North America revenue increased 32% to $806 million and international revenue increased 58% to $452 million.

Apparel revenue increased 35% to $810 million, footwear revenue increased 47% to $309 million and accessories revenue increased 73% to $117 million.

CEO Patrik Frisk said: "Under Armour is off to an excellent start for the year. Our first-quarter results demonstrate that our improved operating model and investments we're making to amplify our connection with consumers are enabling us to deliver against strong demand for our brand.

"Additionally, with a solid balance sheet and well-managed inventory, we're confident in our ability to drive well through 2021 as we get back on offense and make measured progress to returning to sustainable, profitable growth over the long-term."

Under Armour has undergone a “comprehensive restructuring effort” - a $550 million to $600 million plan designed to “rebalance its cost base to improve profitability and cash flow”, which included hundreds of job losses over the past few years.