I’ve done a couple of marathons before and not really paid too much attention to what my heart was doing. I mean, as long as it’s still beating, I was figuring I was doing just fine.

Turns out, I’ve been wrong. It is important. I have been running what is generally known as ‘junk miles’. When training for endurance events, its important to train up the the energy system you have for long distances – this is your fat burning system. To do this is fairly straightforward, you exercise at a rate that uses this system. Makes sense so far, if you are training for a running event, you use your legs, it’s not much good doing press ups.

The difficuly is, training this long distance energy source requires you to keep track of your heart rate, and counter-intuitively it means you often have to keep much slower than feels ‘right’.

To find the zones you need to run in you need to find your maximum heart rate, and then use percentages of those. The general rule is something along the lines of 220 – your age. Mine is more like 192 (which I found after running a 5km pretty quickly).

This makes my zones:

Zone HR
Z4 173 to 182
Z3 163 to 173
Z2 144 to 163
Z1 125 to 144

The vast majority (90% or so) of my training will be in Z1 and Z2 – almost none of the training I have ever done has been in this zone!