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EFFECT OF WARM-UP WITH DIFFERENT WEIGHTED
BATS ON NORMAL BASEBALL BAT VELOCITY
BRIAN S. MONTOYA,LEE E. BROWN,JARED W. COBURN,AND STEVEN M. ZINDER
Human Performance Laboratory, Department of Kinesiology, California State University, Fullerton, California
ABSTRACT
Montoya, BS, Brown, LE, Coburn, JW, and Zinder, SM. Effect
of warm-up with different weighted bats on normal baseball
bat velocity. J Strength Cond Res 23(5): 1566–1569, 2009—
Traditionally, baseball players have used a heavy bat for
warm-up before competition. Because bat velocity is an essen-
tial component to hitting a baseball, and because players warm
up differently, there is a need to investigate the best way to
maximize post warm-up bat velocity. The purpose of this study
was to determine the effects of warm-up with different weighted
bats on normal baseball bat velocity. Nineteen recreational
male baseball players (age, 24.5 63.9 years; height, 181.1 6
8.4 cm; body mass, 87.9 618.4 kg) participated in this study.
Three different randomized warm-up conditions were com-
pleted and analyzed for velocity and for their effect on post
warm-up normal baseball bat velocity. Subjects were instructed
to perform 5 maximal swings with each of 3 different weighted
bats—light (LB = 9.6 oz), normal (NB = 31.5 oz), and heavy
(HB = 55.2 oz)—followed by 30-second rest and then
5 swings of the NB. Analysis of variance revealed that warm-
up velocity of the LB (63.57 63.58 mph) was significantly (p,
0.05) faster than that of NB (51.25 63.01 mph) and HB
(41.79 63.01 mph), whereas warm-up velocity of NB was
also significantly faster than that of HB. For post warm-up, LB
(52.29 62.68 mph) and NB (50.60 63.04 mph) produced
significantly faster velocity of the normal bat than the HB
(48.26 62.98 mph). Warming up with 5 swings of a light or
normal bat appears to increase post warm-up velocity of the
normal bat when compared with warming up with a heavy
bat after a rest period of 30 seconds. Within the bat weight
spectrum of this study, it is suggested that when preparing to
hit, 5 warm-up swings with either a light or normal bat will allow
a player to achieve the greatest velocity of their normal bat.
KEY WORDS hitting, specificity, speed
INTRODUCTION
Baseball is a game of many skills, including fielding,
throwing, and hitting. Within a practice session,
a tremendous amount of time is spent training the
baseball swing to enhance performance in game
situations. There are many variations of the swing (10,14), but
they all share one very important common aspect: bat
velocity. Bat velocity is commonly referred to as bat speed or
swing velocity and is an important component to successful
hitting (4,6). Because the pitched baseball is coming at the
batter at a very fast velocity, the bat must be swung at a fast
velocity to hit the ball (1). Once the hitter decides to swing,
the velocity of the baseball bat is important because
maximum bat velocity meeting maximal ball velocity will
produce maximal force against the baseball, thus resulting
in maximal velocity and distance of the hit ball (1). In an
attempt to increase bat velocity, coaches have players warm
up using different techniques (3,9). Also, different training
programs to increase bat velocity are specific to the muscles
involved (7,12,13,15). Therefore, it would also seem
appropriate to have warm-up programs follow the same
rule of specificity.
Traditionally, baseball players have used a heavy bat in
the on-deck circle for warm-up before competition. Many
players stretch or swing a heavier bat to get themselves
ready to compete when it is their time to bat. This warm-up
consists of similar swings of varying velocities and bats of
different weights. These warm-up swings are easy to perform,
but they may increase or decrease normal bat velocity (8,11).
Most players who participate in this type of warm-up before
their at-bat commonly feel it helps them increase their
bat velocity (8). A common warm-up implement seen on the
on-deck circle is a baseball bat with a weighted donut
placed on it. Players will warm up with this heavy bat and
then switch back to their normal bat with the intent of
increasing swing velocity. However, previous research has
shown that swinging a heavy bat in warm-up produced
a decrease in normal bat velocity of college players (8).
They also demonstrated that players felt the warm-up helped
them increase bat velocity because after the warm-up with
a heavy bat, the normal bat felt lighter and felt they could
swing it faster (8). In this case, the donut had a positive
mental effect yet a negative physical effect on actual normal
bat velocity.
Address correspondence to Dr. Lee E. Brown, leebrown@fullerton.edu.
23(5)/1566–1569
Journal of Strength and Conditioning Research
Ó2009 National Strength and Conditioning Association
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Other studies have examined the effects of warming up on
bat velocity with a wide range of weighted bats. One study
demonstrated that bats weighing between 27 and 34 ounces
produced the greatest amount of post warm-up normal
weight bat velocity with the lightest and heaviest bats
producing the slowest post warm-up velocities (5). Similarly,
other studies have also demonstrated decreased bat velocity
when a warm-up with a heavy bat was performed and then
compared with a light and regular bat (2,11).
Because there are a multitude of recreational baseball
players currently participating in various leagues throughout
the nation and there is a paucity of research on this
population, we sought to investigate them. Also, based on
some conflicting previous research, there is a need to
investigate the effect of weighted bat warm-up on bat velocity
using traditional (heavy donut) and nontraditional (light
plastic bat) means. Therefore, the purpose of this study was to
determine the effect of warm-up with different weighted bats
on normal baseball bat velocity in recreational players.
METHODS
Experimental Approach to the Problem
We were interested in investigating what effect traditional on-
deck circle warm-up routines had on ultimate baseball bat
swing velocity in recreational players. Therefore, this study
used a repeated-measure design by having subjects swing 3
differently weighted bats 5 times and then swing a normal bat
after 30 seconds of rest. This activity mimics that done in a real
baseball game situation from the on-deck circle to home plate.
Subjects
Nineteen recreational male baseball players participated in
this study (age, 24.5 63.9 years; height, 181.1 68.4 cm; body
mass, 87.9 618.4 kg). All subjects had previous competitive
athletic baseball experience at either the high school or junior
college level. Only position players (no pitchers) who
participate in hitting during recreational games were allowed
to participate. Each subject read and signed a university
institutional review board–approved informed consent form
before participation.
Procedures
On the first visit, each subject completed a general warm-up
by cycling for 3 minutes on an upper-body ergometer at 50
rpm and was then randomly assigned to one of 3 conditons:
light bat (33 in./9.6 oz), normal bat (33 in./31.5 oz), or heavy
bat (33 in./55.2 oz). The choice of different bat weights was
made according to the normal average bat weight used by
subjects and previous research (4), a commerically available
average donut (23.7 oz) and a commerciallly available light
plastic bat. To maximize velocity in our study, we used
a much lighter plastic warm-up bat than previously used
(2,4–6).
All subjects stood on a batter’s box grid and had their rear
heel position recorded to ensure body position replication on
subsequent visits. The batter’s box grid was a 3 35-foot
rectangle comprised of 2-in. squares, which ensured the
subject was in the same starting position for every swing. The
grid was situated in front of a custom bat velocity mea-
surement device, which consisted of 2 vertical photoelectric
sensors (Model E3Z; Omron Electronics, Schaumburg, IL)
seperated by 45 cm (the depth of home plate) (Figure 1). The
sensors were situated so they were coincident with the
front and rear of the simulated home plate. Therefore,
each subject positioned themselves at the plate in the same
manner they would in a real hitting situation. Subjects swung
the bat through the device breaking the 2 sensor lights in
succession, which sent signals to a data acquisition computer
sampling at 10,000 Hz (as a result of very high bat velocity
and a very short distance between sensors) running custom
LabView (version 7.1; National Instruments, Austin, TX).
Distance traveled (45 cm) was then divided by time (4
decimal places) between the 2 signals, resulting in average bat
velocity. Reliability measurement on this procedure with
a subset of 9 subjects resulted in a significant (p,0.001)
intraclass correlation coefficient of 0.94.
After the general warm-up, subjects were not allowed
any familiarization swings. Each subject then completed 5
maximal warm-up swings (i.e., swing as fast as possible) with
each of the 3 different bats on 3 different days separated by at
least 48 hours. After each swing, they were instructed to reset
Figure 1. Custom bat velocity measurement device and batter’s box grid.
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their batting stance (rear heel) on the grid. After the warm-up
swings were completed, they rested for 30 seconds and
then completed 5 maximal swings with a normal bat through
the recording apparatus. The velocity of the 3 warm-up
conditions and of the post warm-up normal bat swings were
all recorded for analysis.
Statistical Analyses
Two 1 33 (bats) repeated-measures analyses of variance were
performed to determine differences in warm-up velocity of
the 3 conditions and to determine post warm-up velocity of
the normal bat. Alpha was set a priori at 0.05. Significant
differences among the 3 bats were followed up with pairwise
comparisons with Bonferroni correction. Sphericity was not
violated in either analysis.
RESULTS
Warm-up velocity of the light bat (63.57 63.58 mph) was
significantly (p,0.05) faster than that of the normal bat
(51.25 63.01 mph) and the heavy bat (41.79 63.01 mph),
whereas warm-up velocity of the normal bat was also
significantly faster than that of the heavy bat. For post warm-
up velocity of the normal bat, the light bat condition and
normal bat condition produced significantly (p,0.05)
greater velocity than the heavy bat condition (Figure 2).
DISCUSSION
The purpose of this study was to determine the effect of
warming up with 3 different weighted bats on normal baseball
bat velocity. The main finding was that a light and normal bat
warm-up produced significantly faster post warm-up velocity
of the normal bat than a heavy bat condition. As expected, the
3 weighted bats were swung at different velocities during the
warm-up conditions. The light bat was the fastest followed by
the normal bat and then the heavy bat.
A previous similar study also demonstrated decreased bat
velocity when warming up with a heavy bat compared with
warming up with a light or regular bat (11). They used warm-
up bats that were very close in weight to the ones used in our
study, and they used a 5-swing warm-up condition followed
by 5 post warm-up swings with a normal bat. They found no
difference between light and normal conditions, but
velocities of both conditions were faster than that of the
heavy condition, thus supporting our research findings.
Our findings are also similar to those of another study (8),
which found that a decrease in normal bat velocity occurred
when male and female college players warmed up with
a weighted implement. Their main finding was that after
warming up with 5 swings of a heavy bat, the first post
warm-up swing with a normal bat was significantly slower.
However, the mean velocity of the next 4 swings was not
significantly slower. The heavy bat warm-up condition in our
present study produced significantly slower maximum
velocity of the normal bat than did the light and normal
warm-up conditions. The main difference between our
studies was that their time between warm-up swings was
15 seconds, whereas we only allowed our subjects enough
time to reset their rear heel stance and then swing again
when ready (approximately 5 seconds). The additional 10
seconds supplied by the previous study may have allowed
any effects of the heavy bat condition to wear off and the last
4 swings to return to a normal velocity.
Yet another study demonstrated that bats weighing
between 27 and 34 ounces produced the greatest amount
of post warm-up velocity of the normal bat (5). We found that
a bat as light as 9.6 oz produced the same amount of velocity
as a normal bat of 30 oz and that both produced more
velocity than the heavy bat. The heaviest bat used by the
previous study was 64 oz and the lightest bat was 23 oz, with
each producing the slowest normal bat velocities. However,
their warm-up condition was 4 swings followed by 2 swings
of a normal bat compared with our warm-up condition,
which was 5 swings followed by 5 swings with a normal bat.
Therefore, our conditions consisted of greater extremes in
regard to swing dose and bat weights, which may explain the
different results.
In a similar study, Division I-A baseball players used
variable velocity warm-up with a spectrum of bats from
lightest to medium to heaviest (2). They found that medium
bats increased normal bat post warm-up velocity, whereas
the lightest and heaviest bats decreased normal bat velocity
after the warm-up. We found similar results with regard to
the heavy bat but different results with regard to the light bat.
Our light bat warm-up had the same effect on the normal bat
as warming up with the normal bat and both produced faster
velocities than a heavy bat warm-up. This may be explained
because the other study only used a 3-swing warm-up and
a 3-swing post warm-up test, whereas we used 5 swings for
both. Once again, our greater volume could possibly explain
the differences.
In our study, we measured and analyzed the maximum post
warm-up velocity of a normal bat, whereas previous studies
have used mean velocity. Maximum velocity as well as mean
velocity may be important aspects after warm-up in the
Figure 2. Normal weight bat velocity (mean 6SD) after 3 different warm-
up conditions. *Significantly (p,0.05) faster than heavy bat condition.
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Baseball Bat Velocity
on-deck circle. If a batter swings at the first pitch, then post
warm-up maximum velocity may be more appropriate.
However, if the batter swings numerous times, then mean
post warm-up velocity may be more appropriate. We felt
maximum velocity would be a more useful indicator of
performance because maximum bat velocity results in greater
batted ball velocity (1).
Another difference between our study and previous studies
was subject population. Most previous studies used college
baseball players, whereas we used recreational players.
Therefore, college baseball players might be engaged in
a regular practice schedule as compared with our recreational
players who may only play on the weekends. This difference
might allow recreational players to demonstrate a greater post
warm-up effect as a result of being less trained and beginning
with lower swing velocity, thus leading to a greater potential
training effect.
Also, our study used extreme differences in bat weights. We
used a much lighter bat than previously used but similar
normal and heavy bats when compared with other studies
(2,4–6). This extreme in bat weight may account for our
results. We also only had 2 different physical bats (light
and normal) and used a donut attached to the normal bat to
make up the heavy bat, therefore making them the same with
regard to length but varying only in weight. Using different
swinging implements such as a power swing or a different
bat for each weight (5) may alter other biomechanical
aspects (11,14). The conditions in our experiment were very
practical to the real on-deck circle situation in that all was
needed in the laboratory was a normal bat, a donut, and
a light plastic bat.
Although the present study used recreational baseball
players, we feel the results might transfer to an athletic
population. Our subjects all had competitive athletic experi-
ence in high school or junior college, meaning that they were
closer to an athletic population than a sedentary population.
Also, previous research (2,4–6) using athletes have shown
similar results to ours, albeit with slightly different imple-
ments. Therefore, there is a need for future research in this
area with high-level athletic populations and women while
using extreme bat weight differences like in this study.
PRACTICAL APPLICATIONS
When preparing to hit in a real game situation, a player in the
on-deck circle is not only trying to warm up the muscles used
during the swing but also attempting to maximize bat velocity
when they step up to the plate. Traditionally, this has been
accomplished through the use of a heavy donut attached to
the bat; however, this may be detrimental to bat swing
velocity. Within the bat weight spectrum of this study, it is
suggested that 5 warm-up swings with either a very light bat
(approximately 10 oz) or a normal bat (approximately 31 oz)
will allow a player to achieve maximum velocity of their
normal bat. The use of warm-up swings with a heavy donut
attached to the bat is discouraged because this appears to
reduce speed when returning to the normal bat.
REFERENCES
1. Adair, RK. The Physics of Baseball. New York: Harper Perennial, 1994.
2. DeRenne, C. Increasing bat velocity. Athl J 62: 28–31, 1982.
3. DeRenne, C and Branco, D. Overload or underload in your on-deck
preparation? Schol Coach 32: 69, 1986.
4. DeRenne, C, Buxton, P, Hetzler, R, and Ho, K. Effects of weighted
bat implement training on bat swing velocity. J Strength Cond Res
9: 247–250, 1995.
5. DeRenne, C, Kwok, W, Hetzler, R, and Chai, D. Effects of warm up
with various weighted implements on baseball bat swing velocity.
J Appl Sport Sci Res 6: 214–218, 1992.
6. DeRenne, C and Okasaki, E. Increasing bat velocity: Part 2. Athl J
63: 54–55, 1983.
7. Hughes, S, Lyons, B, and Mayo, J. Effect of grip strength and grip
strengthening exercises on instantaneous bat velocity of collegiate
baseball players. J Strength Cond Res 18: 298–301, 2004.
8. Otsuji, T and Kinoshita, H. After-effects of using a weighted bat on
subsequent swing velocity and batters’ perceptions of swing velocity
and heaviness. Percept Mot Skills 94: 119–126, 2002.
9. Sergo, C and Boatwright, D. Training methods using various
weighted bats and the effects on bat velocity. J Strength Cond Res
7: 115–117, 1993.
10. Shaffer, B, Jobe, F, Pink, M, and Perry, J. Baseball batting: An
electromyographic study. Clin Orthop Relat Res 292: 285–293, 1993.
11. Southard, D and Groomer, L. Warm-up with baseball bats of varying
moments of inertia: Effect on bat velocity and swing pattern. Res
Quart Exer Sport 74: 270–276, 2003.
12. Szymanski, D, McIntyre, J, Szymanski, J, Bradford, J, Schade, R,
Madsen, N, and Pascoe, D. Effect of torso rotational strength
on angular hip, angular shoulder, and linear bat velocities of
high school baseball bat players. J Strength Cond Res 21: 1117–1125,
2007.
13. Szymanski, D, McIntyre, J, Szymanski, J, Molloy, J, Madsen, N, and
Pascoe, D. Effect of wrist and forearm training on linear bat-end,
center of percussion, and hand velocities and the time to ball contact
of high school baseball players. J Strength Cond Res 20: 231–240,
2006.
14. Welch, S, Banks, S, Cook, F, and Draovitch, P. Hitting a baseball: A
biomechanical description. J Orthop Sports Phys Ther 22: 193–201,
1995.
15. Yessis, M. The role of specificity in ÔstrengthÕtraining for track,
gymnastics and other sports. Natl Strength Coaches Assoc J 5: 20–22,
1981.
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