Nike Inc. has launched a lawsuit against Lululemon Athletica Inc. accusing the athletic apparel maker of patent infringement with its new Mirror home gym.

The legal scuffle between two of the world's biggest fitness players highlights the mounting competition in the booming exercise market.

In documents filed in a U.S. court, Nike claims Vancouver-based Lululemon's electronic device for streaming workout classes and its accompanying mobile applications violate Nike's "robust portfolio of patents."

The American fitness giant said it has spent decades creating "game-changing digital sport technologies."

In its claim, Nike cites multiple patents included one filed as far back as 1983 for a device used to determine a runner's speed and other metrics.

The list includes wearable activity trackers, footwear with built-in sensors, a fitness video game and multiple mobile apps.

It said these digital sport innovations contribute to Nike's success and competitive positioning.

"Nike pursues intellectual property protection for its digital sport innovations, and Nike protects its hard-earned rights against infringement," the company said in court documents.

It called Lululemon's alleged infringement "objectively reckless, knowing, intentional, deliberate, and wilful" and is claiming damages up to three times the amount found or assessed by a court.

Lululemon did not immediately respond to a request for comment.

However, a lawyer for Lululemon dismissed Nike's initial notice claiming patent infringement last month.

"We have completed an initial review of the patents identified in Nike's notice," California-based lawyer Diek O. Van Nort said in a letter to Nike included as an exhibit in the case files.

"Lululemon does not believe that Nike's patents are relevant to the Mirror (device) and Mirror app."

The case comes on the heels of Lululemon's lawsuit against Peloton Interactive Inc.

It accused the stationary bicycle maker of selling "knock-off" bras and pants.

Lululemon acquired Mirror in 2020 as the pandemic catapulted the at-home fitness market to new heights.

The device sells for a base price of $1,895 in Canada plus a $49 monthly subscription fee to access live and on-demand workouts including yoga, kick-boxing and meditation.

This report by The Canadian Press was first published Jan. 11, 2022.