First the Sahara, now America for Charlie Engle

The last time ESPN.com caught up with ultramarathon runner Charlie Engle, he had just finished running across Africa's Sahara Desert with two friends. They ran the equivalent of two marathons per day for 111 straight days. Their concluding mileage totaled nearly 4,500 miles. They often ran in temperatures that exceeded 120 degrees and didn't sleep more than five hours per night.

As if that weren't enough, Engle, 45, and new partner Marshall Ulrich, 57, have their sights set on a possibly more daunting challenge. They're attempting to break the 46-day speed record for running across the United States and plan to run nearly 70 miles each day for 45 days. Their journey began Saturday in San Francisco and will conclude in New York City.

Here's our Q&A with Engle from Friday:

Question from Graham Bensinger: Charlie, we've spoke about this before. I enjoy risky challenges, have climbed some moderately difficult mountains before, and have interest in summiting Everest one day. That said, I see nothing even mildly gratifying in what you're attempting. It seems like absolute torture. Explain how you finding this satisfying.

Answer from Charlie Engle: When I'm out there some days, I can assure you I have the exact same question running through my head! I've thought for years about writing a book, and my working title has always been, "What the Hell Was I Thinking?" Really, though, what is gratifying is being able to force myself to get up day after day and run. It sounds crazy to a lot of people, but it is the ultimate test in self-torture with the ultimate goal of self-knowledge.

Q: Whether it's "Running the Sahara" or "Running America," as the ultramarathon nears, what are you thinking about?

A: [Laughs] Considering that's exactly where we're at right now, I'm thinking about a couple of things. I'm certainly concerned about my mileage and my body. You know, this run is much different than Sahara because, from Day 1, I have to run 70 miles [each day]. With Sahara, we had the luxury of being able to ramp up from 20 to 30 to 40 to 50 miles over the period of the first 10 days of the run. Because this is a speed record, this has to be 45 days straight of 70 miles per day every day. I've just really been trying to get as much rest as possible this last week.

Q: Since there's no time to gradually build up your daily mileage, how much more challenging does that make it?

A: Honestly, Graham, I think this is much more difficult [than Sahara] because of a couple simple factors. No. 1, I'm on a hard surface. I'm on asphalt for 70 miles a day every day, which is really hard on the body. Secondly, it is just the pressure of needing to run that many miles. If you do the math -- and believe me, I've done every possible calculation -- if I miss half a day on Day No. 5, that's 35 miles I have to make up, but I have 40 days to do it. Instead, let's say I miss half a day on Day No. 40. Then, I only have five days left to make up that 35 miles, and it completely changes the complexion. Look, it's not a question of if I'm going to have problems, it's when I'm going to have problems. The first 10 days are by far the most dangerous for having the possibility of falling apart. My hope is if I can get through those days, the body has an amazing adaptive ability. I think, then, I at least have a shot.

Q: [Laughs] Yeah, 700 miles over the first 10 days. That's scary to even consider. How did this idea even come about?

A: My friend Marshall Ulrich and I had been talking about this idea in some form for many, many years. This attempt marks the 100-year anniversary of the first run across the U.S. The guy that did it ... was actually 71 years old. Since then, there have been more than 200 successful crossings. The current record holder is Frank Giannino, who lives in New York. He did it in 1980. I mean, this is like the oldest significant ultrarunning record in the world. The reason it has lasted so long is because he set the bar incredibly high. This is a really difficult attempt and something that many far more talented runners than me have taken a shot at [and failed]. We have the experience that it will take, but we don't have near the physical ability that Giannino did when he set the record because he was a young man in his 20s and we're both much older.

Q: Why bring a running partner?

A: I should tell you just to give the absolute fact here … Marshall and I have decided we are not necessarily staying together. Every single day, our goal will be to start at the same place and end at the same place. Part of [the reason for] taking a running partner is having that mutual support for each other.

Q: While the goal is to start and end each day at the same place, why won't you be running with each other?

A: Frankly, because injury and illness are inevitable. In the Sahara, the goal was to get from one end of the desert to the other. If somebody got sick, we could afford to take a few hours, let that person recover, and get some medical treatment. In this case, there's just no time. It's already going to be about 15 hours a day of actual running for me. There is no time to sit for two or three hours and wait. In a perfect scenario, we would finish together in Times Square right at the end of October as the new co-owners of this record. Reality says that the odds of both of us staying healthy and on pace for this entire run are pretty remote.

Q: If you're both starting at the same place on the last day of the run, just 70 miles left … will it be an all-out sprint to see who can finish first, or will you guys both go in together?

A: I think at that point we'd be having a lot of discussion, and I can guarantee you that we would finish it together.

Q: Explain what your training schedule is like in getting ready for this.

A: I have to tell you that I just polished off a pint of ice cream, and that's a really critical aspect of my training right now [laughs]. I've run almost 50 miles a day every day for the last two weeks. I'm not a small guy, either; I'm 6 feet tall and 180 pounds. I'm not your typical small runner dude. It takes a lot of wear and tear on my body, but it's necessary because I have to be ready.

People won't feel sorry for me here … I have to also be ready to eat 10,000 calories every day. It sounds funny, but you can't just wake up one day and eat 10,000 calories. You have to train your body to do that because otherwise it's just too much for the body to process while I'm trying to run that many miles. I have to teach my body to process this much food and use it wisely. I just actually got a Vita-Mix blender and, because of that, I've been taking stuff that I never in my life thought I would eat!

Q: Like what?

A: I'm doing things where I'll take the 10 fruits that I can find – peaches, oranges, grapes, apples, bananas, anything – and tossing them in with a handful of almonds, kale and spinach. You put it in this blender and it comes out as the best tasting thing you can possibly imagine. Running that many miles a day, I cannot possibly eat solid food that would really be useful for my body. My goal is to take as many calories as I can in liquid form.

Q: I remember you said you drank over 1,400 liters of Gatorade during Running the Sahara. After a run one day, would you have anything against getting a Big Mac, large fries and a soft drink?

A: I'll do it! As additional calories on top of a pretty healthy diet, those are great calories because there's so much fat. I need to keep the weight on. I lost almost 40 pounds in Africa. My hope is, this time, I can limit my weight loss to 15 to 20 pounds maximum.

Q: How did you come up with the route?

A: This is basically the route that the current record holder took. We'll start at City Hall in San Francisco and finish at City Hall in New York City. Many of the roads from 1980 don't actually exist anymore, so we can't do it exactly. But it will qualify for the record as long as we average more miles per day and finish in less total time.

Graham Bensinger is a regular contributor to ESPN.com. Visit his Web site at: TheGBShow.com. You can e-mail him at graham@thegbshow.com.