Second, the AP looked at players who gained more than 20 pounds in a single season — the high end reported in the 2004 study of bodyweight gain by athletes. More than 4,700 players fell into that category, although it's unclear based on the data how much of that amount was muscle.
Finally, reporters examined players who, in any one year, also increased their body mass by more than 21 percent. That's the extreme change that former NFL star and admitted steroid user Lyle Alzado saw when he first started doping in college. During the last decade, more than 130 players had done so.
As with any statistical analysis, the tests are as good as the available information. Schools don't routinely make available their team body composition, strength training or speed data. One explanation for the unusual gains is that NCAA players said they were just getting really fat.
"I could easily increase your weight just by pouring a quarter cup of olive oil on everything you eat. Believe me when I tell you, your weight is going to go up," said Dan Benardot, director of the Laboratory for Elite Athlete Performance at Georgia State University.
While former players who have admitted using steroids said they quickly put on lean muscle, it's impossible to extrapolate those anecdotal accounts to the entire population without knowing about each player's body composition.
"There's a big mass increase that occurs. Is it muscle? Is it fat? Is it a combination of the two? You don't know," Benardot said. "If it's mainly muscle then there are suspicions that there are anabolic hormones being used to aid that accrual. If it's predominantly fat, then they're just eating a lot more to increase."
The AP consulted on its methodology with George Shambaugh, a statistician and professor at Georgetown University.
"The outliers suggest there are some underlying factors that make these players different," Shambaugh said. "Sure, it could be steroids, or it could something else. But steroids are certainly a possible culprit, so it's worth opening up the box and taking a look inside."