Under Armour completed its planned $150 million purchase of fitness technology firm MapMyFitness Inc. Friday, marking the Baltimore-based sports apparel maker's first-ever acquisition.

Austin, Texas-based MapMyFitness, creator of the MapMyRun and MapMyRide mobile applications, has more than 20 million registered users who map, record and share their workouts using GPS and other technologies.

Self-described as the largest social network of fitness buffs on the Internet, MapMyFitness is expected to help Under Armour compete with rival Nike and others in the growing fitness technology market. Nike reported earlier this year it had about 18 million registered users in Nike+, who use its mobile applications, wristbands and sports watches.

MapMyFitness will operate as a wholly-owned subsidiary of Under Armour. The company financed the deal with a combination of cash and $100 million borrowed under an existing $300 million revolving credit facility while it evaluates longer-term funding options.

lorraine.mirabella@baltsun.com