You've probably heard that adults should aim for 10,000 daily steps. This one-size-fits-all approach provides a clear message, though it doesn't consider how varied human lifestyles and bodies are.
An international team of researchers has found that even the most sedentary among us could ward off the harmful effects of sitting by incorporating more steps into our day.
Sedentary lifestyles are increasingly common, and we know they're linked to higher odds of dying from cardiovascular disease (CVD), greater risk of cancer and diabetes, and a shorter lifespan. And those risks are lower for people with higher step counts and faster-paced walkers.
But until now, it hasn't been clear whether highly sedentary people might be able to offset those alarming health risks with daily steps.
The more steps that people in the new study took, no matter how sedentary they were otherwise, the less risk they had of CVD and even early death. So those of us with desk jobs are not totally doomed, though the researchers emphasize that it's still important to try to reduce sedentary time overall.
"This is by no means a get out of jail card for people who are sedentary for excessive periods of time," says population health scientist Matthew Ahmadi from the University of Sydney in Australia.
"However, it does hold an important public health message that all movement matters and that people can and should try to offset the health consequences of unavoidable sedentary time by upping their daily step count."
Ahmadi and colleagues analyzed data from 72,174 volunteers contributing to the UK Biobank, a large long-term dataset established in 2006 that will continue to track participants' health measures over at least 30 years.
There was an average of 6.9 years' worth of general health data for each participant included in the study. Participants had worn wrist accelerometers for seven days to estimate their physical activity levels, such as the number of steps they usually took and the time they usually spent sitting.
The median time spent sedentary was 10.6 hours each day, so those who spent more time than that were deemed to have 'high sedentary time', while those with fewer hours were deemed to have 'low sedentary time'.
Participants whose stats in the first two years might have been affected by poor health weren't included in this study, so the findings apply only to people who, for at least the first two years' worth of data, were generally healthy. It's unclear whether the data included participants with disabilities affecting step count.
The team found between 9,000 and 10,000 daily steps were optimal to counteract a highly sedentary lifestyle, lowering incident CVD risk by 21 percent and mortality risk by 39 percent.
Regardless of a participant's sedentary time, the researchers discovered that 50 percent of the benefits kicked in at around 4,000 to 4,500 daily steps.
"Any amount of daily steps above the referent 2,200 steps per day was associated with lower mortality and incident CVD risk, for low and high sedentary time," Ahmadi and colleagues conclude.
"Accruing between 9,000 and 10,000 steps a day optimally lowered the risk of mortality and incident CVD among highly sedentary participants."
This research was published in the British Journal of Sports Medicine.