EDITOR’S NOTE: Rich Roll, a California-based entertainment attorney and ultra triathlete, has become one of the principal advocates for vegan diet among endurance athletes in the U.S. Roll was a swimmer at Stanford University, but after college hung up the goggles. At 40, he was 50 pounds overweight, stressed and exhausted. He became a vegan and started training for triathlons.

Within years, he was a top finisher at the three-day endurance challenge, the Ultraman World Championships, with a 6.2-mile swim on Day One, a 170-mile bike race on Day Two and a 52-mile run on Day Three. In 2010, he finished the Epic5 Challenge, which involved completing five Ironman-distance triathlons on five islands of Hawaii in five consecutive days.

Now 46, Roll detailed his experiences in the 2012 book, “Finding Ultra,” and will give a talk at 4:45 p.m. today at the College of Charleston School of Sciences and Mathematics Building, Room 129. It is free and open to the public.

Q: Along with ultra runner Scott Jurek, you’ve become a principal voice of eating a vegan diet for en- durance ath- letes. How did that transpire?

A: I wasn’t exactly vegan overnight. I started with a juice cleanse, and as a result ... I felt incredible. I couldn’t believe how much better I felt. My wife is into yoga and holistic health and more progressive lifestyle methods.

It was pretty radical for me to try something like that. I didn’t think it would have much of an impact on how I felt. It hammered home the idea of what you eat and how you feel — imagine that.

When I finished that and it came time to start eating, I first started eating a vegetarian diet but I really didn’t do it right. You know, I was eating a lot of dairy, processed food, and figured out I could eat french fries and still be vegetarian. So it came as a shock that my energy level went down again.

After about six months of that, I was kind of ready to throw in the towel and forget about the whole experiment. But ... I wondered what would happen if I took the dairy and processed foods out of it. I did that to prove that it wouldn’t work and not make a difference. But about seven days after that, I felt as good as I felt in the final days of that juice cleanse. So it was about a six-month learning curve until I locked into this way of eating.

Q: I’m sure you have endurance athletes ask how you do it. People think you have to eat beef and drink whey protein shakes to repair your body. How do you respond?

A: I think that the first thing I always do is that I’m not here to tell you what you should or shouldn’t do, but I’m just here to show you what I did and that I feel great and continued to get stronger and faster.

The bottom line is that you don’t have to eat the way you have always been eating.

Also, you have to look at all the marketing and that you have to eat red meat to be strong. Who’s behind the messaging? It’s the powerful meat and dairy lobbies, especially now because people are discovering that it’s healthier to eat plant-based.

They are dialing in their marketing messages to hold on to share and that you have to continue to eat their foods to be a strong athlete.

But I’m saying that’s not necessarily the case. I think a lot of people look at myself, maybe Scott (Jurek), and others, and what we are doing despite their vegan diet. I’m actually doing this because of my plant-based diet.

I would not have even attempted to do all these things had I not changed my diet and felt energized. I believe my plant-based diet allows me to train harder and faster.