By the time former Chiefs offensive lineman Will Shields pulled away from Blue Springs High School on Thursday morning, Wildcats head coach Kelly Donohoe could only chuckle at the looks on his worn-out kids’ faces.Shields, who owns a sports facility called 68 Inside Sports in Overland Park, had just wrapped up a 90-minute training session in which he and four of his trainers put over 100 players through a heap of drills on an 85-degree day. And, well, let’s just say it was unlike anything they’d ever experienced.”I’m dead, pretty much dead tired,” said senior lineman David Johnson.”I’m 10 times more tired than normal,” said junior lineman Austin Reyes.The sentiment was parroted word for word by junior lineman John Keltner.That’s saying a lot. Like many programs around the area, Donohoe’s football team prides itself on its offseason conditioning. This is when championships are won and lost, and Blue Springs — a perennial power in Missouri — trains like it. Since school ended, the Wildcats have been working out four times a week, lifting weights and running and generally pushing themselves to the limit in hopes of winning the school’s fourth state title. Shields’ recent visit — which was set up when Donohoe asked Shields to come back after Shield’s appearance at a Blue Springs football camp in late June — only reinforces the notion that hard work now will pay off later.”It’s a nice change-up for us,” Donohoe said.The proof was in the slow way in which these teenagers — who so often run coaches ragged with their youthful enthusiasm and energy — walked throughout the school’s hallways afterward. Their day began at roughly 8 a.m., when Donohoe and his coaches lined them up for the first of roughly 35 40-yard sprints (they hope to build up to 50 by the end of the summer). The belief is that this will pay off come fall, when the Wildcats hope to overwhelm their opponents in the fourth quarter of games.But for the moment, it only served to soften up their legs for when Shields and his staff got hold of them almost 30 minutes later.They set up five different stations for the players, who rotated between them. At one station, players did strength movements using 10-pound sandbags. Another was lineman-specific, where players did quick-feet drills and worked on hand fighting. The other three focused on abdominal work, weighted jump roping and sled-pushing. “The sled was the hardest one,” said junior lineman Rasheed Hobbs. “We pushed it across the field and back, like 50 yards. All the weight, you could feel it in your legs. When you got off, you could barely walk.”Together, the drills equaled a workout that hammered home the importance of mental toughness and pushing through adversity.”The thing I wanted them to know,” said Shields, a 14-year NFL veteran, “is that you have to sacrifice and give up some of those extra hours to get to where you want to go.”Shields and his staff — which also held a similar workout at Shawnee Mission South on Wednesday and hope to hold one at Washington High next week — weren’t above using some tactics to help the kids endure, either. At the weighted jump rope station, Johnson said some of his teammates were complaining about their shoulders hurting.In turn, the trainer informed them that players at Rockhurst — the team that eliminated Blue Springs from the playoffs last season — aren’t complaining during their workouts.”We all got mad about it,” said senior lineman Jacob Clark. But they did push through it. And to Shields, that was the important thing.”I don’t know what Rockhurst has this year, but I like what the kids gave,” Shields said. “They keep that effort up, hopefully they’ll get to where they want to be.”@ Go to KansasCity.com for the Red Zone blog.