NEW YORK — There’s little evidence of Americans’ passion for fitness at the tens of thousands of small and independent gyms around the country.

Gyms, health clubs and workout studios began reopening in late spring following government-ordered shutdowns aimed at halting the coronavirus spread. But most are only allowed to have a fraction of their regular clientele on-site at one time. And some clients are staying away for fear of catching the virus.

The International Health Racquet & Sportsclub Association, an industry group, estimates that gyms, health and fitness clubs lost an aggregate $13.9 billion during shutdowns as of Aug. 31. The group warns that without government help, at least a quarter could close by Dec. 31 as limits on indoor workouts continue.

Michael Hanover is lucky if he gets 45 client hours a week in his Northbrook, Illinois, gym, Fitness Hero Wellness Center, down from his usual 60. He sometimes opens at 5 a.m. or stays late at night to get those hours; many clients are too uneasy to come in when other people are there.

“We don’t have people pounding on the door trying to get in,” Hanover says.

In Illinois, gyms currently can operate at 50 percent of capacity, leaving Hanover with no more than 10 people onsite at any time. He feels small gyms have been lumped in unfairly with big fitness chains where there might be hundreds of people exercising at once and coming into contact with one another.

Hanover’s big worry: A surge in cases that might prompt officials to force gyms to go back to holding only outdoor classes and one-on-one training sessions indoors.

“It will be devastating and most likely, the end of Fitness Hero Wellness Center,” Hanover says.

Maine’s gyms and fitness centers reopened this summer as part of Gov. Janet Mills’ tiered approach, and they must follow COVID-19 health and safety guidelines.

James Mitchell works out on the ladder machine at Foley’s Fitness in Scarborough on June 17, the day gyms reopened in Maine. Ben McCanna/Staff Photographer

Over 80 percent of the 40,000 to 50,000 health and fitness clubs in the U.S. are small businesses, according to the IHRSA. Whether yoga studios or fully equipped gyms, these businesses provide a livelihood to their owners. Last year, the overall industry employed 3 million trainers, instructors and other workers.

Owners now must follow Centers for Disease Control and Prevention guidelines calling for bikes and treadmills to be spaced further apart or unplugged so some can’t be used. Equipment is disinfected after each use. Masks are required.

Owners are also installing ventilation equipment to lessen the chances of breathing in concentrated amounts of coronavirus germs. But these procedures don’t reassure many people who used to work out several times a week.

Jeanne Carter and Julie Bokat held online classes while their Fuel Training Studio in Newburyport, Massachusetts, was forced to shut. Outdoor classes began in June and were well-attended; but when indoor classes were permitted in July, few clients wanted to be inside.

So, Carter and Bokat keep dragging bikes and other equipment in and out of the gym each day.

“We do a lot of schlepping. You do what you have to do,” Carter says.

The owners now plan a greenhouse-like structure that has heaters but no walls that Fuel Training Studio can use into the winter months. Clients have already shown on 40-degree mornings that they’re fine with working out in chill air.

“They started with a coat and hat on and within five minutes they were in tank tops,” Carter says.