SAND JUMP TRAINING VERSUS GROUND JUMP TRAINING
FOR VOLLEYBALL PLAYERS
A Thesis
Presented to the faculty of the Department of Kinesiology
California State University, Sacramento
Submitted in partial satisfaction of
the requirements for the degree of
MASTER OF SCIENCE
in
Kinesiology
(Movement Studies)
by
Alicia Anne Karver
SUMMER
2012
© 2012
Alicia Anne Karver
ALL RIGHTS RESERVED
ii
SAND JUMP TRAINING VERSUS GROUND JUMP TRAINING
FOR VOLLEYBALL PLAYERS
A Thesis
by
Alicia Anne Karver
Approved by:
__________________________________, Committee Chair
Dr. Harry Theodorides
__________________________________, Second Reader
Vera Nelson
____________________________
Date
iii
Student: Alicia Anne Karver
I certify that this student has met the requirements for format contained in the University format
manual, and that this thesis is suitable for shelving in the Library and credit is to be awarded for the
thesis.
__________________________, Graduate Coordinator
Dr. Michael Wright
Department of Kinesiology
iv
___________________
Date
Abstract
of
SAND JUMP TRAINING VERSUS GROUND JUMP TRAINING
FOR VOLLEYBALL PLAYERS
by
Alicia Anne Karver
Introduction
The purpose of the study was to examine the effects of plyometrics on two different
types of surfaces using volleyball players. The study examined specifically sand versus
ground.
Methods
Twenty-one participants joined in the study where they were divided into two training
groups. There was a sand plyometric training group and a ground plyometric training group.
The participants trained twice a week for 6 weeks. Each participant performed a vertical
jump height test with a vertec measuring device for a pre-test and a post-test.
Results
On average the sand group increased their vertical jump heights as well as the ground
group. The analysis indicated that there were no significant differences between the sand or
the ground group when it comes to increasing their vertical jump height.
Conclusion
The results of the study show that both sand and ground plyometric training can be a
good way to train volleyball players. Both the sand group and the ground group increased
their vertical jump heights, which can help them to play the game at a higher level.
_______________________, Committee Chair
Dr. Harry Theodorides
_______________________Date
v
ACKNOWLEDGEMENTS
I’d like to dedicate my thesis to all of the people that helped me make this happen. The first
two are my parents. They would do anything for me and I know I wouldn’t have made it this
far without them. It’s hard to put into words how much I appreciate everything that they’ve
done for me. The third person is my sister. She’s always there to listen and she’s an
inspiration to me herself. Also, my good friend Vera. She not only gave me a job but also
became a great friend and a great mentor who has helped me the whole way through.
I’d also like to thank my professors at Sacramento State, specifically Dr. Theodorides and
Dr. Wright. They have been very helpful along the way and I really appreciate everything
they’ve done for me.
Lastly, I’d like to thank the game of volleyball. Volleyball has been my life since I can
remember and its something that will always be there when I need it.
vi
TABLE OF CONTENTS
Page
Acknowledgments ................................................................................................................... vi
List of Tables ........................................................................................................................... ix
Chapter
1. INTRODUCTION. ................................................................................................................ 1
Statement of Purpose ................................................................................................... 3
Significance of the Study ........................................................................................... 3
Definition of Terms .................................................................................................... 3
Limitations ................................................................................................................. 4
Delimitations .............................................................................................................. 4
Assumptions ............................................................................................................... 5
Hypothesis .................................................................................................................. 5
2. REVIEW OF LITERATURE ............................................................................................ 6
The Vertical Jump ..................................................................................................... 6
Plyometric Training .................................................................................................... 9
Combined Training ................................................................................................... 12
Different Types of Surfaces ..................................................................................... 14
Youth and Plyometric Training ................................................................................ 15
Summary .................................................................................................................. 16
3. METHODOLOGY ............................................................................................................. 17
Participants ............................................................................................................... 17
Design ....................................................................................................................... 17
Training .................................................................................................................... 18
Data Analysis ........................................................................................................... 18
4. RESULTS........................................................................................................................... 19
Subjects ..................................................................................................................... 19
Results ....................................................................................................................... 19
vii
5. DISCUSSION ................................................................................................................... 22
Summary of Results ................................................................................................. 22
Recommendation for Future Studies ........................................................................ 23
Appendix A. Sets and Repetitions .......................................................................................... 24
Appendix B. Parental Consent Form for Volleyball Jump Training Program ....................... 25
Appendix C. Participant Consent Form for Volleyball Jump Training Program ................... 26
Appendix D. Physical Activity Readiness Questionnaire ....................................................... 27
Appendix E. Weekly Volume ................................................................................................. 28
Appendix F. Daily Volume .................................................................................................... 29
Appendix G. Daily Volume By Exercise ............................................................................... 30
References .............................................................................................................................. 31
viii
LIST OF TABLES
Tables
Page
1 Results in Inches ........................................................................................................ 21
ix
1
CHAPTER 1
Introduction
Volleyball has become more and more popular as the years have gone by. It has gone
from being a recreational game to becoming one of the most popular sports in the United
States. Volleyball was created in 1895 by William G. Morgan (“Volleyball World Wide,”
n.d.). Morgan was an instructor at the Young Men’s Christian Association (YMCA) in
Massachusetts (“Volleyball World Wide,” n.d.). Morgan wanted to combine the games of
basketball, baseball, tennis, and handball. The game was first called “Mintonette”
(“Volleyball World Wide,” n.d.). The name was later changed when someone mentioned that
it looked like the players were “volleying” the ball back and forth. Morgan had people start
playing by having as many people that could fit on the 50 by 25 foot court to participate. The
numbers were later changed to nine and then to six. The number of times that the player can
hit the ball has always been three (“Sportsknowhow,” n.d.). Morgan’s game started by
playing with the bladder of a basketball. Spalding released the first official volleyball in 1896
(“Sportsknowhow,” n.d.). The score has changed throughout the years and it is still different
depending on the level, for example, club volleyball versus college volleyball. College
volleyball plays 3 out of 5 games while club volleyball plays 2 out of 3 games in the US
(“Sportsknowhow,” n.d.).
Volleyball is not only an indoors sport. Beach or sand volleyball and grass volleyball
have also gained a lot of popularity. Beach volleyball is even a part of the Olympic Games.
Beach volleyball started as an activity for families to do when they went to the beach. In
1983, beach volleyball really gained its popularity through the Association of Volleyball
Professionals, also known as AVP (“Volleyball Training for Peak Performance,” n.d.). There
2
are also many grass tournaments that take place throughout the US. This is a great way for
athletes to keep playing in their off-season especially for young kids in high school who want
to keep playing over the summer. USA Volleyball was formed in 1928, previously known as
USVBA (“USA Volleyball,” n.d.). The association is still the nationally known organization
for volleyball.
Club volleyball has grown exponentially over the years. This organization is for boys
and girls ages ranging from 12 to 18. There are hundreds of tournaments throughout the
country. The Junior Olympics has become the most popular tournament to try to attend. The
teams must qualify in order to participate. The first event was in 1980 with a small amount of
teams. It has grown to be the most popular and sought after event in club volleyball (“USA
Volleyball,” n.d.). The very highest level of youth volleyball is held at this tournament.
Volleyball requires a great amount of skill and strength to play at a high level. The
athletes must have a well-rounded fitness level in order to be successful. Jumping is a big
part of this. The higher a volleyball player’s vertical jump, the better. They jump many times
throughout a match, which means that they must be strong and conditioned enough to do so.
In a 3-set match, the athletes can jump anywhere from 36 to 105 times (Black, 1995). This
puts a lot of stress on their lower body muscles and joints.
Plyometrics can be a great way to increase an athlete’s muscular strength and their
vertical jump. Plyometrics can best be described as the performance of the stretch shortening
cycle through movements that involve a high-intensity eccentric contraction, which is
immediately followed by a powerful concentric contraction (Arabatzi, Kellis, & Villarreal,
2010). Research has extensively shown that plyometrics can increase an athlete’s vertical
3
jump height because of the greater muscle activation level and the higher mechanical output
of the muscles (Arabatzi et al., 2010).
Statement of Purpose
The purpose of the study was to examine the effects of plyometrics on two different
types of surfaces using volleyball players; more specifically sand versus ground. The
researcher looked to find the best way to train high school women volleyball players when it
comes to increasing their vertical jumps.
Significance of the Study
Plyometric training has proven to improve athletic performance in volleyball players,
especially by increasing their vertical jumps. One of the major differences between Division I
volleyball players and Division II volleyball players is their vertical jump height
(Forthomme, 2005). Jump performance directly contributes to the ball’s speed. Forthomme’s
(2005) study looked at the difference in speed and vertical jump height of Division I and II
athletes, the Division I athletes being more successful in their vertical jumps. The benefits of
the study being done would be a potential increase in an athlete’s vertical jump.
Definition of Terms
Plyometrics: Explosive movements designed to increase muscle strength and power
by contracting the muscles quickly, for example through jumping and bounding.
Stretch Shortening Cycle: Active stretch of muscle followed by shortening of
muscle, eccentric to concentric movements.
Squat Jump: Start in a standing position with your shoulders wide apart and your
heels on the ground. Keep your back straight with your thighs parallel to the floor. Your
hands should be intertwined behind your head. Jump straight up off the ground keeping your
4
hands behind your head. When you jump, extend your entire body. Squat three-fourths of the
way down as you land and then explode into your next jump.
Countermovement Jump: Stand with your feet hip width apart. Using your arms by
swinging them straight back, jump your body straight off the ground and reach both arms as
high as you can. Land in a 3/4ths squat. Explode straight into the next jump by brining your
arms down and swinging them up again into the next jump.
Switch Jump: Stand with your feet hip wide apart. Step one foot about two feet back
while bending the opposite leg into a kneeling position, a lunge position. As soon as the
opposite thigh is parallel to the floor switch your legs into the opposite position that they
were in. Explode back and forth.
Vertec Measuring Device: I will use this to measure the participant’s jump height.
The participants will jump up and touch the highest spot on the pole as they can, which will
then be recorded.
Limitations
1) Consistency of athletes showing up to the training sessions.
2) Accuracy of the vertec measuring device.
3) Weather, since the training will take place outdoors.
4) Amount of effort given by the participants.
5) The participants will not take place in outside training.
6) The subjects will have good nutrition throughout the training program.
Delimitations
1) One group will be working in the sand.
2) One group will be working on the ground.
5
3) The study will take place outside.
4) Feedback will be given to subjects on their form
Assumptions
1) The subjects will all be well-trained volleyball players.
2) They will understand the directions and be able to perform the jumps.
3) The subjects will follow the pre- and post-testing procedures.
4) The subjects will give maximal effort in the jumps involved in the training program.
5) The subjects will be playing volleyball during the same time period of the training
program.
Hypotheses
1) There will be no significant difference between the sand group and the ground group.
2) There will be no significant difference from pre- to post-test in the sand group.
3) There will be no significant difference from pre- to post-test in the ground group.
6
CHAPTER 2
Review of Literature
The purpose of the study was to examine the effects of plyometric training on two
different surfaces, more specifically, on sand and ground, using volleyball players. I looked
to find the best way to train high school women volleyball players when it comes to
increasing their vertical jumps. As the level of competition rises, this becomes more
important especially when playing in the front row. Volleyball players are constantly looking
for ways to improve their vertical jump. An athlete performing the vertical jump must
perform a deep countermovement, with bend in the knees and hip before takeoff to maximize
the vertical jump. Additionally, in the vertical jump, the feet of the athlete must stay in
contact with the ground until their hip and knee joints are almost extended (Vanrenterghem,
Lees, Lenoir, Aerts, & Clercq, 2004). Vanrenterghem et al. did a (2004) study that ,stated
that a deep countermovement and more bend in the knees and hip before takeoff results in a
better vertical jump.
The Vertical Jump
The vertical jump is an important component to many sports, including volleyball.
Studies have shown that the jump height of an athlete contributes to the velocity of the ball
the most in serving and hitting (Adams, O’Shea, O’Shea, & Climstein,1992; Arabatzi, et al.,
2010; Holcomb, Lander, Rutland, & Wilson, 1996; De Villarreal, Kellis, Kraemer, &
Izquierdo, 2009; Faigenbaum, McFarland, Keiper, Tevlin, & Ratamess, 2009; Khlifa et al.,
2010; Kotzamanidis, 2006; Kubo et al., 2007; Lyttle, Wilson, & Ostrowski, 1996; Mihalik,
Libby, Battaglini, & Mcmurray, 2008; Thomas, French, & Hayes, 2009; Wilkerson et al.,
2004). When looking at Division I and Division II athletes, Forthomme, Croisier, Giccarone,
7
Crielaard, & Cloes (2009) found that the biggest difference between the two groups of
athletes was their vertical jump. Forthomme et al. (2009), also measured their shoulder
strength. A higher vertical jump resulted in a higher velocity on the ball hit by the athletes
(Vanrenterghem, Lees, Lenoir, Aerts, & Clercq, 2003).
Vertical jump height depends on the athletes and the type of training that they do.
Ugrinowitsch et al. (2006) did a study that looked at three different types of athletes. They
were power track athletes, recreational body builders, and physically active adults. The
power track athletes demonstrated the highest counter movement jump but it did not relate to
their leg press 1 repetition max. The body builders and physically active adults had a greater
correlation between their counter movement jumps and their 1 repetition max. This study
showed how vertical jump height is important in some sports compared to others, like
volleyball compared to bodybuilding or just being physically active.
Buchhiet’s (2010) study showed a relationship between a person’s vertical jump and
sprint speed. It was found that a faster sprint speed equals a higher vertical jump height.
Volleyball players are constantly moving and jumping from play to play. The athletes may
have to sprint down a ball and then jump very soon after. An effective way to train can be to
do repeated sprints then jumping in between (Buccheit, 2010). This will mimic the moves
that are required in a volleyball match.
There are many components to what influences a person’s vertical jump. Some of
these are the run-up speed before attacking the ball, the single leg jump height, the double leg
jump height, and the single leg jump for clearance (Ham, Knez, & Young, 2007). First, Ham
et al. (2007) looked at the results for the double leg jumps. The involvement of the reactive
leg power was minimal from a stationary position. The reaction of the leg and the amount of
8
power has to do with how quick the athlete can switch from eccentric to concentric
movement in what Ham et al. (2007) called a stretch shortening cycle. The study concluded
that the athletes should be trained to increase their concentric action power of the ankle
plantar flexors, knee extensors, and hip extensors; these should all be trained at the same
time. Weight training would be a good way to increase this power through cross sectional
training.
The observers then analyzed what was found through the deterministic model at the
single leg jumps. The study also found that the speed of jumping off of one leg can be
improved by increasing the threshold for buckling, which will change the body position and
change the height of the center of mass. There will also be improvements by rising the
lowering of the arms and free leg during the pre and post take off (Ham et al., 2007).
Training to increase the vertical jump needs to be very specific to the particular jump
that will be used in competition in order to get the most benefit. This can be achieved through
power and strength training that focus on technique and the specific sport and type of jump
involved (Ham et al., 2007). The research here shows how much goes into the vertical jump
(Ham et al., 2007). The research found that the vertical jump uses a person’s entire body. It is
important that the program an athlete uses is specific to their sport to get the best results. The
vertical jump has to do with the efficiency in which force is produced at the hop, knee, and
ankle joints. Power is the most important component in the vertical jump (Buchhiet, 2010;
Candi & Weiss, 1994).
Adolescent volleyball players make up the largest number in USA volleyball.
Melrose, Spaniol, Bohling, and Bonnette (2007) found that the strength measured by a grip
test was significantly different between the older and younger girls, the older girls being 10%
9
stronger. The spiking velocity was similar but the serving velocity was stronger with the
older girls. The study showed that the physical characteristics of the girls are what most
people would assume, that the older girls are stronger and more powerful. The vertical jump
is very important for an athlete’s success in the game. Athletes will endure different types of
plyometric exercises in hopes of increasing their verticals, therefore improving their play,
especially in their ability to hit the ball (Buchhiet, 2010).
Plyometric Training
Plyometric training has shown to increase an athlete’s vertical jump in many different
studies (Adams et al., 1992; Arabatzi et al., 2010; Chimera, Swanik, Swanik, & Straub, 2004;
De Villarreal et al., 2009; Faigenbaum et al., 2007; Holcomb et al., 1996; Kotzamanidis,
2006; Kubo et al., 2007; Wilkerson et al., 2004). Plyometric training can help lead to an
increase in lower body strength, speed, and power. Plyometric training can also help with
explosiveness, which is key in the sport of volleyball. There are two factors that are
important to what a quick initial movement and a shorter time between the eccentric and
concentric contractions. There should be no hesitation in a good plyometric training program
(Institute of Sports Medicine and Athletic Trauma, 2005). Plyometric training requires
technical ability and coordination (De Villarreal et al., 2009). De Villarreal (2009) performed
a meta-analysis study that analyzed what contributed to the vertical jump, more specifically,
plyometrics. The study looked at the counter-movement jump, the drop jump, and the squat
jump. It also looked at 56 different studies that included at least one of these key words; jump
training, drop jump, depth jump, stretch-shortening cycle, plyometric, and training of power.
Once De Villarreal et al. (2009) determined the 56 studies to analyze the effect size of the
training was determined. The results showed that the average effect size of the plyometric
10
groups were higher than the control groups in the studies. This demonstrates that plyometric
training is an effective way to increase a person’s vertical jump. The study showed that the
vertical jump is increased by 10% on average.
The fact that plyometric training may increase an athlete’s vertical jump is also
demonstrated in the Wilkerson et al. (2004) study. This study looked at collegiate female
basketball athletes and the neuromuscular changes made when participating in a plyometric
jump training program. This study included stretching isotonic strengthening and plyometric
drills. Wilkerson et al. (2004) found that the plyometric training increases the knee strength
by 20%, which can lead to better performance and a better vertical jump.
Chimera et al. (2004) performed a study on plyometric training and performance in
female athletes. The purpose of the Chimera et al study was to look at the effects of
plyometric training on muscle-activation strategies and performance of the lower extremity
during jumping exercises. The analysis of electromyography signals of the vastus medialis,
vastus lateralis, medial hamstrings, lateral hamstrings, hip abductors, and hip adductors. The
study also measured their vertical jump height using the VERTEC. There was a control
group and an experimental group that did plyometric exercises for 20 to 30 minutes twice a
week, the counter movement jump, depth jump, and squat jump. The plyometric group
increased their adductor and abductor muscle activation time. Plyometric training gave the
athletes a quicker response off the ground, which can lead to a better vertical jump as well
(Chimera et al., 2004).
There have been studies done that demonstrated that plyometric training is better than
other types of training when it comes to increasing an athlete’s vertical jump. Kubo et al.
(2007) conducted a study on plyometric and weight training programs. The participants
11
performed plyometric exercises on one side of their body and weight training on the other
side of their body. The side that used plyometric training had a bigger increase in their
vertical jump than the weight training side. Plyometric training is more explosive and faster
than weight training just like the volleyball attack (Kubo et al., 2007).
Plyometric training has shown to increase an athlete’s vertical jump more than other
types of training. The Holcomb et al. (1996) observed in a study five different groups—
control, countermovement jump training, weight training, conventional plyometric depth
jump training, and modified plyometric depth jump training—and compared the findings to
determine which one increases an athlete’s vertical more. The results between the four
training groups were all similar as far as strength gains and vertical jump changes except the
countermovement jump increased more than the plyometric depth jump training program.
This increase was significant at an average of 1.32 inches. This could lead to an athlete
having a higher vertical due to the plyometric training through increasing their strength and
muscle size (Holcomb et al., 1996).
Plyometric training can also help with the mechanics of landing and the strength of
the lower body in a volleyball player (Hewett, Stroupe, Nance & Noyes, 1995). Hewett et al.
(1995) did a study tested the theory that plyometric training can help with landing and
strength in the lower body by testing high school volleyball players. The participants trained
for six weeks using different jumping and landing techniques that are used to increase
vertical jump height and strength. They focused on proper jumping technique, jumping
technique to increase strength and power, and jumping technique to achieve maximal vertical
jump. Ten of the girls decreased their landing force, which can help decrease injuries. Their
12
vertical jump height increased an average of 1.5 inches, which is considered a performance
gain (Hewett et al., 1995).
Plyometric training can be effective with or without added resistance or load but it
may be more effective when there is more resistance added. Khlifa et al. (2010) completed a
study with three groups, one control, one without load, and one with load in the form of a
weighted vest that was 10-11% of their body weight. The two training groups both showed
significant increases in their vertical jump height. The group with the added weight showed a
higher increase in vertical jump height. Khlifa et al. (2010) measured vertical jump height
through squat jumps, and countermovement jumps. Plyometric training is successful in
increasing an athlete’s vertical and can be even more successful when there is more
resistance or load added.
Plyometric training not only increases an athlete’s vertical jump but it can also
increase their neuromuscular strength. Wilkerson et al. (2004) conducted a study that sought
out to find just that. The study involved female Division I collegiate basketball players.
Wilkerson et al. (2004) measured the athlete’s hamstring and quadriceps isokinestic peak
torque. The training program lasted six weeks with two sessions a week of training. They
found that the athlete’s neuromuscular strength did increase according to the same types of
measurements that they used in the beginning of the 6-week program.
Combined Training
Combined training has shown to increase an athlete’s vertical jump in many different
studies. Combined training includes at least two different types of training that an athlete
does in the same time period. Adams et al. (1992) took on a study with four different groups.
These groups were a squat group, plyometric group, squat-plyometric group, and a control
13
group. While all three groups increased their vertical jumps, the group that increased their
vertical jump the most was the squat-plyometric group (Adams et al., 1992).
Combined training produces the same results as a plyometric training program, which
is an increase in vertical jump, increased muscle size and strength, and increased muscle
endurance (Lyttle et al., 1996). Lyttle et al. (1996) observed another program that involves
one group that trains through maximal power lifting, one group using a plyometric program,
and one group that using a traditional weight-training program and a plyometric program
combined. The maximal power lifting group performed squats and bench press on the
Plyometric Power System. The combined group did squats, bench press, rebound depth
jumps, and drop medicine ball throws. The plyometric group did rebound depth jumps and
drop medicine ball throws. The results were inconclusive as to which group was the most
successful in increasing their vertical jump. The subjects all improved but none of the groups
improved significantly more than the other (Lyttle et al., 1996).
Most young volleyball players play all year around. It has been shown that plyometric
training can be best used during season even when the athlete’s are training at a high level
(Arabatzi et al., 2010). Arabatzi et al. (2010) collaborated in a study that compared an
Olympic lifting program to a plyometric program, and a combination of the two type of
program. The Olympic lifting program showed to increase the athlete’s vertical the most by a
counter movement jump height test. The plyometric group was right behind them and was
suggested to be used during the season. Athletes can participate in a plyometric program
without negatively affecting their volleyball training.
Most volleyball players, especially youth club volleyball players, are in season almost
year around, with only a month or two between high school season. This makes it important
14
to be able to train and increase their vertical while they are in season without negatively
affecting their performance. Marques, Tillaar, Vescovi, and Gonzalez-Badillo (2008) did a
study on the changes in elite female volleyball players. The research participants had to go
through a 12-week training session during their season. The participants trained two times a
week doing 3-4 sets of 3-8 repetitions of the exercises given (Marques et al., 2008). The
exercises were a four repetition max bench press, an overhead medicine ball throw, and
loaded and unloaded countermovement jumps. The countermovement jumps are what
showed an increase in vertical jump. The unloaded group increased by 3.8% and the loaded
group increased by 11.2% from the original measurements. The loaded group had the highest
increase during their season.
Different Types of Surfaces
Gregory, Martel, Harmer, Logan, & Parker (2005) did a study on female volleyball
players who trained in the water. This study was looking to see how much their vertical jump
increased. The researchers believed that there would be a decrease in injury because of the
small amount of impact in water. Gregory et al. (2005) used two groups: one that did aquatic
plyometric training, and one that did flexibility exercises on land. The aquatic group
increased their vertical 8% more than the flexibility group. This study used a different
surface than the girls were used to training on, like sand training. The study concluded that
training in water may increase an athlete’s vertical with a decreased risk in injury and
soreness due to a higher resistance provided by water.
Sand training may have a similar effect as aquatic training because the impact is still
less than a volleyball court. Impellizzeri et al. (2007) performed a similar study to this one
using soccer players. Impellizzeri et al. (2007) observed the difference between training on
15
the sand and training on the grass to increase a soccer player’s sprint time, squat jump, and
countermovement jump. Both groups did a plyometric training program either in the sand or
on the grass. The study demonstrated that the sand group improved both jumping and
sprinting ability, plus the athletes experienced less soreness. The grass surface was better for
increasing the athlete’s countermovement jump performance, while the sand group was better
for increasing the athlete’s squat jump performance. The increase for both groups was an
average of 20% better than the subjects initial vertical jump test. Since both groups seem to
have experienced a positive change in their vertical jump height, Impellizzeri et al. (2007)
believed that different types of surfaces can be effective in training athletes and may cause
less soreness, this study using swimming as an example.
Sand training may also help decrease the risk of injury for an athlete and cause less
muscle damage and soreness (Miyama & Nosaka, 2004). Miyama and Nosaka (2004)
conducted a study on the difference between sand training and training on a solid surface.
They found that after the athletes performed drop jumps consecutively in either the sand or
the grass, the sand group experienced less soreness and muscle damage. This can allow the
athletes to train longer and harder, giving them more gains. According to Miyama and
Nosaka (2004), the athletes will be able to perform harder with less muscle soreness.
Youth and Plyometric Training
Plyometric training has shown to improve vertical jump height and strength in young
adults, but also youth. Christos Kotzamanidis (2006) did a study on prepubertal boys.
Kotzamanidis’ (2006) study included a plyometric training program looking to improve
running velocity and squat jump performance. The subjects participated in a 10-week
plyometric training program and a sprinting program; there were two groups, one being the
16
control group. The program had the boys training twice a week; the reps went from 60 to 100
reps total in one training session. The boys increased their squat jump height (Kotzamandid,
2006).
Faigenbaum et al. (2007) organized a study on a plyometric and resistance programs
used on boys ranging from 12 to 15 years old. There were two groups, one using only
resistance training and one using plyometrics and resistance training combined. Faigenbaum
et al. (2007) tested the participants with a vertical jump test, a long jump test, a medicine ball
toss, a 9-meter sprint, and flexibility testing. The combined group increased their long jump
by 10.2 cm compared to the resistance training alone that increased just 2.2 cm. This study
showed that a combined training program is more beneficial for kids than just the resistance
training alone.
Summary
A change in surface could either help or hurt the athletes. Training on the sand can be
very beneficial because it has less impact than the ground. Plyometrics can also be
successful when combined with other types of programs, such as weight lifting. Combined
programs showed to be the best when increasing an athlete’s vertical, compared to the other
programs.
17
CHAPTER 3
Methodology
The purpose of the study was to examine the effects of plyometrics on two different
types of surfaces using volleyball players. More specifically, it looked at the effect of training
in sand versus ground. There was a lower body power test done on the participants.
Participants were tested in the vertical jump in the first week and the last week, six weeks
total.
Participants
The participants in this study were volleyball players in the greater Sacramento area,
more specifically from Rocklin, California. Athletes acceptable for the study ranged from the
ages of 14–18. They came from the Northern California Volleyball Club (NCVC). The
participants were recruited by advertising through the club’s website and by sending an email
to all of the players at the club. The participants were required to sign a consent form along
with their parents (Appendix B & C).
Design
A vertec vertical measuring device was used to measure the participant’s vertical
jump height. A sand court was used, along with a grass surface. The testing took place at the
sand court located at the Springview Park in Rocklin, California.
A pretest and a posttest was performed and used to evaluate improvements of the
groups. The participants followed the same warm up procedure for six weeks. The subjects
were randomly assigned to one of two groups. These groups were the sand group (SG), and
the ground group (GG). The program lasted for six weeks for both groups. The training took
18
place twice a week. The sand group and ground group did the same exercises except one
worked on sand and the other on ground, more specifically on grass.
Training
The exercises in this program were the squat jump with their hands behind their
heads, a split squat jump, and a countermovement vertical jump.
My responsibility was to be in charge of the workouts and to instruct them as needed.
I recorded the participants’ vertical jumps at the beginning and at the end of the 6-week
program. The participants were taught how to do all the exercises correctly on the first day.
The participants then continued to receive feedback throughout the six weeks to make sure
that were getting the most benefits.
Data Analysis
The researcher looked to see if the participants’ vertical jump heights increased after
the six weeks of training. The two groups were compared, the sand and ground. The
researcher used a two-tailed independent t-test to compare differences between the groups. A
2-tailed paired t-test was used to compare within group differences pre test to post test. The
alpha level was set at P<0.05.
19
Chapter 4
RESULTS
The purpose of the study was to examine the effects of plyometrics on two different
types of surfaces using volleyball players. Out of 21 girls, 17 of their vertical jump heights
increased, two of them stayed the same, and two of them decreased. The sand group’s (SG)
average vertical jump height pre-test was 21.64 inches. The ground group’s (GG) average
vertical jump height pre-test was 21.1 inches. The SG average vertical jump height post-test
was 22.59 inches. The GG average jump height post-test was 21.9 inches. There were no
significant differences between the sand training group and the ground training group.
Subjects
Twenty-one participants took part in the study. The pre-test and post-test for the study
was a vertical jump height test done with the vertec measuring device.
Results
The researcher used a 2 tailed independent t-test to compare the sand pre test to the
ground pre test and the sand post test to the ground post test sand. A paired t-test was used to
compare the sand pre test to the sand post test and the ground pre test to the ground post test.
A P value of <.05 was considered statistically significant; a P value of >.05 was not
considered statistically significant. When comparing the sand pre-test to the sand post-test
the P value was .0431. When comparing the ground pre-test to the ground post-test the P
value was .0020. When comparing the ground pre-test to the sand pre-test the P value was
.92. When comparing the sand post-test to the ground-post test the P value was .61. With the
P value at <.05 the sand pre test to sand post test was statistically significant and the ground
pre test to ground post test was statistically significant. After finding a statistically
20
significant result the researcher ran another test to examine the power of the significant
results. In order to find the meaningfulness of the results, the researcher found the effect
size. An effect size (ES) test was calculated using the formula of, ES= (M- M2) /s. An ES
of .08 or greater is larger, an ES around .5 is moderate, and an ES of .2 or less is small
(Nelson, 2001). From sand pre-test to post-test the ES was .360, which is moderate. From
ground pre-test to post-test the ES was .29, moderate, but more close to small. The sand
post-test compared to the ground post-test had an ES .079 which is small.
21
Table 1
Results in Inches
Sand Pre-Test
Ground Pre-Test
Sand Post-Test
Ground Post-Test
(inches)
(inches)
(inches)
(inches)
Mean
21.64
21.1
22.59
21.9
Standard
2.51
2.69
2.63
2.77
Deviation
Hypotheses
1) There will be no significant difference between the sand group and the ground group.
The researcher found that there was no significant difference between the sand and
the ground group.
2) There will be no significant difference from pre to post test in the sand group.
The researcher found that there was a difference between the pre and post test in the
sand group.
3) There will be no significant difference from pre to post test in the ground group.
The researcher found there was a difference between the pre and post test in the
ground group.
22
Chapter 5
DISCUSSION
The purpose of the study was to examine the effects of plyometrics on two different
types of surfaces using volleyball players. The present study found that a 6-week jump
training program significantly improved the vertical jump of participants in the sand and
ground group from pre to post-test. Although both groups improved, there were no
significant differences between groups.
Summary of Results
Both of the groups increased their vertical jump heights but there was only a .10 inch
difference between the two. The current studies results were similar to Impellizzeri et al.’s
(2007) study. Both studies compared sand to ground training.
Impellizzeri et al. 2007 performed a study on soccer players comparing sand to
ground training very similar the current study. Impellizzeri et al.’s (2007) study found that
both the sand and ground groups improved their vertical jump height; the ground group
increased their countermovement jump more while the sand group increased their squat jump
height more. Since both groups improved, Impellizzeri et al. (2007) concluded that both
types of training can be effective in increasing an athlete’s vertical jump height. The current
study found that both the sand and ground group increased their vertical jump height with a
difference of .10 inches between the two. Although both groups improved and had small
differences between groups, the researcher believes both sand and ground plyometric training
may still be an effective way in increasing an athlete’s vertical jump height.
The countermovement jump is used in every volleyball match through the approach
23
jump. This was one of three exercises performed in the study. Holcomb et al. (1996)
performed a study that looked at five different groups and compared the findings to find
which one increased the athlete’s vertical jump the most. Holcomb et al. (1996) discovered
that all of the groups improved their strength and vertical jump heights; the
countermovement jump training group improved more than the plyometric depth jump
training group. This study used the countermovement jump as part of their training which
contributed to the increase of the vertical jump heights in the athletes.
Recommendations for Future Studies
While there are many studies done on plyometric training programs, there is always
more that can be done (Khlifa et al., 2010, Chimera et al., 2004; De Villarreal et al., 2009).
The current study compared sand plyometrics to ground plyometrics but could have used
more participants. The intensity can also be manipulated by changes in the amount of sets or
repetitions of the exercises. The duration of the study can also be increased. The results may
have been different if there were an extra two weeks.
24
Appendix A
Sets and Repetitions
SJ
CJ
Total
Session
Volume
SwJ
Week
Session
Sets
Reps
Total
Sets
Reps
Total
Sets
Reps
Total
1
1
3
5
15
3
5
15
3
4
12
42
1
2
3
5
15
3
5
15
3
4
12
42
2
1
3
8
24
3
8
24
3
6
18
66
2
2
3
8
24
3
8
24
3
6
18
66
3
1
4
8
32
4
8
32
3
8
24
88
3
2
3
8
24
3
8
24
3
8
24
72
4
1
5
6
30
5
6
30
4
6
24
84
4
2
4
6
24
4
6
24
3
6
18
66
5
1
6
6
36
6
6
36
4
6
24
96
5
2
4
6
24
5
6
30
3
6
18
72
6
1
7
6
42
7
6
42
4
6
24
108
6
2
4
6
24
5
6
30
3
6
18
72
Squat Jump- SJ
Countermovement Jump- CJ
Switch Jump- SwJ
25
Appendix B
Parental Consent Form for Volleyball Jump Training Program
Hello players and parents. My name is Alicia Karver and I coach for the Northern California
Volleyball Club. I am working on earning my Master’s degree in Kinesiology at Sacramento
State University. Your child will either be participating in a 6-week jump-training program or
they will be in a control group. The control group will participate in their normal activities,
including volleyball of course. The training will involve different types of exercises on either
a sand or ground surface. There is minimal risk involved in this program especially since
your daughter is already a volleyball player at a high level. There are possible risks of
injuries as with any other training program. I will have ice available in case of injury and a
cell phone to call 911 if necessary. I will be supervising all of the training sessions.
Your daughter may benefit from this program by in theory increasing her strength, reducing
injuries on the court, and increasing her vertical. This program is free of cost to everyone.
I will be measuring your daughter’s vertical jump before the program begins and again after
the 6-week program. Your daughter’s information will be kept completely confidential; only
I will have access to it.
There may be some soreness involved in this study to the lower extremities, more
specifically the ankle, knee, and hip.
If your daughter can only attend some of the training sessions than I will request that she
does not participate in the study. They will not be held accountable for missing sessions but
in order for the study to be accurate I would like the girls to have a good level of
commitment to it. If at any time your daughter wants to withdraw from the study she has the
freedom to do so.
If you have any questions or concerns please contact me. My phone number is (209) 2560461 or you may email me at leash@clearwire.net. If you have any further questions you
may email my professor Dr. Harry Theodorides at theodor@csus.edu.
Thank you for participating in my program.
Sincerely,
Alicia Karver
Please enter your daughter’s name and your name with a signature to the consent of your
daughter participating in this program.
Daughter’s Name _____________ Signature____________ Date_____________
Parent/Guardian Name _____________ Signature _______________ Date___________
26
Appendix C
Participant Consent Form for Volleyball Jump Training Program
Hello players, you are being asked to participate in a researcher project conducted by myself,
Alicia Karver. I am working on earning my Master’s degree in Kinesiology at Sacramento
State University and I coach for the Northern California Volleyball Club. You will either be
participating in a 6-week jump-training program or you will be in a control group. The
control group will participate in their normal activities, including volleyball. The training will
involve different types of exercises on either a sand or ground surface. There is minimal risk
involved in this program especially since you are already a volleyball player at a high level.
There are possible risks of injuries as with any other training program. I will have ice
available in case of injury and a cell phone to call 911 if necessary. I will be supervising all
of the training sessions.
You may benefit from this program by in theory increasing your strength, reducing injuries
on the court, and increasing you vertical. This program is free of cost to you.
I will be measuring your vertical jump before the program begins and again after the 6-week
program.
Your information will be kept completely confidential; only I will have access to it.
There may be some soreness involved in this study to the lower extremities, more
specifically the ankle, knee, and hip.
If you can only attend some of the training sessions than I will request that you do not
participate in the study. You will not be held accountable for missing sessions but in order
for the study to be accurate I would like you to have a good level of commitment to it. If at
any time you want to withdraw from the study you have the freedom to do so.
If you have any questions or concerns please contact me. My phone number is (209) 2560461 or you may email me at leash@clearwire.net. If you have any further questions you
may email my professor Dr. Harry Theodorides at theodor@csus.edu.
Thank you for participating in my program.
Sincerely,
Alicia Karver
Participants Name _______________ Participants Signature______________
Date_____________
27
Appendix D
Physical Activity Readiness Questionnaire
yes
no
1. Has a doctor ever said that you have a heart condition and recommended
only medically supervised physical activity?
___ ___
2. Do you ever experience chest pain or an irregular heart beat as a result of
exercise?
___ ___
3. Have you ever lost consciousness or fallen over as a result as of dizziness
during or after exercise?
4. Has a doctor ever said that you have high blood pressure?
___ ___
___ ___
5. Do you have a bone or joint problem that can be aggravated by the proposed
physical activity?
___ ___
6. Do you suffer from lower back pain, i.e., chronic pain or associated
numbness in a lower extremity?
___ ___
If you answered yes to any of questions 1-6 please explain.
____________________________________________
___ ___
7. Have you had surgery as a result of an injury to the back or lower body
(ankle, knee, or hip) in the last 6 months?
___ ___
If YES, please specify
____________________________________________
8. Have you had a recent (within the last 6 months) injury to the lower body
that has received medical attention? If yes, please specify.
___ ___
I certify that the above statements are true and correct. I understand that a Doctor’s note
may be requested. If a note is requested, I should not proceed with this program until the
note is received.
28
Appendix E
Weekly Volume
200
180
160
Number of Reps
140
120
100
80
60
40
20
0
1
2
3
4
Week
5
6
29
Appendix F
Daily Volume
120
100
Number of Reps
80
60
40
20
0
1
2
3
4
5
7
6
Day
8
9
10
11
12
30
Appendix G
Daily Volumes By Exercise
45
40
35
Repetitions
30
SJ
CMJ
SwJ
25
20
15
10
5
0
1
2
3
4
5
6
7
Day
SJ- Squat Jump
CMJ- Countermovement Jump
SwJ- Switch Jump
8
9
10 11 12
31
References
Adams, K., O’Shea, J.P., O’Shea, K.L., & Climstein, M. (1992). The effect of six weeks of
squat, plyometric and squat-plyometric training on power production. Journal of
Applied Sport Science Research, 6(1), 36–41.
Arabatzi, F., Kellis, E., & Saez-Saez De Villarreal, E. (2010). Vertical jump biomechanics
after plyometric, weight lifting, and combined (weight lifting + plyometric) training.
Journal of Strength and Conditioning, 24(9) 2440–2448.
Babcock, B. (2010). The effects of a strength and conditioning program on performance of
female soccer players: starters vs. nonstarters.
Black, B. (1995). Conditioning for volleyball. Strength and Conditioning Journal, 17(5), 53–
55.
Buchheit, M. (2010). Performance and physiological responses to repeated-sprint and jump
sequences. European Journal of Applied Physiology, vol #(issue #), 1007-1018.
Candi, A.D., & Weiss, L.W., (1994). Vertical jump performance and selected physiological
characteristics of women. Journal of Strength and Conditioning Research, 8(1), 5-11.
Chimera, N., Swanik, K., Swanik, C., & Straub, S. (2004). Effects of plyometric training on
muscle-activation strategies and performance in female athletes. Journal of Athletic
Training, 39(1), 24–31.
De Villarreal, E.S., Kellis, E., Kraemer, W.J., & Izquierdo, M. (2009). Determining variables
of plyometric training for improving vertical jump height performance: a metaanalysis. Journal of Strength and Conditioning Research, 23(2), 495–506.
32
Faigenbaum, A., McFarland, J., Keiper, F., Tevlin, W., & Ratamess, N. (2007). Effects of a
short-term plyometric and resistance training program on fitness performance in boys
age 12 to 15 years. Journal of Sports Science & Medicine, 6(4), 519–525.
Forthomme, B., Croisier, J.L., Giccarone, G., Crielaard, J.M., & Cloes, M. (2005). Factors
correlated with volleyball spike velocity. The American Journal of Sports Medicine,
33(10), 1513–1519.
Gonzalez-Rave, J.M., Machado, L., Navarro-Valdivielso, F., & Vilas-Boas, J.P. (2009).
Acute effects of heavy-load exercises, stretching exercises, and heavy-load plus
stretching exercises on squat jump and countermovement jump performance. Journal
of Strength and Conditioning Research, 23(2), 472–479.
Ham, D.J., Knez, W,L., & Young, W.B., (2007). A deterministic model of the vertical jump
implications for training. Journal of Strength and Conditioning Research, 21(3), 967–
972.
Holcomb, W.R., Lander, J.E., Rutland, R.M., & Wilson, G.D. (1996). The effectiveness of a
modified plyometric program on power and the vertical jump. Journal of Strength
and Conditioning Research, 10(2), 89-92.
Jumping Lunges (n.d.), retrieved from http://eat-spin-run-repeat.com/2011/07/15/
Khlifa, R., Aouadi, R., Hermassi, S., Chelly, M., Jlid, M. (2010). Effects of a plyometric
training program with and without added load on jumping ability in basketball
players. Journal of Strength & Conditioning Research, 24(11), 2955–2961.
Kotzamanidis, C. (2006). Effect of plyometric training on running performance and vertical
jumping in prepubertal boys. Journal of Strength & Conditioning Research, 20(2),
441–445.
33
Kubo, K., Morimoto, M., Komuro, T., Yata, H., Tsunoda, N., Kanehisa, H., & Fukanaga, T.
(2007). Effects of plyometric and weight training on muscle-tendon complex and
jump performance. Medicine and Science in Sports and Exercise, vol 5(issue 10), 2428.
Lyttle, A.D., Wilson, G.J., & Ostrowski, K.J. (1996). Enhancing performance: maximal
power versus combined weight and plyometrics training. Journal of Strength and
Conditioning Research, 10(3), 173–179.
Marques, M., Tillaar, R., Vescovi, J., & Gonzalez-Badillo, J. (2008). Changes in strength and
power performance in elite senior female professional volleyball players during the
in-season: A case study. Journal of Strength & Conditioning Research, 22(4), 1147–
1155.
Melrose, D.R., Spaniol, F.J., Bohling, M.E., & Bonnette, R.A. (2007). Physiological and
performance characteristics of adolescent club volleyball players. Journal of Strength
and Conditioning Research, 21(2), 481–486.
Mihalik, J.P., Libby, J.J., Battaglini, C.L., & Mcmurray, R.G. (2008). Comparing short-term
complex and compound training programs on vertical jump height and power output.
Journal of Strength and Conditioning Research, 21(1), 47–53.
Miyama, M., & Nosaka, K. (2004). Influence of surface on muscle damage and soreness
induced by consecutive drop jumps. Journal of Strength & Conditioning Research,
18(2), 206–211.
34
Nelson, J., Thomas, J., & Nelson, J. Research methods in physical activity. Champaign:
Human kinetics, 2001 5th ed.
Plyometrics for speed and power. (2006). Running & FitNews, 24(2), 8-9.
Sports Know How- Volleyball retrieved from
http://www.sportsknowhow.com/volleyball/index.html.
Thomas, K., French, D., & Hayes, P. (2009). The effect of two plyometric training
techniques on muscular power and agility in youth soccer players. Journal of Strength
& Conditioning Research, 23(1), 332–335.
Vanrenterghem, J., Lees, A., Lenoir, M., Aerts, P., & Clercq, D.D. (2003). Performing the
vertical jump: movement adaptations for submaximal jumping. Human Movement
Science, 22(6), 712–727.
USA Volleyball. (n.d.). Retrieved on date from volleyballusa.com
Volleyball training for peak performance. (n.d.). Retrieved from http://www.strength-andpower-for-volleyball.com/
Volleyball World Wide (n.d.). Retrieved from volleyball.org.
Wilkerson, G.B., Colston M.A., Short, N.I., Neal, K. L., Hoewischer, & Pixley, J. J. (2004).
Neuromuscular changes in female collegiate athletes resulting from a plyometric
jump-training program. Journal of Athletic Training, 39(1), 17–23.