In a soundproof room at the Dallas Cowboys’ training facility, players can pull on a pair of goggles and get instantly transported to the practice field. The Cowboys are one of six NFL and 10 college teams using virtual reality technology to give players more of what Dallas coach Jason Garrett called “mental reps”: Opportunities to recognize plays, formations and opponents’ movements in a realistic setting (and without worrying about whether you’re going to be tackled).

From inside the Oculus Rift headset, players get a 3-D look at the field while headphones provide realistic sound. Teams capture the footage by filming their practices with 360-degree cameras, so the experience inside the VR headset looks and sounds like the real thing rather than a video game.

The setup is provided by STRIVR Labs, which has grown over the past year with the speed of the best startups in Silicon Valley. That’s not necessarily surprising, given that STRIVR was born where many startups begin, on the campus of Stanford University.

In 2014, Derek Belch combined his activities as an assistant football coach and as a graduate student working on a virtual reality project to create an early version of the system. Stanford used that first footage to train their quarterbacks, and by the end of the year, Cardinal coach David Shaw agreed that Belch’s future lay in business, rather than on the sidelines.

“I was on the staff and he basically kicked me off and said, 'Go do this,'” Belch said. Shaw even invested some of his own money to help get the business off the ground. Since then, STRIVR has expanded from a training tool for quarterbacks to include footage for every position. It’s particularly useful in college, where practice time is limited to 20 hours per week. Both starters and backups can squeeze in more repetitions in the same amount of time.

“We have been using virtual reality for about a month now and have found it to be very helpful in our game preparation,” Temple Coach Matt Rhule said in November, when his Owls were 8-1 and ranked #21 in the country. “We are probably just scratching the surface of its capabilities, but our quarterbacks, offensive line, linebackers, and safeties are really getting the benefit of extra practice reps each week.”

In recent months, more sports have jumped on board as well, with pro basketball and hockey teams signing up for the service. The technology is moving forward quickly, Belch said, so that over the next 10 to 20 years, the simulations will allow companies to map the environment down to the micrometer, creating more and more high-fidelity worlds. The opportunity lies in creating an experience that keeps up with the technology.

“One of the issues that we remind all the coaches is that everybody imagines this is something like a Madden game. While that may make a lot of sense, your brain just doesn't respond to that stuff the right way,” Belch said. “So even when it gets really good, it may not be good enough. We're constantly saying, 'That's technologically possible, but it's not a good experience, so we don't want to do it.'”

It’s not difficult to imagine that experience moving from the players to the fans. In fact, STRIVR recently launched their biggest fan entertainment effort so far: a virtual reality goalie experience set up in the Madison Square Garden concourse, where fans can feel what it’s like to stand in the crease for the New York Rangers.

Similarly, future NFL fans could put themselves themselves in the middle of a highlight reel as their favorite player or walk amongst their team as they leave the tunnel and head to the field. In a series of videos called NFL Next, the league talked to experts in the field—including Jeremy Bailenson, the founder of the lab where Belch and STRIVR got their start—about those possibilities and more.

Beyond putting you in a player’s shoes, VR could put you in a 50-yard-line seat at the Super Bowl, without leaving your living room. But why keep the experience to yourself? Why not create an avatar of your buddy—complete with his voice and distinctive movements—and exchange virtual high-fives from across the country?

“Decades into the future, yeah, you'll see some pretty sweet stuff,” Belch said. “I think where we are is the tip of the iceberg.”