Rick Berks is one of the pioneers of no-frills fitness centers that court the budget-minded with membership fees of $10 a month. Once a Gold’s Gym franchisee, he co-founded the Planet Fitness chain 20 years ago in South Florida. After a falling out with a group that acquired the franchise rights, the independent-minded entrepreneur split off in 2008 to launch a new version called Youfit Health Clubs.

From a single gym in St. Petersburg, Youfit has grown to 33 locations -- including branches in Miami, Sunrise, Pembroke Pines, Margate, Pompano Beach, Coral Springs -- with six more under construction and plans to hit 50 within a year.

Berks, 58, did it his own way by sticking to the basics: exercise machines, free weights and cardio equipment. Youfit claims more than 100,000 members, with the typical club open more than a year drawing 5,000 to 8,000. Here’s a condensed version of Berks’ chat with the St. Petersburg Times.Q. You turned one of your original gyms in Sunrise into a budget fitness center in the 1990s after a glitzy LA Fitness with basketball court, yoga classes and swimming pools opened nearby. What happened?

We were like the hardware store when Home Depot opens next door. I cut our $45-a-month rate by $10 a month by making extras like day care and exercise classes optional. I learned 93 percent of our members were only there for cardio and basic Lifecycle machines. So I dropped the amenities, put cable TV screens on every treadmill, eliminated commissioned sales and cut staffing to about a dozen. That’s still enough for a laser focus on cleanliness and customer service. Personal trainers work for a contractor.You’ve been at $10 a month now for three years, less than a third of what most clubs charge. Is that permanent?

I never say never, but I have no plan to raise prices. I’m seeing competitors now at $9 or less, but they don’t understand the business model to survive.Part of that was winning favorable rent deals from shopping center landlords eager to fill space since the recession. Is another element investing in money-saving eco-friendly equipment?

I don’t know if global warning is real. But many scientists do, so I want to err on the side of caution. Even if it’s only 10 years old, we replace the air conditioning with a very high-efficiency system and insulation that cuts our electric bill 30 to 40 percent. The flooring is ground-up tires and Nike shoe soles. The bathrooms have waterless urinals that each save 45,000 gallons of water a year and high-speed hand driers, so we don’t buy paper towels.What about serious body builders?

Most people are intimidated when they go to a gym and see some guy slamming barbells around or aerobics queens in full makeup. They want to feel like they "fit in" and don’t need the sophisticated equipment created to train Olympic athletes. So our heaviest free weights are 75 pounds. We tell those who grunt loudly when lifting to stop or we’ll terminate their membership. We limit mirrored walls, because some don’t like people watching them from behind. The result is a very broad mix of members.You found Youfit’s decor colors of purple and lime on gift wrap. Your daughter said you always carry pieces of it in your wallet.

Sure. Here they are. I always liked purple and didn’t want to use white. So I use lime to tone it down. The first time my girlfriend bought wrapping paper with both of these colors was a hint. The second time I saw them on paper with a different pattern and the same colors, I considered it a sign. People have called our colors quirky and hideous. But they are memorable.After Florida State, you spent five years as a Broward County sheriff’s deputy, three of them as a detective at the height of the Miami Vice cocaine wars. What was that like?