Weighted Bats + On Deck Circle = Slower Bat Speed?
By Adam Marcus
STRIKE! Contrary to popular belief around the diamond, researchers say swinging
a heavier bat during practice actually hurts bat speed.
If you watched the World Series at all you saw a familiar ritual: Batters
standing in the on-deck circle will swing a weighted bat (or even a heavy,
pipelike club) while they wait to hit. The exercise is intended to improve
players' bat speed, with the idea being that the regular bat feels lighter after
taking cuts with the heavier one. But a new study suggests batters who add
ounces to their practice swings may be making an error.
Practicing with a heavier bat significantly slows down the velocity of the bat
head-depriving the batter of slugging power, exercise researchers at California
State University, Fullerton, say: Swinging light or normal weight lumber just
before stepping up to the plate helps players become accustomed to swinging
fast,
Repetition that is key to athletic training, the
researchers say.
For the study the researchers recruited 19 recreation league baseball players
(all men) and had them take five practice swings with bats of different weights:
a light bat, weighing just 9.6 ounces; a standard-weight bat (31.5 ounces); and
a heavy warm-up bat (55.2 ounces). After resting for 30 seconds, players then
took five "real" swings with the standard-weight bat. The researchers recorded
bat speeds using a computer that calculated the time it took the bat head to
pass between two sensors spaced 43.2 centimeters apart, the length of home
plate.
During warm ups, players swung fastest with the light and standard bats,
averaging 101.4 and 82.1 kilometers per hour, respectively. Both were far
quicker than hacks with the heavy bat, which averaged just under 67.6 kilometers
per hour. More important, players practicing with the light or standard bats
were able to maintain higher velocities on their real swings-averaging 83.7 and
80.5 kilometers per hour, respectively. The heavy bat practice group averaged
77.2 kilometers per hour with their real swings-not as quick as the other two
groups.
Steven Zinder, a researcher who helped conduct the study, said the findings do
not prove that swinging faster makes a hitter better, although from a
biomechanical perspective that makes sense. "If you want to swing faster, you
need to practice by swinging faster," says Zinder, now an assistant professor of
sports medicine in the exercise and sport science department at the University
of North Carolina at Chapel Hill. "Training to swing fast made you swing the
normal bat faster. With the heavy bat, you're training yourself to swing more
slowly."
Although no follow-up studies are planned, Zinder says it would be intriguing to
convince a team to swing light bats in the on-deck circle and see if it improved
their batting averages and home run production. The findings appear online in
the Journal of Strength and Conditioning Research.