In an interview with "20/20," Ryan Hughes, a personal trainer in New York City, confessed a truth about gyms that we had to see to believe.
"Most of the time at these large corporate gyms, you're going to get a better rate if you're thin and attractive rather than overweight," Hughes said.
Why? Gyms think hot chicks boost their business, Hughes said.
"Having an attractive person on the floor is always a win-win," he said. "If you are going to attract other clientele to come into the gym, you might get a better rate than somebody else."
"20/20? hired models Kristin Garofalo and Abby Smith - Smith is a plus-size model - and hit the streets.
At our first stop, Smith walked out pleased with the membership offer from one of New York's most exclusive gyms. Soon after, she even got a follow-up email.
"[It] said it was great meeting me and he's going to set me up with my complimentary guided workout," Smith said.
Then it was Kristin's turn. Would she get the same offer? Would it be worse, given she was already fit and might therefore be less motivated over time to work out? Or was Kristin going to open Abby's eyes to how gyms really do business? And if there was "wiggle room" in the price, how much?
Find out on "20/20: True Confessions" Friday at 10 p.m. ET, and in the meantime, tell us what you think by voting below!