Michael Phelps discusses life after swimming, how his notorious diet has changed, and Katie Ledecky

The most decorated Olympian in history, Michael Phelps says he's done competing.

After winning five golds and a silver at Rio 2016, Phelps hung up his suit and moved onto the second stage of his career.

That second stage includes many projects, from running his foundation, starting a swimwear line, raising a family, and most recently, working with Colgate on water conservation campaign called "Save Water."

Phelps spoke with Business Insider about the importance of water conservation, his life after swimming, his notorious diet, Katie Ledecky, and the future of US swimming.

This interview has been lightly edited for length and clarity.

Scott Davis: What attracted you to this campaign with Colgate about water conservation?

Michael Phelps: "It was something that as soon as I heard about it I was super excited about having the opportunity to be a part of. For me, obviously, I've been around water for most of my life and I know how much of an important resource it is. To be able to kind of help people understand just more about it and how much actual water we're truly wasting on just some of the small things that we do every single day. Whether it's just brushing your teeth and leaving the water running, that right there is four gallons down the drain. So it's like all these little, small things that end up really adding up.

"When you have hundreds of millions of people, not only in the US, but all over the world, we're wasting a lot of water. And it's something that we all can work together to really try to change. It's a couple small things that we can do. For me, growing our family now, it's something that [Phelps' son] Boomer is very aware of, just because he watches and sees us do it every day. And now, getting ready to be a family of four, the craziest stat is, a family of four uses roughly 400 gallons per day. And who knows how much of that is actually wasted or used. I think it's something that we can all join together and make sure we're conserving as much as we can, but also to teach people that every drop does count."

Davis: When would you say you first started becoming aware and involved in environmental causes?

Phelps: "Like I said, I've been around water my whole life, so I basically really learned at a young age the importance of it but also one day, at one point, clean water will be hard to find. There's so many people throughout the world that don't have access to clean water. Obviously we're extremely fortunate to have the opportunities that we have and to have all the water that we have. Like I said, and I can't say it enough, we all should work together to try and conserve as much as we possible can."

Davis: What do you find yourself doing with your time now? Are you still training, do you have future plans in swimming?

Phelps: "I am back in the retirement days of my life from the sport of swimming. I think for me, the big thing of why I wanted to come back was I wanted to kind of finish my career on my terms and my way. I think after preparing myself how I did really the last two-plus years going into Rio, I have a feeling that 20 years down the road, I'll be able to look back and be able to be happy with how or when I hung my suit up. And I am right now.

"A lot of people have asked if I'm coming back or coming out of retirement. I feel like I could swim again, but I just don't want to. I feel like it's time to start the second chapter of my life and kind of continuing things that I'm so passionate about, whether it's teaching people about water conservation, or mental health, or learn to swim, continuing to build a swimming brand."

Davis: Are there any new hobbies you've picked up with your free time now?

Phelps: "Not really. I would say I've continued to work out and I've had the chance to play golf a little bit more now. But other than that, it's really spending a lot of time traveling. I'm very fortunate to be able to have my family with me sometimes, but other than that, it's pretty typical [laughs]."

Davis: How does your diet now compare to when you were training? You obviously had a very famous diet for several years.

Phelps: "It's a lot different now than what it once was. Now I'm really just trying to eat more clean, but also to just get what I need. I think for so long eating was like a job. Because I was always trying to maintain a weight, but it was just frustrating to constantly shove calories down your system. For so long, that's what it was, a job. So now, just being able to get nutrients that I need. It's not 8,000-10,000 calories like it once was. I would say, 'the normal diet.' I don't know what that is, but I would say it's more typical."

Davis: US Soccer didn't qualify the World Cup. I feel like soccer and swimming are both a little more off the radar for the main sports in the US, but US Swimming dominates while soccer has struggled. Why do you think that is?

Phelps: "I think for swimming, if you look at the history just throughout the sport, we've basically been the best country in the world. I think a lot of national team members will tell you, we wanna keep that tradition alive. For the roughly 20 years I was on the national team, that was what we always wanted to do, we wanted to be the best. It is a very solitary sport, I guess in a way, besides relays, and we are all working toward the same goal of representing our country the best way we can. We're able and have been able, through the whole history of the sport, to prove to the world that the US does have the best swimming team. I'd like to see it continue, hopefully it does. I'm always available if any of those guys need help. Some of the things that I've gone through, they might see first hand, so hopefully we can continue to build."

Davis: Who are some of the young stars that fans should get to know now for the 2020 Olympics?

Phelps: "Obviously you have to say Katie. Ledecky has just been on fire the last couple of years. I think you'll really see Caeleb Dressel kind of come into the party more and more and he's starting to swim more and more events. It'll be fun to watch those two. But honestly we have so many great leaders on our team now. And I'm sure in a couple years we're gonna see a lot of fresh faces and there is a lot of young talent out there that has the opportunity to kind of take over their event in the swimming world and hopefully bring back a gold medal for the country."

Davis: There's a lot of examples of Ledecky's greatness and dominance, from the world records to pushing guy swimmers in practices. Is there a moment that sticks out as most impressive to you?

Phelps: "It's a combination of everything. I've had the chance to train with her and I've had the chance to watch her compete the last couple of years. She's someone that's very goal-oriented. When she writes a time down or she writes a major milestone down, she's gonna do whatever she can to make sure that happens. I've only seen that really a couple times in the sport. So it's a true treat for me to be able to see her kind of truly coming up in the sport like she is.

"It's gonna be interesting to see where she goes over the next couple of years. Obviously she's gonna have the chance to swim anything from the 100-free all the way up to the mile, plus a couple relays, so a heavy workload and potentially the chance to win seven or eight gold medals."

Davis: Will you feel competitive if she starts pushing your medal record?

Phelps: "I mean, I've always said that records are made to be broken. If it happens, great, I'd love to be there to watch it and witness some of the greats that are probably gonna be in the sport over the next couple of decades.

"It's also getting more challenging I think just because, I guess you have so many people that are starting to specialize in one event or two events. When you start building a program like that, when you're swimming seven or eight races, it's just a combination of everything, mental, physical, emotions. that really have to be pretty much perfect throughout that whole eight-day program. I would love to see it, I would enjoy watching it, and I hope somebody has that chance to make history again."

Davis: When 2020 rolls around will you feel the pull of the pool? Will you have trouble staying away?

Phelps: "No [laughs].

"No, not at all. And like I said, being able to look back, I think I always wanted to hang my suit up at the right time, what I thought was the right time, and for me, having the opportunity to come back and swim one more and have that Olympics be as good as it was, for me, that's all I could really ask for."