Koby Fulks, a former helicopter crew chief in the Marines, looks comfortable in camo prints.

Every night, when Koby Fulks gets home from work, he hauls out his bow and shoots between 20 and 40 arrows. For Under Armour’s beefy and bearded outdoor marketing manager, the routine isn’t just a way of relating to his customers. It’s part of a fitness plan designed to keep him ready to bag big game.

“I’ll hand someone my bow, and most people can’t pull it back,” says Fulks, who definitely needs to keep his strength up now that his hunting trips out west are being filmed for the show “Under Armour Presents Ridge Reaper.” The 30-minute, “documentary-style” series premiered last week on Outdoor Channel, poised to make stars of Fulks, his brother Kip (Under Armour’s chief operating officer), their colleague Bryan Offutt and, of course, the Under Armour stuff they’re all wearing.

The trio is joined by host Jason Carter, who’s made a career out of hunting only the most enormous and elusive animals around. His trips through the deserts of Utah, the plains of Wyoming and the mountains of Nevada can stretch on for weeks, as he and his team hike up to 25 miles a day loaded down with all of their gear.

“You can’t be a fat slob to do what we’re doing,” Carter says, recalling the times he’s found himself hanging from ledges and in similarly perilous situations.

And when guys show up for these grueling trips with any weight to lose, it’s gone in no time, adds Fulks, who dropped 12 pounds in eight days in Nevada last year.

Chris Petersen, Carter’s longtime photographer who’s also featured on “Ridge Reaper,” says he can’t eat enough during hunting season to keep up with the rigors of their journeys.

“You’re in the mountains for 20 days, with the elements against you,” Petersen says. “And every day, you’re telling yourself you want to give up, but you can’t. It’s honestly not something many people do, because it’s so hard.”

So what’s the appeal? It’s the thrill of “harvesting” (aka killing) the sorts of animals most hunters never even glimpse, says Carter, who’s always chasing the feeling that he’s experiencing something no one else has before.

“There’s a professional side of hunting, like any sport, and there are people who are every bit as committed as other athletes,” Carter says.

Hunting season starts up again at the end of the month, so Carter is already scouting and sweating. He regularly hikes near his Utah home with a 40-pound pack or huffs through climbs on a StairMaster.

Since he’s already at a high altitude, Carter doesn’t need to worry as much as the Under Armour crew does when it’s time to ascend mountains. Fulks says it’s tough to prepare suitably for that aspect of the hunts, even with the top-of-the-line fitness facilities available on the Under Armour campus in Baltimore.

But with a turf field, the well-equipped gym and a stable of personal trainers, Fulks and friends find they can still push themselves pretty far. (One of his regular workouts: 1,000 meters rowing, 30 pushups, repeated three times, as fast as possible.) They practice shooting off-site and seek out nearby wilderness to hone their outdoor skills.

“I’ll throw weights in my backpack, throw my kids over my shoulders and head out to Gunpowder Falls State Park,” says Fulks, who’s also normally a die-hard runner — although he’s recovering from Achilles surgery at the moment.

Maybe that will be a plot point as Fulks tries to run down an elk in Season 2.

Ridge Reaper Workout

Try these exercises to shape up for hunting season, suggests Under Armour trainer Rick Logan, who says Ridge Reapers require core strength, shoulder stability and endurance. Start with a rope pull (demonstrated by Chris Petersen, left) by dragging a heavy bag toward you. With a partner on each side of a heavy bag, practice hoisting it up to a high platform. Do step-ups while grasping a weight (just like Koby Fulks, below). Work on your archery by holding a Body Bar vertically in front of you while pulling back on a resistance band with the other hand. (Then switch sides.) Then use a Body Bar to mimic a gun: Kneel down and repeatedly swing the tip of the weight up from the ground.

Tune in: New episodes of “Under Armour Presents Ridge Reaper” air at 11 p.m. Mondays on Outdoor Channel. For more information about the series, including video clips and an episode guide, visit outdoorchannel.com.