The concern relates to the (now) everyday items that people wear on their wrists or as part of other devices. For many people these are used for fun or semi-seriously to improve their step count. For some others, though, the devices are used to make serious decisions about health and fitness and this reflects the way that some devices are marketed. A review of the accuracy of many of the commercially available devices has been made by Dr. Roy J. Shephard, from the University of Toronto. His review takes the form of a new academic paper.
Commenting on his study, Dr. Shephard tells Controlled Environments magazine: “Advances in the development of objective monitoring devices such as accelerometers have spurred hopes of defining more accurately the relationships between habitual physical activity and chronic disease.”
For his study Dr. Shephard reviewed the results of 12 studies that have put a variety of accelerometers and step counters under scrutiny, against different objective measurement of physical activity. The benchmark was the standard requirement that people should undertake 150 minutes of moderate activity per week.
READ MORE: Fitness trackers underestimate calories
If people opt to follow the 150 minutes per week target then most fitness devices calculate that they need to be taking between 7,000 to 8,000 per day (based on typical walking pace). However, current devices cannot account for the intensity of effort which, according to Dr. Shephard, is limiting. If a person elects to complete the 7,000 to 8,000 steps at moderate walking speed then fitness trackers appear to be reasonably accurate. However, for slow walking and vigorous running, as well as for people who move less ‘smoothly’ (that is atypical gait patterns), then the accuracy of the devices diminishes.
What is needed, according to the researcher, is an assessment that also looks at the optimal exercise “dose” needed for maximum health benefit (that is the amount of effort extended).
To make activity trackers more reliable and accurate, the researcher has identified some key measures that can help to improve the devices. This includes using GPS tracking to take into account the terrain that a person is moving along and measurements of posture and the rate of acceleration. These need to come together with together with advancements in computer-assisted checking of records and processing of data.
The research is published in the journal Progress in Preventive Medicine. The research paper is titled “The Objective Monitoring of Physical Activity.”
