Under Armour has been hit by industry headwinds that have hurt other sports brands, such as more competition from lower-priced apparel manufacturers, a slower pace of sales in both the performance apparel and footwear categories, and changes in buying habits amid the rise of online shopping. But analysts say the brand also has begun to fall out of favor with younger consumers, losing some of its cool factor, and some recent product launches have registered only a lukewarm reception.