The global revenues for smartphone-connected fitness tracking devices and equipment will grow from $2 billion in 2014 to $5.4 billion by 2019, according to a report from research firm Parks Associates.

"Our latest data finds adoption of connected health devices increased from 24 percent of US broadband households at the beginning of 2013 to nearly 30 percent by the end of 2014," Harry Wang, director of health and mobile product research at Parks Associates said in a statement. "The most popular devices are exercise equipment with built-in app support and digital pedometers with wireless connectivity." 

In a report published last month, Parks found that 5 percent of US broadband households use a smartwatch that offers health and fitness tracking features and 8 percent of US broadband households use a digital pedometer or activity tracker. At the time, a Parks analyst pointed out that unless smartwatch makers can convince consumers that these devices offer features separate from their smartphone, they won’t see wide adoption.

"In the case of smartwatches, these devices are regularly marketed as companion or ‘tethered’ smart products," he explained. "Companies need to rally consumer interest in smartwatches by educating them on the unique experiences and benefits of these and other wearables. Otherwise, the majority of consumers may not see the reason to purchase another device that has similar, if not the same, capabilities as their smartphone.”

And a few weeks prior, Parks released a report that found more than 40 million US smartphone owners are active users of at least one wellness or fitness app. The firm also reported that one in four heads of household — at homes with broadband — use a mobile app to track their fitness or track their caloric intake.