Widerstrom, a former Naperville North High School gymnast, will be one of three trainers who help the show's obese contestants shed weight and reclaim their health when the 16th season debuts Sept. 11. Filming began last week.
Widerstrom was previously the pink-haired "Phoenix" on NBC's "American Gladiators," and is the lead female trainer for InterContinental Hotel Group's "Even" wellness line.
Widerstrom also volunteers at orphanages and schools in Africa, and has gone on Goodwill Military Tours in Kuwait, Iraq and Asia.
Roughly a dozen suburban residents have appeared on "The Biggest Loser" over the years, and two have won the televised weight-loss competition. Season 9 winner Michael Ventrella grew up in Carol Stream, and Season 14 winner Danni Allen lives in Wheeling. The show even has a "Biggest Loser" resort and fitness center in Itasca.
But this is the first time the show has featured a trainer with suburban roots.
Widerstrom will join trainers Jesse Pavelka and Dolvett Quince, along with host Alison Sweeney.