Heart Rate 101

Sports scientist Garth Fox explains the whats, whys and hows of heart rate training

by Garth Fox

heart rate running

It's a twee Valentine's card marketing slogan, but the saying 'Listen to your heart' is also useful advice for runners. Here are some Q&As explaining why.

What does my heart rate tell me?

With each beat, the heart pumps blood-borne oxygen molecules out to working muscles. The harder a run, the more oxygen muscles need, so the quicker the heart beats. This makes heart rate a useful measure of physical exertion, helping you avoid the most common training mistake of all - going too fast during long, slow runs.

How do I work out the stats?

First, work out your maximum heart rate (HR max) using a heart rate monitor. Run easy for 15 minutes, hard for five, then as hard as possible for another minute. The highest number your monitor records is your maximum heart rate. Now use this figure to calculate your three basic training zones:

Low Intensity 60-70% of max

This zone encompasses recovery and steady runs and should feel fairly easy. It encourages fat burning and a strong cardiovascular system. New runners should spend 90 per cent of their overall training time in this zone to keep their enthusiasm in check and help build time on their feet. More advanced runners should aim for 70-80 per cent.

Moderate Intensity 70-80% of max

This zone includes faster steady runs and marathon pace runs for more experienced runners. Spend 10-25 per cent of your training time here.

High Intensity 80-95% of max

The lower end (80-85 per cent) of this zone encompasses tempo (or lactate threshold) runs - a 'comfortably hard' intensity that can be sustained for a few miles, but isn't all-out. Running at this intensity burns more stored carbohydrate (glycogen), rather than fat.

The higher end of the zone (85-95 per cent) includes speedwork reps. These develop speed and improve VO2 max, but can only be maintained for a few minutes at a time.

Heart rate tends to lag behind effort, so most runners prefer to look over heart rate data after high-intensity sessions. Once you reach a good level of conditioning, spend five to 10 per cent of training here.

What else should I know?

Over time you'll run faster at the same heart rate. Let the monitor be your guide, not your taskmaster: don't slow to a crawl when running uphill just because the monitor tells you to. Just aim to stay within the zone most of the time.

Also, research has shown that dehydration, heat, altitude, time of day and natural variation between individuals can all influence heart rate by up to 20 per cent.

Dehydration in particular can lead to 'cardiac drift', when your heart rate increases during a session even when you're holding a constant pace. It happens because the volume of blood in your system drops if fluid lost in sweat isn't replaced.

Denser blood means more work for the heart, hence a gradually rising heart rate for the same level of exertion. It's not a cause for concern, but if it happens, up your fluid intake and perhaps slow down.

Invest Wisely

Take the following into account before buying a heart rate monitor, says Fox

  • Ideally you want an alarm to alert you when you stray into a different  heart rate zone.
  •  A lap counter helps when sessions involve training in two or more zones, such as in an out-and-back run.
  •  It's useful to be able to download  data after your workout to computer software that helps you analyse and track your progress.
  •  GPS-enabled devices provide a sophisticated way to analyse training as they can also record pace, routes and gradient, using satellites.

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Discuss this article

The article reiterates some common place knowledge. Well, there's nothing wrong with it but ignores the fact that many new runners and not so new ones find it too hard to run with heart rates below 70%. With my strong aerobic background from cycling even when I start slowly and shuffle along my heart rate always goes over 70% in 10 minutes.
Posted: 03/11/2011 at 07:25

If i am reading this correctly. I too would find it hard to run at 60-70% of max. My high rate is 175 so @ 65% I would be running at 114 average heart rate. 

Is this really correct? Most of my training should be done at what for me would be not much more than a fast walk!! 

Posted: 03/11/2011 at 08:54

Apparently you will get faster just by keeping the HR under 70%. Your fast walk will move up to a fast jog. I presume you are referring to new runners?

Posted: 03/11/2011 at 09:03

I run regularly and have run a marathon in 3hrs 46min but want to improve next year.

I normally train around the 150 HR average, meaning about 85% of high rate. If I train at 65% it would be slightly more than a fast walk.
Posted: 03/11/2011 at 09:24

Sub 70%max HR seems very slow when you start ... but the pace does increase gradually over time. It's well worth the investment.
Posted: 03/11/2011 at 09:28

Thank you doctor... I will give it a go, sounds nice to train without the pain!

Posted: 03/11/2011 at 09:41

Nick - what are your times for other distances? (Say 5k, 10k and Half?)
Posted: 03/11/2011 at 09:43

No 5k -

10k around 48 min

1/2 around 1.43

These are last year times not what I could do right now.
Posted: 03/11/2011 at 09:48

Nick thanks

The reason I asked that is to see what your conversion rate was like (i.e. - are your times for shorter distances comparatively much better than your Mara time). Yours seem ok actually, but lots of folk have a major discrepency due to a lack of aerobic conditioning.

Just for info really (to help you understand the rationale behind running to low HR) - see the Hadd info below. It's worth reading, even if it's just to enhance your knowledge.

Hadd document 

There's then a handful of us having a dabble with it (in my case before a Spring Mara).

Hadd thread


Posted: 03/11/2011 at 10:15

My heart rate raises to 180 on hard runs and I've had it to 200+ on a fast 10k is this ok. I"m a 48 year old man.
Posted: 03/11/2011 at 12:33

Hi LS21,

I have downloaded the Hadd document and had a quick scan through but want to digest properly as I am very interested in this and think I would like to give it a go.

It is a very interesting theory and I want to read and understand more before I commit but sounds very interesting way to train for next springs Marathon.

I will report back here when have read the document in it's entirety.

Thank you for the advice and link - sounds like the beginning of a plan...


Posted: 03/11/2011 at 18:17

Simon - I think you'll be fine. Max HR is different for different folk and is no indication of fitness. My personal max is about 178bpm (I'm 37), yet I have friends who are 190bpm+ (aged 45+), and others whos max HR is less than mine. It's training in the correct zone based on your max that's key really.

Nick - I'm just starting to dabble in it now really, but I know 2 good friends who pretty much swear by it (and both are sub-3 Marathoners a bit older than me). If you fancy joining in and discussing some of your views/findings then the thread I linked to above is pretty good.

It's an 'interesting' way to train though. For info I ran 2'49 at London this year, yet I've been out and done 6.5 miles at 9'59 pace tonight! I actually really enjoyed it as well - takes you back to why you started running in the first place really. No pressure, just enjoyment. My plan is to use it as base training for 12 weeks or so, and then do a 12 week Mara-specific block.

Once you read the document in full you'll see that after 8 weeks or so you start building in some longer runs at a bit higher HR anyway, and a bit of quicker running (the 200/200 session). But the idea is to lay a base of big mileage - you can run for a long time and run every day because the pace is steady - so there's no need for rest or recovery days really. It does make sense to me in theory, so I'm giving it a whirl.

Posted: 03/11/2011 at 22:28

Hi LS21,

Thanks for the reply, I am still reading the thread, around half way through at the moment...

Feel sure that I will be joining up though so watch this space for another view point.

My only reservation is that I probably should have started on this plan a month ago, I did not get into London so my training is aimed at Brighton in mid April. I think I need to complete the research this weekend and commit straight away.

Thanks for taking the time to help.

Posted: 03/11/2011 at 23:30

I felt a little like that too, as if I'm a month behind. But if you read the document (this will make more sense after you've fully read it) - the pace you run the 4th rep of the 2400m test will pretty much equate to your Mara pace I think (if well trained). Joe's aim was a sub-2'25 Marathon, so he had to hit 5'32 pace. He managed to do this after 14 weeks of training, despite not running anywhere near that pace for THE WHOLE time - so in effect a lot of the base was done and 5'32 pace was now 'very comfortable' due to his increased lactate threshold. This is why I'm thinking 12 weeks Hadd (or maybe 16 if it goes really well), followed by either 12 or 8 weeks Mara-specific stuff.

One thing I'd say is (in my opinion) a lot of Mara programmes have you running sessions that don't benefit you massively. I really don't think specific speed work or VO2 Max is needed until quite late on in the programme (6 weeks out). So even with your limited time you could still do 12 weeks of Hadd and then do some sharpening nearer the time. See the Hadd phase as baking a cake - you've got to be patient, not rush it and not keep opening the over door every 5 minutes to check progress. And if you burn it then that's it - you've overcooked it. So be patient and do the base for 12 weeks. Bake the cake and then see the last 6 weeks as putting some icing on it with your speed stuff.

Remember - the Marathon is 99% aerobic. Hadd trains your aerobic system and nothing else, teaching you to be more efficient at fuel burning etc (I only had 1 gel at VLM and only drank water). I therefore see it as ideal early Mara training, and genuinely have no issues if I keep at this until 6-8 weeks pre-race.

Good luck!

Posted: 04/11/2011 at 08:22

I thought Heart Rate Training Zones were worked out using your WORKING heart rate, not your maximum heart rate? According to this article anyway -

Heart Rate Training - The Basics

It doesn't say anything about this in the above article, unless I'm missing something?

Posted: 06/11/2011 at 00:15

Interesting to see this thread mentioning HADD so much as I was the one who started the thread that LS21 has linked to. Today is the end of my first 6 week training period and I have not run below 8'30 pace in that time whereas most of my running would have been 7:30-7:45 pace normally.

I must admit that below 70% must be very hard to maintain as I am sticking to 75% (125bpm for me) and that is quite tough. However the principles are sound and once you have done some foundation work then you can go faster. From tomorrow I will be putting at least two 8-13 mile runs at 135bpm and everything else will be done at 125. That takes me up to Xmas and then I start following a plan to get me ready for a spring marathon (maybe Hull or Manchester, although London is still a possibility)

Posted: 06/11/2011 at 08:26

I'm nowhere near as fast as you guys but, no matter how counterintuitive it seems, running slow does make you faster. I just applied this principle to preparing for my first half marathon and I got 23% faster below the 70% threshold over an 11 week period.

It's really difficult to stick to in the beginning because it is hard to believe that such gentle workouts can be doing you any good. However you will return from them feeling refreshed and energised instead of knackered and start to look forward to them.

What's surprising though is that the hard workouts in between the easy ones become harder because you have to work so much harder to get your heart rate up above the higher threshold.

What's also nice is to see your resting heart rate drop over time too giving you more capacity to work.

Someone on these forums recommended the book Heart Monitor Training for the Compleat Idiot to me. Same principle but it uses % WHR or HRR. The book has good explanations of why it works, some inspirational testimonials and guidance on how to pace yourself in the races which I found particularly useful. Worth a read IMO.
Posted: 06/11/2011 at 11:21

I always thoought you had to take into consideration your resting heart rate as well when calculateing zones.

ie with resting HR of 60 and Max of 180,

70% would be 60 + (70% of 180-60) = 144

80% would be 60 + (80% of 180-60) = 156

 Is this right?

Posted: 14/11/2011 at 14:30

The key point in reading this article is to understand how hard it is get to your max heart rate. I am an experienced runner (sub 2.25 marathon in my youth). Currently 55 years old with a theoretical max heart rate of 220-55=165. In training I sometimes get my heart rate to 165 for brief periods (30-60 secs) BUT in races I can keep it at 165 for 20 mins or so, meaning that 165 is NOT my max heart rate.

 So...many of you are probably underestimating your max heart rate and consequently your 70% heartrate.

Posted: 16/11/2011 at 21:50

Philip (and others), the 'most important' takeaway is to find out your, actual, 'max' heartrate.

This is mentioned right at the beginning of the article.   You state your 'theoretical' rate, which is exactly that, theoretical, based on a 'guideline' that is well known, but only a guideline.

There may well be scientific research on _actual_ max HR's.  I was on a Neilson holiday a few years back, and the gym instructor was doing her science Masters partly on this, and was asking guests to do an exhaustion test on a treadmill, to establish Max HR.  (a controlled, and gradual, increase in speed and inclination) I don't have other examples, but mine was 199 for a 39 yr old male.... so a substantial amount higher than 'guide'.

I typically find I run at 175, when doing 8min30 pace. 

Once you have this as a starting point, you can use the percentages with confidence, although I suspect that even there, your 'most suitable' percentage may vary. 

Posted: 20/11/2011 at 13:05

This is how i always understood it but there seems to be conflicting info. Even on this site it has an article taking into account resting heart rate, whilst all the others seem to use only MHR. The problem is the two different methods result in massive discrepancies in heart rate.

           ie MHR:190 X 70% = 133BPM

              MHR:190 - RHR:60 = WHR:130 X 70% = 91 + RHR:60 =151BPM

Where RHR is resting heart rate and WHR is working heart rate. Just using MHR is far easier but doesn't take into account the huge difference between beginners and elite athletes working heart range. Using the two methods causes so much confusion that experienced athletes think they can walk and still improve!! This article and anymore that talk of heart rate training must be more clear.

Posted: 22/01/2012 at 19:23

I've been using MAHR maximum aerobic heart rate to put on a base.

180-age (+5 if you have been working out for a year)=MAHR

Its the pace you can run while carrying on a conversation. You are not tired at the ned of a run. It builds your ability to use oygen and fat for fuel instead of carbs as you do in anaerobic zones. I reckon it's the same thing discussed here. I have a half marathon in 8 weeks and am using some interval work on the short runs for the next 4 weeks before taper. It's my first half so I have no comparison.

Posted: 03/02/2012 at 23:01


Lots of good information here, but I still have questions.  I've owned the John Parker book on HR training for years.  Every time I pull it out to use it, I quit again after two or three days because, at <70%, I'm walking.  Really?  Even the 12 week program for intermediate runners has be doing a "jog" at 65% - that's a slow, slow walk for me.  My HR monitor is beeping every 30-50 steps and driving me crazy.

 So what's the problem?  Is my heart stronger than average and should I bump up my numbers a bit? Or is my heart not as strong as I think and I just need to get used to walking?

Posted: 27/04/2012 at 17:10

Have you read the book properly?  How have you ascertained your max HR? A ''slow, slow walk'' will be less than 50% of your true max, even if you're not very fit at all.
Posted: 27/04/2012 at 23:05

i did a very slow jog for about an hour on tuesday and my hearth rate was anything between 165-179. 60% of my mhr is supposedly about 129 so something is wrong.

Posted: 28/06/2012 at 16:02

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