Thin to win

In 1970, just one player in the NFL tipped the scales at 300 pounds or more. By 1980, 94 players had reached that threshold, and the race was on to fill rosters with behemoths. Coaches drooled over 300-pounders like fat men in a burger joint. That demand produced supply-500 such heavyweights reported for training camp in 2010.

Just two years later, as teams prepare for their season-opening games, the NFL is on a diet. Many of the largest players have shed their former bellies. Arizona Cardinals defensive end Vonnie Holliday, who once maintained a playing weight of 320, now holds steady at 270. His reason for dropping the pounds is now shared throughout the league: "The game is getting faster."

That speed stems from new philosophies of offense. The old ground-and-pound style of moving the ball three yards at a time has given way to exotic passing attacks requiring speed at every position. Passing has increased 60 yards per game over the past decade. Coaches now ask defensive players to drop into pass coverage rather than clog running lanes. Coaches also ask them to shed the extra pounds.

Many linemen are happy to oblige. Doctors have long warned NFL players that carrying excessive fat increases the risk of diabetes, heart disease, and stroke. A 1994 study from the National Institute for Occupational Safety and Health found that former NFL linemen had a 52 percent higher rate of death from cardiovascular disease than the general population. Plus, what professional athlete wants to look like a fat slob?

Four-year wait

In the wake of defeat, many athletes find consolation in that old refrain, "There's always next year." Not so Olympians, whose four-year wait between golden opportunities can prove physically or emotionally insurmountable. Here's a look at a few American athletes who fell short in London and may never get another chance.

Lolo Jones

Four years ago in Beijing, the 100-meter hurdler tripped over the penultimate hurdle and did not medal. The long road back to the games in London ended bitterly when Jones finished fourth. A New York Times article bashing her as all hype made things worse. But Jones, 30, is planning a possible third try at the 2016 games in Rio de Janeiro: "I didn't walk away with the medal or run away with the medal, but I think there's lessons to be learned when you win and there's lessons to be learned when you lose."

Morgan Uceny

She may be the best female middle-distance runner in the world, but she has no hardware to prove it. At last year's World Championships, Uceny, 27, tripped over a fallen competitor and finished 10th. One year later in the Olympic final, Uceny tangled feet with another competitor and tripped again. This time, she didn't finish, smacking both palms on the track and sobbing. "It's been a lot more difficult dealing with the fall at the games than from worlds last year," she said.

Ryan Hall

In London in 2007, running only the third marathon of his life, Hall posted the fastest time ever by a U.S.-born American citizen, 2:06:17. Five years later, in the same city and with Olympic glory at stake, Hall pulled out of the marathon after 10 miles due to a right hamstring strain. It was a disappointing follow-up to his 10th-place finish four years ago in Beijing. Hall's Olympic shortcomings have critics questioning his training practices. The 29-year-old left the prestigious Mammoth Track Club and coach Terence Mahon two years ago, moving to Redding, Calif., to join Bethel Church, a faith-healing ministry. Hall believes his Christian faith and self-awareness preclude his need for a coach. - Mark Bergin