm training on an erg w/ a paddle adapter.