Shannon Miller

Olympic Gold Medalist, Health Advocate & Cancer Survivor

Bill Rancic

"The Apprentice" Winner; Entrepreneur; Star of "Giuliana & Bill"

Mike North, PhD

Science & Engineering Expert; CEO/Founder ReAllocate, Inc., Innovator & Master of "Nano"

J.R. Martinez

Actor, Best-Selling Author, Motivational Speaker, Advocate & Wounded U.S. Army Veteran

Dominique Dawes

Three-time Olympian, Olympic Gold Medalist, Healthy Lifestyle Advocate and Gymnastics Academy Owner

Ali Vincent

First Female Winner of "The Biggest Loser"

Nev Schulman

Producer, Actor, Photographer & TV Host Known for MTV's "Catfish: The TV Show"

Lisa Oz

Best-Selling Author, Producer, Host & Entrepreneur

Greg Louganis

4x Olympic Gold Medal Diver; LGBTQ Activist & Author

Josh Altman

Successful Real Estate Agent & Star of Bravo's "Million Dollar Listing"

Randy Fenoli

Fashion Designer & Bridal Consultant; Star of TLC's "Say Yes To The Dress"

Mark Ballas

Dancing with the Stars Champion & Mental Health Activist

Tavis Smiley

Broadcaster, Author, Publisher, Advocate, and Philanthropist

Fabio Viviani

Celebrity Chef, Former "Top Chef" Contestant, Cookbook Author

Bob Harper

Personal Trainer & Former Host of "The Biggest Loser;" Heart Attack Survivor

Maintaining A Healthy Body & Mind | Bob Harper Q&A

Sarah Colonna

Comedian, Author & Actress; Known for "Chelsea Lately" and "Shameless"

NeNe Leakes

Actress featured on "Glee" and "The New Normal," Cast member of "The Real Housewives of Atlanta," Speaker on Domestic Violence

Jack Hanna

Naturalist, Adventurer & Director Emeritus of the Columbus Zoo

Ted Allen

Host, "Chopped," Contributor, "The Best Thing I Ever Ate"

Andrew Jenks

Filmmaker and Star of MTV's "World of Jenks"