ZonesIf you go to the gym, or read about working out in really any capacity you've probably at least seen reference to heart rate zones. If you were to know your range, resting rate to max, then you can break it up into zones.
For the most part, the lower zones (1 and 2) are an effort that is pretty easy to maintain for a while, and are good for establishing a basic level of fitness and fat burning. Zone three is medium to medium hard effort, zone four is where many people would be when they are pushing themselves comfortably hard and could possibly hold for a while, and zone five is the start of the red line and really most people can't hold it there for very long.
Running vs. CyclingMuch to my surprise you HR zones are likely different for running vs. cycling. This is primarily due to a difference in fitness between sports. Or to put it another way, most people's threshold (basically the red-line) is lower on the bike than the run due to different muscles being used. Because of that you end up with a different max HR on the bike than the run. Granted this may not be true for everyone, but for most it is. Since the zones are based on that threshold, it's important to be able to figure out where that is. There are different ways to figure out your threshold, you can go get tested, or you can self administer the torture. For sure though, it's torture, as the goal is to find the place where basically your body can no longer be efficiently fueling your efforts, it's not a pleasant place to be for very long.
My Cycling TestSo to figure out my threshold I basically just did some warm up and then a 40 minute time-trial like effort and then took my average HR over that 40 minutes and use that as the basis to figure out my zones. This isn't the most persice, but it at least gave me a starting point.
My Running TestI didn't really do one, I just used my max HR and applied a known formula. I did try to figure out my max HR though. If you use the old 220 - <fill in age here> that makes my zones all wonky. I can train pretty comfortably in zone four if I do that.
After a weekMy bike max might be a little low. Zone three isn't easy, but I wouldn't say it's all that challenging either, it's pretty easy to get into zone four and zone five. Also my zone five is only about 3 beats wide, so I end up outside of it pretty fast. I may fiddle with that number a bit.
My run zones are stupid. I had done a run recently where my heart rate monitor recorded a spike of 213. So I used that, it seems high since most formulas start at 220 or lower. But when I look back at my old data there are at least five efforts with a higher recorded max - surprisingly all on the bike. So I used it. Then yesterday I had some intervals which called for some sustained zone four (six or seven minutes,) and honestly I could not figure out how to get my heart rate that high and still keep moving. So I I'll be adjusting that number too.