Walk past Pottruck at 11 p.m. on just about any weeknight and you'll see scores of students burning calories on treadmills and stationary bicycles.
But ten years ago, the Pottruck Health and Fitness Center didn't even exist, let alone have such accommodating hours.
Penn's fitness facilities have expanded with the campus' growing interest in exercise, and recreation officials say it isn't stopping anytime soon.
With the centrally-located fitness center open until 1 a.m. four nights a week, it's possible to get a workout at almost any waking hour.
Michael Diorka, director of recreation at Penn, said he was hired 10 years ago "to come in and define recreation [and] build a staff."
The University wanted to "provide something that Penn could be truly proud of," he added.
At that point, Pottruck didn't exist. The only weight room on campus was in Hutchinson Gymnasium. The Gimbel Building, which is now part of the Pottruck center, housed a pool, basketball courts and squash courts.
But Hutchinson wasn't adequately meeting students' recreation needs, Diorka said. It didn't open until noon and was mainly frequented by men. During 1999 and 2000, the University converted Gimbel's squash courts into the Katz Fitness Center, with lifting equipment and cardio machines.
After the small new facility was added, the Gimbel building suddenly went from getting 600 daily visitors to 2,000.
"That's really when it became clear that if you build it, they will come," Diorka said.
So, five years ago, Penn began construction on the $23.8 million Pottruck center, which has 19,000 square feet of fitness space. It has a climbing wall, virtual-golf center, Olympic-sized swimming pool and a pilates studio. Students can register and pay a nominal fee for classes like yoga and dance.
Today, the facility averages 3,500 visitors every day, and that number increases to over 4,000 in the winter, Diorka said.
A 2004 study conducted by Penn's Department of Recreation found that 80 to 85 percent of undergraduates went to Pottruck at least once over the course of the year, and Diorka thinks the percentage is probably similar now.
By comparison, Diorka estimates that only 40 percent of the undergraduate population used Penn's recreational facilities before the Katz center was built. After that milestone, the percentage jumped to about 60 percent, still much lower than the percentage Pottruck garners today.
And Penn students sure do love to exercise.
On average, Penn students work out twice each week, according to Director of Health Education Susan Villari.
"All of my friends go to the gym," said Nursing junior Adela Di Camillo, who works out at Pottruck six times a week. "The majority of students are very focused on fitness."
Some take full advantage of Pottruck's late hours. Engineering junior Vasudev Kulkarni said he goes to Pottruck five nights a week, often from 9 p.m. until midnight.
Diorka said he jokes with his colleagues from the Athletics Department that more students go to Pottruck than attend Penn football games.
"They have a football game coming up, but our game day is every day. The facility has to open up on time, has to be clean, and the programs have to be effective," Diorka said. "In the course of a week, we might have 20,000 users pass through here - I don't think we get that many at a football game."
And as the workout craze hits more and more students, the University is responding.
Penn is preparing to grow eastward, and will acquire 24 acres from the U.S. Postal Service next year. Recreational facilities are a top priority for that land.
"The healthy lifestyle that [students] learned in their four years - they can carry that over into the corporate world," Diorka said.
