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Updated: Jul 6, 2026

Assessing the Accuracy of Fitness Smartwatch Data for Cardiovascular and Physical Activity Monitoring: A Validation Study in Digital Health
Published on: February 21, 2025
Validity of 2 devices for measuring steps taken by older adults in assisted-living facilities
Randall J Bergman1, David R Bassett, Suresh Muthukrishnan
1Dept of Physical Education and Health, Kentucky Wesleyan College, Owensboro, KY 42302, USA.
Background:
This 2-part study examined validity of selected motion sensors for assessing physical activity in older adults residing in assisted-living communities.
Methods:
Twenty-one older adults (mean age = 78.6 +/- 13.1 years) wore the StepWatch 3 Step Activity Monitor (SW3) and the Yamax Digi-Walker SW-200 pedometer (DW). Part I compared accuracy of these devices for measuring steps taken over 161 m. Part II compared devices over a 1-day (24-hour) period.
Results:
In part I, the DW recorded 51.9% (r2 = -.08, P = .75) and the SW3 recorded 102.6% (r2 = .99, P < .001) of steps. In part II, the DW measured significantly fewer steps (1587 +/- 1057 steps) than did the SW3 (6420 +/- 3180 steps).
Conclusions:
The SW3 pedometer was more accurate in counting steps and recorded higher 24-hour step counts than the DW pedometer. Thus, the SW3 is a valid research instrument for monitoring activity in the assisted-living population.

