The global market for connected wearable devices accelerated at the end of 2015, with Fitbit pacing the leaders and Apple closing ground, a survey showed Tuesday.

The IDC survey found fourth quarter sales of wearables such as fitness trackers and smartwatches surged 126.9 percent compared with a year earlier, with 27.4 million units.

For the full year, sales of  wearables sales were up 171.6 percent at 78.1 million devices.

The jump in sales shows "that wearables are not just for the technophiles and early adopters, wearables can exist and are welcome in the mass market," said IDC's Ramon Llamas.

"And since wearables have yet to fully penetrate the mass market, there is still plenty of room for growth in multiple vectors: new vendors, form factors, applications, and use cases. This will help propel the market further."

Market leader Fitbit sold 8.1 million units in the fourth quarter, for a 29.5 percent share, IDC said.

Even though Fitbit sales grew more than 50 percent, its leadership is under assault from other vendors, notably Apple and Chinese maker Xiaomi.

Apple has not publicly released sales figures for its Apple Watch, but IDC estimated the company sold 4.1 million in the fourth quarter and 11.6 million for the year. That gave the California giant a market share of around 15 percent for both periods, even though its smartwatch sales began in June.

Xiaomi was number three for the final quarter of the year with sales of 2.7 million units and a market sahre of 9.7 percent, paced by sales growth of 258 percent.

For the full year, Xiaomi held the number two spot, with a 15.4 percent share, paced by sales of its fitness tracker selling for as little as $11.

Among the other major vendors, Samsung was number four for the past quarter with a 4.9 percent share and Garmin fifth with 3.5 percent.

IDC's Jitesh Ubrani said he sees newer devices coming into the wearables market, with "fashion and design" playing a key role.

"The wearables market isn't just about smartwatches and fitness bands," he said.

"Though the top five certainly dominate with wrist-worn devices, there's been an immense amount of growth in other form factors like clothing, footwear, and eyewear -- form factors that arguably require even more fashion sense than watches or bands."