2020 was a big year for Nobull. The 6-year-old Boston athletic-apparel and -footwear brand has become a cult favorite of the CrossFit community.

Nobull grew sales and revenue by over 80% in 2020 and is on track to double growth in 2021, the company said.

In April, it announced a Series B funding round of an undisclosed amount that brought its valuation up to more than half a billion dollars. Nobull has raised $32 million in total funding, according to Crunchbase.

Cofounders Michael Schaeffer and Marcus Wilson said that the investment came after a year in which the brand further embedded itself in the world of health and fitness during the pandemic.

"Every single day felt like a week trying to wrap our heads around what was going on," Wilson said. While Wilson said it initially felt insensitive to launch new products, the Nobull team decided to move forward with product launches at full force to deliver for their customers and keep employees at work.

Like Nobull, fitness-apparel and -footwear brands like Lululemon and Nike also reaped the benefits of a renewed focus on wellness and physical activity during the pandemic. Running-footwear brands such as Brooks, On, and Hoka One One similarly experienced sales surges in the past year.

Nobull's success during the pandemic can largely be attributed to its existing online presence. While Nobull has partnerships with retailers like Rogue Fitness and sells its merchandise on Amazon, 95% of its business comes from direct-to-consumer sales online, Wilson said. Nobull operates three brand-owned stores in Boston, Miami, and New York City, which remain closed.

A pair of classic Nobull training shoes, its best-selling item, goes for about $140. During the darkest days of the COVID-19 pandemic, Nobull faced a series of supply-chain and logistical challenges in getting shoes into customers' hands, it said. But the inability to host in-person events — meant to drive community engagement — also helped the brand keep operating costs low.

Schaeffer and Wilson decided to start their own footwear company after hitting it off while working together at Reebok.

"We really had a lot of fun working together at Reebok, and we had this desire to create something of our own," Wilson, who worked as Reebok's head of brand strategy, said. (Schaeffer was the global creative director). "We weren't exactly sure what that was going to be, but we did know that we wanted to partner up and work together on things," Wilson added.

Both avid devotees of CrossFit, the popular strength and conditioning regimen, Schaeffer and Wilson decided over a series of monthly breakfast meetings to leverage their footwear experience to launch a brand with a simple motto in mind.

"It's really about you putting the work in, and that's how you are going to get fitter — not by wearing certain product," Schaeffer, who previously worked at And1 Basketball and Puma in addition to Reebok, said of the philosophy that guided the launch of Nobull. With this goal in mind, Nobull launched its first product — a training shoe — in 2015 and quickly found a home within the CrossFit community.

Nobull is based on the idea of "No BS" when it comes to getting the results you want in your training and exercise, Schaeffer said, adding that this motto made it "a no-brainer" to launch into CrossFit because of its emphasis on hard work through functional fitness.

Similarly, Wilson described Nobull as "a training brand for people who work hard and don't believe in excuses."

Nobull has partnered with a roster of athletes, including the professional weightlifter Tia-Clair Toomey, who has her own training shoe with the brand.

In March, CrossFit announced Nobull would be the title sponsor for its annual CrossFit Games this summer in a partnership that will span at least the next three years. Reebok sponsored the CrossFit Games up until June, when the brand cut ties with CrossFit after then-CEO Greg Glassman tweeted an insensitive comment about George Floyd. Glassman ultimately stepped down in light of his comments and was replaced by Eric Roza.

Nobull has also expanded its reach beyond the CrossFit world, with shoes for cycling and lifting as well as apparel and accessories. It also has plans continue expanding into other categories in 2021 but did not disclose which ones. Schaeffer and Wilson see global potential for the brand, which is largely focused on the US.

"The beauty of having such a concise brand message is that it works globally," Schaeffer said. "It's close to our hearts to make sure that the attitude and the voice of the brand is the same everywhere you go."