LULU GARCIA-NAVARRO, HOST:
In back-to-back marathons, two runners made records this month. What they had in common was their shoes. Both runners wore versions of a superfast Nike shoe called the Vaporfly. Their feats were so impressive, in fact, that the shoes are being investigated now for possibly giving the wearers an unfair advantage. Here to talk more about this is Amby Burfoot, former editor-in-chief at Runner's World and winner of the 1968 Boston marathon. Welcome.
AMBY BURFOOT: Thank you very much.
GARCIA-NAVARRO: So let's start with the basics. Can you describe these marathoners' shoes, and tell us why they make you faster?
BURFOOT: Yes. What's interesting about these shoes - I've been running for 50 years. And for 48 of those years, marathoners wore very, very thin shoes, figuring that lighter was better. These shoes are very thick. And yet they maintain lightness because they have a miraculous new foam. And they also increase energy return - or the bounce that you get from your shoes. So it appears that people are running faster in them.
GARCIA-NAVARRO: About 3-4%, I read.
BURFOOT: It's close to 3%. And, of course, it varies from race to race. And Nike is updating the shoes so fast that it's kind of hard to keep up with them.
GARCIA-NAVARRO: So this isn't the first time these shoes have made noise. Nike released the Vaporfly 4% in 2016. Tell me about that.
BURFOOT: That was really, to me, the most controversial aspect because those shoes - in 2016 - were so new that nobody else in the world, except for a handful of Nike scientists, the Nike runners - knew about them. Nike athletes did wear them in the Rio Olympics. And they took first, second and third in the...
BURFOOT: ...Men's marathon. And nobody else had access to those shoes.
GARCIA-NAVARRO: Let's talk about the investigation. The International Association of Athletics Federations has appointed a committee to investigate these shoes. What are the current shoe rules athletes have to abide by?
BURFOOT: The rules say basically two things. The shoes cannot provide an unfair advantage. But nobody knows what an unfair advantage is. And the shoes must be reasonably available. That's the issue I was speaking to with regard to 2016. It's not so much an issue now because the other shoe companies are rapidly catching up. But if the Nike lawyers, in fact, can enforce patent protection, it might not be possible to catch up.
GARCIA-NAVARRO: So what do you think this investigation may prove? I mean, are - do you think an investigation is the right way to go? And where do you think it'll lead?
BURFOOT: I do think that the investigation is very important because I've been reporting on marathon racers for 40 years now. And every race, we go to the press conference - we say, so how's your training. And from now forward, we're going to go to the press conference and say, what shoes are you wearing? So it's no longer about the athlete and their conditioning. It's gotten to the point where it's about the technology on their feet. And I believe the IAAF has to do something. And I hope they'll do something.
GARCIA-NAVARRO: When you say you hope they'll do something, what do you hope that something is?
BURFOOT: I like a proposal that came up in the British Journal of Sports Medicine in the last week. And that proposal was that the height of the bottom of the shoe should have a limitation. It should only be, let's say, 31 millimeters. The Nike shoes are now up to about 50 millimeters. And if you simply limit the height of the shoe and don't tell people what they can put in there - they can put the kitchen sink in there if they want. But if it can only be a certain height tall, that seems like a very simple and perhaps effective rule, to me.
GARCIA-NAVARRO: That's Amby Burfoot, former editor-in-chief of Runner's World and winner of the 1968 Boston Marathon. Thank you very much.
BURFOOT: Thank you, Lulu. Transcript provided by NPR, Copyright NPR.