The more you walk, the lower your risk of death from all causes and cancer, according to a new study, with the benefits stabilizing once you hit 10,000 steps per day. So clearly that’s the number of steps to aim for – or is it?
Studies that compare health outcomes to step count seem pretty convincing, because nowadays we all have step counters on our wrists or In our pockets. A step count also seems very concrete and precise: 10,000 steps are synonymous with health and happiness, and this is automatically measured for us. Cool.
But already, I bet you noticed some major caveats. Our bodies are messy meat machines, not neat step counters. If exercise is what matters, wouldn’t a cyclist have fewer steps than a runner and be just as healthy? Besides, couldn’t a walker and a runner end up with a similar number of steps despite very different exercise intensities which probably have different effects on the body?
On the other hand, there are some ways that step count is a good way to track activity, so I don’t want to completely discount the idea, even if I am skeptical of the sharpness of an image it provides. Step counts are higher in people who move around more in daily life (“incidental” activity, as it’s sometimes called) even if they don’t do a lot of structured exercise. Steps are also counted automatically: OYou may not remember if you worked in the garden for 20 minutes or 45, but your tracker probably has a good idea of how many steps you took.
There is another set of caveats: TThese studies are generally observational. They tell us that people who take more steps per day tend to be healthier. But is it cause or effect? People in poor health may have less energy to run errands and take daily walks. And people who use wheelchairs or other mobility aids probably don’t count their steps, even when they do.
With that in mind, here are some published step numbers from recent research, along with some of their caveats.
For all-cause mortality and cancer mortality
This study found that people who took 10,000 steps had a lower risk than those who took 8,000, who in turn had a lower risk than those who took 6,000, and so on. Step counts above 10,000 seemed to have a similar risk to 10,000. In other words, if this represents a true, causal relationship – which we can’t be sure of – going from 10,000 to 12,000 wouldn’t change your risk of cancer or death.
The 78,500 people tracked were from the UK, were between the ages of 40 and 79, and were 97% white.
This study found that participants’ risk of dementia decreased as they took more steps, up to 9,800 per day, similar to the study above. (It was also conducted by the same team and drew from the same group of subjects.) They also note that people who took 3,800 steps had about half the reduced risk of people who took 9,800, so perhaps this lower number would be a good target if you are currently more sedentary. That said, this was also an observational study, and most of the participants were a bit young to start developing dementia.
For all-cause mortality in older women
This study found a reduced risk of death from any cause in women who took 4,400 steps compared to those who took 2,700 steps per day. More was better, until about 7,500 steps, after which the risk of dying seemed to level off. The number of steps comes from the quartiles: the 25% of people with the lowest number of steps averaged about 2,700.
The participants were 16,741 women with an average age of 72 years. They come from Women’s Health Study, which began as a trial in the 1990s on aspirin and vitamins for the prevention of heart disease and cancer. Participants are 95% white and most are nurses.
For mortality in middle-aged people
This study compared steps per day to the risk of death in middle age (41 to 65). It found that people who took more than 7,000 steps had a 50-70% reduced risk of death compared to people who took less than 7,000 steps per day. This number was chosen as the threshold because it is the number that estimates from the American College of Sports Medicine such as a 30 minute walk each day plus a small amount of non-athletic activity.
The 2,110 participants were 57% female, 42% black, and were followed for about 11 years on average after the study.
For arterial stiffness
Stiffening of the arteries is a component of cardiovascular disease. This systematic review found that increasing steps by 2,000 per day appears to reduce arterial stiffness by about the same amount as starting a structured exercise program. The categories compared in the analysis ranged from those who took less than 5,000 steps to those who took more than 10,000. The authors write: “Put simply, these results suggest that some physical activity is better than nothing, but also that more is better than less.”
The results come from 20 previous studies. Most were cross-sectional (comparing groups of people by the number of steps they took), but a few were randomized controlled trials or prospective studies.
For the risk of diabetes in Latinx adults
This study found that every 1,000 more steps per day was associated with a 2% reduction in the risk of diabetes. People who took between 10,000 and 12,000 steps per day had an 18% lower risk than those who took less than 5,000 steps per day.
Study participants were 6,634 Hispanic and Latino adults, half of whom were women, with an average age of 39.
For all-cause mortality, but at different ages
This study is interesting because it breaks down the results by age group. Data from 15 studies suggest that mortality declines with more steps up to 6,000 to 8,000 steps for people aged 60 and older, but the equivalent in young adults is 8,000 to 10,000.
What do we do with all this?
I think it would be a mistake to take these frontline results completely at face value. Can you reduce your risk of death by a certain percentage simply by deliberately walking a few thousand extra steps a day? Almost all of these studies compared people who already market different amounts, rather than tasking groups of people to increase their step counts and see how their health has changed.
But the results suggest that healthier people tend to have step counts that are toward the higher end of the typical range. In almost all of these studies (and others in this area of research), people who take, say, 8,000 steps tend to be in a lower risk category than those who take, say, 2,000 steps. So , if you are currently quite sedentary, it may be worth trying to count your steps, even if there is no specific study indicating that you have to meet such and such a number.
It is also interesting, I think, to see that there is no specific optimal number that these studies have identified, although we like to talk about these studies in detail. It’s not like you have to hit 10,000 because something different will happen than if you hit 9,500.
The curves on the graphs in these articles tend to level off somewhere in the upper four digits, but the estimates also become less certain there because there just aren’t many people getting more steps that. A person who regularly takes 25,000 steps a day, for example, is simply out of this world. They may be in super shape or have an active job that makes them work harder than they can easily recover from; these studies are not designed to disentangle the difference.
So the bottom line is probably what you would have assumed before you even checked the numbers: if you sit a lot, moving more will probably be good for you. And if you want specific advice, you can follow the good old 150+ minutes of exercise per week directive, or follow the different government project guidelines who recommend 8,500 steps per day (US presidential challenge), 7,000 to 10,000 (UK National Obesity Forum) or 8,000 to 10,000 (Japan).
#steps #day #science