Higher daily step count linked with lower mortality risk: Study

Higher daily step counts are associated with lower mortality risk from all causes, according to a study.

The research, published in the Journal of the American Medical Association, found that the number of steps a person takes each day, but not the intensity of stepping, had a strong association with mortality.

"While we knew physical activity is good for you, we didn't know how many steps per day you need to take to lower your mortality risk or whether stepping at a higher intensity makes a difference," said Pedro Saint-Maurice, from the National Cancer Institute (NCI) in the US.

"We wanted to investigate this question to provide new insights that could help people better understand the health implications of the step counts they get from fitness trackers and phone apps," said Saint-Maurice.

Previous studies have been done on step counts and mortality. However, they were conducted primarily with older adults or among people with debilitating chronic conditions.

This study tracked a representative sample of US adults aged 40 and over.

About 4,800 participants wore accelerometers for up to seven days between 2003 and 2006.

The researchers calculated associations between mortality and step number and intensity after adjustment for demographic and behavioural risk factors, body mass index, and health status at the start of the study.

They found that, compared with taking 4,000 steps per day, a number considered to be low for adults, taking 8,000 steps per day was associated with a 51 per cent lower risk for all-cause mortality.

Taking 12,000 steps per day was associated with a 65 per cent lower risk compared with taking 4,000 steps, the researchers said.

In contrast, they saw no association between step intensity and risk of death after accounting for the total number of steps taken per day.