"It's a short cut," Gundersen said. "If we were doing it without the belts, they would have to lift heavy weights for hours and hours to get the same benefits."
With the Olympics set to open this week, athletes are tapering their training. Demong says he's resting more and allowing his body to feel the benefits of an entire year of intense training and racing.
"At this point it becomes about allowing your body to recover and reach its highest point," Demong told Discovery News. "The volume (of training) is being slashed, the volume is being focused in terms of days off. From massage to contrast baths, you allow yourself to be fully recovered. The net achievement is you can reach a plateau of fitness relatively easy and you will be fast."
Demong likens it to a wave of fitness that he has been riding all year, now about to crest just before his Olympic race on Feb. 12.
Demong, 33, says that as he gets older, he actually does fewer ski jumps than when he was younger in preparation for a big race.