But on the conference call that followed with management shortly after, analysts still raised a few key questions — not everyone was swayed by CEO Kevin Plank's confidence in the company's ability to grow sales amid an increasingly competitive sports retail landscape.
Even with Wednesday's gains, shares of Under Armour's Class A shares are down more than 50 percent for the 12-month period and have fallen more than 25 percent since the start of the year.
Here are 5 things to watch with Under Armour:
1. Decelerating sales in footwear
Under Armour said Thursday that sales in its footwear segment grew only 2 percent for the quarter, compared to a whopping 64 percent increase in shoe sales during the same period one year ago. The difference was primarily due to "significant strength in basketball sales" last year, Under Armour said.
On Thursday, CEO Kevin Plank outlined a plan to tackle footwear this year and beyond, telling analysts, "it always comes back to product innovation — building great, great product — and I want to detail that our [shoe] pipeline is full."
One innovation will be the launch of a personalized e-commerce shoe platform where customers can design and order their own unique sneakers online. This is an area where Nike has excelled.
Under Armour also will open a "footwear building" in Nike's home turf of Portland, Oregon, and, shift its focus to shoes priced at more than $100.
While Plank was optimistic his company will grow market share in footwear moving forward, not everyone is buying his lofty ambitions.
"Footwear growth of just 2% after 36% growth in 4Q and 50%+ in the last couple of years suggests wholesale orders & shipments are catching up with weak sell-through at retail," Evercore retail analyst Omar Saad wrote in an updated note to investors Thursday morning, reacting to the latest dismal footwear sales. "The underlying fundamentals suggests the company still has some work to do in a couple of its core categories."
Don't forget Adidas, which is gaining footwear market share, Jefferies analyst Randal Konik said in a note to clients.
2. Under Armour struggles to make a fashion product
With more shoppers looking for casual wear to sport throughout the day rather than hard-core performance apparel or compression shorts, Under Armour has begun "interpreting and authenticating" its brand within fashion. Plank said getting into
Under Armour recently struck deals to beef up its lifestyle apparel offerings, with Misty Copeland and Dwayne 'The Rock' Johnson, which should give the brand more credibility in that category as they launch and sales pick up.
But there is much more progress that needs to be made. For the first quarter, Under Armour's apparel revenue climbed 7 percent and was fueled by gains in training, golf and team sports, the company said.
"Demand for [Under Armour] products is waning given subpar innovation and the lack of a compelling lifestyle offering," research firm Susquehanna said in a note to clients Thursday morning.
3. Blame it on the bankruptcies
Under Armour's North American sales fell 1 percent for the quarter, and the company said that was largely because of " ... new distribution [being] more than offset by the absence of business lost to bankruptcies in 2017," which include those of Sports Authority and Sports Chalet.
"We don't like it, and we don't really accept it," Under Armour Vice President of Corporate Finance David Bergman said on Thursday's call.
Though, Under Amour wouldn't have been the only sportswear retailer impacted by numerous big-box store closures. Nike (NKE), for example, recently reported revenue growth in North America, excluding currency exchanges, of 3 percent for its third quarter ended Feb. 28. This included 3 percent growth in both its North American footwear and apparel divisions.
"We do not believe that the travails of the U.S. sports market are solely responsible for Under Armour's lackluster performance," GlobalData Retail analyst Neil Saunders said in a statement Thursday. "Especially as a number of other sporting brands and retailers have done relatively well over a similar period."
"A step up in competition from players, including Nike and Lululemon (LULU), is one of the reasons for Under Armour's slower growth," Saunders added. "Unless North American growth gets back on track, earnings will remain under pressure."
Outside of North America, though, Under Armour still has higher growth potential, he said. The company's international sales represented 20 percent of total revenue in the quarter and were up 52 percent overall.
4. Distribution deals put on hold — for better or for worse?
Under Armour made it clear Thursday that the company is no longer in acquisition mode, but instead in "activation" mode, with around 13,000 points of distribution today.
Starting in March, Under Armour began selling its products — many at a discount — in more than 1,000 Kohl's stores.
Much of Wall Street, though, is still concerned the Kohl's deal could dilute Under Armour's brand image in the long run.
Under Armour "has begun utilizing select markdowns (of 25%) on its new apparel offerings in KSS," Citi Research wrote in a note to clients earlier this month. This implies a rough start to the partnership, according to analysts who performed Kohl's store checks.
On Thursday, Plank said the Kohl's deal has "exceeded our expectations to date, and they are a very good partner." But, he emphasized: "I don't believe we have to open any new distribution... I'm really giving my team the ability to just relax and just focus on what we have right now."
5. Profit margins under pressure
Under Armour's first-quarter gross profit margin fell 70 basis points to 45.2 percent, as discounts continued to weigh on results. The pressure will continue as it grows its international and footwear businesses.
"Our outlook on profits remains relatively gloomy"
"We believe that a push to more direct sales, including via e-commerce, will dilute margins," he wrote to clients. "We also think that more marketing will be necessary to keep the brand on the consumer radar, which will likely have an impact on costs."
Under Armour has forecast its gross margin to be "slightly down" in 2017 compared to a margin of 46.4 percent in 2016, with changes in foreign currency and shifts in overall sales mix also creating challenges.
By Thursday afternoon shares of Under Armour were trading up over 10 percent, on pace for their best day since Jan. 28 of last year, when the stock jumped nearly 23 percent.
Watch: Cramer says wouldn't hurt to buy UA here
More From CNBC