According to the University of British Columbia researchers, the iPhone's built-in pedometer missed about 1,340 steps during a user's typical day when compared to a purpose-built accelerometer worn on the waist.
The results suggested that for people who are already tracking their steps, they can rest assured that if their phone says they are getting the recommended 10,000 steps in a day, then they are probably getting at least that many and they are working toward better health.
Lead study author Mark Duncan that in order to make accurate conclusions, the team of researchers need to know that the data is actually representative of real behaviour.
The team analysed 33 participants and were divided into two parts: a laboratory test and a test in regular living conditions.
the findings suggested that personal iPhones underestimated steps by 9.4 percent at the slowest speed of 2.5 km/h.
At faster walking speeds, the phones were off by less than five percent, which is generally considered acceptable for a pedometer.
The results suggest researchers should use caution when relying on smartphone data, but Duncan said the average person should not be discouraged from using health apps for motivation.
From a public health point of view, it's better that it underestimates than overestimates, they concluded.
The research appears in journal of Sports Sciences. (ANI)