There's a bitter wind whipping through the streets, and the sun is just starting to creep up behind the mounted bronze George Washington overlooking the intermittent traffic of the Benjamin Franklin Parkway. Yet Dan Layo and Suzanne Allaire are already running determinedly up the steps of the Philadelphia Museum of Art.

Since October, through the polar vertex, and including workouts on Christmas Day and New Year's Day, Philadelphia's chapter of the nonprofit fitness group November Project has held a free, open-to-all workout at 6:25 a.m. every Wednesday on the Art Museum steps.

Coleaders Allaire and Layo lead a gleeful and intense 45-to-50 minute workout that varies weekly, but typically consists of sets of running the stairs continuously or in sprints, as well as group sit-ups, push-ups, and other calisthenics.

Most workouts include some type of variable to mix up the order of the routine, such as a deck-of-cards workout, in which each card pulled dictates the number of sit-ups or push-ups.

"It's a bounded area, so it's ideal for all fitness levels," said Layo, a litigation attorney for Ansa Assuncao L.L.P. "It's not like we're running five miles, so if you're not a runner you're not going to be able to catch up. No one gets left behind."

Allaire, a 37-year-old regional account executive for the Greater Philadelphia Chamber of Commerce, occasionally shows up with her 10-year-old daughter.

The original November Project was founded in Boston in 2011 by two former Northeastern University rowers who were dissatisfied with the commitment and limited socialization of their fitness lives after college.

They missed the camaraderie of being on a team, and that, back then, they would never miss a practice.

Cofounders Bojan Mandaric, 32, and Brogan Graham, 31, expanded the November Project from a few friends meeting at Harvard Stadium one cold Boston November to a free fitness-palooza of more than 2,500 people in 16 "tribes" meeting in cities across the U.S. and Canada.

The tribes, each an eclectic mix of professionals and students, work out at sunrise in iconic locations from the Lincoln Memorial to the Hollywood Bowl to the Art Museum steps, and communicate with raucous, encouraging posts on social media (Facebook, Instagram, Twitter, and their blog at

The posts encourage anyone interested to "just show up" - rain, sleet, or snow - rather than join an e-mail list or fill out a form.

"It's almost like we use social media tools for the opposite of their typical use," Mandaric said.

Many fitness and psychology experts tout the benefits of working out in a group: motivation, accountability, and a built-in social schedule.

A study published in the BMJ in 2007 found that there were psychological and functional benefits to regular participation in a weekly group exercise program for women in the early stages of breast cancer treatment.

Thomas Plante published a study in Psychology Today in 2001 concluding that social exercise improved the stress-reducing benefits of a workout for participants, though it also increased exertion during and fatigue afterward.

"We are sociable beings," said Plante, a psychology professor at Santa Clara University. "We are tribal. We like to affiliate with others of like mind or like interest. That's part of the human condition and it's been true for millennia. So if we can steer people toward a direction toward health and wellness and have them bond that way, so much the better."

Laughter and yells fill the air at 6:30 every Wednesday morning, with 40 to 60 people from all over the city coming to the Art Museum steps, many wearing spray-painted black November Project letters on favorite T-shirts.

Attendees don't need to pay fees or sign papers. But they do need to meet one another with a hug, not a handshake, and ask one another's name.

Said Layo, "When you get up in the morning and you're told to turn to somebody random and give them a big hug and tell them you're glad they're here, that's just a good human feeling."

Amanda Collett, 34, a development officer at the University of Pennsylvania, said the hugs are her favorite part. "When I leave," she said, "my day is set."

A former member of the U.S. National Rowing Team, Meghan Sarbanis, 36, works as an occupational therapist and Baldwin High School rowing coach, yet believed that something was missing before she found the November Project.

"I was used to having a team every morning," Sarbanis said. "And this allowed me to transition and have that again."

Many people speak of feeling isolated, even in a big city, outside of their immediate work or school groups. Community fitness is one way to turn that on its head.

Added Layo, 28: "Our generation particularly feels so connected through social media, but we lack something that probably older generations had, which is a lot of personal interaction. I think as humans we all want or need that on some fundamental level, whether we know it or not."