Nathan Adrian's body was built to swim

Nathan Adrian built to swim (1:07)

Behind the scenes for Nathan Adrian's Body Issue 2016 shoot. (1:07)

This is an online exclusive story from ESPN The Magazine's Body Issue 2016. Subscribe today! And for more from the 2016 Body Issue, check out espn.com/bodyissue, and pick up a copy on newsstands starting July 8.

Freestyle swimmer Nathan Adrian is used to showing a lot of skin in front of large crowds, so perhaps it's no surprise that he agreed to pose for this year's Body Issue. But, as Morty Ain discovered, the three-time Olympic gold medalist is still full of the unexpected. Here are eight things we learned about Adrian:

1. His feet are super flat, but also super flexible. I don't have arches. When I get out of the pool and I walk on the cement, I make a full footprint. It's horrible on land. Your arches are pretty elastic, so when you run you kind of store energy as your foot falls on the arch -- as you push off the toe you use that stored energy to move you forward. Unfortunately for me, whenever I had to do land sports I wasn't that good; I wasn't that efficient at running. And for jumping, it's kind of the same thing -- you have to transfer a lot of energy through your foot onto your toe, and for me I don't really have an efficient medium to transfer that energy.

Kicking your feet through the water day in and day out is huge in terms of developing that flexibility in your feet. One of the reasons that it's harder for people to develop into great swimmers if they start swimming when they are a little older is because their ligaments are not necessarily as loose and pliable as they were before. So for us, kicking and being able to point your toe are huge. I'm not quite as flexible as a ballerina, but there are some swimmers that are pretty darn close to that. I get my flat feet from my dad, but I get my mobility from my mom. For someone as tall as I am, I have hyper-mobile joints.

2. He was born to swim. A ton of people ask me, "Hey, why did you choose swimming?" And my answer to them is usually, "Swimming chose me." A lot of that has to do with my body type. I have this long torso, I have super flat feet, I have pretty flexible shoulders. All of those things are things you look for in a swimmer.

A lot of swimmers are able to internally rotate their shoulders. So in a streamline position, for instance, to be able to have your elbow in a position where it's facing upward is important because it helps you get leverage onto the water and helps you use your lats to pull through the water. That's something that's big for us. Also, with flexible shoulders you are able to be in a streamline position and still be able to move your upper body while you are doing dolphin kick. Everybody can do that to a certain extent, but the more flexible you are, the more like an arrow through the water you are, the better. We all have a natural curvature to our spine, but we try to eliminate that when we're swimming.

I work with the body I'm given. There's a genetic skeleton outline to what it is, and through swimming I have sculpted it to be very functional and workable in the water. I guess that's how I think about it. I like my body because it's functional. It goes back to swimming choosing me and me using my body to try to perform in the sport.

3. Yes, of course he compares himself to Phelps. I think Michael is 6-4, but I think I'm significantly heavier. So when it comes to generating power, I think that's where my advantage is. And when it comes to energy and efficiency, I think that's where Michael's advantage comes. I think the cool thing for me is that those two intersect at the 100-meter freestyle, where I get to be on a relay with Michael. That's phenomenal, I love doing that. But advice that works for me in how to swim the 100-meter freestyle wouldn't work for him, because our bodies just work differently. We have a different percentage of fast-twitch versus low-twitch muscle fibers. And his lactic acid buffering capacity is just insane, which is why he was successful in so many different events. Whereas overall, I'm sure I can produce more lactic acid than him, which is what makes me successful.

Also, I don't have that super absurd calorie thing that Michael had going on. I'm like 5,000 to 8,000 calories a day. I also weigh around 225 to 230 pounds, so throughout the day I try to get that many grams of protein, especially when we're in training. When I'm eating 8,000 calories is when I'm doing a lot of hypertrophy work in the weight room. Also, keep in mind that we're still hitting eight water sessions a week through that. I'm not exaggerating when I say every two hours I'm really hungry for a full meal. I'll wake up in the middle of the night really, really hungry again, so then I have to try to eat something so I can go back to sleep. That's really when that kind of kicks in.

4. Dude's got guns! With my roommate every now and then, I jokingly break out the little tailor measuring tape and I measure my biceps and make it a little competition about who has a bigger bicep, me or him. That's ultimately a joke. My biceps aren't helping me move through the water or to drop 0.5 a second in my 100-freestyle. But it's fun every now and then ... for lack of a better term, bro-ing out. This is what you do if you're a couple of swimmers hanging out. Let's see, hold on, I actually have the tape here right now: 16.5 inches [laughs].

But honestly, if I had to answer the question of what I am most proud of, it would have to be my lats. We work on our pullups and lats a lot. Not necessarily the most beautiful muscle in my mind, but to be able to put on 100-plus pounds and be able to do a pullup, when I used to not be able to do more than five pullups at all, that's progress, that's something I'm really proud of. I can do a pullup with three 45-pound plates on. So 135 pounds doing a pullup. I can do that probably two or three reps.

5. He's ridiculously afraid of open water swimming. Open-water swimming just scares me. Once I put my head in the water, if it's super murky or whatever and I can't even see my hand, then I just freak out ... it's not OK. I remember an open-water swim in the Bay where that specific instance happened. I was OK as long as I was 100 to 150 yards from the shore, but the second that that opened up into the channel, I absolutely freaked out and had a ton of anxiety. I just had to lay on my back and put my hands up until a boat picked me up [laughs]. It was my freshman year in college [at California]; the upperclassmen didn't let me forget it.

I just get really bad anxiety. I can go bodysurfing and do all that stuff as long as the shore and the shore break are right there, but the second that I get too far away from shore -- and there is a particular tipping point, I don't know exactly what it is -- the anxiety really starts to set in. The "Jaws" theme starts playing in my head. All sorts of things just start going over in my head. It's completely irrational, and I understand it's irrational, but it's still there. Lakes are OKish, but if I let myself think about it too much, it starts to get me. But think about this: I'm usually in water that has a visibility of 150-plus feet. And then you go to water that has a visibility of 8 inches. That's pretty eerie to me. I can see the line of the bottom of the pool, it's crystal clear, I know there's nothing else in here because nothing could possibly live in chlorine water. I don't know, it's just scary for me.

6. He's kind of old (for a swimmer). It's weird now to me that people call me the veteran on the team. Like, "When the heck did this happen?" The age of a professional swimmer is ever-increasing. Thanks in part to people like Michael [Phelps], who are showing us that you can do it beyond what was previously thought to be your prime. But with that, you certainly have to make adjustments. People in high school are trained differently than people in college. And people who are in post-college, I think in order to be successful at the highest levels, need to train a little bit differently than people in college. Having a coach who is receptive to different ideas is so important; it really is. You're not going to get too many coaches with a ton of experience in coaching older swimmers. That's another thing that kind of makes it fun is that it's kind of a game of experimentation -- "Hey, what can my body adapt to, and what sort of things will throw me into the absolute pit of overtraining?"

"Open water swimming just scares me. The second that I get too far away from shore, the "Jaws" theme starts playing in my head." Nathan Adrian

7. Growing up, he was insecure about his acne. I had acne as a kid. I certainly wasn't the only one, but it doesn't make it any easier to be walking around in a Speedo. The acne wasn't ever bad enough to go on Accutane or anything, but it was certainly bad enough to warrant several trips to the dermatologist. I just kind of dealt with it. It was not something I necessarily tried to hide from; for me, I just had to own it. I was lucky that I got to see my older brother and sister and be like, "Thank God there is light at the end of the tunnel."

8. His older brother used to beat him up. I'm six years younger than my brother. Six years is enough that there's just nothing physical I could ever possibly win against my brother. Nothing. And my parents let us fight it out. There was obviously a certain extent where they would step in and say, "Hey, knock it off, guys." But for the most part it was in good fun when I look back on it. At the time, I probably wasn't so sure. If we were trying to fight or wrestle, he definitely made it very clear that he was bigger, stronger, faster, you name it.

I remember at one of the swim meets there was one of those big inflatable jump houses with boxing. So we would put on this huge padded helmet and these gloves and you hold a PVC pipe. I was playing in the bounce house all day, I was beating up on all the other kids. And then my brother comes along, and I'm ready to go and take him on. He jumps in there, and I'm not even exaggerating, I think he put extra power behind his first punch and he literally lifted me up off of the bounce house and threw me against the side of the wall [laughs]. Again, I tried and I tried, but every time he wanted to he would just regain control immediately. I think I was around 10 at the time and he was 16.

But it was great, and it fostered an absolutely competitive spirit -- I just wanted to find a way to win something, anything really. I guess just being denied that for so many years boils up and creates a competitive person.