Couch to 5K

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IannodaTruffe profile image

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With the ubiquity of Fitbits and other heart rate measuring devices, the title of this post has become a very frequent query on this forum and the answer is always the same……”Well, it all depends.”

That is a not a very informative response, so in this post we will look at the very basics of heart rate measurement and how it can be useful and also downright misleading to runners, if they do not understand those basic principles. It is not intended to be a guide to using heart rate monitors.

Your heart is a muscle that can be trained and developed to be more efficient at doing its job, which is to pump oxygenated blood from our lungs to all the cells of the body that require it to function. The circulation also removes waste material, such as carbon dioxide and returns it to the lungs for exchange.

We are all individual in our heart rates and the maximum number of beats per minute (bpm) will reduce as we age. Children tend to have a higher resting and maximum heart rate than an adult. Women tend to have higher resting heart rates than men. Very fit people tend to have lower resting heart rates and will also have a lower heart rate when working at the same effort as someone less fit, but not necessarily a higher maximum heart rate. Resting heart rates can range from below 40bpm to over 85bpm. Being at the extremes of this range can indicate dangerous conditions……..but again, not necessarily so. A maximum heart rate for an average 20 year old is calculated at approximately 200bpm and 135bpm for an average 85 year old. These averages are at the root of most cases of the title question and you can begin to see the complexity in a question that at first appears so simple.

Those average figures are calculated by many different formulae which are somewhat crude and only return averages. Most of us, by definition, are not average. The most common formula is 220 minus your age, used for the figures above. Another, slightly more sophisticated formula is 208-(0.7x age), which returns 194bpm for our twenty year old and 148.5bpm for the 85 year old. These formulae give you your theoretical maximum heart rate (MHR), upon which your heart rate monitor (HRM) zones will be calculated, which can be very useful for training, but only if they are accurate.

If your actual MHR is higher than this average, then the upper zones are not going to be true and your device may warn you that you have exceeded your MHR……….by definition, this is not possible if you are still standing upright. By the same token, if your MHR is actually lower than average, then you may well be working in a zone higher than you intend when you do your workout. The questions about MHR only ever get asked by those who are exceeding the estimates, while an equal number may well be working too hard, which is why the easy conversational pace is one of your best friends.

There are various training heart rate regimes, some with only three zones, but the majority of athletes work with a five zone system similar to the one set out below.

ZONE 1: Very light, 50-60% of MHR

ZONE 2: Light, 60-70% of MHR

ZONE 3: Moderate 70-80% of MHR

ZONE 4: Hard, 80-90% of MHR

ZONE 5: Very hard, 90-100% of MHR

For any established runner it is recommended to spend most of their running time (80%) at an easy conversational pace, which equates to approximately 70-75% of MHR and only push MHR to above 85% for about 20% of their running time. For any new runner, developing their aerobic base, stamina and endurance it is recommended to do all your running at an easy conversational pace. Pushing harder can be counterproductive and in extremes can actually damage muscle mitochondria.

So, I imagine you are asking, “How do I establish my actual maximum heart rate?”

My answer is that you do an internet search, because, for reasons of safety and liability, I am not going to answer that question. The best way to find out your MHR is to have a laboratory test with medical back up available, because this is a potentially risky venture. You will find alternative methods on the internet and if you decide to follow them then I would suggest that you have a responsible adult alongside you, should you require medical attention or resuscitation. This might sound overdramatic, but at least you won’t sue me.

In my view, you don’t actually need to know your MHR to train at different levels. The ability to speak aloud, clear ungasping sentences as you run, means that your breathing is optimal and consequently so will be your development of greater capillary density and more numerous mitochondria. At the upper end of this ability, as stated above, this is approximately 70-75% of your MHR and relates to Zone 2 to 3 above. As you get fitter the pace at which you can comfortably hold a conversation as you run will increase and you can use your HRM to identify this pace and track its progress. What you are looking for is trends.

Comparison of HR on different runs is only valid if you are working at the same degree of effort. So a level one kilometre run at a steady pace (after you have fully warmed up) can help show you changes in your development, if you repeat it methodically over time. Do not make the mistake of seeing one reading and believing that shows dramatic changes, when it may be caused by many other external influences, such as hydration, temperature, illness, drugs, state of restedness etc, or even glitches in the HRM itself. These devices can give misleading readings, so while they are a reference, they are not gospel. Even good quality equipment can deliver erratic results.

I used an HRM for a while and did the basic research when, at the age of 60, I found I could run quite happily for over an hour with my bpm in the mid 150s, which if I had believed the estimated zones, was right at the top of my range ……...over 95% of my estimated MHR………..clearly impossible and indicating that my actual MHR was considerably higher. I felt fine and recovered quickly afterwards, which is actually the answer to the question in the title……….your heart rate is only too high, probably, if you feel ill, light headed or feel palpitations after recording a high rate and you do not recover quickly. I no longer use one, preferring to listen to my body and be as tech free as possible.

While using an HRM to set zones can be very useful, especially for an elite runner, for the average recreational runner it is an unnecessary complication……….unless you are willing to do considerably more research into this complex area and get a fuller understanding of the mechanisms involved. Below are some of the resources I have used to research into this topic.




I also highly recommend The Runner’s Body by Ross Tucker, Jonathan Dugas and Matt Fitzgerald to anyone who wants to understand what is happening in their body when they run.

If you have concerns about your heart rate or how you feel while, and immediately after, running, then talk to your doctor.

There are more FAQ posts giving general information here healthunlocked.com/couchto5...

17 Replies
Curlygurly2 profile image

You also need to take into account the accuracy/fallibility of these devices. My Garmin told me I was in Zone 5 when running at 11 mins pace, that's slower than walking pace. It also tells me I have pulse oxygen of 78% when a proper medical oxymeter confirms I actually have 98%.

I don't know if chest straps are more accurate, but frankly I think these little devices are really only useful for guidance.

IannodaTruffe profile image
IannodaTruffeAdministrator in reply to Curlygurly2

I have mentioned the fallibility of the tech.

CBDB profile image

Fabulous article, Iannodatruffe. I don’t have a heart rate monitor but at times have wondered if I should get one as many runners like to measure their improvement by monitoring their progress in relation to heart rate.

So thanks for reminding me again that each to their own and if I keep to listening to my body and keeping running at a conversational pace most of the time, that is absolutely a great way to go!

Thank you!

What an interesting article. Thank you for posting.

John_W profile image

Tim, that's a very informative and useful post for those wanting to learn about HR.

However, from my scientist perspective, my responses to HR posts tend to errr on the sceptical side because, as Curlygurly2 alludes to, if you can't trust the measurement, and therefore the number you're quoting in your typical 'should I be worried' post, then frankly, the exercise (bad pun) is a waste of time.

I would always ask:

- how are you measuring your HR? (i.e., can we trust the numbers you're quoting?)

- what does the HR graph from your run look like?

Invariably, wrist-based heart-rate measurements from your Fitbits and even relatively pricey dedicated running watches like Garmin, Polar, TomTom, Suunto, Coros, return numbers that often do not make much sense.

These points are lost on the casual observer/beginner of course! Just shows that this tech, coupled with Dr Google at your fingertip, can cause unnecessary worry to those who naturally place a lot of trust in it.

To end, I'm a huge fan of HR training, and use a £25 CooSpo chest-strap HRM the links to my Garmin FR 235.

IannodaTruffe profile image
IannodaTruffeAdministrator in reply to John_W

I agree, John and do state that even good quality equipment can deliver erratic results.

This was just intended to put some perspective on that perennial title question and was never intended to be a guide to HRM usage, (perhaps you could write that for the FAQs), but also to encourage anyone who intends to use an HRM to do their own research

John_W profile image
John_WAmbassador in reply to IannodaTruffe

I have something in mind, if only to show how NOT to trust your HR measurement ... but yes, that could be useful.

Curlygurly2 profile image
Curlygurly2Graduate in reply to John_W

I think it needs stressing much more strongly, I've spoken to many runners about the problem I had with my watch, every single one of them told me most definitely I had not set my zones up properly, not one considered for one moment it might be the device that was at fault.

I'm sorry if I sound like I'm being critical Tim, I'm not - it's a great read, and very well written. I've just got the arse-ache, following those the plans to the letter have ruined my running....someone else here also said if you do enough slow running you wont be able to go faster and it's absolutely true. Seven years in and I'm now slower than I was on my first runs....

IannodaTruffe profile image
IannodaTruffeAdministrator in reply to Curlygurly2

I agree with your comment, Sarah and will give it some thought, but I believe most people who read the post will also read at least the first few responses and see this discussion.

Curlygurly2 profile image
Curlygurly2Graduate in reply to IannodaTruffe

Perhaps I'm making too much of it because I've been very disappointed with my experience of it all. I guess I was just unlucky to get a wonky watch, I've not heard anyone else say that have had the same problems, that's probably why they all put it down to my error rather than the watch.

CBDB profile image

Just adding another link to an 8min James Dunne Video which I saw dropped a couple of days ago, talking about low heart rate running:

James Dunne (9 min) The awkward truth about LOW HEART RATE RUNNING (MAFFETONE TRAINING)


backintime profile image

Great post!

I'm late to the party here, but I distinctly remember some posts from a while back whose HR watches were synching to their footfalls and not their heart rate - can't remember who posted those though

IannodaTruffe profile image

Thanks for pointing that out. I will edit it.

Runnf profile image
RunnfGraduate in reply to IannodaTruffe

Cool - I've deleted my original comment now. Makes total sense with your edit :-)

IannodaTruffe profile image
IannodaTruffeAdministrator in reply to Runnf

I had read and reread my post and not spotted that, which just goes to show the need for independent proof reading.

Runnf profile image
RunnfGraduate in reply to IannodaTruffe

Best tip I know is to get the computer or your phone/tablet to read the text back to you. You'll tend to see what meant to write, but technology will only read what you really put. Saves my bacon often! :-)

Oldbadknees profile image

Thank you for (as always) a very informative and relevant post which has answered all the questions I wanted to ask.As I progress (just did w7r1) my heart rate has increased so now is in the 140s. My max heart rate is either 157 or 163.9 so somewhere in zone 4 or 5. I know I'm working hard but I'm not flat out by any means. You pointed out that women have a higher HR and I've read elsewhere that thyroid medication can raise it too so overall you have reassured me I'm probably not overdoing it. As you suggest I listen to my body as I run, it's too complicated to check HR on the move. If in doubt I slow down.

Thanks again.

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