Earlier this month, Nike announced it was rolling out a cutting-edge new running shoe as part of its mission to break the two-hour marathon barrier.

The shoes feature ultra-light midsole cushioning designed to preserve a runner's energy and, quite literally, put a spring in their step. But does this technological advancement cross the line into performance enhancement?

"We normally think of performance enhancement and trying to police it and control it as doing drug testing—peeing in a cup, finding needles for blood doping—but we forget that technology is a performance enhancer, too," said medical ethicist Arthur Caplan of NYU's Langone Medical Center. 

Does that mean the shoes should be banned along with other performance enhancers like steroids and blood doping? Caplan says there are three factors to consider: safety, accessibility, and whether the technology makes the race more about engineering feats than human accomplishment.

"One key factor of this is: is it safe?" Caplan asked. "There doesn't seem to be safety issue [in this case], but there are safety issues in car racing where cars get ahead of the ability of people to drive them. So they limit technology in Formula One and other races so you're not trying to race this big rocket mobile."

On the issue of cost, Caplan said the shoes shouldn't be so expensive that they're only available to wealthy competitors. If everyone can't access them, they should be banned from big races, Caplan argued.

Finally, he said, the shoes shouldn't be so technologically advanced that they make the competition more about a race between engineers than a race between athletes.

"If it doesn't hurt you...if everyone, in theory, can use it, and you don't reduce a human to a spectator in the sport...that's the combination," Caplan said.

To hear more from Art Caplan, click on the audio player above.