Mastering heart rate and HR zones is a great way to slash your PBs, and by adding an element of science to your schedule, you can make gains faster and more sustainably.
The process has been made all the easier thanks to the latest running watches many of which now pack in optical heart rate tech making this scientific method of training accessible to all – but it's not easy to master.
Whether you have a dedicated running watch like the Forerunner 45 or Polar Ignite – or something more lifestyle like the Fitbit Charge 4 or Apple Watch Series 5 – each has the power to track and report your heart rate during exercise. With a live readout, you can take your eye off your pace and ensure you're working in the right effort level.
Common runner errors
"The most common issue I find with runners – from beginners through to more experienced – is that they run most of their sessions within a very small range of effort," explains Tom Craggs, running coach with marathon training experts Running With Us.
Without heart rate monitors we're struggling to spot when we're running at the right – or the wrong – intensity.
"Their easy runs are too hard to fully recover and get the full aerobic benefits they should accrue, while threshold and VO2 max run (the harder, interval sessions) aren't specific or hard enough to get the full benefits at the top end.
Therefore runners plateau easily and find it hard to achieve significant progress after the first couple of years of training."
So how do you start thinking about training with heart rate zones? Read on to find out.
Understanding heart rate zones
(Image: Garmin)
Understanding what's happening in each of the heart rate zones is also vital if you want to make the most of that expensive running watch on your wrist.
Giuseppe Minetti, founder of PaleoGym, which specialise in using advanced sports science and personalised functional fitness, explains how your heart rate zones break down and what happens in each zone.
1. Easy rest and recovery
65-70% of Maximum HR (MHR)
"There is no such thing as overtraining, only under recovery. At PaleoGym we prescribe recovery days and phases to help with a list of essentials that include muscle and tissue repair; removal of waste products; the reduction of inflammation; the restoration of energy stores and nutrients necessary for cellular activity; and the recuperation of the central nervous system. In simple terms, the repair of the connection between the brain and body. This is necessary for anyone in training, from Mo Farrah to you."
2. Endurance base training
70 - 80%
"It's essential for any new runner, but too many athletes spend far too long developing this component, but doing the right amount of endurance training is a very fine balance to achieve, particularly if you're looking to run faster. Doing too much of this will wipe out any speed you've gained, doing too little will prevent you from adding the distance to your speed required over marathon distance."
3. Aerobic capacity
80-90 %
"Aerobic capacity improves with your exercise age i.e the amount of years you have trained. It's all about running at medium effort and putting in many hours. For anyone running less than a marathon distance it's not necessary to develop a huge aerobic base."
4. Anaerobic threshold
90 - 98% of MHR
"Otherwise known as race pace or lactate threshold, this is the point where things start to burn. Perfecting this requires strategic planning over many months and years. Get this right and you'll get fast, get it wrong and you'll go backwards even faster. This training requires the most amount of effort, but with low volume and is a necessary evil for all people looking to improve their running."
5. Max aerobic
98-100% of MHR
"There is conflicting research surrounding Max Aerobic/VO2 Max exercise. Too many athletes exhaust themselves with constant VO2 max training, whilst completely disregarding the speed elements of their discipline."
How identify your personal HR zones
Image: Greg Whyte (CHHP)
Well, we put those questions and concerns to Professor Greg Whyte, former Olympian, fitness trainer to the stars and Fitbit ambassador. He's a huge advocate of using heart rate data to train – so we went to his Centre for Human Health & Performance in London.
"There are a number of ways of doing it. The generic training schedules you'll find on the internet actually dictate when to run at different intensities. There are a number of solutions to working out those intensities in terms of target heart rates, from the very simple to very complex.
"If you come and see me it's complex: we will take blood lactate and some gas analysis and run you on the treadmill. At the simple end of the spectrum there are four main categories:"
1. Recovery run – And that is very easy
2. Threshold running – That is marathon race pace
3. Half marathon pace
4. 10k pace running pace
"So you just have to work out your heart rate for those four zones, and for me the easiest one to anchor everything from is the marathon race pace. That is a pace at which you can sustain indefinitely. We can fundamentally all do that.
"To work it out go for a run on your own, with your heart rate monitor, for a minimum of 30 minutes and in that run you should have the ability to hold a conversation. When you're at a pace you think you can carry on indefinitely, for 30 minutes, and can hold a conversation, take a look at what your heart rate is. Take that heart rate and put a five beat range either side."
Start your BPM plan
(Image: Fitbit)
"Once you have your heart rate for that marathon pace zone you can work out the rest," says Prof. Greg Whyte. For the half marathon pace add 10%, and for your 10k pace add another 10%. That's 20% above marathon race pace. And for an easy/recovery run, subtract 10% from the marathon rate."
1. Recovery run – (-10%)
2. Threshold running – (+/- 0%)
3. Half marathon pace – (+10%)
4. 10k pace running pace – (+20%)
"When you take that generic plan from the internet it should say easy (marathon), moderate (half marathon) or hard (10k). So keep it simple. It's just about translating it.
"Try not to overthink it, but keep the quality. But make sure you get the best out of your high intensity sessions don't back-to-back them, and everything else will slot into place."
So now you have to apply that into a plan. Luckily we have one for you here, straight from Dr Whyte at CHHP. You can download it here.
Top tips for training by heart rate
After spending 12 weeks following Greg Whyte's heart rate training plan, Wareable cofounder James Stables offers his tips for getting into bpm training. You can read his journey in slashing 15 minutes off his half marathon PB in his heart rate training diary.
1. Spend time finding your levels
(Image: Wareable)
One of the first hurdles to heart rate training is finding your levels, and that takes time. You need to find the sweet spot of your lactate threshold bpm – the point where you can run and run, while still having a conversation.
This will take multiple runs and you need to make sure you don't start your heart rate monitor until you're 10 minutes into your run. If you do, the lower HR at the beginning will skew the data with lower averages. Make sure you run for over 30 mins for a proper reading, and I'd recommend taking the average of three or more workouts.
2. Heart rate is personal, don't stress on the numbers
One thing that always troubled me when training is how high my heart rate was. Is it because I'm a poor runner that I run a half marathon at 180bpm, while others don't get above 160bpm? Well, I asked Prof. Greg Whyte:
"It demonstrates beautifully the individuality of heart rate. I have worked with 2:10 marathon runners with a max hart rate of 165 and worked with another with a max heart rate of 220. The differences are similar between elite and average populations as well."
3. Check for overtraining
My achievements via heart rate training are for all to see, but the truth is I trained hard, and I would have made gains whether I ran by heart rate or by speed. But there's one comment I can make: half way through the schedule I was struggling to keep up.
"You get immediate feedback on how you're going because it's such a great global measure and it's exactly the thing to do. If the quality goes, you're better off stopping, recovering and keep the quality," Greg told me.
Had I been training by speed I would have just kept hitting targets and suffering, but by looking at heart rate, I could see my speed plummet at the same bpm around nine weeks into my training. This is one of the few times I've trained injury free and that's no coincidence. Watch for the tell tale signs.
4. Heat is a nightmare
The training plan started in mid-summer, straight in the middle of a heat wave – and I struggled. So I asked Greg Whyte about the effect of heat on training:
"A one degree change in core temperature can be 10bpm higher. On hot days your core temperature rises and while we're good at regulating it can be around 10bpm difference. It's a challenge for everyone," he said.
Get out early in summer month when training, but if life gets in the way and you have no choice but to run when it's hot, add 10bpm to your target zones.
5. Intervals rule but heart rate is tough
At least one of my sessions per week was interval based, and these are the secret to really unlocking your speed. But I found using heart rate to be really tough here. Firstly, a lot of sensors lag, and I found it distracting checking the bpm while hitting peak output, and downright motivation killing when you realise the sensor has crapped out. I never really got to grips with HR during intervals – I had better success managing sessions by speed.
If you're struggling to monitor your bpm while giving it full beans, don't get disheartened. Check your bpm peaks after; if you're finding that you're not hitting the heights of 190 in your intervals, you can hold yourself to account.
6. Look for patterns and benchmark
Unlike running to speed, heart rate is all about benchmarking and patterns. Greg set up sessions every six weeks (MISO cycles) to compare speed at similar heart rates to check how performance was improving. Make sure you do the same, but save it for every six weeks – that's how long it takes your body to adapt. Also, look for patterns. Do you run better after certain foods? Training by heart rate keeps your effort constant and lets you see the true effect of your strategy.
7. It all changes on race day
Wareable
One mystery of my experience was how my heart beat higher on race day, and it caught me off guard on my first half marathon. But Greg confirmed it's normal, and explained why:
"When you taper you tend to run at a faster velocity, so that heart rate tends to rise slightly. And then there's psychology. You're under stress, pressure and excitement, which leads to adrenaline which drives heart rate upwards. You can see a 5bpm increase and that's not unusual at all."
How we test
By Kieran Alger
Kieran is a world record-setting runner and one of the UK's most experienced running journalists.
A constant tester of the latest fitness technology, he's always hunting for innovations that can make him run faster, further and generally be in better shape.
Kieran is often found wearing four GPS running watches at once. And to date he's tracked more than 50 marathons, 13 ultras and countless half marathons - including the Marathon Des Sables.
In 2022, he became the first person to run the river Danube from sea to source, a measly 1,830 miles in 66 days. And still had time to test running gear.
Kieran regularly takes running tech to the extremes for Wareable and the likes of Runner's World, Mens Health and Wired.