Steve Caldwell took a breather from barking at 20-year-old defensive linemen last week as the Boise State football team enjoyed spring break.
He shifted his attention to a 4-year-old.
Caldwell went home to Tennessee, to help his wife prepare for the move to Boise and visit his two children and two granddaughters.
"He's been wrestling with my 4-year-old all day today," Lauren Rudd, Caldwell's daughter, said last week. "She likes to jump off of the stairs and onto his shoulders."
Caldwell, 58, is the oldest member of Boise State's youthful new coaching staff.
Yet his colleagues and players use the same word when describing him: "energy."
"He is always yelling, screaming, laughing, kicking," sophomore defensive end Kamalei Correa said. "He's just full of energy. I can see it in his eyes that he loves the game and has a lot of passion for the game. It's exciting to have a coach like that - there's not going to be a day with no energy."
Caldwell - a former walk-on linebacker at Arkansas State who thought he would be an electrician, not a football coach - will enter his 36th season this fall. He spent 14 seasons at Tennessee, but since then is on his third school in five years.
He followed coach Bryan Harsin from Arkansas State.
"I enjoy it so much," Caldwell said. "I enjoy being around the kids. I want it done the right way and I want my guys to do it well. I tell them they all represent me - they are my resume. I try to bring the energy. I expect it out of them, so I need to have it myself."
Harsin learned that the hard way.
He offered Caldwell an interview at Arkansas State on the recommendation of Athletic Director Terry Mohajir. Caldwell had worked at the school twice, covering eight years, after his playing days. And he was in the job market after Bobby Petrino's staff at Arkansas was displaced by Petrino's off-the-field scandal.
"Most guys (at an interview) want to stand up and show you something," Harsin said. "He's throwing me around the room. I said, 'That's enough.'
"He's got it. He loves the game. There's a passion for it - that's why he's done it for as many years as he's done it. The thing I like about Steve, he's got his experience but he's got the rookie mindset of every day he comes in there he's got something to prove, something to do, something to get better on."
Caldwell grew up in Thayer, Mo., a small town on the Missouri-Arkansas border. His wife, Leisa, lived 2 miles away in Arkansas and they married right after high school.
Caldwell planned to become an electrician like his uncle. During his last semester of high school, he attended classes half the day and worked for his uncle the other half.
"I just missed the game so much," Caldwell said.
One of his teachers, an Arkansas State graduate, suggested he walk onto his alma mater's football team. Leisa got a job at Arkansas State and Caldwell enrolled for $3 per credit. He never earned a scholarship or became a starter, but he stuck with the program as a graduate assistant coach.
"Thirty-six years later, I'm still doing it," he said.
His career also includes stops at Northwest Mississippi Community College, Tennessee, Pacific, Nevada, Ole Miss and Arkansas.
The longest stop: Tennessee, where he was the defensive ends coach from 1995 to 2008 under former coach Phillip Fulmer. The Volunteers won the 1998 national championship.
Fulmer called Caldwell "one of the best position coaches I've ever been around."
"He has great enthusiasm and great work ethic and has fun - he has fun on the practice field, he has fun in the office," said Fulmer, whom Caldwell visited last week. "He's excitable, and that's a good part of what makes him special to the kids. I just like his demeanor about life."
The stay at Tennessee is special to Caldwell for more than just the success, which included five trips to the Southeastern Conference championship game.
After bouncing around the country, his family settled there. Lauren, 33, and Lendl, 25, still live in Tennessee. Caldwell's middle child, Landon, committed suicide when he was 20.
Lauren ate lunch with her dad every Tuesday and Thursday while she was a student at Tennessee.
"Probably some of my best years were when I was at Tennessee and the kids were at the school," Caldwell said. "I'd get to have lunch with them a couple times a week. When they're growing up, you're never around them because this game takes so much of your time."
But the game also gives back to Caldwell - fueling him with all that energy that spills out on the practice field.
"It's still what he wants to get up and do every morning," Lauren said. "He texts us all the time. The first day of spring practice this year, he sent a text to me and my brother and my husband saying how blessed he felt to be able to have another year in the profession that he loves."
Caldwell returned to Arkansas State last year - even Leisa was surprised by that - because of his belief in Harsin. He answered the phone at Starbucks with his family and liked the enthusiasm he heard from the young, first-time head coach.
A year later, when he discovered that Harsin would interview for the Boise State job, he stopped by to see his boss.
"I'd sure love to be on that blue turf," Caldwell told Harsin.
As much, it turns out, as all those former Broncos on the staff.
"You can hear him on the football field no matter where you're at, and he coaches the kids up hard," defensive coordinator Marcel Yates said. "He loves them. He cares about them. And he just brings that fire, which you want at the D-line position.
"He's a guy who brings that fire."
Chadd Cripe: 377-6398, Twitter: @IDS_BroncoBeat