A new generation of smart activity trackers that keeps tabs on the calories spent, the hours one sleeps in a day and even mood swings is becoming popular, writes Karthik Subramanian

The metadata generated through the day because of our digital lives fuels the online marketing and advertising business. But how about making some of that metadata work constructively for our benefit? More specifically, with regard to our personal health?

Wearable

A new generation of wearable activity trackers — mostly in the form of wrist bands — is gaining mainstream adoption in the U.S. and Western markets. They track everything from calories burnt and calories gained to sleep hours and even mood swings through the day to help plot one’s daily health chart. Add to the mix goal-setting, and what one gets is a digital personal assistant that could be invaluable not only to those following a fitness regimen but also to those who are genuinely concerned about their health.

Though they have been around for around five years now, often marketed as niche products to athletes and sports enthusiasts, wearable activity trackers have gained acceptance mostly because of the increased ability among devices to “listen to one another”. The proliferation of mobile platforms of the likes of iOS and Android and their ability to sync over the cloud has helped.

The most popular brands in activity tracking today include Nike+ Fuelband, Jawbone Up, Fitbit Flex and Basis Band.

How do they work?

Almost all the devices have a 3-axis accelerometer that helps measure the steps people take in a day. There is some debate on whether the accelerometer is effective when worn on the wrist as against the hip (there are some pin-up activity trackers that one can just attach to their trousers). While wrist movements can sometimes register what is termed as “false positives”, the devices attached to one’s hips don’t lie as much.

For the calorie counting function, there is a bit of manual work involved. Most of the activity trackers come with a database of food and the effective calories of different foods. (This can be a bit of a problem in the Indian scenario because most of the foods featured are Continental or from other Western cuisines.) After entering the data online about the calories consumed in a day, one will be able to find out how it figures in achieving one’s daily calorie goals.

Though not all activity counters have these, a few specialised ones such as Basis Band come with additional sensors like a skin sensor and optical heart rate sensor that improve the calorie count considerably.

Almost all these activity trackers have mobile Apps on either Apple’s iOS platform or Google’s Android platform that have nice user-interfaces, interactive health charts and even a unique ‘incentive’ mechanism to motivate a person to reach his set health goals.

Like most digital devices, there is still some chatter online about the effectiveness of the measurements. This is an argument I have heard even about the digital blood pressure measuring device versus the conventional one.

But the argument is less about accuracy of the data than it is about making everyday fitness a fun activity. Those who adhere to their fitness goals get special badges and can even compare their results with friends online, who use similar devices.

When Apple’s CEO Tim Cook spoke at the All Things Digital Conference, earlier this year, about “wrist devices” being of considerable interest to the company, he was probably referring to the trend of these new devices becoming increasingly popular.

How to buy?

Almost all the companies mentioned — Jawbone, Nike, Fitbit and Basisband — retail through their online stores. Those in India wanting to purchase the activity trackers can opt for services like Shop and Ship.