The Gophers football training room has been more crowded than Al's Breakfast in Dinkytown this fall, as 17 first- or second-string players have missed games with injuries.

The list includes All-Big Ten cornerback Briean Boddy-Calhoun, stalwart safety Damarius Travis and four of five starters on the offensive line.

"I've never seen anything like it in my 32 years of coaching," coach Jerry Kill said.

Dr. Pat Smith, who's in his 31st year as a Gophers team physician, views it as part of a national trend, with several factors contributing to more injuries.

Notre Dame has lost eight players for the season, including quarterback Malik Zaire. Texas Christian has played without seven injured defensive starters. Michigan State has suffered injuries to its best linebacker, safety, cornerback and tight end, a top running back, and two decorated offensive linemen.

Among the national stars who've suffered serious injuries: Georgia running back Nick Chubb (knee injury), UCLA linebacker Myles Jack (knee), BYU quarterback Taysom Hill (foot), Arizona linebacker Scooby Wright (foot), Pittsburgh running back James Conner (knee), Wisconsin running back Corey Clement (sports hernia) and Clemson wide receiver Mike Williams (neck).

Safety Damarius Travis (hamstring) has missed five games. He stood with coach Jerry Kill during the TCU game, his lone start.

"There have been some big players go down, but I guess I haven't seen it be a whole lot different than what we've seen over the years," said Iowa's head team physician, Dr. Brian Wolf.

"Unfortunately injuries are part of football, and as it gets to be bigger, faster, stronger, we're potentially seeing more injuries building up over time."

The NCAA conducted a five-year study from 2004 to 2009, concluding that 8.1 football injuries occurred for every 1,000 athlete exposures, with an "exposure" defined as a game or practice.

As Smith noted, the number of exposures continues to rise, as college football has practically become a year-round sport.

"We start in June with captains' practices, rather than in August," Smith said. "We've gone from an 11-game season to a minimum of 12, with a bye week that extends it to 13 weeks. You have the playoff and conference championships, and the number of bowl games, for heaven's sake, has gone from four to [40]."

With more coaches running up-tempo offenses in recent years, teams are snapping the ball more, too.

"Each snap increases your exposure," Smith said. "So we go from, let's say, 55-60 snaps in the past, to all of a sudden having 80 offensive plays or more with some of these higher-powered offenses."

Smith noted that scholarship limits have decreased from 105 to 85, leaving fewer players. Freshmen often get thrust into action.

"We're playing younger kids sooner than they maybe should play," Smith said. "So they're just not as physically mature or mentally mature to stand up to it.

"Then, we've changed our surfaces. We don't play on mud anymore. We play on these turf surfaces, which are fast and firm and don't give way. And so the whole game has changed a great deal."

Smith said each time he goes to practice he wonders, "What's going to happen today?"

"The trainers are getting worn out," Smith said. "They have been on overtime. They're working beyond belief, trying to get these kids back, and believe me, they are consummate professionals. Ed Lochrie [Gophers head football trainer] and his staff are the best I've ever been around.

And the players themselves are committed to getting better as well.

"I think Eric Klein's a great strength and conditioning coach. I think our kids are in the best shape we've ever been in."

The Gophers and other teams use GPS technology to track how far and how fast players run during practices and games. They are constantly trying to monitor fatigue and slow the workouts accordingly.

Each team takes great pride in its strength and conditioning program. The athletes are in superior shape, but some wonder if they're overtrained, especially with kids specializing on specific sports at younger ages.

"That's a good question. We don't know," Wolf said. "It's always a fine balance. You'd like to keep athletes training to minimize the up-and-down cycle that they go through. On the other hand, every training episode, every practice, every game is just another exposure. It's another potential for injury."

Joe Christensen jchristensen@startribune.com