Heartbeats per mile

Heartbeats per mile

Endurance athletes are used to using heart rate per minute to monitor training, but new evidence suggests measuring heartbeats per mile could be even better…

When you want to know how expensive your car will be to run, you ask about its miles per gallon, not its miles per minute, right? So why not take a similar approach with your body to find out how much effort is needed to run/bike/swim a certain distance by looking at heartbeats per mile, instead of heartbeats per minute (heart rate).

Looking at heartbeats per mile, instead of heartbeats per minute, is much like monitoring fuel economy rather than acceleration, which sounds pretty useful for endurance athletes.

Make sense so far? If not, don’t worry, all will become clear.


heartbeats per mile 1

Fuel economy, not acceleration, is key to endurance success. Using heartbeats per mile gives you that data


Firstly, you’ll no doubt be aware of how useful heart rate can be to monitor intensity of training, general fitness and health. This is traditionally measured by beats per minute (and we discuss how to use it with polarised training here). 

But some of the world’s best endurance athletes are measuring their fitness by calculating how many heartbeats it takes to go from A to B - in other words, heartbeats per mile.

Steve Way, who came third at this year’s Comrades Marathon - a 56-mile epic endurance race in South Africa - has been using heartbeats per mile for years.

It helped him transform from overweight smoker to 2hr 15min marathoner, and landed him in the England team for the 2014 Commonwealth Games.

Steve uses the website fetcheveryone.com to log his training and says this about heartbeats per mile on his blog: “It can vary a little day-to-day depending on various factors (type of run, terrain, weather, when I last ate).

“But if you look for the pattern/trend over a number of weeks you should see the value come down as you become more efficient aerobically.”

How do you measure heartbeats per mile?

Thankfully the maths are quite simple.

For example, if you run an 8min/mile and your average heart rate is 140bpm, you will be running at 1,120 beats per mile (8 mins x 140bpm)


Heartbeats per mile 2

Heartbeats per mile may sound as confusing as this picture looks, but it’s actually dead simple

Returning to our car analogy, fuel economy is typically provided in miles per gallon, which can be flipped to give us the amount of fuel taken to travel a set distance.

Imagine each heartbeat is equivalent to a unit of fuel. The lower the number to travel the same distance, the better the economy. Simple.

How accurate is heartbeats per mile as a fitness guide?

Heartbeats per mile is an entirely individual metric, so you can only measure you against you (or your former, less fit self!).

We all have different maximum heart rates (that gradually decrease over the years), and the individual nature of the data means comparing your data to other athletes in meaningless. This is all about you.

Secondly, as Steve points out, mixed terrain and weather and general health and diet are all factors that can skew the results.


Heartbeats per mile 3

External factors may skew your heart rate, raw terror being one of them…

Instead, for a test you can reproduce to measure overall fitness gains, set yourself a flat course on consistent terrain and try and run an even pace - then repeat it a month later, measuring both at heartbeats per mile.

Can I find my optimum pace with heartbeats per mile? This is where it gets interesting - and slightly geeky.

Instinctively, we might think that the easier we run, the more efficient (in beats per mile) we’ll be. But this may not be the case.

Take our earlier example. Running an 8min/mile at an average of 140 bpm, means 1,120 beats per mile.

If you speed up to a 7min/mile and your heart-rate rises to 160bpm, you’re now up to 1,155 beats per mile (7 mins x 160bpm)

But if you instead slow down and run a 9min/mile with a heart-rate of 130bpm, you’re also up, this time to 1,170 beats per mile (9 mins x 130bpm).

Both the slowing down and speeding up take more heartbeats per mile so we can - for our hypothetical athlete here - deduce that 8mins/mile is his more efficient pace.

Heartbeats per mile - conclusion:

Have a play with heartbeats per mile in you training and see if you enjoy it. The maxim ‘what gets measured gets managed’ is at the heart (no pun intended) of this and if you find it a useful and enjoyable metric that helps, then add it your performance toolkit.

On the flip side, keeping tabs on every metric possible isn’t for everyone, and even for those who do love the stats there are some days the plain enjoyment of running, riding or swimming is more important than any spreadsheet.

So if at any time you find heartbeats per mile, or any other training stat, is capping expectation - rather than inspiring it - it’s counterproductive.


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