Busy people who can’t find time to squeeze in their daily workout before midnight may get relief if a proposed 24-hour fitness club gets approval from the town.

Developers have plans to build a 4,000-square-foot Fitness Authority at 337 Route 101. The building, appraised at $580,400, formerly housed a car audio showroom and installation facility.

On July 20, the Zoning Board of Adjustment gave the club a special exception to operate in a commercial zone. If the project gets final approval from the Planning Board, the fitness club would offer state-of-the-art Precor cardio and strength-training equipment, high-definition televisions and four private changing rooms.

Club members, who would be issued key tags, would have access to the building 24 hours a day.

The proposed club would be the second Fitness Authority for project developer WJP Development, LLC. The developer operates its flagship club at Littleton Commons, a development it owns in Littleton. The group also owns Exeter Commons in Exeter, Globe Plaza in Rochester and Airport Plaza in Gilford.

A total of 28 parking spaces would serve the club, which would be located across from Hannaford on a busy stretch of Route 101. The developers commissioned a traffic analysis that showed how the fitness club would generate less traffic than a traditional retail business.

According to the study, a retail operation at the site would generate 51.1 vehicle visits between 7 a.m. and 9 a.m. on a typical weekday. In comparison, the fitness center would generate 10.3 vehicle visits during the same time period.

Mark Fernald, the general manager at Fitness Authority in Littleton, said an average of 50 to 60 members visit the club each day during the summer, with up to 100 member visits on winter days.

“The beautiful part about the 24-hour point is that it spreads everybody out, so the flow is very even,” Fernald said.

Fernald said members will have key tags that allow them to access the building at any time. The key tags are also linked to an alarm system, which can be activated by members who experience health emergencies or security threats.

John Phillips, an abutter and owner of The Wholistic Pet, said he worried that a steady stream of club members would cut across his own parking lot to access the fitness center.

“That opens up my facility to liability and also undue hardship because of safety reasons and so forth,” Phillips said.

Attorney Rob Miller said the developers would work with Philips to create a barrier between the two properties to eliminate crossover traffic.

Having received approval from the Zoning Board, the proposed club will present its site plan to the Planning Board, which will conduct a complete analysis of impacts to abutters and area traffic patterns.