Archive for the ‘Numbers’ Category


First training plan & Why I use the PZI

April 19, 2011

There is a first for everything. For a while I thought about planning my training sessions, but this was impossible because I didn’t know how. Even now I’m not completely sure but at least I found a way of planning while maintaining full control over my training. Thanks to the book “the runner’s edge” I learned a lot on training with numbers. More important I learned how to use the numbers I was already seeing during my “just go run” training past months. While I was already training by “intensity zones” but wasn’t until I read about the pace zone index to realized things could be even better.

Hearth rate Zones

I’m going to assume you already know about training with hearth rate zones. If you don’t know how this system works check out the site of Polar – why train with a hearth rate monitor. The hearth rate is used to tell us the “current intensity” of our training. While this system proves to be a pretty good indicator there are a few reasons not to base your training on hearth rate zones.

Hearth rate can be raised or lowered by “stress” alone. Stress can be fear, excitement, worries and many other mental or physical (such as illness or pain) factors. This makes hearth rate “not a constant factor”. You would not be able to measure properly if your ruler kept changing the length of a meter.

Hearth rate is also very difficult to calculate. You have to determine your maximum hearth rate which you will need to set your personal hearth rate zones. This can be a major problem. There a many formula’s to calculate your maximum hearth rate. Some of these come pretty close, but not a single one will give you an exact match. Only way to determine your maximum hearth rate is by undergoing a test. Then you will have to do such a test regularly, these tests aren’t very cheap.

So current hearth rate zone is influenced by “stress” AND “wrong maxHR”.

PZI – Pace Zone Index

Now here is where the pace zone index comes around. Instead of hearth rate zones you base your training on “tempo”. At a few given points during your training you do a test and based on this result you can set tempo values for different pace zones. The pace zone index system is an invention of Matt Fitzgerald and used by A full detailed summary on the Pace Zone Index system can be found right here. A detailed explanation of each Pace Zone can be found right here.

Wil this make hearth rate and there zones absolute? No! This still remains a very good indication of your fitness and the intensity of your run. Even better if you are interesting in knowing “how intense” your past or next workout is going to be it’s best done on hearth rate data. You can compare hr data against other training sessions to see if you your hr got lower or higher … if you got fitter and better.


I hope I explained a bit why you should base your training around “tempo” rather than “HR”.

In upcoming posts and pages I will explain more about the tools I’m using to train, analyze and plan my workouts. How you can benefit from such tools and how they can tell you what your training status is. How these tools can tell you if your working too much or maybe not hard enough!