Performance apparel, footwear and accessories brand Under Armour has booked an increase in fourth-quarter earnings and sales and upped its full-year fiscal 2014 outlook.

For the three months to the end of December, net profit climbed 9.4% to reach US$64.2m from $50.1m a year earlier.

Gross margin for the quarter was at 51.3% compared with 50.3% in the prior year, primarily driven by the strength of the brand contributing to a favorable sales mix.

Sales increased 35% to $546m from $405m in the same period of the prior year, due to expanded fleece offerings and new ColdGear Infrared products.

"By any measure, 2013 was a banner year for the UA Brand," said CEO Kevin Plank. "We surpassed $2bnn in net revenues for the year, which culminated with our 15th straight quarter of at least 20% total growth. While we are proud of what we have accomplished to date, we firmly believe we are just getting started and that our performance in 2013 is indicative of the opportunity that lies ahead for Under Armour."

Under Armour said it expects 2014 net revenues in the range of $2.84bn to $2.87bn, representing growth of 22% to 23% over 2013. Operating income is expected in the range of $326m to $329m, representing growth of 23% to 24% over 2013.