The 10k Steps Lie – Do this instead

Chapters:

00:00 Intro

00:57 Fat loss

04:13 Trackers

06:17 Health

10:15 Practical application

Transcript:

More and more people are paying attention to their step count. Many people have the explicit goal of hitting 10,000 steps a day. However, the figure of 10,000 is a conveniently round number that doesn’t come from any evidence based source. In fact, it comes from a 1965 advertising campaign from a Japanese company that sold – you guessed it – a step counter.

Of course, the origin of the goal does not invalidate it. You come to this channel for the evidence based fitness critiques, so in this video I will help you decide should you be walking 10,000 steps a day.

This is largely a discussion of cost benefit rather than of benefit alone. It is very clear that there are health benefits to being more physically active, and you also burn more calories. Conversely, there is no real physiological reason to be less active, so generally being more active is good. However, is it worth the time and effort for you to actively spend time on increasing your step count for the health or fat loss benefits?

For fat loss a higher step count means a higher activity energy expenditure, meaning higher total daily energy expenditure and therefore an easier time getting into an energy deficit, which is what drives you to lose fat. However, the total additional energy expenditure from walking versus resting or whatever else you would be doing is not that large.

A rule of thumb that’s often used in exercise science is that you burn roughly 40 extra calories for every 1000 extra steps that you walk, if your body weight is around 80kg. The average fit guy may therefore expect to burn some 200 additional calories if they increase their step count by 5000 steps a day. If we look at the real life effects here, we can see that this is relatively difficult for people to adhere to, for relatively little fat loss.

For example, in a meta analysis of 32 walking interventions, that’s a serious walking intervention, not just a little bit more walking, the average fat loss in the studies was 1.4kg, amounting to 1.2% body fat reduction. In many of the studies with more moderate interventions or less clear interventions such as “I’m just going to try to be a little bit more active”, there was no significant effect on fat loss at all. The effect of higher step counts on fat loss is often smaller than you would expect based on the superficial mathematics for three reasons.

Reason #1: Unlike exercise, non increase activity thermogenesis tends to increase at libitum energy intake. Basically, people eat more when they are more active and this offsets much of the benefit.

Second, there is a substitution effect. When people are more active at one part of the day they often reduce their activity at another time of day. Part of these effects is for sure psychological, but there’s also clear physiological effect, namely #3: constrained energy expenditure.

When you increase your energy expenditure, especially when you’re in a deficit and you’re already lean and you’re already quite active, the body increases the energy efficiency of all your expenditure. Basically, as you get more active and you burn more calories, the body becomes more efficient and tries to reduce your energy expenditure. It tries to conserve energy because it doesn’t want to just waste it.

The finding of constrained energy expenditure was quite revolutionary and upset the whole linear thinking in terms of fat loss science, but I already explained it in a recent video, so I’m not going to go into it in too much detail here. What matters for this video is that the effect of increased energy expenditure on fat loss plateaus over time, in part due to constrained energy expenditure. So most people, they increase their step count a lot and they are a little bit leaner, but not that much. And they don’t keep getting leaner. So basically they reach a new equilibrium.

These exact same arguments also apply to cardio for fat loss, which is why we have the sayings in fitness that you cannot out train a bad diet, and abs are made in the kitchen. The good news is that none of these effects seem to apply to resistance training. So lifting weights does not make you more hungry. It does not increase your appetite, it does not have a displacement effect, and it also doesn’t seem to suffer from constrained energy expenditure.

These differences between lifting weights and other forms of exercise explain why research has generally found that lifting weights is more effective than you would expect, based on the rather limited calorie burn for fat loss, and cardio and increased step counts are less effective than you would expect based on the increased energy expenditure.

At this point, you may be protesting: “Menno, all of your fancy papers of science… I have a smartwatch right here, real tech, modern tech, not your ancient papers, and it’s telling me that I’m burning at least 500 additional calories per day.” That might be true, and smartwatches these days are pretty good at tracking your step count, but they are unfortunately quite bad, if not to say very bad, at estimating your total daily energy expenditure.

The correlations between energy expenditure estimated by a smartwatch, regardless of brand, and that of gold standard measurements like calorimetry, range from basically nonexistent to moderate at best. Multiple studies have found error rates in the vicinity of 40%. That means that the total daily energy expenditure estimate, or the expenditure estimate of the additional walking can be off by several hundred calories a day easily, regardless of brand or how new and high tech your gadget is.

The reason that these gadgets simply have a hard physical constraint on their accuracy is that it’s just measuring your wrist movement and your heart rate. So when your smartwatch is detecting vigorous wrist movement and an elevated heart rate, it could mean… …a lot of different things.

You could argue that it’s not the accuracy of the energy expenditure estimates that you’re going for, it’s the fact that you’re monitoring something that is important, and when you monitor something like your step count, you automatically increase it and you improve your lifestyle.

A meta analysis of 32 studies on the effect of starting to monitor your step count, sometimes combined with counseling or other interventions, but often just monitoring your step count, resulted in an increased step count, yes, over the first few months of 1126 steps, so about 1000 extra steps in the first months. Still not that large. And this decayed rapidly to 464 steps at year’s end. And after two years the effect was no longer statistically significant at all.

So if you’re monitoring your step count specifically to lose fat, then you’re monitoring something that is of questionable importance to begin with, and you’re measuring it in a very unreliable manner. The good news is that there is arguably a much better reason to increase your step count than to lose fat, and that’s the health benefits. A recent meta analysis of 31 studies found that higher step counts are associated with better health in almost every possible dimension. Cardiovascular health benefits, all cause mortality, basically all measures of your health are better in people that have higher step counts than people that have lower step counts.

The benefits are highly meaningful, even for outcomes like depression and anxiety. A step count of 7000 steps compared to a very low step count resulted in a 47% lower risk of all cause mortality.

However, it’s not the case that more is always much better. There are sharp diminishing returns in most of these analysis. The analysis generally converge that around a step count of 7000, in this latest meta analysis around 5000 to 7000 steps per day, the benefits start decreasing significantly, and there’s a virtually a plateau, depending on who you are and the rest of your lifestyle. The people currently tracking their step counts the most are the people that have the least benefit from doing so, because they are usually already somewhat lean and already physically active.

For example, a previous 2022 meta analysis found that all cause mortality basically plateaued at a step count 8000 steps in adults, but in elderly individuals above 60 years old higher step counts were associated with better health. So if you’re already quite healthy, you’re already lean, you already exercise, then the benefits of higher step counts are much less dramatic. In fact, in these analysis, one of the biggest confounders is that it includes exercise. So when you strip out the benefits of exercise, the additional benefits of also having the high step count are significantly lower.

Moreover, step counts are a very crude measure of someone’s total physical activity level for multiple reasons. First and foremost, they suffer from massive reverse causality. When you measure someone’s step count and their health outcomes, you are measuring an association. This is not a randomized controlled trial over a very long duration because it’s simply impossible to do these things. So when you’re looking at very long term data we have associative data. People with higher step counts live longer. People with higher step counts have lower rates of disease than people with lower step counts. But it’s not the case that the higher step count necessarily causes the people to live longer. There’s high reverse causality.

Reverse causality means that the correlation is actually explained by the opposite causation. So it’s people that are less healthy that walk less because they are very unhealthy, because they have difficulty walking, especially in elderly individuals this makes a lot of sense.

Second, there is what’s called residual confounding, meaning that other variables might explain both the effect on step counts and the effect on health. For example, people that are happier are generally more physically active, so being happy might cause a higher step count. And we also know that people that are happier live longer. So being happy might also cause people to live longer. And the relation between the step count and health outcome might therefore be partly an artifact, basically not a real effect.

Last but not least, there are many covariates in this type of association, meaning there are many other factors that correlate with someone having a high step count. People that are more physically active differ from people that are less physically active in many ways, and generally these are always that make them healthier to begin with. Like I said, a high step count is in part a proxy or a measure of someone’s general healthiness. People that have higher step counts probably also have a healthier diet, for example. Another very notable finding in health sciences is that effect of total physical activity and sedentary time are partly independent. You might think that these are the same things.

Clearly, someone that is more physically active is less sedentary, right? Well not necessarily. It’s also about how you distribute that physical activity time over time. So if someone has one long workout or one long walk, and then the rest of the day they are completely sedentary, just sitting on their ass in front of computer, then that might actually not be as healthy as someone that has multiple exercise snacks, as researchers like to call it these days, throughout the day. So how you break up the sedentary time might be as important as the total level of physical activity to begin with.

So what does this all mean in terms of practical application? This is basically how I explain it to my students and my clients. There is no doubt that being more physically active is good for you. The only question is, are the relatively small benefits worth the time and effort?

For most people, deliberately just trying to be more active, to lose more fat or to be healthier is not very sustainable and has relatively marginal benefits, especially compared to putting that energy into your diet or formal exercise like lifting weights or cardio. I see some people these days obsessing over their step count, as if it’s some vital target that they have to hit. 10:00 at night, you’re wasted, you want to go to bed, but you haven’t hit your step count, so you have to go for a long walk. That is not a sustainable lifestyle. And sustainability is everything when it comes to your lifestyle.

So the real focus should be on sustainability and lowering the cost. If you can find ways in your life to be more physically active, but it doesn’t cost you more time and it is not more effortful than those are the ways that I recommend you try to implement higher physical activity in your lifestyle. For example, if you can conveniently go to work by bicycle instead of by car, that is most likely worth it. If you can work from a standing desk or even better, a treadmill desk, that is amazing. That is extremely good. It doesn’t cost you more time. In research we see that it also does lower productivity, and you get a significantly higher total daily energy expenditure and better health benefits. Same for phone calls and video calls. If you can do those walking, that is amazing. Or if there’s, say, an hour long podcast that you listen to every week, that’s a great time to do it while walking.

The key in all of these examples is that they involve a restructuring of your lifestyle without a higher total time or effort requirement. These strategies, in my experience, are far more effective than tracking your step count and trying to hit 10,000 steps a day. 10k steps a day for most individuals is above the point that they really need for their health. The benefits at that point are increasingly diminishing, and for fat loss you also run into serious constraint energy expenditure at this point.

Big picture: The things that really matter for your physique are your diet and your strength training. If you get those two right and you do them well, you have a good training program and you have your diet under control, the vast majority of my clients have gotten six pack lean without even monitoring their step count, or even wondering about their total physical activity level. Now, if you can increase your physical activity level in a sustainable way with habits, routines, and other ways that you can sustainably incorporate it into your lifestyle without requiring more time or effort, that is great. Definitely do it.

Beyond strength training and your diet the next big addition you should be considering is cardio. Cardio has established health benefits and can burn a lot of calories in a limited amount of time. Only after that point, when you’ve done all of these things, would I really consider monitoring your step count every day and making it a point to hit some relatively arbitrary high step count.

I hope this video helps you optimize your lifestyle based on your specific goals. If you’re into evidence based fitness and you want an in-depth review of all topics fitness, check out my online PT course. It is the most comprehensive review of basically all evidence based fitness topics on the market, bar none. Check it out, and you can also keep watching this video about constrained energy expenditure.