The German group said on Wednesday it had completed the acquisition from majority owner Axel Springer SE, along with the company's founders and an "angel" investor, in a deal valuing the Austrian company at EUR 220 million (roughly Rs. 1,523 crores).
Rival Nike Inc was a pioneer in fitness tracking, teaming up with Apple Inc on the Nike+ running programmes for the iPod and iPhone and launching the FuelBand in 2012.
Adidas has been losing market share in sporting goods to its bigger U.S. rival and launched its own miCoach fitness device only last year.
Fast-growing Under Armour Inc, which last year overtook Adidas as the second-biggest sportswear maker in the United States, earlier this year bought diet and exercise app MyFitnessPal for $475 million (roughly Rs. 3,028 crores) and social fitness network Endomondo for $85 million (roughly Rs. 541 crores).
Under Armour said those deals had given it a total of 120 million registered users on its Connected Fitness platform, which it said made it the largest digital health and fitness community in the world.
Adidas said Runtastic offers over 20 apps covering a variety of endurance, health and fitness activities in 18 languages.
© Thomson Reuters 2015