Heart Rate Zones

How intense should a session be? How do you measure intensity? There are several schools of thought on this, I personally combine Heart Rate and perceived exertion (PE) to assess my intensity, others go on power but that requires a power metre on the bike which I cannot afford. Even when using Heart Rate for measuring intensity there appears to be numerous systems. I use a simplified Jo Friel categorisation:

The trick is to accurately calculate what heart rate zones are relevant to you; they change with improved fitness so need to be revised every now and then. They are also different depending upon the type of exercise you are doing, so heart rate zones for running and cycling generally differ. My calculations are based on some recent runs and rides with a slight tweak based upon how I felt at the time of the tests.

I estimate my current zones to be:

So if I am going for a Tempo run (to improve Muscular Endurance), my target Heart Rate should be 145-152bpm. I read on Lance Armtrong’s Twitter that he competed in a 2 hour Mountain Bike race recently and kept his heart rate at 180bpm throughout; I have no idea how anyone can keep their HR up at that level for so long, it really does demonstrate the difference in class that some people have.

Knowing your heart rate when training enables you to ensure the session is specific. So if I was training for building my endurance then I need to be training in Zone 2 to. Working in Zone 4 will not have the same effect on endurance as working in Zone 2. Likewise, if I am looking to improve my lactate threshold (which will enable me to stay at a higher intensity for longer when racing) then a session may be an interval based workout whereby my HR is alternating between zones 3 and 5.