Transcript for ESPN Magazine's Body Issue 2015: Behind the Scenes
The U.S. Women's national team captured the world cup and America's heart over the weekend. With power, speed, grace they showed us what world class athletes look like on the field. Tonight a look off the field and out of uniform if you will. ABC's reporter got Aun precedessgot -- an unprecedented look at the new body of ESPN's "The bodier to." On the field, Ali Krieger turned heads with the team's jaw dropping wins during the women's world cup. But off the field, she will be turning heads for totally different reason. My mascara is my war paint. I don't go get the mail without wearing it. Reporter: Stripping down and baring it all for the cameras and 14 million people to see. Look good. Feel good. Play good. That's my motto. Reporter: She is not the only one. Ali is one of 24 athletes going nude tastefully for the ESPN magazine "Body issue" joining stars from nearly every sport including Venus Williams, rob gronkowski and Michael Phelps. This year's list includes the big, burly bodies of the NFL gridiron. Then there is also my body type. I have more muscle to me. To the nimble body of the balance beam. This one I am not flexible enough to do that one. I would break my back. Reporter: With some athletes taking pride in their body's natural form. One thing that being older definitely benefits. I am so much stronger than I have ever been. Reporter: Others expressing the beauty and changing shape. I put in some work. A big transformation for me. Reporter: While the poses and glossy pics make athletes come to life it is a different picture behind the camera. ESPN, ABC's sister company, granted access to the closed off set, university of Nevada las Vegas for the first time of in the seven year history of the body issue outside cameras were allowed to go behind the scenes with one of the issues coveted athletes. Bryce Harper is having an mvp season for the Washington nationals. And ills the leading vote getter for the national league all-star game. And this season he is letting his fans get a closer more personal look at his body of work. I have been wanting to do this since I was 15 years old. This is something that is really cool to me. And you know, god gave me a body, so I am going to. Feel good. Smell good. Play good. Normal, hair, makeup? Makeup, I don't usually put that stuff of on. It depend on what shoot it is for. Guys it is kind of easy. The weird and stuff. Do just a little bit. Reporter: The magazine says it is not pornography and they don't show privates in their images. Rather they see the issue as artistic expression of the athletic form. How do you take it from nudity to art? That's the part of the experiment, basically we have to find the right angle and the right light just to -- to stay on the right line. Take me through the moment of removing the robe for the first time. Was that nerve-racking? No. Not really. I don't care. I mean it's -- you know, I'm, I guess I am just very comfortable in what my body looks like. And it's -- I'm not scared to do anything. Reporter: Scared or not. We still caught him getting in a few sets to make sure he looked camera ready. Did you do anything specifically preparing for knowing you might do this? The last couple days, organic juicing. Vegetables, fruits. I think that's huge. Six hours of this. They're still going. Reporter: But even after dropping robe and strugt their stuff for the cameras, the athletes have to make it past these people. Definitely looks more cut here. In Bristol, Connecticut, we're there as the team behind ESPN the magazine inspects every photo. This is an amazing line. Ultimately deciding which make the cut and which get left behind. Why do we like this one better? Initially we liked it because of the tattoo, you can see the tattoo really well. And his face looks great there. You can see his eyes a little better. Reporter: Why do you decide to do this? It is a great way to show athletes in an entirely different way to a public that only sees them on the floor, on the court, on the field. I can't believe I am doing this. The rules for every athlete are the same. They all shoot entirelien the buff. Gronkowski's 2012 suit legendary, for dictching the robe and walking around the set nude the majority of the day. Reporter: How do you convince them to do this an let it all hang out so to speak? We actually have a lot of athletes that come to us saying I'm dying to be in the body issue. Reporter: Any bed oody out there right now, Steph curry, what's your wish list? You know, Lebron is on there. Sharapova. Reporter: After multiple shoots and thousand of photos only six get chosen for the famous body issue cover. What's the toughest part about this issue every year? Narrowing it down. We have ten possible covers. We will choose six covers. And we'll be upset about all the ones we don't get to choose. And this year, price gets picked as one of the lucky few. How did it go? You know, I enjoyed it. It's something I always wanted to do. To just show that off a little bit and have some fun with it. It was a lot of fun for me. For "Nightline," behind the scenes at the ESPN body issue. Who should be the next to grace the cover of the body issue? Tell us on our "Nightline" Facebook page.
This transcript has been automatically generated and may not be 100% accurate.