The research house IDC said in its worldwide wearables forecast that 45.7 million of the devices will ship in 2015, and that shipments will reach 126.1 million in 2019. That represents a five-year compound growth rate of about 45 percent, IDC said.

IDC attributed the rapid growth to a combination of new vendors, new devices, and greater end-user awareness.

“Smart wearables” — that is, wearables capable of running apps — will fuel the growth of the space. These devices include the Apple Watch, Motorola’s 360 smartwatch, and the Samsung Gear watches.

Such smart wearables sold about 4.2 million in 2014, but IDC expects that number to rocket up to 25.7 million units this year. Dumber wearables, like basic fitness trackers that don’t run apps, will grow from sales of 15.4 million units in 2014 to 20 million units in 2015, IDC said.

Screen Shot 2015-03-30 at 11.32.02 AM

“Smart wearables are about to take a major step forward with the launch of the Apple Watch this year,” said IDC analyst┬áRamon Llamas. “The Apple Watch raises the profile of wearables in general, and there are many vendors and devices that are eager to share the spotlight.

“Basic wearables, meanwhile, will not disappear,” Llamas said. “In fact, we anticipate continued growth here as many segments of the market seek out simple, single-use wearable devices.”