Extending the duration of your daily walks may benefit your heart, new research suggests.
In a study among healthy adults, people who packed most of their daily steps into periods of 15 minutes or longer had significantly lower risks of heart disease and death nearly a decade later than those who took several shorter walks throughout the day. The study was published Monday in Annals of Internal Medicine.
What’s more, adults who had been less active in the past and took longer walks showed the greatest health benefits.
An international team of scientists analyzed the daily movements of 33,560 adults aged 62 on average living in the United Kingdom, using information collected between 2013 and 2015 in a medical research database called UK Biobank. For three to seven days, participants wore an accelerometer on their wrist that recorded their physical activity.
The researchers divided people into four groups, based on how they recorded most of their steps each day: in sessions of less than five minutes, five to less than 10 minutes, 10 to less than 15 minutes, and 15 minutes or more. The largest group (42.9% of participants) fell into the less than five minutes category.
After about nine and a half years of follow-up, the researchers found that people who had walked in periods of 15 minutes or more had the lowest chance of dying during the study period, while people who walked less than five minutes had the highest risk.
People who walked for longer periods also had lower risks of heart disease during the follow-up period, and the risk increased as the duration of walking became shorter.
The study’s lead co-author, Borja del Pozo Cruz, a professor and researcher in the sports sciences department at the European University of Madrid, calls the four walking durations “doses.”
“There is a clear dose response,” del Pozo Cruz said. “The longer the fight, the better it is for the different health outcomes we looked at.”
The decision to study people’s health through step accumulation patterns, as opposed to the total number of steps or intensity of physical activity, was intentional, he said.
“It’s easy to translate; everyone understands the steps,” del Pozo Cruz said. “Basically, everyone can measure steps with their smart watches, smartphones, pedometers or whatever. We thought focusing on steps would be much more impactful because the translation is immediate.”
Forget ‘exercise snacks’ and 10,000 steps a day
The notion that adults should strive to take 10,000 steps a day is more of a marketing ploy to sell fitness trackers than a scientific guide, according to Steven Riechman, an associate professor in the department of kinesiology and sports management at Texas A&M University, who was not involved in the study.
Riechman said the body goes through a series of adaptations as it goes from rest mode to exercise mode, changes that take a little time. That could explain why people who walked in sessions of less than five minutes didn’t see big improvements in their health, he said.
“All systems need to be activated and fully functioning, and that’s where the health benefits come from,” Riechman said. “The one I particularly thought about, [which] “What the article doesn’t mention is that the increase in body temperature probably won’t occur in less than five minutes of walking.”
Despite mixed research on the health benefits of 10,000 steps a day, the study deemed people who achieved an average daily count of less than 8,000 to be “suboptimally active.” All study participants logged fewer than 8,000 steps per day, and those who logged fewer than 5,000 were considered sedentary. The average activity of all participants was 5,165 steps per day.
The researchers found that the link between longer walks and lower risks of premature death and heart disease was most notable among sedentary participants. Within this group, people who walked in periods of less than five minutes had a 5.13 percent risk of death during the study period, compared to a 0.86 percent risk for people who walked in periods longer than 15 minutes. Their risk of developing heart disease over the decade-long study period was 15.39% and 6.89%, respectively.
“There are huge benefits from nothing to something,” Riechman said. “Then you continue to receive benefits, but they are lower and lower. When you reach 10,000 [steps]You are not accumulating many more benefits.”
The study is at odds with previous research touting the merits of “exercise snacks,” or bursts of physical activity that last less than five minutes. For example, a study published earlier this month in the British Journal of Sports Medicine found that exercise snacks improved the fitness levels of physically inactive adults. However, that study defined short periods as structured, moderate to vigorous activity. The short periods in Del Pozo Cruz’s study, on the other hand, included unstructured, low-intensity steps that one could accumulate throughout the day.
“Every step counts,” according to the American Heart Association, a mantra Riechman supports. Some physical activity is always better than none.
“Going out and doing some of the steps, without a doubt, is definitely a benefit,” he said. “To me, you’re just not optimizing the benefits.”
‘It’s never too late’ to start walking
The study had several limitations, including the fact that 97% of the participants were white.
Another limitation of the research is that participants’ walking patterns represent a snapshot in time, and people’s exercise habits can fluctuate over years. Still, the study’s large sample size likely stabilized that variation, said Carmen Swain, director of the health and exercise sciences program at Ohio State University, who was not involved in the research.
One of the biggest strengths of the study, he said, is the average age of the participants: 62 years old. It is a time in life when people can assume they are past the point at which they can reduce their risk of heart disease and premature death.
“You can start [walking] at any age; “It’s not too late,” Swain said. “The physiological adaptations that occur in a 20-year-old will also occur in a 60-year-old.”
Yes, a 60-year-old may already have underlying signs of heart disease, he said, making it even more important for older adults to maintain a walking regimen.
“Unfortunately, it’s often a challenge for this population to get started because they haven’t done it for a long time,” said Swain, who teaches her students about the power of walking. “There has to be motivation.”
With heart disease being the leading cause of death among men and women in the U.S., Swain hopes the heart health benefits of walking are motivation enough.
“Walking is very democratic. You can do it wherever you want, whenever you want and however you want,” he said. “It’s a good form of exercise.”
