The “weekend warrior” exercise pattern once dismissed by experts as not quite good enough may not be so bad after all. A study in this week’s JAMA Network Open finds that people who walk 8,000 or more steps a day once or twice a week achieve cardiovascular benefits and lower mortality rates that are almost as good as people who go the same distance but do it nearly every day.
That distance is about 4 miles a day.
“We’ve long wondered what is the minimum physical activity we need for health. This study tries to answer that question,” said Dr. J. Sawalla Guseh, a sports cardiologist and director of the Cardiovascular Performance Program at Massachusetts General Hospital. “This is putting an exclamation mark on something we already knew: that a little exercise goes a long way.” Guseh is the coauthor of a commentary article accompanying the study.
“We’re trying to find ways to encourage movement. This gives us permission to exercise even if it’s only two days a week,” Dr. Alysia Robichau, an ex-gymnast and primary care sports medicine physician at Houston Methodist The Woodlands, who was not involved in the study.
How much exercise are you supposed to get?
The Department of Health and Human Services recommends that adults get at least 150 minutes of moderate-intensity aerobic activity a week as well as muscle-strengthening exercises two days each week. That’s about half an hour a day, five days a week of aerobic activity, plus strengthening.
However, Americans have perpetual trouble meeting these goals. Less than half of adults meet those aerobic guidelines and only 24% fit in the appropriate aerobic and muscle-strengthening activities, according to a report from the Centers for Disease Control and Prevention.
While there’s no official step-based guidance in terms of how much walking and running is optimal, people, including doctors and researchers, are starting to talk in these terms.
The evidence suggests that 6,000 to 10,000 steps per day is optimal, Guseh said, which translates to about 2.5 to 4 miles daily. For reference, the average number of daily steps for people in the US is 4,800, or about 2 miles, based on smartphone data. (And that was an estimate from a prepandemic study conducted in 2017.)
In the past, many health experts have warned against being a weekend warrior largely due to the risk of injuries like muscle tears and strains, said Dr. Eric Ascher, a family medicine physician at Lenox Hill Hospital in New York City, who was not involved in the study. The danger is particularly high if you go from being a couch potato during the week to very intense activity on free days.
“If you’re not doing any exercise during the week then sprint and run for long distances, you’re still probably going to hurt yourself,” he added.
If you avoid that pitfall, being a weekend warrior may pay off.
What the study found
The authors of the study looked at step data from accelerometers worn by some 3,100 people who took part in a large national health survey. The participants wore the devices for one week and were separated into groups depending on the number of days a week they managed 8,000 steps or more: zero days, one to two days, or three to seven days.
It’s not clear if the study participants got in their steps by walking, running, or some other activity — the researchers just measured the total amount.
The participants were followed for 10 years while researchers kept track of total deaths as well as deaths from cardiovascular causes like heart attacks.
Compared with people in the “zero” group, those who walked at least 8,000 steps on one or two days had a 15% lower risk of mortality during the following decade while those who did three to seven days had a 16.5% lower risk.
The risk of dying from cardiovascular disease was roughly equivalent between the lower and higher nonzero groups: 8.1% and 8.4%, respectively.
What the study didn’t show
One of the advantages of the study is that it incorporated objective exercise data from a wearable device, rather than participants’ often faulty memories. On the other hand, steps were only measured for one week.
That means there was no firm data on whether exercise patterns persisted for months or years. “A lot could go wrong between Day 1 and 10 years,” Guseh said.
The authors also didn’t take into account the level of exertion or type of exercise, but walking is an exercise that many people find doable.
Keeping up with a changing world
The transition from minutes to steps reflects what patients are actually doing, which is buying and wearing devices like Apple watches or other fitness trackers, which provide achievable markers.
“We’re trying to get data for what people are actually presenting us with,” Robichau said. “I think in this world of sedentary obesity taking over the world in both children and adults if someone says they got 10,000 steps, that’s enough. Let’s make it realistic.”