The motto for college football running backs these days might go something like this: smaller, faster, quicker.
With high-tempo spread offenses proliferating the sport, teams are turning toward quick-twitch athletes who can zip past defenders in space. Think burners like Oregon's Kenjon Barner.
That's why Saturday's game between Iowa and Michigan State stands out as something different. It features two offenses led by big, powerful running backs -- the 244-pound Le'Veon Bell for the Spartans, and former fullback and 235-pound bruiser Mark Weisman for the Hawkeyes. That kind of beef in the backfield is increasingly becoming out of style
"I definitely think it's a little more rare to see bigger running backs, especially ones at 230-plus pounds," Bell told ESPN.com. "Nowadays, people consider backs to be big backs when they're at 215 pounds. I look at that as average. It's a little more more rare to see guys my size, in the 235-to-240 pound range, be able to carry the ball."
Consider that of the top 25 running backs in the current FBS rushing statistics, only Bell (No. 9) and Weisman (tied for 22nd) have a listed weight of more than 218 pounds. Of those 25, 12 of them weigh 200 pounds or less.
Neither Bell nor Weisman will ever be confused for a scatback. Weisman is a weight-lifting enthusiast whose running style is about as subtle as a steamroller.
"He'd love to juke this way and juke that way, but I'm not sure his body will do that,'" said his father, Dr. Larry Weisman. "So he says, 'If I can't juke left and can't juke right, I'll go straight ahead and run over a few people and see where we go.'"
Where he has gone is from completely off the grid, a guy who walked on as a fullback at Iowa after spending one semester at Air Force, to one of the best stories in college football. Weisman has averaged 169 rushing yards in three games since being pressed into service because of multiple tailback injuries, including 217 yards versus Central Michigan and 177 against Minnesota. The Hawkeyes never envisioned using him as their main, or even a frequent, ball carrier. But it's worked out extremely well for both sides.
"I haven't been around a tailback that is 235 pounds," said Iowa offensive coordinator Greg Davis, who previously worked at Texas. "Ricky Williams, when he was a senior, probably weighed 225, and he was the biggest tailback I'd ever been around. But he was a tailback. Mark is extremely stout. I just know I'm glad we got him, and thank goodness he was there to step in when we needed him."
Bell has a lot more shimmy and shake to his game and is famous for his hurdles over defenders. Yet his main attributes remain his size and strength, which can wear on an opposing defense.
"Especially in the first half, I like to get in there, lower my pads and let them feel my physical presence," he said. "That way in the second half, they don't want to tackle you any more. They try to dive at my legs, which makes it easier to make guys miss that way."
For big backs to thrive, they first need someone to believe in them -- and not see their large frames as more suitable for another position. Bell wasn't heavily recruited out of high school, and teams like Ohio State and West Virginia wanted him as a safety. Michigan State coach Mark Dantonio told Bell he could start out at running back, but if he didn't excel there, he would move to defense.
Weisman was even more under the radar out of high school despite running for more than 1,600 yards as a senior. One of his best offers was from Western Michigan -- which recruited him as a linebacker. He might have jumped at that if Air Force hadn't entered the picture with its fullback-heavy offense.
Part of what attracted Weisman to Iowa after he bristled at the military academy lifestyle was the program's history with running backs. Kirk Ferentz has had success with big tailbacks like Marcus Coker (230 pounds) and Shonn Greene (235), as well as smaller ones like Fred Russell (190).
"Good backs come in all shapes and sizes," Ferentz said this week.
The Big Ten seems more apt than other leagues to have bulldozer backs. In addition to Bell and Weisman, Ohio State's Carlos Hyde and Penn State's Zach Zwinak, both listed at 232 pounds -- have become focal points of their teams' attacks. Who could forget former Wisconsin bruisers like 248-pound John Clay and -- in maybe the most obvious big back example -- Heisman winner Ron Dayne?
Carrying a few extra pounds surely doesn't hurt while carrying the ball those cold November Big Ten slobberknockers. And good luck trying to simulate that in practice if you don't have a road-grading running back of your own.
"Teams usually don't have guys like me on the scout team," Bell said. "So guys aren't used to tackling guys as big as me and don't know how to defend it. You need a lot of gang-tackling, and a lot of times you don't really have to gang-tackle smaller guys."
Gang-tackling will be at a premium on Saturday in East Lansing. Smaller guys need not apply.