The heart of the matter

Can using a heart-rate monitor transform your running? Yes it can! But how? I give you all the information you need to train to your heart rate

Have you heard other runners mention working to their heart rate, or seen them wearing a heart-rate monitor (HRM)? Are you wondering what the fuss is about? More importantly, can training to your heart rate improve your running?

Earlier this year I went for a running assessment at the Porsche Human Performance Centre, which gave me my heart-rate training zones. Even though I had the same assessment four years previously, I hadn’t embraced the science behind it back then. Fool I was! Being given your heart-rate training zones is like being gifted a pot of running gold.

One of the tests I did at Porsche

One of the tests I did at Porsche

This year was different; I read my report more thoroughly, started wearing a HRM, went along to the Running School to improve my gait, then, bang, in my next two 5Ks of the summer I achieved PBs, and the allusive, coveted sub 21 minute barrier. I put this down to heart-rate training.

Every beat counts
Dr Charlie Pedlar is a physiologist at the St Mary’s Clinic, St Mary’s University, a performance and rehabilitation centre for athletes – professional or amateur. “Your heart rate (the number of heart beats occurring each minute) is an excellent measure of the overall stress your body is under,” he says.

It’s shows the physiological (and sometimes psychological) ‘load’ your body is dealing with. “Not only this, it can be used to objectively set your training intensity and monitor your gains in fitness,” he adds. As you get fitter your heart, which is a muscle, adapts, gets larger and more efficient – it can then eject more blood into your circulation for each heartbeat, resulting in a lower heart rate.

What are training zones?
Runners draw on the aerobic and anaerobic systems. Slow running is predominantly aerobic, and fat and carbohydrates produce the energy we need to run. As the intensity increases we use our anaerobic system, and rely more on carbohydrate. The deeper you get into anaerobic running the more limited your performance is. “Training allows you to run faster and remain in the more efficient aerobic zone,” says Dr Pedlar, “and training plans include running at different intensities, using the transition (or threshold) between aerobic and anaerobic exercise as a key reference point. Terminology such as ‘steady’, ‘threshold’, ‘tempo’ and ‘interval’ running may be used to describe training zones.  Each zone has subtly different training effects.”

Having your blood lactate measured while running isn't easy!

Having your blood lactate measured while running isn’t easy!

There are five heart rate zones, split into 10 per cent zones, which all have different training benefits (see the box below). For example, for a steady recovery run after a hard session, or race, you should aim for your heart rate to stay between 50-60 per cent of your maximum heart rate. If you are doing short, fast intervals to improve your leg turnover and speed endurance aim for 80 per cent. And don’t forget, your breathing can also help you estimate your training zones. Below threshold conversation is easy; at and above threshold you should only be able to give one-word answers. For intervals expect heavy breathing, and no conversation.

Working out your resting heart rate
HRMs help you ensure you’re working at the right intensity (this can be to hit a target training zone, or to make sure you don’t work too hard and go into a higher training zone). “They also help you pace yourself in races and hard training runs,” says Dr Pedlar.

So how do you work out your zones? First you need to find your resting heart rate, as well as your maximum heart rate. “Resting heart rate is best measured before you get out of bed in the morning, by measuring your pulse for 30 seconds (and multiplying by two),” says John Brewer, a professor of applied sport science at St Mary’s University.

My treadmill assessment felt harder than a 5K threshold run!

My treadmill assessment felt harder than a 5K threshold run!

Do this for four days, then work out the average value. If you find that your daily value then rises above the average for a couple of days or more, it could suggest that you are tired or have a minor illness. “This should be seen as a signal to reduce the quantity and intensity of your training,” says Professor Brewer.

Maximum heart rate decreases with age; a simple way of calculating it is to subtract your age from 220. This method can be inaccurate but it gives you a rough figure to work towards. Most people find that training at an intensity of between 60 and 80 per cent of maximum heart rate works best. However heart rate does gradually increase during a run, even when the run is at a constant pace. “Make sure you don’t set off at the top end of the range otherwise you will soon find the session too demanding,” suggests Professor Brewer.

Visit the pros
Alternatively you can visit a human performance laboratory, such as St Mary’s or Porsche, to get a more accurate assessment of your training zones.

Heart rate data can provide a valuable means of measuring improvements in your cardiovascular fitness, and guide you to be able to work harder, and get faster. “Lower heart rates at given speeds are indicative of improved fitness. Similarly, reductions in resting heart rate can also indicate improved cardiovascular efficiency,” says Jack Wilson, a sports scientist at Porsche. “Repeated lab tests can provide detailed insights into changes in cardiovascular fitness. Alternatively, repeating key training sessions each month whereby you run at a fixed speed for at least 20 minutes over a set route are useful,” he says. Recording your average heart rates during these sessions allows you to evaluate changes in heart rate over time.

This graphic shows you your heart rate training zones (source:

This graphic shows you your heart rate training zones (source:

Keep track of your progress
It is through analysis of your data that you will get the maximum benefit of heart-rate training. The scientific feedback you get allows you to plan and adjust your racing programme. “Training with heart rate is an easy way to achieve your goals,” says Liz Shenton, the performance and training manager at Polar UK.

“Many Polar devices download into the Polar Flow web service via a smartphone app so you are always connected,” says Liz. “Flow online houses your training diary, showing when you trained, the results of your fitness tests, maps and graphs of training sessions and giving training feedback (training benefit and load), to guide and motivate you.”

A few words of warning: running in hot conditions, dehydration and caffeinated drinks can cause your heart rate to elevate above normal. Be aware that these factors may affect your heart rate before you start training. It may be worth consulting your physician before engaging in strenuous exercise.

Random heart-shaped leaf daughter no.2 found and turned into a meme for me

Random heart-shaped leaf daughter no.2 found and turned into a meme for me

And remember, there is no correct training recipe to tell you how much of each kind, or zone, of running is optimal. However, science has shown that repeatedly including various intensities of training gives greater gains than either plodding along at the same speed, or thrashing out your miles as fast as possible.

“Just as important, don’t become a slave to your heart rate monitor,” says Professor Brewer, “rather use heart-rate training to get a ‘feel’ for the intensity you should train at, and rely on feedback from your body, not just your HRM.”

Heart-rate monitors: my favourites!

Polar M400 (high res)
You get 24/7 activity tracking with the Polar M400, as well as advanced GPS and training features. The M400 Pink comes with a wristband that’s 2cm shorter than the other colours available.



Mio FUSE is a heart rate monitor and activity tracker that measures the blood flow and temperature under the skin to analyse your movements and provides a daily assessment of heart rate, step count, distance travelled, speed, pace and calorie burn.


TomTom Cardio black back front
You get a wrist-based based HRM that uses sensors to track blood flow to calculate your heart rate. It’s not exactly subtle, and runners with smaller wrists might find it a little heavy. The Runner Cardio is geared towards zone training with five levels of intensity, from sprinting to marathons to basic warm ups.


Garim with strap
This is my favourite GPS watch of the year so far simply because it offers so much and is ultra-thin – a GPS you can wear all day without it feeling cumbersome. Its apps include running, biking, swimming, and golf; it’s worth investing in.

Get in touch with my experts: St Mary’s Clinic:, 0208 2404070, Porsche Human Performance Centre:, 08443 577911.

2 thoughts on “The heart of the matter

  1. has2run

    This is a lot of great information!!!. I do not wear my HRM because I don’t like the stupid strap. I probably should just get over it and try it out. thanks

    1. shewhodaresruns Post author

      Yes, just try and get used to it… I was the same, now I just get on with it! Eventually you won’t focus on it – some watches like the Epson Runsense SF 810 have an-inbuilt HRM in the watch if you really like your tech 🙂


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