STRIKE! Contrary to popular belief around the diamond, researchers say swinging a heavier bat during practice actually hurts bat speed.
Image: © ISTOCKPHOTO.COM/ ROB FRIEDMAN
Tune into tonight's baseball All-Star game and you'll see 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.
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5 Comments
Add CommentUsing the data provided and applying the formula for kinetic energy: [ (weight x velocity ) / 2g ] it can be argued that swinging a heavier bat, even with a measurably slower head speed, will produce a significant increase in power. Based on the data given (82.1 km/h for a 31.5 oz. bat and 67.6 km/h for a 55.2 oz. bat) the heavier bat will provide nearly 19% more kinetic energy when contact with the ball is made. This could translate into a 400 ft. fly ball travelling as far as 475 ft., neglecting air resistance, etc. While it would seem that bat velocity is very important (and will almost certainly translate to a higher batting average), it seems just as likely that a heavier bat (even with a slower head speed) will produce more home runs whenever fly balls are hit.
Reply | Report Abuse | Link to thisthe study is not talking about hitting withthe heavier bat but practicing with it. then hitting with a normal/regulation bat and marking the difference. according to the formula you gave and the numbers they gave, practicing with the lighter bat would produce more kinetic energy with the regulation bat.
Reply | Report Abuse | Link to thisHmmm, I figured this out 45 years ago in Little League. All my friends used the 31 oz. Louisville Slugger bat, I chose the 28 oz. version. Why? I could swing it much faster and hence...well you get the idea.
Reply | Report Abuse | Link to thisSorry joiii63, any ball player worth the cost of their cleats knows that what counts is momentum. That means you go with a lighter bat when hitting in order to increase the bat speed and thus get a greater increase in the speed of the ball when it is hit (momentum must be conserved and there is a square of the velocities in that equation.) The real trade-off is between bat speed, bat control and bat integrity. Pitchers throw breaking balls and change-ups for a reason. And a good fast ball coupled with a low weight bat and high bat speed is only good for the economy - when the team has to order a new bat because the one just used shattered on impact! MLB still uses wood bats. Lighter materials are used elsewhere specifically to achieve greater bat speed while maintaining bat integrity. But with those bats comes a greater potential for significant injury when a player or spectator is struck by a batted ball. The threat from such bats is one reason MLB has not moved away from wood bats. Hence if warming up with a heavier bat actually decreases bat speed at the plate, that should be considered. But warmup swings are more about stetching and preparing the muscles. Players rarely swing in warmup with the same speed they swing at the plate, whether they use a weighted bat during warmups or not. In fact, during the warmup most MLB players don't take many "cuts". The goal is to stretch/exercise the upper arms, shoulders and back. Watch a few MLB players and the warmup routine (ritual for some) they go through while on deck. A few cuts is usually all they take and that is at the end of the warmup routine. You will see some, if not most, players actually take the weight off their bat before actually taking a few true high speed cuts.
Reply | Report Abuse | Link to thisTo Krabcat: Yes the article was about practicing with a lighter bat, but the last paragraph alludes to more home runs. According to the data supplied the best way to increase the distance of a batted ball is to increase the weight of the bat. Not all players can control a heavy bat well but Babe Ruth, Ty Cobb and Joe DiMaggio all used bats that were 40 oz. or more. (Ruth began his carrer with a 54 oz. hickory bat.)
Reply | Report Abuse | Link to this"Roger Maris participated in a 1962 experiment in which he batted for distance with 5 different new bats whose weights varied from 33 to 47oz. He hit 5 long fly balls with each bat and the distances were measured and correlated to bat weight. The heavier bats, on average, resulted in further distance."
Source - P. Kirkpatrick, "Batting the ball," American Journal of Physics (1963)
Never the less, Roger Maris preferred to use a 33 oz. bat at the plate.
To RDH: Yes there is a "square of the velocities" component to the equation and a little arithmatic will show that the heavier bat for which data is given (55.2 oz. @ 67.6 km/h) will produce almost 19% more momentum (mv²) than the 31.5 oz. bat swung at 82.1 km/h. In other words, the 21.5% increase in speed for the lighter bat is not nearly enough to compensate for the 43% loss of mass. Just my observation.