For Susie Neubaur, part of being a good Christian means trying to be physically fit.
She works out at the Lord's Gym in Clermont, Fla., beginning her day with Bible study and a program called "Body by God."
"Christians, your body is the Holy Spirit's temple," she says. "You want it to look good and be healthy."
There is little spirituality at many of the nation's millions of gyms. In fact, it is probably fair to say the deadly sins like envy, pride and lust are more prevalent than the cardinal virtues.
And that was the motivation for a trend in faith-based fitness, where divine inspiration comes with perspiration. At the Lord's Gym, the walls are covered with motivational messages, and the instructors shout out stimulating quotations from scripture.
Body by God classes are now taught at dozens of gyms and churches across the country.
The 40-day program claims to be more than just the latest workout fad. Ben Lerner, author of "Body by God," says his workout has staying power.
"The bottom line is that if you're a Christian, you go to heaven," he said. "There's no weight limits, there's no height limits, nothing like that in heaven. But the bottom line is we are called to honor God with our bodies."
Body by God is not the only program of its kind. "What Would Jesus Eat," "The Prayer Diet" and "The Hallelujah Diet" are other popular titles aimed at devout Christians who want to keep body and soul together.
And many Christians -- including Patricia Bodine, now a regular at the Lord's Gym -- say they do not feel at home in regular gyms.
"With most modern gyms, the tight clothes, seems as though a lot of people stare at you," Bodine said. "Here, I just feel like it's family. I don't have to compare myself with anybody else."
Fitness merchandisers also are cashing in on this growing sector of the fitness industry. One of the big sellers at the Lord's Gym snack bar is the Bible bar, containing the seven foods of Deuteronomy.