The AlterG reads your weight, and then you choose how weightless you want to be while you walk or run on the treadmill.
Imagine a workout without gravity.
NASA technology is making it possible; not just for athletes, but for anyone.
Jack Weiss, 63, has run 31 marathons and finished numerous Ironman challenges. But an injury stopped the man some call "Iron Jack" in his tracks.
"I don't know what I would do on a Sunday morning if I wasn't training," he said. "I would go crazy," Weiss said.
It was originally created gravity for astronauts. But the company realized the machine could also do the opposite and rehabilitate injured athletes.
"When you get on, you can set your body weight so that you can start out at 100 percent of your body weight or reduce it all the way down to 20 percent of your body weight -- just as close as you can get to walking on the moon," said Lezlie Maloy, a doctor of chiropractic and owner of Spring Valley Chiropractic.
A spandex suit zips into the machine. The AlterG reads your weight, and then you choose how weightless you want to be while you walk or run on the treadmill.
Weiss is running on the AlterG twice a week and is getting stronger. He has signed up to compete again at the end of the month. Weiss credits the space-inspired workout for his success in getting back on the track and bringing his passion back in focus.
"Everything else I do in life has to be fun," he said. "If it's not fun, then I don't do it anymore. This is still fun, so I'm still doing it."
At Spring Valley Chiropractic, patients pay $20 to use the AlterG for 30 minutes.