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Study: Steroids Can Power Home Runs

Study: Steroids Can Power Home RunsTufts physicist Roger Tobin found that increased muscle mass that can be generated by steroid use could help batters knock 50 percent more baseballs out of the park.

Medford/Somerville, Mass. [09.24.07] With Major League Baseball cracking down on performance-enhancing drugs and several high profile ball players being implicated in their use, the possible impact of steroids has been a popular topic of conversation among sports fans. According to research by Tufts' Roger Tobin, the muscle mass that one could reasonably acquire with steroid use can lead to a player hitting substantially more home runs.

In a paper to be published in an upcoming issue of the American Journal of Physics, Tobin reports that a 10 percent increase in muscle mass could help batters who are already exceptional sluggers hit 50 percent more home runs. Earlier studies indicate that such an increase in muscle can be achieved through steroid use.

In the 1990s, home run totals skyrocketed to historic levels, notably dropping off after steroid testing was instituted in 2003. Tobin, a baseball fan whose usual area of study is condensed matter physics, pursued this research out of curiosity about whether steroid usage could truly improve a player's performance that substantially.

"If you look at other sports, you don't see radical changes in performance," he told Reuters. "No one is running a 6-second 100-meter dash, no matter what they are taking."

Tobin's research was covered widely in the media, including The Boston Globe, United Press International and EE Times.

The 10 percent increase in muscle mass helps a batter swing five percent faster, increasing the speed of the ball leaving the bat by four percent. This extra speed, applied to a model distribution of trajectories, could result in 50 percent more home runs, Tobin found.

For pitchers, the results are good but less sensational: pitch speed can increase by approximately five percent, or four to five miles per hour, for a pitcher who throws a 90-mile-per-hour fastball, dropping his earned run average by a half-run per game, Reuters reported.

"That is enough to have a meaningful effect on the success of a pitcher, but it is not nearly as dramatic as the effects on home run production," Tobin said. "The unusual sensitivity of home run production to bat speed results in much more dramatic effects, and focuses attention disproportionately on the hitters."

Tobin cautions, however, that the increased muscle mass could also be obtained through legitimate means such as weightlifting, and that other factors such as changes to ballpark dimensions and league dynamics could also account for an increase in homers. He notes, however, that none of those factors are timed to the home run explosion of the 1990s.

"This doesn't prove anything," he told Reuters. "This is not an indictment of Barry Bonds or anybody else."

All his research does, says Tobin, is show that the idea that steroids can substantially enhance home run production is consistent with known physiology and physics..

"Physics cannot tell us whether a particular home run was steroid-assisted, or even whether an extraordinary individual performance indicates the use of illicit means," he said. "These results certainly do not prove that recent performances are tainted, but they suggest that some suspicion is reasonable."

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