For last summer’s megahit “Man of Steel,” Snyder sent Cavill to work out with Twight. “I wanted Henry to be the personification of physicality,” Snyder told me. Cavill and Twight worked together for five months before production started and continued training during the six months of filming. Twight packed the pounds onto Cavill’s 6-foot-1 frame by putting him on a 5,000-calorie-a-day diet. Leading up to Cavill’s two shirtless sequences — a few days at the beginning of October 2011 and about six days at the end of that month — Twight scaled Cavill’s caloric intake back to about 2,800 calories. According to Twight, the pressure on Cavill was intense: “Henry was not a well-known guy, and he had chosen to be one of greatest comic-book icons ever. You’re not going to give that guy an inch.”

A number of trainers and actors told me that steroids were out there and that everybody had a good idea of who was on them — though nobody is willing to name names. But as trainers like Twight make obvious, the Hollywood fitness mechanism is brutal and advanced enough to make any performance-enhancing drug seem primitive by comparison. “Post-‘300,’ there is a machine in place — it doesn’t work for everyone, though,” Twight said. “Not everybody can handle the training.” I wondered aloud if this system could, paradoxically, open up contenders to even more competition. Twight bristled. “Arguing that process leads to disposability is a tough sell for me. Not everybody that gets brought into this process comes out the other side living up to their potential. You make yourself disposable by your actions. If you come in and you’re complaining about having to train or having to eat, then nobody has to work with you anymore.”

By the end of last year, after the rounds of hypertrophic training, things were starting to look up for Till. He flew to Montreal last summer to reprise his role as Havok in “X-Men: Days of Future Past.” While Till was on set, Sullivan, his manager, was on the hunt for his next role. There was a western, a rock ’n’ roll biopic, a biblical thriller, a flick about a rich kid who saves his boarding school from terrorists. In mid-July, Sullivan hinted that Till might be in line for a role in the “Expendables” franchise. The holdup, according to Sullivan, was that Sylvester Stallone wasn’t sure Till was macho enough for the role. Sullivan sent a highlight reel of Till’s stunt fights and a video of him shooting targets at a range. Sullivan drove to Comic-Con in San Diego in the middle of the night and slept in a hotel lobby to persuade David Hayter to send fight scenes from the unreleased “Wolves” to Stallone’s people. He even offered to put Till in the ring with Stallone.

The fight never came to fruition, and Till was not cast in the movie, but it turns out that he may not need that break. He was approached about an endorsement deal with a deodorant company, and he was the lead candidate for the starring role in Paramount’s “Monster Trucks.” He was even approached about a sequel to his “All Superheroes Must Die.” And in mid-January, after months of waiting, a new company called Ketchup Entertainment bought the distribution rights to “Wolves.” It is scheduled to be released this year. Till was finally going to get his chance to be carried by a movie. To celebrate, Sullivan pulled his phone from his pocket and showed me a recent video of Till in a white T-shirt grunting and sweating through a set of seated rows. Till was thicker than he was the last time I saw him. He now resembled one of those six-pack hunks that he had told me he wished to distinguish himself from.

Of course, in the zero-sum game of Hollywood action stars, Till’s success narrowed his competitors’ chances. In December, Grundy realized that the film he had hoped to shoot for six months was dead. (His consolation was that he was cast in the sequel to “The Lackey.”) Greaux, meanwhile, was still waiting for a finished version of his movie and seemed to be growing impatient, maybe even desperate, to get it out in the world. It would be too late for Besson, who in mid-February announced that his company was rebooting the “Transporter” franchise with an unknown named Ed Skrein. I broke the news to Greaux the next day. He was confused, shocked and temporarily crestfallen. Then, after taking a moment to regroup, he said: “Everything happens for a reason. I’m not even worried about it. That guy’s got nothing on me.”

Momoa, at least, seemed to have caught a bit of a break. He was cast as the lead in “The Red Road,” a Sundance Channel drama about a sheriff fighting to keep his family together while policing two warring communities, and he had plans to start shooting his own film, a period piece about a 19th-century Hawaiian outlaw. Of course, it wasn’t the career he expected back when he was filming “Conan,” but he seemed unfazed. “Sometimes it hits, sometimes it doesn’t, but I’m not going anywhere,” he said, insisting, “I’m not a dime a dozen.”

Seeing those actors on the ropes, so to speak, reminded me of some advice Hayter had given to Till: “I told him to watch a lot of Harrison Ford and Mel Gibson movies before we started filming,” Hayter told me. “They’re so compelling because of the kind of beating they can take. It’s not how hard Harrison Ford can punch that makes him great; it’s when he gets hit so hard that his knees buckle and he just keeps going. It’s that blend of iron-jawed heroism with human vulnerability, his woundability. ‘Wolves’ has got to be a story about a kid who pulls through.” That was beginning to sound like valuable career advice.