Ladies and gentlemen, Kellan Lutz on the pluses and minuses of playing the Greek demigod Hercules and his high-hemlined tunic:

“You're wearing the skirt, and sometimes you do certain moves, and [certain parts of the male anatomy] would fall out -- not to be inappropriate, sorry,” grins the mightily muscled -- and VERY candid -- star of the new film The Legend of Hercules. “But fighting in a skirt: I mean, it was just out all the time! So, towards the beginning of the movie, people would be whispering, 'Kellan! Kellan!'... 'Oh God -- I'm so sorry!' Towards the end they're yelling, 'Kellan! It happened again!' I'm like, 'All right.' You just tuck it back into your drawers!”

That was only one of the tricky physical challenges faced by the former Twilight supporting player, who’d long been hungry to whip himself into peak condition to take on a superheroic action hero role. “I live an active lifestyle," he explains, "but I had never ridden a horse -- well, I had ridden a horse but never learned how to ride a horse correctly. And so it was a little bit of, 'Okay, Kellan, you've got to get your stuff together and learn how to ride really well. Learn how to fight with a sword really well. Learn how to shoot a bow and arrow really well. Learn how to use a spear really well.' I was really great [at committing to those things], but then once production started and I was working 16-hour days, there was no time to go to the gym because the gym was closed by 9 p.m. and I'd wrap at 10 p.m. So I'd work out on set.”

The secret to staying in “tip-top shape,” Lutz reveals, was as much about what he was consuming as the amount of reps he could squeeze in between shots. “I wasn't feeding myself all the Gummy Bears that I usually do, and I adapted the paleo diet, which is high protein,” Lutz says. “So I started to add meat for the protein for working out, but then also no carbs, no dairy, no processed sugars  -- which is my candy! That was pretty tough, but as soon as I learned what the payment of that was, I started enjoying salads. it was really quite easy, and I still do it to this day.”

Lutz admits he was thrilled to land a big-screen hero role after spending the past few years getting very close to some of the most plum gigs in Hollywood. “You audition for characters like Thor, and Chris Hemsworth got it, and Chris Evans got Captain America -- all these characters that I would have loved to have been,” he says. “But then when Hercules came around, I was like, ‘Yes!'”

Of the many actors to have played Hercules on-screen over the decades, Lutz easily zeroes in on two favorites: Arnold Schwarzenegger -- “He was Hercules!” and Kevin Sorbo -- “He really just has the demeanor of Hercules, and I’m a fan of him.”

The 28-year-old actor got to live out another dream, starring alongside Schwarzenegger in the upcoming The Expendables 3, in which Lutz plays the leader of a team of young mercenaries who serve as rivals to the veteran soldiers of fortune. Even though the former governor of California is used to a leadership role, it was franchise creator and star Sylvester Stallone who was in command of the younger guns, drill sergeant-style.

“Sly would always critique us because he is the hero,” says Lutz. “Don't break eye contact. Don't blink. You stay here and you tell me lines and you just keep in my face!”

But beyond his intimidating star power, Stallone earned the respect of his new costars for his creative chops as well. “It was such a badass script. Sly would come in every day, having a better script than the one before him,” says the actor. “He'd rewrite the scenes, and we were like, 'God, that's really good. He's a great writer.' You really learned not to memorize your lines because they're not going to be there tomorrow, and just to roll with the punches. We'd improv quite a bit, and that was really fun to do with Sly.”