We all know we should be up and about if we want to maintain our health and increase our chances of living a longer life, but just how important are daily steps anyway?
While the famous goal of getting 10,000 steps a day might not be quite what you think, we nonetheless know that getting more steps is better for our bodies in all sorts of ways, which in turn is linked to living longer.
What's more, having a higher daily step count shows a linear association with living longer, meaning that the health and longevity boosts we get out of walking are linked with how much walking we actually do.
So the numbers matter, but there's still much we don't know about the link between daily steps and longevity. For example, what about the composition of those daily steps: Does it matter where they're coming from during your day?
Older research examining this area was constrained by self-reported data from study participants, but in the age of the activity tracker, scientists can reveal ever more granular insights about how daily steps contribute to longevity.
"Technological advances made in recent decades have allowed researchers to measure short spurts of activity," says epidemiology researcher Christopher Moore from the University of North Carolina at Chapel Hill.
"With the help of wearable devices, more research is indicating that any type of movement is better than remaining sedentary."
In a new study, Moore and fellow researchers analyzed data collected in the Women's Health Study, a national trial investigating cardiovascular disease and cancer in a cohort of almost 40,000 American women, which began in the 1990s.
In a subset of the data, the researchers examined the longevity of 16,732 women who wore a waist step counter that measured their daily steps and walking patterns for four to seven days between 2011 and 2015.
Of the group studied, all of whom were individuals over 60 years of age (with an average age of 72), 804 of the women had passed away by the end of the study period in 2019.
Among the cohort, however, those who walked more tended to live longer. A previous analysis of the same group revealed that women who walked 4,400 steps a day on average had significantly lower mortality rates than the least active women in the group, who took approximately 2,700 steps a day on average.
Now, the new research sheds more light on what kinds of walking activity might confer the protective effect we see in these kinds of analyses.
In the study, Moore and his team divided daily steps into two different categories: steps taken sporadically in short bursts throughout the day (such as taking the stairs, walking to a car, or doing work around the house) versus longer, uninterrupted bouts of activity of 10 minutes or longer (which could include planned exercise, such as going for a walk or going to the gym).
While sporadic bursts of walking may be unplanned, they still seem to be an important contributor to overall health and longevity – and something that we shouldn't forget about, even if it's a somewhat randomized and invisible form of exercise.
After adjusting for steps taken in longer bouts, the researchers found that women who took more steps in short spurts lived longer than those who took less steps no matter how many steps they had in longer bouts, although the effect leveled off after about 4,500 such steps were taken.
Before that step count threshold was reached, however, the effects of sporadic steps look to be significant, with each initial increase of 1,000 sporadic steps per day being associated with a roughly 28 percent decrease in mortality compared to no daily steps during the study's follow-up period.
Uninterrupted bouts of walking are of course important too, with women taking over 2,000 daily steps in these longer walking sessions being about 32 percent less likely to pass away during the study than women who didn't.
It's worth pointing out that these findings, presented last week at a conference organized by the American Heart Association (AHA), have not yet been subjected to peer review or formally published, so we should treat the conclusions as preliminary for now.
That said, the results largely confirm something we already knew: higher daily step counts are inversely associated with mortality.
The new takeaway here is that it doesn't really seem to matter too much how those steps are accumulated during your day – which is great news for people who, for whatever reason, find it harder to engage in longer exercise sessions.
"This is just one study, but it suggests that there is a lot of flexibility in the way people can accumulate physical activity throughout the day," Moore explained to Today.
"A lot of people think you need to go to the gym and have long bouts of continuous exercise, but you can be active without going to the gym. And that's more feasible for a lot more people, especially those like the participants in this study who were older women. Older adults have a lot of barriers to doing more structured exercise."
The findings were presented at the American Heart Association's Epidemiology, Prevention, Lifestyle & Cardiometabolic Health Conference 2021, held virtually last week.