Steve Knurr likes to run beside his girlfriend in bike races, help his roommates move furniture and chase after his dog — all in sandals.

Trouble is, he beats them up. "I feel like I often put sandals in a situation that sandals were never designed for," says Knurr, who lives in Madison, Wis.

That's why when some of his friends developed a durable, comfortable alternative to the traditional sandal, Knurr was an instant convert.

Called Bokos, the new rubber sandals have been getting considerable attention in sports and fitness circles. James and Matt McManus, the twenty-something brothers from Plymouth who launched the $16 sandals earlier this year, tout them as a cheap, multipurpose alternative to Tevas and other brands that tend to sell for $40 and up.

The one-piece, cross-strap sandals are designed to slip on and off easily and endure the wear and tear inflicted by someone like Knurr, who was on a college cycling team with James McManus.

"One thing that makes them stand out from 90 to 95 percent of what's out there is the durability," Matt McManus said. "You can get them wet, you can get them dirty, and they're never going to break or tear."

The McManus brothers have joined a fast-growing segment of the sporting goods industry. Manufacturers sold $190 million in sport sandals in 2012, a 6 percent increase from the year before, according to a report from the Sports & Fitness Industry Association. That's the biggest increase for any kind of athletic footwear.

Crocs, the popular neon clogs, was the fastest-growing shoe company in the world a few years ago, raking in hundreds of millions of dollars. The Colorado-based company got its product on the feet of thousands of mall-trotting Americans who didn't care whether it was a fashion faux pas.

Meanwhile, Nike's foam-rubber one-piece sandals, at $22 a pair, have become a post-game staple for athletes. And the shower sandals Adidas Slides made their way into high-fashion photo shoots and count Justin Bieber as a celebrity endorser.

But the McManus brothers think Bokos sandals have something those other shoes don't.

Crocs, Matt McManus said, are "not really touting the durability." And athletic brands are usually either "unfathomably uncomfortable" or don't stand up to dirt, water and odor the way that Bokos do.

"I think, generally, the styles I've seen, many of them have a Velcro strap," he said. "You're not going to want to get Velcro wet, which is kind of funny because they're supposed to be locker-room shoes."

So far, the brothers have marketed the shoes, inspired by a pair James brought back from a trip to Beijing, mostly via fitness blogs. Following a launch in April, the Bokos website, bokosusa.com, saw a jump from 350 visitors in its first month to 5,000 in its second.

The brothers said they've been surprised that the product's appeal goes beyond active consumers.

"We've gotten, actually, feedback from even older consumers that don't care at all about durability or water or anything like that," Matt McManus said. "They just like that they're comfortable."

More than half of their orders are for multiple pairs, he added, because people are using them as a house shoe. The women's shoes have sold as well as the men's shoes, another surprise. The sandals come in four colors each for men and women.

The sandals are only available online now, but the brothers will attend a surfing expo in Orlando next month to try to enlist retailers to sell them.

Their friend Knurr uses one pair outside and another to traipse around his three-story house.

"For whatever reason, this pair of sandals, I feel like I've just put through the wringer," he said. "And they look pretty good."

Celia Ampel • 612-673-4642