At the most recent wearable technology conference in Melbourne we had speakers from industry and industry all weighing in on the latest developments of wearables. I had as conference chair the at times challenging task of facilitating an emerging debate on wether ‘product’ should be rushed to market, or first scientifically validated and then released to market. Not surprisingly in a rising growth market being first to market is critical for gaining market share so hanging back and validating might not be desirable…unless of course it doesn’t work, which has brought undone a few companies playing in this space in recent times.
After the conference I spent some time with colleague James Lee musing this over and considering the adoption of wearables in the sports science community we published this invited article for the Journal of Fitness research (get the full issue here , its open access). Have a read…what do you think?
THE INCREASING ADOPTION OF CONSUMER GRADE WEARABLES: COMPARING THE APPLES AND ORANGES OF SPORT SCIENCE
Volume 5, Issue 1, April 2015 | JOURNAL OF FITNESS RESEARCH
Daniel James1 and James B. Lee2
The increasing adoption of off the shelf wearable technologies by sports scientists is a real sign of the times. It was not so long ago that the thought of using lab based body mounted sensors was new and even treated with suspicion. Today, specialist products for sports science exist and the use of the underlying sensors has been well validated1 and since that time, have been applied to all manner of sporting applications2,3. Body mounted instruments offer comparable (though sometimes different) method of the quanti cation of human activity. It has opened the way for consideration of the use of body mounted sensors for a variety of purposes and offered an opportunity to study human movement in relatively unconstrained environments4 where considerations such as ecological validity could be removed. Not only outside the lab, but for the rst time the performance environment could itself be assessed. In competitive sport the issue of feedback and unfair advantage had to be considered and today GPS sensors are accepted in many forms of team sports during competitive practice.
This change has been driven in no small part to worldwide trends in electronic industries that make this possible. The well-established trend of
miniaturisation of electronic components, rst proposed by Moore in the 1960’s shows the doubling of complexity every 18 months5. The net effect of this is that devices become proportionally smaller and cheaper. This has led to market place convergence of a range of technologies (of which smart phones are a mash up of many components including computer platform, sensors, video camera and web aware telemetry platform). In turn the market responds with a greater demand for these products as they become increasingly useful and inexpensive in the growing consumer sports technology market6.
It is here that sports science’s traditional approaches to measurement and instrument is itself subject to digital disruption and the Fitbit is a good example of that7. Here we have a consumer product, itself a trickle down by product of the work that has been undertaken in sports science and allied health, that not only have their origins as tools of science creating a market, but also opening up opportunities not possible by these more mature and dedicated products.
Whilst products like the Fitbit and what are used professionally on the surface are measuring the same thing and do so using the same basic sensors, i.e. accelerometers, each product is driven by its different market segment and achieves its goals through different design decisions. Understanding these, leads to making better decisions when choosing what is the best tool for a particular application.
Lab based technologies (ambulatory or xed) have a signi cantly higher cost, both the capital required to purchase and the more hidden cost, that of having a user suitably experienced to use it. Thus they are suited to high accuracy studies of not too many participants. Commercial wearables on the other hand are at least an order of magnitude cheaper to purchase and can be used widely. They represent an opportunity to do larger scale studies of more participants and don’t require a sophisticated operator. These products, driven by the desire for social engagement (consumers like this interaction and are more likely to continue to use and purchase in the future) over data aggregation opportunities across whole communities. Therefore commercially popular devices can possibly be an option for researchers to consider using.
Research quality monitoring platforms, typically use high rate sensors, today in the order of 1000 Hz. In addition they may also have other sensors, modularity and to accommodate for long periods of operation large capacity batteries. All data is collected and stored in raw form with the minimum of ltering, to allow for the most robust of analysis later on8. Fitbits and other commercial wearables need to make substantial compromises to achieve their small form factor and lower cost, so available computational power, sensor sets and batteries all must be substantially smaller. These compromises necessitate much lower sample rates, typically around 10Hz, or interrupt driven footfall events. Raw data is stored in aggregate form, usually in epochs that provide enough accuracy for a user and reduce the required amount to be stored, for example a 1 minute epoch of 10 Hz data is a 600 times reduction in data, but the trade off is resolution and accuracy.
As these consumer products continue to create a market appetite for such technologies, so too the market eventually becomes more sophisticated and the appetite for greater accuracy grows. Coupled with
technology trends we will increasingly see products like the Fitbit grow ever closer to their research quality cousins. Consider this, rather than doing studies of n=20 for statistical signi cant that n=2M is well within the realms of possibility…how exciting.
For now though they each have a role and a place. Understanding both of these in conjunction with either accepting an accuracy compromise, or that accuracy is paramount, for a sports scientist. Therefore, the sports scientist has to not only understand his or her objective, but needs to have considerable knowledge in the technology to be able to make an informed choice. In comparing apples with oranges it is perhaps helpful to see them as a fruit salad for the consumption of the discerning fitness professional.
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