FIT Challenge contestants are working out in ways they never thought possible.
"Knees up, march it out as fast as you can," said Tyra James, owner of Weigh of Life. "Breathe, you have five seconds, come on."
FIT Challenge contestant Kristin Gleis, 26, marches like a member of a high school band performing at halftime, holding a fitness ball above her sweaty head.
"It burns your arms like fire; you wouldn't think it does," James said with a smile only a personal trainer could wear.