Why Bigger Isn’t Always Better

The Indianapolis Colts defensive starters are not diminutive people. If everyone in America weighed 240 pounds, on average, we’d be dealing with a health crisis of epic proportions.

But in the NFL, that number places them well below the league average. And it’s not just their weight that stands out: The Colts defense is also shorter, on average, than the starters from all but one other team.

Their size has become such a point of intrigue that when the team appears on TV, sportscasters rarely miss an opportunity to wonder, out loud, how the Colts can play the most physical sport in the world with so little meat on their bones. When the Colts meet the New Orleans Saints in Sunday’s Super Bowl, it’s safe to assume these comments will continue.

But for the past few seasons, the undersized Colts defense has done something extraordinary. It hasn’t just played the game ably, it has dominated opponents. The Colts’ defense allowed the eighth fewest points in the NFL this regular season and, more impressively, showed the ability to stiffen in the late stages of games—when the players would have every reason to be exhausted. With his defense keeping the other guys off the scoreboard, Colts quarterback Peyton Manning engineered seven fourth-quarter comebacks this season, an NFL record.

In the divisional round of the playoffs against the Baltimore Ravens, the Colts held one of the league’s most dangerous runners, Ray Rice, to 67 yards. The play of the game for the Colts defense came with just over six minutes left in the third quarter, when they were able to use a relatively simple four-man rush to hurry a throw from Ravens quarterback Joe Flacco. In the AFC Championship game against the New York Jets—the league’s No. 1 running attack—the undersized Colts held the team’s top two backs to just 83 rushing yards.

The Colts’ success stems from a philosophy that borders on treason in the modern NFL: the idea that bigger is not always better. The average NFL player has grown over time to 246 pounds this past season, according to Stats Inc. That’s a 6% increase over the average two decades ago and 12% more than the average 50 years ago.

Simple physics would suggest that this is a good idea—that it’s easier for a player with more mass to move a player with less. Height on defense also helps players knock down passes thrown by the opposing team’s quarterback, or to leap high enough in the air to disrupt the other team’s receivers.

There is also a mental quotient to being smaller, fitter and ultimately less fatigued at the end of a game. Some studies have shown that mental fatigue hinders decision-making. During a 17-week regular season, players who are less fatigued can concentrate better in two-hour practices and the four hours a day of team meetings and film review.

“Even the big-frame guys, they need to make sure they aren’t carrying a lot of extra body fat on them,” says Todd Durkin, owner of Fitness Quest 10 (www.FitnessQuest10.com) in San Diego. Mr. Durkin says he trains defensive players on the San Diego Chargers like Luis Castillo and Shaun Phillips with endurance drills meant to mimic football. They do four explosive weight-training drills in succession, then rest for about the time they have to catch a breather between plays.

He says it’s all focused on staying fresh in the game. “If you have absolute strength and power, you may be strong in the first quarter, but games are won in the third and fourth quarter,” says Mr. Durkin.