Taking it steady

Taking it steady

June 20, 2019 3 By Stuart

Quite literally in this case. After I came back from Seattle I was tired all the time, and when I went for a run it was a slog all the way round with no real enjoyment. So I decided to take some time off. Looking for something to do I picked up Matt Fitzgeralds 80/20 running book.

I’d gotten the idea of doing mostly slow runs with some fast runs as the best way to improve running performance but was never 100% sure on how slow or how fast I should be going.

I’d read Jack Daniels book, the vDot system made sense but it didn’t seem to really cope with cross country / fell / longer trail running that I enjoy doing. The road miles are realy just so I don’t get too muddy on the way to work or have to drive somewhere to run

The books starts off with the reasoning behind the plan. This is a pretty easy read (compared to say the Lore of Running) with good references. If you accept all the online acceptance of the plan then you can skip this, but if you want to make sure that it’s right for you then it won’t take long.

Once you get into the meat of things then it actually becomes quite simple to work out your zones. The biggest takeway for me was that you’re meant to use you Lactate Threshold heart rate as the base, not your maximum heart rate. He gives a number of ways of calculating this in the book, doing a timetrial, percieved effort, blood lactate analysis or a rule of thumb

Given that (in order) I’m:

  • Not confident on my pacing
  • Don’t trust my feeling of effort as I have a habit of overcooking it
  • Don’t fancy spending lots of money

I decided on the last one.

80/20 Heart Rate Zones

Matts’ rule of thumb was that for someone with a max HR of 180 bpm, their lactate threshhold was likley to be about 160 bpm. So all I needed to do was a max heart rate test then

Luckily I inadvertently did one on the first uphill on the Kinder Downfall. On that uphill I’d been pushed to where I couldn’t go any further, and at that point my heart rate topped out at 188 bpm. So using a bit of maths (160/180)*188 = 167.

Using the calculator at http://8020endurance.com/8020-zone-calculator/, this gives me the following zones:

80/20 running heart rate zone results

So I’ve reset my garmin, and am now doing 80% of my running at below 150bpm, or at least trying to!

It’s taking some effort and a bit of concentration but it’s starting to come. With some baby steps I’m starting to stick below 150 mostly, with some excursions above that at the end of long runs, when a hill comes along or more commonly when I’m just not paying attention.

80/20 Pace Zones

Also interesting is plugging my recent 5k PB from Beeston ParkRun into the pace calulator

80/20 running pace zone results

Which gives me paces that don’t match up (for me) with the HR zones. 8:00-8:25 miles for me are at the top of heart rate zone 2. Since the name of the game appears to be going easy, I’ve been relying on heart rate.

I’ve been doing all of this with my Garmin Vivoactive 3. I know wrist HR isn’t the best measure, but it’s the easiest for me to use atm. And my thinking is that it may not be completely accurate, but as long as it’s reliably inaccurate then I should be ball park adjacent most of the time.


Easy runs are definitely feeling easier atm. Not raced for a while so not sure if there’s been a performance improvement, but I’m thinking that will take a while to come as I need to work on the harder fast runs as well.

If it lets me ramp up the milage without getting the niggles then that’s also going to be a bonus,