Bringing Multisite Trials to Exercise Medicine

Marcas Bamman, Ph.D., wants to take exercise research to a whole new level. “While we all know that some exercise is good for us, there are a number of scientific questions that have yet to be answered,” says Bamman, director of the UAB Center for Exercise Medicine (UCEM). “What’s the right exercise dose for a patient with heart disease versus someone with Alzheimer’s, or a patient who has just had a joint replacement? How often should they exercise, and at what intensity?”

Studies to answer those questions are already underway at UCEM, Bamman says, but no single site can generate the data needed to make definitive recommendations for every type of patient. Bamman illustrates his point by citing a recent UCEM study, in which investigators tested a hybrid workout regimen for patients with Parkinson’s disease. “Two things are happening in Parkinson’s that we haven’t much of an answer to before,” Bamman says. First, patients have an “increased perception of fatigue” they just don’t want to do much,” he explains. Second, their mitochondria the powerhouses of the cell have reduced capacity, not just in the brain but “all over the body.”

Bamman’s team designed a workout that would improve patients’ mitochondrial capacity while reducing their perception of fatigue. “It combines strength training with high-intensity intervals so that patients rest very little during the exercise sessions,” which lasts about 45 minutes, Bamman says. By the time fatigue takes over, the sessions are done. In a pilot study, Bamman notes, “we had really good responses.”

But what if there was something about the participants’ ethnicity or genetic makeup that skewed the results? It’s possible that the UAB investigators just know how to push patients to perform harder, where other, less-experienced instructors might fail. “Not everyone responds the same way to certain drugs or devices, and exercise falls into that same category,” Bamman says.

To get truly definitive results, Bamman continues, exercise researchers need to follow the standard practice for drug treatments and expand into collaborative multisite research. He’s leading the way by founding a national exercise clinical trials network known as NExTNet, with UAB as the coordinating center. NExTNet already has 48 member institutions, and a first meeting is scheduled to take place at UAB in February 2014.

Adding more patients, and therefore more statistical power to the results, is one benefit of such a network, Bamman says. “But another major one is that you can standardize the conduct of the treatment itself,” he adds. “Today, one site will prescribe a three-day-per-week exercise regimen, with a very particular intensity or type of equipment.” And even though on the surface the regimens seem the same, “another site may define a very different intensity, or use different equipment,” potentially skewing the results, says Bamman. “Just like any trial, the first step is to make sure we collect data the same way.”

Bamman’s UAB team recently submitted a two-site exercise trial with a group from the University of Kentucky, which will take advantage of the NExTNet infrastructure. “We have visited each other’s facilities and have matched equipment and testing procedures, so we’re not combining apples and oranges,” Bamman says. “Our goal for the network is to stimulate interactions that will catapult this field forward into the treatment realm with definitive exercise prescriptions.”