Like an avalanche gaining steam, the pressure chases them everywhere.

It followed Brandon Johnson to a football summer camp, where campers told him he'd better be ready to be hit hard this season. It followed Ryan Callahan on the nights he spent out with friends, when they'd ask him: "So, Ryan, how many yards are you going to run for this year?" It followed Damien Kinchen to his dinner table, where his family asked if he could double his production from last season.

For running backs Kinchen (Annapolis), Callahan (Old Mill) and Johnson (Broadneck), as well as a few others in Anne Arundel County, an ability to handle significant pressure will determine much this high school football season. Their challenge is daunting: Live up to the high expectations they set for themselves after dominating last season.

But the stakes are even higher: If they succeed again, Kinchen, Callahan, Johnson and Spalding's Mike Whittles will be rewarded with team success, individual accolades and, maybe, college scholarships. If they fail, their senior seasons will be remembered with at least some disappointment.

"I think about it and I get some butterflies," said Callahan, who rushed for a county-record 2,303 yards and 36 touchdowns last fall. "When you do something great, everyone expects you to come back and do it again. It doesn't always get easier."

In fact, for Callahan, it will become considerably harder. Defenses that he embarrassed last season have had eight or nine months to prepare for him. Opposing coaches might even stack eight defenders near the line of scrimmage to prevent him from running all over them. "They're going to be after him this year, there's no doubt," Old Mill Coach Mike Marcus said. "His job won't be easy."

That's why Callahan prepared harder this summer than in years past. He worked on his speed at the school track and might even have improved his 4.4-second time in the 40-yard dash. More important, he lifted weights to become stronger and more resilient. He ran 253 times last season, and he is likely to get a similar number of carries this year.

As for what he'll do with those carries, Callahan has set lofty goals: to break his county rushing record, score at least 40 touchdowns and lead Old Mill to a victory in the 4A East Region final, where it lost in overtime to Broadneck last year.

"A lot of teams are going to be trying to kill me, but I'll be all right," Callahan said. "The hits don't really faze me. I can kind of avoid a lot of hits just by the way I go down. That's one thing I've learned: If it's not possible to break away, get on the ground so you don't get hurt. I've got to be around for the whole season."

Broadneck's Johnson will also need to be resilient. He ran for just more than 1,500 yards last season, much of it thanks to his big, durable body. After last season, Johnson vowed he would be able to run with speed, not just power, so he spent more than an hour every day this summer running wind sprints and up hills at Broadneck.

Last season, Johnson was caught from behind on three breakaway runs, he said. The replays haunted him during his daily training sessions.

"That's all I thought about. That was my motivation," Johnson said. "Nobody is going to catch me this year. I'm quicker than before, that's the biggest thing. I'm in better shape, too. Last year I got tired in the fourth quarter. This year, that's not going to happen."

Said Rob Ciancaglini, a Broadneck offensive lineman who will block for Johnson: "If anything, he wants it this season more than ever. It's his senior year, and he's going to get a ton of touches. He knows what he has to do. A lot of our success is going to depend on him."

There's that pressure again. It follows running backs, though, for a good reason. Last season, the two county teams with the most productive running backs, Broadneck and Old Mill, finished a combined 21-4. Annapolis's Kinchen and Spalding's Whittles both ran for about 800 yards, and pushing those totals beyond 1,000 could mean a lot for their teams.

"Any team with a 1,000-yard rusher has a lot to feel good about," Annapolis Coach Brian Brown said. "If you've got a guy who can get 1,000 yards, you've got a workhorse. That's the kind of player that you keep going back to, that can get you through the long, tough games."

Kinchen, Brown said, is that kind of player. At 6 feet and 180 pounds, he's big and durable, and he's fast enough to break a long run for a touchdown. He improved his bench press by 50 pounds to 250 this summer. He hopes to run for 15 touchdowns -- five more than last season -- and attract college recruiters.

"If I play to my potential, things are going to go great," Kinchen said. "I just need to be in my best shape, and I'm almost there."

Said Annapolis quarterback Matt Vollono: "Damien is going to be on his game this year. We can run, and we can use the pass to set up the run. That's a deadly combination. If you don't have a running back, the whole offense doesn't work."

And if you have a good one, the offense runs smoothly. Take Spalding last season, which used a grinding running game to set up occasional long passing plays. Or Broadneck, which would follow seven or eight consecutive Johnson runs with a 50-yard touchdown throw.

It's the running back's job to take pressure off the rest of the offense, coaches said.

"Being a running back might be the hardest thing to do on a football field," Spalding Coach Mike Whittles said. "You're in every play, and a lot of things are up to you."

During an early preseason practice, one of Callahan's teammates asked him if he ever worried that he'd succumb to the pressure. Callahan, recalling the question, said he hardly hesitated.

"I don't worry about living up to it, because I know I can make that happen," Callahan said. "You've almost got to like the pressure. I take it as a compliment. It's like, 'Yeah, you expect a lot out of me, but that's because you know I can give a lot.' "

Clockwise from left: Ryan Callahan, Brandon Johnson, Mike Whittles and Damien Kinchen. Johnson ran for just more than 1,500 yards last season, and Whittles and Kinchen both ran for about 800 yards. Clockwise from top: Old Mill's Ryan Callahan, Annapolis's Damien Kinchen and Broadneck's Brandon Johnson. Callahan had 2,303 yards and 36 touchdowns last season.