It's a risky performance enhancing practice many Paralympic athletes aren't even aware of.
It's called boosting, and some athletes with spinal cord injuries are using the dangerous technique to deliberately increase blood pressure and heart rate when they compete.
They'll squeeze or block their catheters -- or in extreme cases, break a big toe.
"Some athletes will sit on their private parts. They will not feel it, but it will cause significant activation of spinal cord systems, which will result in blood pressure," UBC's Dr. Andrei Krassioukov told CTV News.
It can also enhance performance, which doesn't sit well with some players.
"Any athlete that does anything to cheat -- and that's what they are is cheaters -- is a disgrace, and I don't care who it is or why you do it," Canadian sledge hockey player Paul Rosen said.
It's officially against the rules, but hard to enforce.
Krassioukov is studying boosting during the Games as he prepares a report for the International Paralympic Committee.
"It's dangerous…and that's one of the reasons IPC is against the boosting phenomenon -- because it puts athletes' lives in danger," he said.
It's also a practice that's getting some high-profile condemnation -- from Man in Motion Rick Hansen.
"One has to wonder about the ethics behind that," Hansen said.
"I guess they're really needing to get a handle on it and make sure people aren't putting themselves in danger, but also not creating an unfair advantage."
With a report from CTV British Columbia's Mike Killeen
