After Alana Burns went through seven surgeries to repair a persistent knee injury, doctors told the 33-year-old to give up running if she wanted to avoid further injury. The former college basketball player for Michigan State University said she was devastated.

That was then. Her spirits are now buoyant, thanks to an athlete-oriented rehabilitation and training program at the Hospital for Special Surgery in Manhattan, where she receives physical therapy.

The hospital, which specializes in orthopedics, recently launched a Sports Performance Center geared toward athletes seeking to regain their former strength, and for average New Yorkers seeking a competitive advantage.

Billed as a stop for “weekend warriors, fitness enthusiasts, and athletes of all ages,” it is a place where clients — even those who are not injured — can receive training under the guidance of registered nurses, physical therapists, and strength coaches.

“We don’t pretend to be your running coach, but we understand the mechanics of what is going to be safe, effective, efficient, and keep you from injuring yourself,” a registered nurse and exercise physiologist at the center, Polly de Mille, said.

For $350, the center’s staff conducts a one-hour fitness assessment that includes a body composition analysis, which measures a person’s body fat and fat-free body weight. In a follow-up session, the staff devises an individual training program to address areas that need improvement. Clients can seek specialized training, such as a running evaluation that includes a video analysis of their running mechanics, the length of their stride, their flexibility, and their overall body position.

A centerpiece of the program is an anti-gravity treadmill originally developed at NASA.

The machine looks like a conventional treadmill that is encased in plastic. With the runner’s lower body positioned inside the plastic, the machine inflates with air, enabling the athlete to run without supporting his or her body weight. The benefit is a cardiovascular workout without any impact on the joints.

The $75,000 treadmill is manufactured by a California company, Alter-G. It was installed last month, and hospital officials said they believe they have one of few machines on the East Coast.

“I’ve been in fitness a long time and when I got on this thing it blew me away,” a certified strength and conditioning specialist and the performance center’s manager, Barry Heyden, said. Ms. Burns, who works as clinical research coordinator at HSS, said she uses the machine often during her breaks.

A licensed physical therapist who evaluates runners, Robert Maschi, said the popularity of the Sports Performance Center, which is based out of the hospital’s existing physical therapy department, is “exploding.” The typical client, he said, is “someone who watches the marathon and says, ‘I want to do that and I don’t want to get hurt.'”

During a recent visit to the center, this reporter attempted a jog on the Alter-G, which was set to neutralize 80% of her body weight. The result was a sprint at a pace never before achieved on land. In a subsequent flexibility analysis, Mr. Heyden observed “very tight” calf muscles, quadriceps, and hamstrings. In a follow-up e-mail message, he recommended a “corrective flexibility program.”

For those who are not injured, insurance does not cover the training sessions. Perhaps as a result, many of the center’s initial clients have been those seeking physical rehabilitation.

After a wrestling injury more than a decade ago, 39-year-old Dan Rosenblum opted for knee surgery in 2006 to avoid future problems with his meniscus, the cartilage ring in his knee. The surgery failed, and he went back for a second one eight months ago.

“I definitely hope to be running, skating, and hiking,” Mr. Rosenblum, an entrepreneur who has been working out at the performance center, said. “The goal is definitely to do at least what I was able to do before. The hope is to be able to do more.”