Step counts and health outcomes - 7,000 or 10,000?

Where did the 10,000 steps recommendation come from? Why has it proven so stubborn? What's the science behind the new recommendations? How strong is the evidence?

Professor Melody Ding joins Gavin to talk about her new systematic review published in The Lancet Public Health, examining the relationship between step counts and health outcomes. We also explore the challenges of measuring physical activity, the importance of inclusive research, and the role of environmental and policy interventions in promoting population health.

Read the article from The Lancet Public Health here:

https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(25)00164-1/fulltext?dgcid=buzzsprout_tlv_podcast_August_25_lanpub

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Transcript

This transcript was automatically generated using speech recognition technology and may differ from the original audio. In citing or otherwise referring to the contents of this podcast, please ensure that you are quoting the recorded audio rather than this transcript.

Gavin: Hello, welcome to The Lancet Voice. It's August, 2025. I'm Gavin Cleaver and I'm very pleased you've chosen to join me today for this episode, we're gonna be talking with Professor Melody Ding, associate professor at the Sydney School of Public Health, to discuss the findings of her recent publication on step counts and health outcomes, which are published recently in the Lancer Public Health.

You've probably seen the work all over the news in recent weeks, but I was excited to get the chance to look more deeply into the systematic review with the author of the paper. We'll be examining the evidence behind why the accepted step count targets, the relationship between physical activity and major health outcomes, and the implications for public health policy and personal wellbeing.

I hope you enjoy this conversation with Professor Melody Ding.

Professor Melody ding, welcome to the podcast. Thanks so much for joining us. It's a real pleasure to have you with us. So you've just put out a systematic review in The Lancet Public Health that looks at step counts, some of the most popular science out there. Everyone loves to think about their step counts.

Everyone's got a step count on their phone, on a smartwatch, wherever. We're surrounded by them these days. But your systematic review obviously had to look at the kind of published history of a step count research. So how broad was the literature that you looked at? 

Melody: Yeah, so we ran the literature search from the beginning of 2014, so it's just about 11 years of literature, and we found 57 studies.

From 35 cohorts in the systematic reviews that we summarized. And of those we included 31 studies from 24 cohorts in the meta-analysis. And these studies covered a broad range of outcomes. Eight specifically, and most of the studies are very recent, published in the last couple of years. 

Gavin: And so what generally were the kind of recommendations on step counts before this study, and where did that information come from?

Everyone's heard of the 10,000 steps recommendation obviously, but how did that arise? Yeah, that's a really interesting question. So we sometimes joke that the 10,000 steps is our unofficial target, because that's actually not based on good research evidence. I think the legend has it that back in the 1960s there was a popular pedometer brand in Japan.

Melody: The name of that pedometer was called 10,000 Steps in Japanese. Around the same time in Japan with the Tokyo Olympics, there was some health promotion campaigns for the Japanese population to be more. Active and then they named that campaign 10,000 Steps as well. So it became really popular and around the world people start talking about 10,000 steps.

And in Australia we also has a very successful health promotion campaign called 10,000 Steps. And it was very successful in motivating people. And I still think 10,000 steps is a good thing because that's a round number. It's very catchy and it motivates people to take more steps. The only thing is that we actually didn't have good evidence to support that.

Gavin: No. I guess in terms of like actual scientific research is it's a bit of an urban, that's also a really good kind of like marketing success. So I guess on that topic, how much conflicting information about step counts was out there before this study? I think in general, we know that the more steps, the better.

Melody: The only thing is we didn't quite know where the sweet spot is because. Usually the risk of major chronic illness and premature mortality will start to decrease as the stack counts increase. We didn't have very good idea in terms of at what point that decrease start to slow down or start to flatten out.

So we had some good indication in terms of all course mortality outcomes, but with other outcomes. There was very little information that has been summarized. 

Gavin: Let's skip straight to it. I'm sure a lot of people will have seen the outcomes of yours matter review in the news as it's been everywhere, especially in the UK over the last week or so.

But what did your study find? 

Melody: Yeah, so we looked at a broad range of outcomes, and we have three major findings. So we have three key findings from our study. Number one is even if we take relatively low that counts, it still offers health benefits. So for example, we use 2000 steps as the reference, so that's our comparators, because that's like a really low step count for, someone to keep basic.

Daily functions and when we increase the 2000 to 4,000, just, still relatively low step counts, we already see quite a sizable decrease in the risk for most of the outcomes that we examined. So I think the message is, every step counts. And even when we increase a little bit in terms of our step counts from a relatively low baseline, we still see good health benefits.

Number two, the dose response curve of the step counts and health relationships seems to decrease quite fast at the beginning, and it start to flatten out around 7,000 steps for most of the outcomes. So that's where we concluded that around 7,000 step could be a good target if one wants to have a quantifiable target, and it's important to clarify, which is our.

Message number three for some of the outcomes beyond 7,000 steps, it still offers additional benefits, but it's just less return on investments. So with more steps you take, you get a little bit less additional benefits as compared with say, moving from 5,000, so 7,000 for example. 

Gavin: Some of the problems generally with using step counts as like a measure of overall health layer, it feels like it must be quite entwined with health issues that people are going through.

And also, you said something in the research about cadence, which I found really interesting as well. 

Melody: Yeah, so we were initially very interested in looking at cadence, which is basically the pace and stepping rate, how fast someone walks. Surprisingly, we didn't find very conclusive findings from these studies, and I think the primary reason is that.

Studies tend to use different cadence measures. I think we're still coming to conclusion which measure we should rely on for which health outcomes. For example, is it how fast one can walk or is it the average speed across the day, across an hour? So this is something we're still trying to understand a bit more steps, data becoming available around the world.

With more researchers being interested in this topic, we can have more conclusive findings in the next couple of years. 

Gavin: Where does it d become difficult with step count to disaggregate it from poor health? Intrinsically I would think that, say if I'm in poor health, I'm likely to walk fewer steps, but then obviously if 'cause I'm in poor health, I will have poor outcomes.

So I guess it's a kind of almost chicken in the egg question. What comes first? Is step count a great measure of follow on issues or do people generally have lower step counts because they already have health issues? 

Melody: Yeah, this is an excellent question and this is an issue that we encounter a lot in physical activity research in general.

Whether or not it's about that counts because in general, people who are healthier have less underlying health issues are more active as a result of their better health, and they're also less likely to develop chronic conditions and. More likely to live longer. So this is what we call the reverse causation issue.

And it is a challenge, especially when we are doing a systematic review. We cannot have control of how the original study is conducted. So what the best we can do is to find ways to select the studies that have less bias, ideally. So for this studies, we only focused on longitudinal studies, so at least we know that step counts are measured years before health outcomes manifested.

And we also assess the quality of each studies, and particularly we're interested in confounding because, other. External factors could be affecting stat counts and health outcomes, and most of the studies that we looked at actually have good quality. The studies really took care in terms of trying to tease out these confounding factors, trying to include participants that are healthy at baseline and excluding those with diagnosed upper chronic conditions.

For the small number of studies that didn't take as much care in selecting the participants, we. Conducted additional sensitivity analysis, excluding them and comparing the results. So we're doing the best we can with the data we have, and I think the data are robust, but still we're dealing with the causation versus correlation issue.

And I think that's going to be an ongoing challenge for physical activity epidemiology research. 

Gavin: Yeah, absolutely. It makes me think, actually, how did you first get interested in the physical health research? 

Melody: The reason why I was particularly interested in this ideas of, what is. Exactly the target for the evidence-based target for stat counts.

That came from my experience of working on updating the physical activity guidelines for Australia. So for the last year and a half, I was working with a team of an excellent scientist in Australia, updating the guidelines. I was really interested in steps because I know in 2018 when. The US updated their physical activity and sensory behavior guidelines.

They concluded that there was not enough evidence to inform a quantitative status guideline, and in 2020 WHO came with the same conclusion. In the last five years, there has been such an increase in step count related research because there are so many more data sets available with step counts, and researchers from around the world have been really investigating step counts very thoroughly.

So I thought that would be really good opportunity for us to look into this unresolved question from previous guideline development. And I also think that. Because now more and more people have devices that can give them that counts. Is really important for us to actually be guided by scientific evidence rather than promotion strategies.

So that is why I was interested in this research. 

Gavin: Does that mean that step count is quite a kind of relatively growing area of research recently? Has there been quite a lot more studies on it in the last few years? 

Melody: Yes, definitely. I think this is probably related to us having more and more tracking devices, and I think in general, step counts is something that people relate to more.

For example, if I ask you, Gavin, how many. Hours or minutes of moderate intensity physical activity you did last week, or how many hours of vigorous intensity activity you did in the last week. It's gonna be really hard for you to tell me because minutes in general is a bit harder to track and sometimes it's a bit harder for people to understand and the steps are quite discreet and easily understandable and easily trackable.

So I think. That is probably the explanation why it's becoming so popular, not only in the general public, but also among scientists. 

Gavin: Definitely. No, I think that makes sense. It's I don't really count the minutes of exercise. I do, but I always can just pull my phone outta my pocket and be like, oh, I've done 5,000 steps today.

Melody: And I also think the other reason why tracking steps is important is that where our understanding about the health benefits of physical activity has really improved in the last couple of years. Back in the days we thought that physical activity has to be continuous over, more than 10 minutes bout, or, longer durations in order to be beneficial, but now we have more and more evidence supporting that. The belts actually don't matter. Physical activity can happen in one goal continuously or sporadically throughout the day. So that. Really gives us opportunity to embrace incidental physical activities like those activities that we don't necessarily plan to do, but it just happen as part of our daily living.

And that kind of activities are particularly hard to track. How do you track the 30 seconds that you take to go up a flight of stairs, for example, but with steps. They capture all these incidental activities along with more structured activities. So I think that just gave people more comprehensive understanding about their overall activity patterns throughout the day.

Gavin: Yeah. So I'm guessing that the devices that people use, like the smartphones, smart watches, et cetera, aren't particularly accurate, when it comes to like exactly recording people's steps or stairs. They've been up all that sort of day, but it's a good sort of ballpark measure.

Melody: Ballpark measure. You're exactly right. And we have extensively discussed that at the end of our paper as well, because these studies, all but one study used commercial grade. Devices, so they're validated in the research setting. And some of the wearables are validated against research grade devices, but not all of them are necessarily validated, and especially with our phone apps.

And that could potentially be a little bit off sometimes. And with our phone, it also depends on where we. Keep our phone, in our pockets or in our purse or in our hands. So there's definitely gonna be all sources of biases there, but it will give us some ballpark. It might not be a hundred percent accurate, but at least it's something that you can track yourself, you can compare against yourself and use that number to motivate yourself if you track steps.

Gavin: And then we've reached the magic number. 

Melody: No, 7,000 is not a magic number. We compare the dose response curves for all the outcomes that we looked at. That seems to be a sensible point that is achievable, but also offers quite sizable risk reduction. 

Gavin: Talking of the health outcomes actually, you discussed in the paper, is the evidence for step count association with some health outcomes stronger than with other outcomes that you discuss.

Melody: Yes, definitely. And also the research evidence seems to be distributed not completely evenly across these outcomes. For example, we have a lot more studies on all cause mortality and cardiovascular disease incidents particularly we take 7,000 steps, for example, the risk reduction we observed for all cost mortality was really high, was.

47%. So it's almost half the risk. But in comparison, some other outcomes like cancer incidents, the risk re reduction that we observed for 7,000 steps was quite small and borderline, statistically significant. So there was a difference there. But it's also important to know that for some of the outcomes such as cancer incident and dementia, the number of studies were really small.

So I really encourage future studies looking to and outcomes like this. That really matter to us, but currently have relatively thin research space. 

Gavin: That's really interesting. I wanted to ask, actually, going back a couple of questions ago. You said this was part of Australia's reassessment of physical activity guidelines.

Do you know what some of the other outcomes were from other kind of other assessments of physical activity guidelines in this Australian piece of work? 

Melody: Yeah, so for the ad adjunct population, these eight outcomes that we looked at are the main, what we call the critical outcomes that we looked at for other physical activity measures as well.

And I just want to probably remind the re the listeners who don't have the papers in front of them, these eight outcomes are all cause mortality, cardiovascular disease, both incidents and. Cancer, both incidents and mortality. Type two diabetes, dementia depressive symptoms, falls and physical function.

And these are the ones that you know, while we're developing the guidelines, based on the consultations with the scientific community and with our stakeholders, we consider these eight to be of critical importance for us to decide what recommendations we include in the guidelines. 

Gavin: Apart from step counts, were there any other recommendations 

Melody: at the moment?

Physical activity guidelines around the world are quite similar in terms of the type of activities they recommend, and it hasn't really changed too much. So in general, the message about 150 minutes of moderate intensity physical activity, or 75 minutes of vigorous intensity physical activity has been pretty consistent across guidelines.

So these. Refer to aerobic physical activity. And another component that has been recommended throughout these guidelines is muscle strengthening activities as well. And I think, the way I think about the 7,000 steps and 10,000 steps, one of the potential benefits that we can consider is that for those who are doing 7,000 steps and may not have the time to do an extra 3000 steps.

The time that you save for the 3000 step could be the time you spent on other physical activities that are important for your health and physical functions such as muscle strengthening activity. So we definitely don't want to say that step counts or walking will be like the physical activity we do, and we know that we really need to do a broad range of physical activities for health benefits.

Gavin: So you can efficiently use your time, take that 3000 steps and go to the gym for half an hour. Instead, 

Melody: I think it's really important for us to not discourage those who are currently already doing 10,000 steps to go back to do 7,000. As I mentioned earlier, there's still some small incremental benefits for some of the outcomes.

But we also know that for the general population, there's a large proportion of us who are really time poured and really struggle to get to the 10,000 steps. For those folks, just 7,000 steps could save you quite some time every day, and then you can redistribute that time hopefully towards some health enhancing physical activity.

Gavin: That's a nice message. I wanted to ask, how did you first get interested academically in, in this area of research? 

Melody: I think it's my personal passion because I've always been quite active in my daily life and a combination of my personal interest and happen to be in the right place at the right time in terms of how I end up with a research group, so a little bit serendipitous as well, and I've just been so passionate ever since the very start because I basically live what I preach.

Gavin: That's always good to hear from academics. One other thing, actually before we finish, I wanted to ask you about was, it was interesting to see in the discussion of the paper talking about how difficult it was to assess subgroup data of participants. So what effect does this kind of have as a limitation?

I. 

Melody: I think it's really important that physical activity, research, or health research in general is inclusive. Oftentimes, we focus on healthy, or we call it apparently healthy adults or children because it's easier to study them and it's messier when we have participants with chronic conditions. I think it's really important because we know physical activity plays such an important role, not only in terms of disease prevention in healthy adults and children, but also in disease management and improving quality of life in those with a chronic condition.

And we did find around. 12 studies out of the 57 that were conducted in subpopulations, particularly populations with a condition or disability, and the conclusion was pretty consistent as well. The more steps was better for them as well. It's just that because these subs samples were so diverse, it's really hard for us to run a meta-analysis and combine the findings from these studies.

We're still inversely associated with health outcomes in these subgroups as well, we just couldn't put the numbers together and put into. Software and come up one magic number. So I think it's really important we don't forget them and it's really important that we continue to encourage them to take more steps and find more opportunities throughout their life to incorporate a little bit more physical activity safely and comparably.

Gavin: What's next for you in your area of research? What are you moving on to after this? 

Melody: My primary research now focuses more on how to get people more active rather than finding more evidence that for physical activity being beneficial. Because I think we already know physical activity offers such a broad range of health benefits and research like this.

Just reinforces that message. Help us fine tune the message a little bit more in terms of the quantitative target, but the actual. Ballpark of my research now has moved on to how do we compare, for example, compare, simulate, and select policies for long-term investment. Because I think it is really important that we take a systems approach to understand physical activity because it's such a systemic problem embedded in our.

Society, our built environment, our social norms, and our policies. So I'm moving a lot more towards that policy and intervention space. So hopefully to guide our decision makers with the right strategies and resources to invest into physical activity promotion. I know, and I'm sure everyone else knows that walking more is beneficial for them, but some days I've had a rough day, it's been a long day at work.

Gavin: I don't want to do the steps. How do you shape policy to encourage people to do physical exercise? We all know physical exercise is a miracle drug almost. It's super important for health, but a lot of people just don't wanna do it or don't have the time or are busy or whatever. So yeah. What are the steps there?

If you, excuse the pun, of course. 

Melody: Yeah. Yeah. This is a really big topic and it's a million dollar or billion dollar question really, but I think it's really important that we look at physical activity within context in Australia through the efforts of decades of physical activity promotion, we are actually seeing, relatively good progress in terms of the increase in physical activity prevalence.

When we start to take a closer look, for example, in the stage of New South Wales where I live, we're seeing widening gaps because when we're only focusing on the message of physical activity being important, it is probably those who are already well resourced and have the skills and capacities well educated.

They're the one who are probably going to increase their physical activity level and improve their lifestyles. But fundamentally, we have. Still a sizable population who lack the resources, lack the capacities, and have many things going on in their life, that physical activity probably is not the most important thing on their mind.

So I think it's really important that we take the equity lens. We really think about the environment that we live in because when we live in an environment when physical activity is not something that we have to do intentionally, but rather we can do it so easily as part of our lifestyles, that becomes a lot more equitable.

So for me, I always advocate for walkable environment, the built environment that makes active lifestyles. The easier, the more obvious and enjoyable lifestyles. And I think when we achieve there, we're going to solve huge problems with inactivity in the population, but also offer additional benefits in terms of better livability, probably better social health outcomes, and also possibly.

Better environmental outcomes in terms of less driving, less carbon emissions and air pollution. So to me, I always want to start with environment. 

Gavin: Yeah, that's a really interesting point actually. I used to live in Texas and now I live in London and obviously in Texas it is completely not set up for people to walk anywhere.

If you want to go to the grocery store at the end of the road, often you'll just have to drive the two minutes there because there's no pavement between your house and the grocery store, for example. But now I live in Central London. I don't own a car. It would be completely pointless. I can just walk everywhere and take public transport.

I guess I didn't have, I don't have the information to hand, but I would imagine that my step count in Texas versus London is a huge world of difference, but that's just me going about my daily business instead, 

Melody: a hundred percent. And I think these two environments cannot be more different. And I personally have made the change from San Diego in the US to Sydney, Australia, and my lifestyle has changed dramatically as well.

I now ride my bike to work and I rarely drive. I used to drive everywhere. So having more walkable, more active travel friendly environment is the very important strategy for us to get the population moving and not just to get a few people out of the population to move even more. 

Gavin: That's fascinating, and I think we've pretty much covered everything on the physical activity front, so professor Melody ding, thank you so much for joining us on the podcast.

It's been a real pleasure talking with you. 

Melody: Thank you so much for having me. Keep stepping.

Gavin: Thanks so much for listening to this episode of The Lancet Voice. Remember, you can subscribe to The Lancet Voice. Where do you usually get your podcasts? And if you're interested in listening to more podcasts from The Lancet, you can go to the lancet.com/podcasts where you can see the in conversation with titles where we have one podcast for every journal at The Lancet.

Thanks so much for listening.