This post is split into two parts and contains some challenges. The first challenge is that I would like you to click on this link documentarymania.com/player... It should take you to a video from Dr Michael Mosley’s popular series, The Truth About Getting Fit. For the challenge, I want you to just watch an excerpt from 38mins to approximately 45mins, which includes an experiment which comes up with a surprising and counterintuitive conclusion. The rest of the video may be of interest, but I believe that this section can justifiably be taken out of context…….and it is about running.
The reasons will become clear later, I hope, so please, don’t read any further until you have watched the video.
When I was originally asked to become a mentor on this forum, about four and a half years ago, I was keen to create some reference resources for the forum and I suggested what has become the FAQ POSTS healthunlocked.com/couchto5... which are a collection of posts covering discreet subjects and frequent queries, as much to save us writing the same old replies to the same old questions, over and over again, as it was to create a repository of knowledge. It was never my intention that these would all be written by me, but despite my challenges to various others, to date, only one other individual has written a piece specifically for the FAQs, although I have requisitioned a few posts with the writers’ permissions.
Once I was asked by pianoteacher if I would write a piece about losing weight and running. I declined, pointing out that I had never been overweight nor ever been on a “diet”, therefore considered myself wholly unqualified to write this and challenged her to write it, which she did most successfully. healthunlocked.com/couchto5...
So my second challenge is to ask any of you, who have the desire, to write a post to be included in the FAQs. Ideally it should arise from a topic that is frequently discussed on the forum, but if it is imparting clear information about any specific running related subject, it would be helpful. Please remember that this is the C25k forum and advice needs to be appropriate for new runners. Topics that I feel particularly ill equipped to write about are: Treadmills, Races, running clothes, a guide to using HRMs, barefoot running shoes and barefoot running, comparison of tracking apps and the mystery that I referred to in the Running Shoe FAQ, where do the boulders that appear in your shoe come from and where do they go when you take your shoe off to investigate?
I ran the first few FAQs past the admin team and they usefully pointed out required corrections or clarifications and it might be wise to do this with any future contributions. You can PM your drafts to me if you wish, or you can put a post straight onto the forum and if it is well received then it can be included in the FAQs, which is, after all, just a list of posts.
The content needs to be able to be backed up by references and citations, although they don’t always need to be included, although further reading and reference is always useful. Don’t put in anything that is going to date unhelpfully. Be prepared to edit your post in future as links will become inactive and received opinions can change.
Exchange of information is one of the joys of this forum. We have diverse life experiences, knowledge and perspectives and a different view of an issue can create a lightbulb moment, sometimes exposing great voids in our own interpretation of the world. Knowledge is power.
There may well be such great voids in my comprehension, because that video that I asked you to watch has left me stumped. It includes an eminent professor of Sports Science, is presented by the affable and reliable Dr Michael Mosley and was originally broadcast by the august British Broadcasting Corporation, so surely it is science that we can all trust?
I suspect, wholly unscientifically, that the majority of viewers will conclude that it proves that walking does more harm than running………I know it doesn’t actually say that. The statistical proof is that “per unit of ground covered, walking exerts more stresses than running”.
Personally, I cannot get beyond thinking that it is just a statistical party trick, wrapped up in an ultrathin veneer of modern science, which is at best misleading and at worst, downright dangerous. ……………….but maybe I have misunderstood some fundamentals, after all, I have had no scientific or statistical training since my O levels………over 50 years ago.
A study of one man, with pronounced heel strike, walking across a room, followed by the same man, still with pronounced heel strike, running across a room cannot, scientifically produce conclusions that can be applied to the whole population, regardless of the motion capture technology, computer generated image overlay of stresses and those techy graphs…….that somehow "prove" a result.
Let’s look at the graphs. The line graph is within my comprehension and displays, as one might expect, that the peak stress loads are far greater for running than for walking, but also that the duration of ground contact is far longer when walking. My brain can cope with that. The block graph that is then produced is what confounds me and what I sincerely hope some member of this forum can educate me about. I assume that an average (either mean or median) is combined with a calculation of ground covered per stride to arrive at the force per metre displayed in the block graph, which magically shows that, per metre, walking creates more stresses than running……….but what does that actually prove?
At 42.05, in the video, Dr Mosley challenges the counterintuitive result by saying that surely, if I punched you hard in the face, it would do more damage overall than hitting you several times gently for slightly longer contact time.
At this point, having watched it several times, I almost convince myself that I see a seed of scepticism in Mosley’s eye…..but I know how dangerous it is to project subjectivity into this.
Instead of sticking with Mosley’s analogy, Professor Brewer makes a leap by saying that the knee is perfectly “designed” (alarm bells for me!) to absorb these peak stresses.
My belief is that the body is perfectly evolved to absorb mean or median loads, whether walking or running. However it is generally not mean or median loads which cause issues for runners. It is the short sharp peak loads of running that, for those whose bodies are not conditioned to handle those loads, causes damage and symptoms such as knee pain and shin splints.
By extension, this result seems to suggest that a runner can reduce the loads by being airborne longer, perhaps by increasing speed and lengthening stride………...actually the opposite of the advice given by most acknowledged experts and certainly not what we would advise, on this forum, to anyone suffering from knee or shin pain.
Can anyone explain to me how “per unit covered, walking creates more stresses than running” can be usefully utilised by a runner in their training?
Maybe, because of a gap in my understanding, the only thing this “science” proves to me is that statistics can prove anything, however counterintuitive. To me this means that we all have to discriminate and question our sources, even Doctors, Professors and the BBC.
I hope this illustrates the challenge that writing an FAQ Post raises. Source materials need to be scrutinised critically, otherwise we can be perpetuating half truths and downright lies or just misleading and unhelpful facts, even if we believe the sources themselves to be reputable.
To me the video seems like a case of The Emperor’s New Clothes, with me cast in the role of a simple and naive young boy. I would dearly love someone to provide information that enables me to see this through a different lens, even if it proves me to be a simple and ignorant old man. Going back to the title of this post, I believe we learn, not by accumulating facts, but by questioning the veracity of those facts, by challenging the status quo and by helping one another to understand what we do not understand.
We live in a world now where knowing and facing up to the truth of what the next few decades will wreak on us is vital. Trust in politicians, of all political persuasions, is probably at an all time low so we have to understand, to the best of our abilities, the real science that may be our saviour. We all have to keep questioning. We all have to keep learning.
I look forward to your replies.
Written by
IannodaTruffe
Mentor
To view profiles and participate in discussions please or .
This is part of the problem , so many variables.I conciously run with a high cadence and short stride length and wouldn't mind betting I contact the ground more often when running
Point taken, but that just illustrates that Brewer's study was ill constructed.
The vast majority (wow, such a dangerously unsubstantiated claim, in the circumstances) of new runners experience pain when they start running, in shins, knees and hips, basically caused by the impact of running. Telling them that walking exerts more stress on their joints than running is confusing, misleading and I believe dangerous.........which is my real beef with this study.
Yes, absolutely agree , it certainly can't be just taken at face value on the results of one persons running form .I also find it incredible that there was no mention of Moseley's heel strike.
So on the FAQ idea, I have some thoughts and will think about them a little more before I decide whether to write it or not!
On this whole walk/run and knees issue, I'm not sure the info in the video stacks up. I think it would be potentially difficult to use this video as evidence that running is, based on this data alone, going to produce less impact on knees than walking. There must be so many other variables at play, particularly stride length? For example, I walk with big strides, but run with short strides. Also, the heel strike was so pronounced I was wincing! As the owner of two arthritic knees it made me grimace.
What I don't see or hear often is the fact that running produces stronger leg muscles and that can mitigate knee problems surely? Exercises recommended for those with knee issues, including arthritis, involve leg strengthening. So from my experience, my stronger legs due to running have resulted in my knees feeling generally better. I am pretty unscientific about it, but I don't feel any impact on my knees when I run. It's like they are there just as a joint so my legs bend in the middle! Thar's my cartoon version of it anyway.
Running certainly improves the supporting musculature, as do strengthening exercises, and I think Professor Brewer's theories about repeated compression and release of knee cartilage are worth pursuing. However, if he is willing to put his name to such a dubious piece of "science" as demonstrated in the video, then any study he released would likely draw extra scrutiny in respect of both his method and use of statistics.
Until somebody educates me to see another opinion, then I will approach Professor Brewer's findings with great scepticism.
I enjoy watching Micheal Moseley’s BBC programs, they are often informative, but are full of generalisations. I am often frustrated by the fact that the ‘science/facts’ demonstrated to the public by the program are based on illustrations of ‘evidence’ collected by testing often tiny cohorts, of 12 or fewer subjects. I feel this misleads the public in to believing that tiny studies can be generalised across whole populations - unfortunately tabloid newspapers often do the same thing.
I do feel that though the programs are enjoyable, the BBC has a responsibility to educate the public that medical/scientific studies can only start to be reliable once repeated many times or when tested across a large population. And all scientific proof has potential to be disproven down the line as beliefs and technolgies for testing theories develop. Having said that, the BBC programs are a good thing as they generate constructive debate!
Have a good scout around the Cochrane medical database to see some the best examples of medical science in action -cochrane.org
With regard to the BBC walking vs running program, all this clip suggests is that walking ‘might’ cause greater impact than running for the particular individual in the video. It can’t possibly be generalised across entire populations.
There are three academics on a train. One of them is an economist and one of them is a logician and one of them is a mathematician.
And they have just crossed the border into Scotland (I don't know why they are going to Scotland) and they see a brown cow standing in a field from the window of the train (and the cow is standing parallel to the train).
And the economist says, "Look, the cows in Scotland are brown." And the logician says, "No. There are cows in Scotland of which at least one is brown." And the mathematician says, "No. There is at least one cow in Scotland, of which one side appears to be brown."
I could have taken the same data and, contrary to Professor Brewer and I believe less contentiously, said that the knees are perfectly evolved to absorb all the impact involved in walking, therefore that level of stress could be ignored in both line graphs, leaving us only with the stresses of running that exceed those of walking. If
I then combined the difference in stride length of walking and running, I could arrive at the conclusion that "per unit of ground covered, the excess stresses of running are greater than those of walking".................but we all knew that already.
I am very aware of the BBCs failings in reporting news, but I am of a generation who still relies on them as the first call for the latest. For the most part, I believe that their reporters aim to be objective and unbiased, but emphasis often changes remarkably in the editing.
As for their science reporting, it has dumbed down to the extent that they will now air such misleading "science" as this piece. Understanding of science and the ability to logically interrogate facts, is abysmally low in this country and this sort of fatuous presentation does nothing to enhance it. In fact, it is putting a half baked "scientific fact" into circulation, which is exactly the sort of example that is picked up by those peddling "alternative facts" to expand upon, undermining real science.
I don't know how anybody can defend it....................I wish they would tell me.
I'm trying to remember when the last Horizon programme which tackled a hard science topic was. The Sky at Night is now unwatchable. (I get more info from Dr Becky on YouTube in half the time.)
I recently re-watched the 1978 Connections series by James Burke. Still worthwhile viewing.
I was brought up on Horizon and I loved how it was hard work to keep up........we couldn't even pause and replay in those days. The standard of science reporting has dwindled to the level of it being pointless to watch, presumably in the hope that dumbing down would retain some of the audience. In actuality, it removed a whole sector who would have liked to be informed and educated..
Wow. What a very interesting post which I thoroughly enjoyed reading. To have someone as dedicated as you on this forum is a godsend. I hope very much that readers respond to your requests. Since I'm contemplating jogging as a first step, so I'm committed to watching the video!
A very interesting post. Thanks for sharing. I find the FAQ and wisdom of fellow runners on this site invaluable. Due to my lack of experience I regret I’m not in a position to impart any knowledge myself.
My opinion on the programme is that it’s primarily an entertainment and not a deep scientific investigation. I can’t see how anyone can both demonstrate and sum up a body of research in a five minute slot. The production team’s priority would be on entertainment value rather than scientific veracity, and likely editing the show would be biased towards entertainment. Also pressures due to the production budget.
Secondly, I didn’t see how Prof. B’s test: walking impact vs. running, over set distance, proved or disproved the question put: is running bad for the knees? To answer that it at least requires the limits at which damage is known to be done, in his case cumulative impact forces. The conclusion given that it was within (unspecified) limits was purely supposition.
I thought Mosley showed his scepticism overtly and deliberately. But possibly carefully expressed on advice of their legal team, who knows. Where did that “punching in the face” come from, I wonder? Mosley read psychiatry, he must be aware of Freudian Slip. 😆
The best knowledge is found in peer reviewed research papers. Even then these can be inconclusive. A lot of different factors at play, not all taken into account.
Btw, that graph didn’t look anything like what I’d expect to see coming from the apparatus used with Mosley. It looked like a idealistic graphic prepared in advance of the test. Of course, I have no proof just opinion. 😁
It’s on osteoarthritis occurrence in non-runners and runners of all sorts, from recreational to elites. It seems the elites suffer from the disease as much as the couch potatoes do.
I have problems with entertainment masquerading as science, as mentioned in my reply to Longsocks The BBC should be more responsible than this, though I applaud their intent to demystify sport and encourage people to get fitter.I suspect that researchers and producers had not fully done their job (perhaps they didn't have science backgrounds) and they expected to be presented with some scientific proofs. Having spent a day shooting this, they probably felt that it couldn't all be binned.
I like your point about the Freudian slip and Mosley's language about the whole episode is very carefully constructed and makes no claims.
Even in science there is a danger that data is made to fit the hypothesis, because scientists are human too. We don’t like to be wrong.
Richard Feynman lectured his students that if the data didn’t agree with the hypothesis, the hypothesis was WRONG! It didn’t matter if you were an undergrad or an eminent professor - wrong is wrong!
That’s why peer review is important in scientific research.
I think you are right to look at this, and all things, with plenty of scepticism!
I agree with what Longsocks said about the nature of Michael Mosley's programme, and in fact the majority of BBC science documentaries. Michael is primarily a journalist, and he is making good telly rather than carrying out significant research. A notable feature of these programmes is that they will say something like "we did an experiment!" - by which they mean that they are going to demonstrate some sort of measurement of an action and reaction. I think it's interesting to see laboratory work being done, but it's pity that they so often seem to conclude that they've somehow proved a hypothesis!
I had a quick look around online, and I think that the questions are being asked in response to some findings that runners as a group statistically experience a lower incidence of osteoarthritis of the knee compared with the general population.
Some studies have found the opposite to be true, and others have their limitations - for example see this response to one study of marathon runners journals.lww.com/jbjsjourna... But as I said, I didn't spend a lot of time looking! There are no doubt other papers I've missed.
But anyway, the research that relates to Michael Mosley's discussion that I have found was headed by a Ross Miller of Maryland University, summarised in this New York Times article: nytimes.com/2020/10/21/well...
Ross Miller originally was looking at the per-unit-distance loads hypothesis as one possible answer to the question pubmed.ncbi.nlm.nih.gov/240... This is to say that, although the initial force on impact is higher when running, the overall load per unit of distance is lower than it is when walking. As discussed on the TV show, maybe this is leading to the reduced arthritis seen.
Of course this is a problematic conclusion - for one thing most runners probably don't run ALL the time!
That paper was dated 2014, but Ross Miller has subsequently considered that there may be different factors that lead to the phenomenon of reduced knee arthritis in runners, particularly the hypothesis that knee cartilage may undergo repair following stress - journals.lww.com/acsm-essr/... and more recently peerj.com/articles/9676/
Prof John Brewer was not involved in any of this research, or any relating to it as far as I can see - his publications are listed here: scholar.google.co.uk/citati... , and he has also produced a couple of books about running. He is a sports science academic, and a keen marathoner, and I imagine that he was available and able to discuss and demonstrate the per-unit-distance loads idea in the documentary. I think it is a great pity that he used the term "designed" with respect to the human body. I agree with you that this is problematic, and I would hope that John Brewer only meant to use it as a layman's term. I had a skim through his Twitter account and couldn't spot any support of "intelligent design" or the like.
Regarding FAQ posts, you know already that I am keen to produce a guide for treadmill running, and I am planning to put out a similar post to this one to collect information for it, because I don't have very much experience (at all!) of treadmills myself. You've stolen my thunder again 😊😊😊
Thanks for the references, Abi. I will look into them.
I think my main issue is that new runners on this forum are bombarded by all sorts of advice, sometimes conflicting, and that we have a responsibility to try to keep it simple and remove all confusing and misleading references, especially if the only substantiation of the assertion is a highly dubious "experiment".
My personal experience, which I know many others will agree with, is that running strengthened my knees.
Whether the underlying structures of bone and cartilage strengthened is difficult for me to judge, so I look to science to give me evidence. That evidence is only of any value if the study can be proved to have been well designed, with a large enough cohort and is ultimately repeatable.............none of which can be applied to the Brewer study in the video.
There will be studies that comply with the above that find one conclusion and others that seemingly find the opposite. As I stated in the post, I am neither a scientist nor statistician, but I have a life long hatred of bullshit................and the BBC ought to know better.
I do recall you mentioning treadmills at one point and an FAQ about them would be a great asset. My experience of them is restricted to falling off one when having a gait analysis.......hence me referring to them as dreadmills.
I think the point where the documentaries fall down is when they claim that what they have shown "proves" something. The papers that the NY Times and I have mentioned do not, I think, make that claim. They do, however, open up the possibility of further discussion. I must stress that the full text is not available for all of them without paying, so it may not be possible to make a thorough assessment of their quality!
My personal thing is to encourage every runner to carry out their own personal research by recording their qualitative experiences alongside the quantitative data collected by these wonderful GPS devices we have at our disposal.
Re treadmills: Ouch! sorry to hear that!! But I will get onto the FAQ soon.
Thanks for the interesting, thought-provoking post. And also, thanks for the link to the Documentary Mania website - there looks to be some fascinating viewing on various topics.
Totally agree with your assessment of this piece! In order to come up with reliable results you would:1. Need a sample representative of the population of a large enough size to have statistical power.
2. Not rely on one run of approx 100 metres! It would have to be a longitudinal study over a time period that might give meaningful answers about how running v walking impacts on our bodies.
3. Actually measure impact eg bone density, muscle mass etc.
4. Given the above - also limit generalising findings to the study sample. Eg whether it was just white men from SE England, an ethnically diverse and gender balanced sample etc.
I'm pretty convinced gender would be important. Women's hips are, on the whole, wider, which presumably translates into a different gait. So yes, it is just one tiny 'study'.I find pseudo-science in running magazines a bit like this too. Contradictory snippets of 'science'.
Extremely interesting how ever one wishes to interpret the 'evidence'.Perhaps we should conduct our own Straw Poll and ask any runners who may have been an avid walker, but who nevertheless had knee problems, and then went on to become a runner. Was there a worsening, healing or no change in the knee?
I fit this category and have had complete relief and flexibility restored since running, but hardly any improvement during several years when only walking/rambling.
Again, not scientific by a long chalk, but if feeling is that Dr Mosley's study isn't reliable scientific fact either, might produce interesting results that we might be able to say leans towards a trend rather than physics etc.
In any case, a worthwhile post Ian and all the responders that covers an area of concern for many runners.
For several years I put aside the idea of running because I had knee issues. Long story shortened, running and strengthening exercises, improved my knees. I do not dispute that.
More recently I have suffered non running knee injuries which kept me from running. I could walk absolutely fine, with no pain or discomfort, but the stresses of running even with drastically reduced pace and stride length, meant that I could not continue. Many months of very gentle physio eventually saw me running again, but only with caution. The stresses of walking caused me no problems. (There is the germ of a new FAQ post about knees just taking hold.)
I can see how Brewer's conclusion is arrived at (though I question his methodology) but I fail to see how knowing that " per metre, walking creates more stresses than running" is a useful bit of information that can be employed by any runner. Should we all stop walking?
I'm not a runner (yet, I say optimistically) but I am a long term sceptic. For me the flaw in that report is that there is no real attempt to explain what mechanism of injury the "force per unit distance" is intended to affect.
We all know without any doubt that in almost all cases excessive force can cause damage or breakage instantly while a lesser force will not cause damage even if applied for a longer time. But in the video I saw no explanation of why the peak force is less important than the total of forces over time or distance.
Maybe such an explanation is possible and was given to Dr Mosley but didn't make the cut for the program, perhaps being thought too technical or sufficiently entertaining. Or perhaps I missed it, but that absence leaves my scepticism unsatisfied.
The only explanation in the piece is Professor Brewer stating "that the knee is perfectly designed to absorb the loads", as I say in the post and which is highly contentious.
You didn't miss anything and there is no explanation of why the peak force, while running, is of less significance than the longer duration, lower forces exerted while walking, apart from the fact that by manipulation of the data he can arrive at his conclusion.
New runners, and experienced runners who increase duration or intensity of running too rapidly, are prone to damage caused by the impact, giving symptoms such as knee pain or shin splints.
There are plenty of reputable studies, such as this pubmed.ncbi.nlm.nih.gov/270... which was the first result in a Google search of using "walking and running stresses" which wholly contradicts the Brewer statement, but may well have been conducted using different criteria.
I can assure you that running really can improve knee strength, but I cannot say that peak running stresses will not cause you issues.
I can see that the ground covered running is greater per stride than walking, and some of the running stride involves being airborne, so yes, I impact with the ground less per distance than when I walk. But to suggest that running is exerting less stress than walking doesn't add up . Then again Michael Moseley is essentially a presenter and should be viewed as such.
I think we can all see that just using common sense and our own experiences, but some scientists seem to have an agenda to confuse the issue with poor science, but I cannot understand either their logic or motivation..........apart, perhaps, from wanting press exposure.
It is a shame that we cannot trust the BBC and one of their most popular presenters.
The science of running is complex and nuanced to the individual. Some years ago, I watched a fascinating documentary about why some people could train the exact same amount as someone else but never achieve the same speed. It was all about gait. The documentary posited that some people have gaits which limit their optimal performance. I would contend that the same surely applies to stress when running. We don't all have the same shaped legs, and we don't all impact the ground in the same way with our feet (which is why there is a recommendation to get a gait analysis when buying running shoes). I am bow legged and duck footed. My stress and impact won't be the same as someone pigeon toed and knock kneed. Whilst for some it may be true that running is lower impact, it may not be true for others simply because of the way they run. Whilst you can follow all available advice about foot placement and all that to mitigate stresses, there will still be some stresses that are unique to the individual because of their gait.
And then there is the surface you run on. If you run on a treadmill, but walk on rutted country lanes, yes, probably your walk causes more stress over time.
All I know is, every thing hurts more after a run. I can walk for hours and not notice it. 10 minutes of running and my legs are shouting at me.
I agree with all you say and will only add that, in my opinion, John Brewer's experiment is neither complex nor nuanced, but it is very individual, making it wholly unscientific and not worthy of being put on this forum as its conclusion is in no way helpful.
Stretching immediately after every run and leg strengthening exercises, as linked to in the guide to the plan healthunlocked.com/couchto5... can make huge difference to the ability of your legs to absorb the impact and there is also advice in there on how to minimise impact.
Yes, I quite agree that this is not a complex and nuanced study. It uses individuals to make broad generalisations as opposed to using individuals to expose the complexities.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
What's this, do we think? 
Why do we run? 
'We were born to do this!'
So how young are we all? 
THE THINGS WE DO FOR LOVE ❤️ AND CHARITY 😊 
