Graduate and professional students can head to the gym for special late-night hours this semester in a trial program that student organizers said may extend to the spring.

The Graduate School Assembly, Graduate and Professional Student Senate and the McDougal Center are sponsoring a new initiative called “Grad Night at the Gym,” which is keeping the doors of Payne Whitney Gymnasium open exclusively to graduate and professional students and their spouses between 10 p.m. and midnight on four consecutive Tuesdays this fall. The event has already proved popular among students, and a similar initiative may take place in the spring if its popularity continues, said Lucas Thompson GRD ’13, one of the event’s organizers and chair of the GSA’s Facilities and Healthcare Committee.

“What we’d like to do is demonstrate that there is a real need to have the gym open late one night a week, that the demand is there,” Thompson said, adding that around 60 students showed up to the first “Grad Night” on Oct. 25, and over 100 came this Tuesday.

Unlike undergraduates, who can use their residential college gyms 24 hours a day, seven days a week, graduate and professional students are limited by the hours Payne Whitney is open, Thompson said. He added that because of this, graduate and professional students were “especially hard hit” when the gym began closing two hours earlier on Fridays and weekends last year due to budget constraints.

Duke Diaz, associate athletic director of Payne Whitney, said he views “Grad Night” as a “test package” to gauge student interest, but he said the gym is not planning to change its permanent hours of operation.

Twelve students interviewed who attended “Grad Night” Tuesday said they appreciated the late hours because their schedules make it difficult for them to access the gym during the day. Several said that courses, lab work or extracurricular commitments often prevent them from getting to the gym before it closes at 10 p.m. Monday through Thursday.

“I’m in lab for most of the day until 7 or 8 o’clock [at night], so I usually either have to come to the gym at 6 in the morning or stay until it closes,” Stephen Liapis FES ’12 said. “Having it open another couple hours is very helpful.”

Pree Gadey SOM ’13 said that as a runner, he does not feel comfortable running after dark in downtown New Haven and appreciates the option to run on the gym’s track late at night.

Students who come to “Grad Night” can use the Israel Fitness Center, the track and basketball and volleyball courts of the Lanman Center, and — as of this Tuesday — the pool and squash courts. The gym’s personal trainers are also available during the event to work with students in 10- to 15-minute “mini-sessions,” said Elias Georges, who oversees the fitness center and personal training.

The event gives graduate and professional students a “unique” time to explore the gym when it is less crowded, said Alyssa Siefert GRD ’14, an organizer of “Grad Night” and a graduate student life fellow for sports and recreation at the McDougal Center.

The three students interviewed who used the gym’s pool Tuesday expressed particular satisfaction that they could have an entire lane to themselves since fewer people were at the pool than usual.

The GSA, GPSS and McDougal Center paid a total of $1,200 to cover the cost of a desk attendant and security guard at the gym during “Grad Night” so that the gym could remain open for the four nights, Diaz and Thompson said.

The final two “Grad Nights” this semester are scheduled for Nov. 8 and Nov. 15.