Pedometer Research

I wrote about Pedometers a couple months ago. Click Here They're the gadget you attach to your belt loop and it counts your steps as you walk or just go on with daily life. Pedometers have several practical applications. They can be used to:

1. Distinguish between individuals who vary based on steps per day
2. Measure increases in physical activity with interventions
3. Conduct cross-study comparisons of different populations (example- I think every culture is more active than Americans)
4. Compare time trends in physical activity
5. We the general public are interested in using pedometers to determine whether we are meeting step recommendations.

The latest edition of Medicine & Science in Sports & Exercise by The American College of Sports Medicine (ACSM) had some studies about pedometers. One study compared pedometers and studied their accuracy and another other one wanted to see if they would work with the frail population. 

Here's a summary of the research: The models cost $10-$200
The most accurate pedometers were Kenz Lifecorder, Yamax Digi-Walker SW-200, New-Lifestyles SW 701, and Sportline 345 got an honorable mention. (Sportline 330 was accurate in this particular study but not in others previously).

The pedometers that underestimated the steps (up to 25%) were Freestyle Pacer Pro, Accusplit Alliance 1510, and Yamax Skeletone EM-180
(I think I'd rather have an underestimation than an overestimation- force me to work harder....so food splurges don't go into the "michelin/fat" stores).

The pedometers that overestimated the steps (by as much as 45%!) were the Walk4Life LS 2525, Omron HJ-105, and Oregon Scientific PE 316CA.

When trying to asses steps on nursing home residents the pedometers weren't as accurate because their steps were slower and their gait was off, (ie they hobbled.)

Explanations for the step count discrepancy that exists between the models may be a differing vertical acceleration threshold required to trigger a step. This feature is related to the internal mechanism of the device. Devices that are highly sensitive would likely overestimate steps and ones that are less sensitive would likely underestimate steps.

FYI- A normal mile is 2000-2500 steps. The goal is to register 10,000 steps a day (like a typical European) or just add 2000 to your current total.

Schneider, Crouter, and Bassett
Med. Sci. Sports Exerc. Vol 36, No2, pp 331-335 2004
and Cyarto, Myers tudor-Locke pp 205-209