Tuesday, March 1, 2011

For Hitters on Deck, Warm-Up Devices Don't Increase Bat Speed


Player Preference Should Determine Warm-Up Routine, Reports The Journal of Strength and Conditioning Research

Donuts, bat wraps, weighted gloves…a wide array of devices are available to help baseball players warm up while waiting to go to bat. But a new study finds that none of ten commonly used warm-up devices has a significant effect on bat speed, reports the February issue of The Journal of Strength and Conditioning Research, official research journal of the National Strength and Conditioning Association.

"Furthermore, heavier warm-up devices did not provide greater bat velocity than the 'standard' bat or lighter devices," according to the new study, led by David J. Szymanski, PhD, CSCS*D, RSCC*D, of Louisiana Tech University, Ruston. They believe their results, combined with previous studies, have implications for recommended warm-up routines for batters in the on-deck circle.

Ten Different Warm-Up Devices Show No Difference in Bat Speed

In the study, 22 Division I college baseball players were tested using various devices designed for use in warming-up before batting. The devices ranged from a simple "donut ring," to weighted bat wraps and gloves, to special warm-up bats. The weight of the warm-up devices ranged from 22 to 96 ounces.

At each testing session, the players took three practice swings, as hard as possible, using one of the ten devices. Then, using a standard game bat (33 inches, 30 ounces), they hit a baseball off a tee, attempting to generate maximum bat velocity. A special device was used to measure the velocity of the bat head to see if any of the different warm-ups led to a significant change in bat speed.

Bat speed is thought to be an important component of hitting performance. "The idea is that swinging a heavy warm-up device in the on-deck circle will increase players’ bat velocity with their game bat when attempting to hit the baseball during an at-bat," Dr. Szymanski and co-authors explain. "If bat velocity is increased, this will allow the exit velocity of the batted ball to be greater, resulting in the baseball being hit farther."

In the study, however, none of the ten warm-up devices led to a significant increase (or decrease) in average bat velocity. Bat speed was no different when the players warmed up using heavier versus lighter devices, or with their usual game bat alone.
From Little League to the Big Leagues, batters in the on-deck circle use a variety of weighted devices to warm up for their turn at bat. Some previous studies have suggested that warming up with a heavier bat may lead to perceptual distortion, or a "kinesthetic aftereffect." Warming up with a weighted bat may make the standard bat feel lighter, providing the player with a psychological advantage.

However, the new report finds no evidence that any type of warm-up device affects objectively-measured bat velocity. "This study suggests that Division I intercollegiate players interested in having the highest bat velocity during a game at-bat can use any of the ten implements tested," Dr. Szymanski and co-authors write.
They note that their result differs from some previous baseball research—including a study by DeRenne and colleagues, which found that warming up with a weighted bat of plus or minus twelve percent (4 ounces) of game bat weight produced the greatest bat velocity (in high school players). Other studies have suggested that using a device that adds weight to the top of the bat, such as a donut or wrap, may actually slow bat speed. Dr. Szymanski comments, "Thus we'd suggest that, if players use a warm-up device, they should follow the recommendations of DeRenne and colleagues and use a weight within twelve percent of their standard game bat, and that the weight should be evenly distributed."

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