Key points from article :
Walking 9000-10,000 steps daily may reduce the risk of early death and heart problems.
The 10,000-step target's origin is unclear, possibly linked to a Japanese pedometer campaign.
A new study analyzed over 72,000 people wearing activity trackers for a week.
Participants were tracked for 7 years, during which 1633 deaths and 6190 heart-related events occurred.
After adjusting for other factors, optimal number of steps per day appears to be 9000-10,000, with the benefits then starting to tail off.
This walking amount linked to a 39% lower death risk and 21% lower heart issue risk.
Experts consider this a step forward in physical activity guidelines.
Others say that wrist trackers may not perfectly measure steps, and walking intensity might be important too.
Study co-authored by Emmanuel Stamatakis from University of Sydney, published in British Journal of Sports Medicine.
