Under Armour revenue jumps as people return to gyms

As home-bound customers returned to gyms and yoga classes, surging demand for sports apparel and sneakers pumped up results at Under Armour. The athletic clothing maker's quarterly revenue nearly doubled, and its adjusted earnings crushed analysts' estimates.

Revenue in three of its biggest markets more than doubled.

Sports apparel makers like Under Armour, Nike and Adidas are seeing a sales boost. While consumers may shift some of their dollars to dressier clothing as they head back to offices, analysts believe the resumption of team sports at schools and colleges could offset that impact.

Under Armour is bullish about the road ahead. It significantly jacked up its annual earnings forecast, betting that it'll benefit from charging higher prices.

Shares in Under Armour, which have risen by a quarter this year, rose in early trading Tuesday.