. >> i love trainers but they can get really expensivexpensive, s app can do the same thing. all for it. >> these wearables can help you track your workout progress and complete with others online. sales are expected to top more than a billion dollars this year, but not everyone is buying into all of the excitement. critics say some users are more interested in feedback from their friends than their scales. the data can easily be manipulated. so are they making us healthier or just feeding our social media obsession. joining us is a fitness blogger and long-time marathon runner, a leading tech expert on the intersection of gaming and technology, and psychologist, researching the behavior of consumers who buy health products. welcome to all of you. ivan fitness devices have been around for a long time. what is it about this wearable technology that has people so gung ho? >> pretty much it's the fact that you are using these devices to move around, and it gives you a data calculation of what you are actually doing. it's sort of making our humdrum activity of walking into someth