Hours before kickoff last Sunday, Whitney Mercilus stood in the end zone with his hands moving at a dizzying pace as he chopped, swatted and spun them to simulate his aggressive brand of pass-rushing skills.

Hours later, Mercilus accelerated past and busted through lumbering offensive tackles at the line of scrimmage to repeatedly slam Jaguars quarterback Blake Bortles to the ground for a game-high 3½ sacks.

The chiseled Texans outside linebacker has operated well above the NFL curve this season, building a higher personal ceiling for chasing down quarterbacks. Between the gold standard of Texans defensive end J.J. Watt and Mercilus, they formed the most productive bookend tandem in the league this season.

The secrets behind Mercilus' breakthrough season - he recorded a career-high 12 sacks and capped the year by being named the AFC Defensive Player of the Month for December - are built around his significant personal investments in his game, his body and his diet.

That includes hiring New Jersey-based body technique coach Jay Caldwell and regularly flying him to Houston to hone Mercilus' pass-rushing moves through a strenuous regimen that combines wrestling, karate and boxing techniques.

Mercilus also has fueled his 6-4, 258-pound body with nutritious and delicious food by employing Chris Shepherd, the owner of the popular Houston restaurant Underbelly, as his private chef. Mercilus maintains a high-protein, low-fat diet that's heavy on fish, vegetables and grains. It's designed to maximize his energy and speed up his recovery from games and workouts.

The main idea behind what Mercilus is doing is to leave no stone unturned in his quest to be as good and healthy an athlete as possible.

"It's huge, especially for a person like me, to develop from where I was as a rookie," said Mercilus, who also credits linebackers coach Mike Vrabel and defensive assistant Anthony Pleasant for his development. "Having somebody like Jay Caldwell coach you up and also adding the nutrition aspect to it with Chris gets you feeling right throughout the week and throughout a long season. It's definitely a big investment in myself, but it's the extra things that allow you to excel, that separate you to become an elite player."

Accomplished clientele

Caldwell has trained several NFL defensive players, including Titans outside linebacker Brian Orakpo, Ravens outside linebacker Courtney Upshaw, Packers nose tackle B.J. Raji, Bengals defensive end Margus Hunt and retired pass rushers Justin Tuck and Jason Worilds.

The primary emphasis from Caldwell is on hand placement, explosiveness and resistance training to build stamina and finish plays.

"It's about your hands, timing, aiming points, wrists, elbows, and piecing moves together," Mercilus said. "You want to move in a fluid motion."

Mercilus is Caldwell's latest star pupil, wasting little motion or energy as he creates speed and power rushing off the edge by employing a bull rush and crisp swim and rip moves to chase down quarterbacks.

"Whitney is an extremely dedicated player who's committed to always trying to get better," Caldwell said. "He would fly me down, and we would work on our technique, even after a full practice. I'm proud to see what he's doing. He's become a student of technique. He understands that opportunities in the NFL don't last long, and he's investing in his career.

"We work on his vision, where his eyes and hands are coming from, deflecting the tackles' hands when he engages them, understanding how to countermove, disengage and pursue the quarterback. We've worked on his stance, eliminating the false step, on posture and hip-flipping to continue his motion and momentum past the tackle. This dude really understands how important his technique and his health are."

The diet component of his life is something Mercilus takes very seriously.

A regular at Underbelly since his rookie year after being drafted in the first round in 2012 out of Illinois, Mercilus became friends with Shepherd and quizzed him about nutrition after becoming convinced that eating properly would provide a boost to his football career.

For Mercilus, it's about treating his body like an expensive sports car and feeding it the best possible fuel to keep the engine running at optimal levels.

"Chris makes nice, lean, healthy things. Lots of vegetables and proteins, adequate carbs - you name it," Mercilus said. "My favorite is this braised goat dumpling. That's pretty good. I ask for it every week. The food gets me right."

Shepherd and Mercilus collaborate on a meal plan, constructing it around his culinary preferences and nutritional requirements in roughly a 6,000-calorie intake per day. Mercilus is careful to avoid too much red meat, particularly later in the week close to games.

"Whitney has a good palate; he loves his kimchi," Shepherd said. "We've been friends since he came to Houston, and he texted me before last season and came by and said, 'I realize how I eat is how I'm going to play,' which is awesome and makes complete sense. He's come full-circle with it. The guy is built like an amazing specimen of humanity.

"He eats a lot of fish and beef during the beginning of the week, and he cuts down on the red meat later because he feels like it slows him down. He'll eat eight ounces of cooked protein for lunch, 10 ounces for dinner, vegetables and starches. He's got a pretty wicked sweet tooth. Our pastry chef will give him his cookies if he wants dessert, but he usually has like one cookie. He's very disciplined."

'Eating clean'

Shepherd, who cooks for several Texans, including running back Arian Foster, had Mercilus purchase a circulator. It's a machine that uses boiling water to heat the food instead of microwaves or ovens.

"It's about eating clean," Shepherd said. "Whitney eats really, really well. He's not eating a 42-ounce bone-in ribeye steak. He'll get the whole fish. His go-to meal on a cheat day is to eat a big fish.

"Whitney has a great attitude toward people and life and an awesome work ethic. He's always positive. It's not a just a business relationship. He's become part of the family. He comes in to the restaurant and sits in on menu meetings and has conversations with the cooks and staff. He's a very thoughtful person. He's playing like a beast right now, which is so good to see."

By diversifying his pass-rushing moves and finding new ways to attack the quarterback, Mercilus has filled a pass-rushing void opposite Watt. As Watt led the NFL with 17½ sacks while former top overall pick Jadeveon Clowney was limited to 13 games and 4½ sacks due to a myriad of injuries, Mercilus thrived.

In 15 games and 10 starts, Mercilus recorded 50 tackles, 16 quarterback hits, 16 tackles for losses, one forced fumble and two fumble recoveries.

"It's a testament to his hard work, to all the time he puts in, and to his perseverance," Watt said of Mercilus, whose previous high for sacks was seven in 2013.

Over the five games spanning December and the first Sunday of January, Mercilus recorded 17 tackles, 10 solos, 5½ sacks, seven quarterback hits, three tackles for losses, a forced fumble and a fumble recovered. He had at least one sack in three of the five games. That included 3½ sacks against the Jaguars last week, along with five tackles, three solos, three quarterback hits, two tackles or losses, a forced fumble and a fumble recovery.

"He's one of those guys who's been flying under the radar, but I've seenhis improvement," defensive coordinator Romeo Crennel said. "I've seen his work habits since I've been here, and I'm really happy that other people see it as well."

Money well spent

Signed to a four-year, $26 million contract extension in May that included a $5.25 million signing bonus and a total of $10.681 million guaranteed, Mercilus devoted some of his financial windfall to his quest for self-improvement. And it's paid major dividends with his best season, justifying the Texans' investment.

"You definitely have that in your mind," Mercilus said. "You want to go out there and make sureyou perform well beyond that."