Host Natalie Morales and a few hundred of her closest friends recently set the world record for the largest fitness ball class. With instruction from trainer Michelle Bridges -- she's the Jillian Michaels of Australia's The Biggest Loser and author of the book Total Body Transformation -- 353 people crammed into New York City's Rockefeller Plaza and bounced their way into Guinness World Record history.

MORE: Stability Ball Pullover

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MORE: Stability Ball V-Pass

Inspired to do your own stability ball workout right about now? Try some of our favorite toning moves:

Stability Ball Roll-Out
Stability Ball Circles
Stability Ball Triceps Extension

Check out these stability ball exercises, which start at the 2:00 mark, as a part of our complete plateau-busting workout routine below.