Mileage curves

Let’s break it down.

One of the big ‘light bulb’ moments for me when I started to get serious about training and racing was that the quantity of miles that you run makes a difference.  Having just listened to what I just said, that’s a big ‘duh!’ statement.  But, there’s a nuance that is the important part.  The curve is non-linear.

I know what you’re thinking; “He’s going full nerd again.  Perhaps if I mumble something about the weather, look at my shoes, check my watch and sidle for the door…” Well, yeah, the thought of creating a graph right here, right now, fills me with childlike joy, but I’ll resist.

Instead I’m going to draw on my business instincts and ask the most important question in the world, “Why do they care?”  Very good question, yes?  Why does anyone care about what you are about to say?  How can you put it in a way that they care?

Gratitude, empathy and kindness.

You care because this curve that plots the benefit of running versus the miles you run per week is not a straight line.  You care because that means, depending on what you are trying to accomplish there are sweet spots where you get more benefit for less investment.  On the flip side there are also dead spots where you get very little benefit for much investment.

You care because if you get the ‘light bulb’ moment about the non-linearity of this curve you can hack it to your own advantage.

What is the objective function that we are going to turn our “I” loose on?  (Not AI, but I).   There is a specific benefit that I’m talking about here.  I’m going to call it ‘the PR function’.  I’m going to define it as showing up for a race, a 5k, 10k, ½ or full marathon and running a PR.  My PR function is a measurement of speed and distance.

I’m going to call it ‘faster’.

It is not a measure of happiness or weight loss or health in any way.

Picture the graph now, like the one any fitness app shows you, time in weeks across the bottom, number of miles (or K’s or even hours) in bars going vertically.  Then overlay the PR function as a red line going from left to right.

It’s not going to be a straight line.  1 mile doesn’t equal one PR point.  In my experience the line looks like an S-curve, which makes sense because we are describing natural systems and that’s a natural curve.

Right.  Specifically, remember when you first started running?  This is one of those places where the gains are very big for very modest investment.  Maybe you started out running 3 miles 3 times a week.  Starting from zero, you get amazingly fit and capable after only a few weeks of this.

And it keeps going! You increase that 9 miles a week to 15 and maybe 20 and all of a sudden you are a runner. It’s exponential.  20 miles a week consistently and those PR’s start to pile up.

Then the curve starts to flatten out.  Somewhere around 20 miles a week your invested miles stop buying as much PR.  And that’s ironic, because this is typically where new runners ‘get the bug’ and start signing up of longer races and joining running clubs and starting podcasts.  😊

All is not lost though.  There is another inflection point where you start getting a sizable return on your invested miles.  In my experience, as you start to approach 50 miles a week consistently you get you more big gains in performance.

50 miles a week sounds a bit daunting to the new runner.  You can only make it work by running 6-7 days a week and/or tossing in a significant long run or two.   That was my light bulb moment.

I really don’t know if there is another steep part of the curve above 60 miles a week.  I was never able to sustain that much volume.  The professional marathoners routinely put in weeks of over 100 miles.  Yup.  That’s an average of 20 miles a day.  For me, after 50 miles a week the curve flattened out.  The invested miles weren’t reciprocated by any big gains.

Back to the why do you care part of the discussion.  You care because most runners hit that first flat spot on the curve and assume they have gotten all the PR performance they can reasonably get.  Whereas the truth is that they have hit one of those plateaus that we often hear about.   A consistent, incremental investment in miles could kick their performance in the pants.

50 miles a week is a lot of miles for most people.  But, if you call that the top of the range and 30 the bottom in a series of waves during a 3-4 month campaign it becomes less daunting.

We’ll leave that discussion for another day.  For now, just remember that curve is not a straight line and that there is another big gain in performance as you get close to 50 miles a week.  That’s why you care.