How plyometric training varies the increase in vertical and horizontal

HOW PLYOMETRIC TRAINING VARIES THE INCREASE IN VERTICAL AND HORIZONTAL
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How Plyometric Training Varies the Increase in Vertical and Horizontal
Abstract
Over the recent years, the importance of plyometrics in horizontal and vertical movements has been established through a number of studies conducted by varied researchers like Ben Campbell, Ramirez Campillo, Dalwinder Singh and Sukhwinder Singh.
Most of these studies were based on qualitative research methodology integrated with purposive data collection techniques based on random samples of participants. The experiments involved the splitting of the participants into four random groups with one group exposed to both horizontal and vertical plyometric training, two groups exposed to either training while one serving as the control. The results of the training would then be qualitatively compared against the control group to check on improvements. Their findings have clearly indicated that plyometrics training has a direct impact on the muscular power, horizontal and vertical movements, running velocity and the overall success of the athlete engaged in the training. Thus as a way ensuring that an athlete is exposed to the most efficient way of training, plyometrics training comes handy. However, excessive increase in their intensity of the training may promote prolonged ground contact which is likely to reduce the Reactive Strength Index, a key indicator of plyometric intensity.

Besides, the choice of this training should also be dependent on the sports the athlete or the specific individual is involved in. This paper is mainly going to focus on How Plyometric Training varies the Increase in Vertical and Horizontal movements, its importance to athletes and how it differs from other training methods particularly isometric training.
Introduction
Plyometrics is a training modality, often some form of jumping or rebounding where the eccentric stretching of muscles is rapidly cut short by a dominant isometric contraction, thereby initiating a myotatic reflex stretch. Plyometrics came into existence in the 1980s when Fred Wilt, a scientist, coined the term after he observed the Soviet athletes prepare for their games. Alongside Michael Yessis, the man behind the exercises in the Soviet Republic athlete’s program, Fred Wilt began disseminating information about this form of exercise leading to its popularity in Russia and other European countries.
Speed and power are individual physical attributes that every athlete needs and covets for success, strength is of immense importance while speed is equally important. A combination of both is even better, this combination has the potential of making a difference in an athlete’s career and can also mark the difference between a winner and pathetic loser. Plyometric training solves this problem for athletes and it is highly recommended by strength and conditioning trainers due to its ability to enable an athlete to train his or her muscles to gain both speed and power.
An increase in speed and power automatically improves an athlete’s performance regardless of the game being played, for professionals, plyometric training is not just an option but a priority. For many centuries, athletes have always used a number of exercises to improve their strength and speed such as jumping, hopping, and bonding exercises. However, the plyometric training exercise has currently proven to be the most effective form of exercise to get athletes ready for their games and to improve their general performance. However, there are two schools of thoughts within the plyometrics exercises, the first school of thought that can be attributed to the origin of the ideas behind plyometric training in the Soviet republic prior to the 1980s, where they believed in intense plyometrics, also referred to as shock methods. In performing the shock method, the duration of the eccentric phase and concentric phase is minimal. The other school of thought, popular in North America and other regions believe in slower transitioning between the eccentric phases and the concentric phases. This research paper looks into the plyometric training exercise and routines to determine why the exercise is effective compared to other forms of training like isometric training, particular cases of proof of its effectiveness will be identified and discussed. However, this paper has its major focus on how plyometrics can enhance the overall performance of athletes with a core emphasis on speed, endurance levels, swiftness, and speed. Nevertheless, it will also shed light on the benefits of plyometric exercises, how it differs from the normal training methods as well as looking at some of the sports best suited for it. All this is through an in depth look at some of the previous studies carried out various researchers, their research methods, findings and recommendations on the implementation of plyometric training.
Horizontal and Vertical plyometric exercises
There are two basic forms of plyometric exercises, the vertical plyometric exercise (vertical depth jumping) and horizontal plyometric exercise (horizontal depth jumping). Plyometrics basically involves the stretching of the muscles and the sudden contraction of the same muscles almost simultaneously. The stretching is also known as eccentric phase while the contraction of the muscle is referred to as the concentric phase. Both the eccentric and the concentric phases of the training are equally important and for trainers, they strive to ensure that the training schedule caters for both. Several pieces of research have been conducted in the past to establish the results of these exercises, athletes, a recent example is a research that was carried out by Sukhwinder and Dalwinder Singh to establish the effect of both the plyometric exercises on an athlete’s agility and speed. They carried out an experiment in which they used random sampling to obtain 80 physically fit male participants from Punjab University. They employed stratified random sampling to divide the participants into four groups, a control group, a vertical plyometric group, a horizontal plyometric group, and a group that combined both the vertical and the horizontal exercises. The aim was to determine the effect and the importance of combining both the horizontal and the vertical plyometric exercises as opposed to using a single form of exercise. Before the experiment, the male students were subjected to a 45.72m sprint in which their respective times were recorded. The researchers compared the recorded times before the exercises and the times they would record after a period of plyometric exercises. All the groups of the players were taken through the plyometric exercises over a span of ten weeks where the training sessions were conducted twice in every week. At the end of the 10 weeks, the outcomes indicated that all the groups that were subjected to the exercises, horizontal, vertical and both the plyometric training gave an indication of improvement in performance when compared with the control group that only underwent the traditional form of exercises including isometric training. However, within the groups, there was another difference which occurred between the groups that did single exercises, either vertical or horizontal and the group that did a combination of both, the group that did a combination of both showed greater performance than the groups that did one form of exercise. The core element used in this evaluation was the Reactive Strength Index which was obtained by getting the quotient of the height jumped and the duration of contact with the ground. By comparing the average RSI’s for the four groups, the researchers came to a conclusion that a combination of both the horizontal and the vertical exercises was much more effective compared to only performing a single form of plyometrics.
Another similar research was performed by Ramirez Campillo at the University of Los Lagos in Chile (Ramírez et al., 2014). In the research, Ramirez, with a group of other researchers aimed at determining the effect of both forms of plyometric training on the performance of athletes and the impacts that an amalgamation of the exercises had on endurance performance, explosiveness and balance on overall balance on teen football players. They also implemented random sampling to get a summation of 40 teen football players of ages between 10-14 who were used in the experiment. The 40 players were split into four groups, the first group formed the control group, the second group was the vertical group and the third group did horizontal exercises while the fourth group performed a combination of both the vertical and the horizontal plyometrics. Each group had a total of 10 soccer players and the experiment was conducted over a span of six weeks after which the outcomes were qualitatively analyzed to draw conclusions. Over the experiment, the researchers measured drip jump responsive strength, the maximum thrusting speed pertaining to all the participants in the exercise, race speed, direction change, and pawn – arm movement and other jump movements. In the control group, no meaningful change was noticed over the span of six weeks while all the other training groups showed a meaningful change in all the measured categories. The measured categories included endurance levels, balance performance, and explosiveness. Although the research did not show a major difference between the experimental groups probably due to the duration of the study, the group that did a combination of both the vertical and the horizontal exercises showed a slightly higher performance levels compared to the groups that did either vertical or horizontal forms of exercises alone. The deduction from this research was that both vertical and horizontal training exercises, when combined, had the effect of significantly enhancing the performance of an athlete in terms of balance, explosiveness, endurance and consequently the overall performance of the athlete.
Another rather different research with a similar objective was conducted by Ben Campbell as part of a thesis paper that was presented for his master’s program in the University of Edith Cowan. The main aim of his research was to determine the impacts that the vertical and horizontal training exercises had on very fast running. In the investigation, He sought to investigate the effect of vertically and horizontally-directed lower body plyometric exercise on an athlete’s sprinting performance over a span of six weeks. The participants here were recreational athletes sprinting over a 40metre distance in squat jumps, counter-movement jumps, depth jumps. The procedures were done twice in a week with subjects asked to maintain their normal exercise routines in order not to interfere with the experiment’s results. The Reactive Strength Index obtained qualitatively from the jump height and ground contact time, was used throughout the experimental procedures to determine the difference in ability throughout the experiment and in performance levels as well. The outcomes of this experiment suggested that both vertical and horizontally-directed exercises of the lower body were similarly effective in improving the level of performance of sprinters. These results meant that a training program could effectively use exercise to improve performance depending on an athlete’s game, such a suitable program only proved to be plyometric training program (Ronnestad et al., 2008).
As evident from these experiments, Plyometrics training programs ideally target the muscles of the body that are responsible for movement in order to enable them to gain power and strength, features that are of utmost importance to athletes in competitions. These two features are crucial in determination as to whether an athlete is able to produce a winning performance or not, in some cases, these two attributes can determine whether an entire team wins a competition or not. This implies that plyometric training exercises are very crucial to the success of any athlete.
Impacts of Plyometric exercises on the functioning of muscles
As Evident from the experiments in the research by Sukhwinder Singh, Ramirez Campillo, Dalwinder Singh and Ben Campbell on horizontal and vertical Plyometric exercises tackled above, it is certainly apparent that the horizontal and vertical plyometric exercises have direct impacts on the muscles. The main goal of these exercises is to strengthen the muscles and to give them more power and speed as well as endurance. Additional recent researches have also continually shown that plyometric training exercises have a direct impact on the muscle function. An example of these researches was conducted by Markovic and a group of other researchers, the research was meant to compare the effect that the standard plyometric training exercise had on an athlete’s performance with those of normal sprint training exercises. A total of 93participants randomly picked physically fit education students were used in the study. The students were split into three random groups, the control group with 33 students, the sprint group with 30 students and the plyometric group had 30 students. The measures recorded in the experiment were squat and counter-movement jump height and power, standing long jump, 20-yard shuttle run, 20m sprints, drop jump performance over 30 meters, as well as maximal isometric squat strength. During the experiment, the control group maintained its routine of normal exercises whereas both the training groups trained thrice in a week. The sprint group did maximal sprints over the experiment period while the plyometric group did drop jumps and hurdle jumps. After the experiment, from a quantitative analysis of the results, it was determined that both the groups produced remarkable improvement in terms of the measurements used. The conclusion from the research was that both the sprint and the plyometric training methods were effective criteria that could be used in helping improve the explosive performances of athletes.
Another similar research was conducted to establish the effect impacts of hefty preloading on vertical and horizontal hurdle performances. The core intent of the research was to establish the critical impact of hefty changing preload on both horizontal and vertical jumps. In this research, a total of 19 randomly chosen males participated in the study. The study also intended to investigate the ability of the subjects to apply the effects of the preload workouts on subsequent training sessions. The subjects participated in four practice and four test sessions being subjected to a heavy and dynamic preload that consisted of a set of five repetition maximum back squats, counter-movement jumps, and horizontal jumps. The testing sessions were meant to determine the effect of the preload exercise on the subjects and to determine if the subjects were able to apply the effects of the preload on subsequent training sessions. A practice session would include a10 minute warm up sessions, 5 of which the subjects would be engaged in cycling and the other five dedicated to stretching. Two sets of vertical jumping and horizontal jumping would follow the warm up session. A five-minute rest separated the two exercises after which progressive back squats would follow and final sets of horizontal and vertical jumping. Over the period of the experiment, vertical and horizontal jumping improved significantly, the back squat strength also increased over the 4 four sessions workout period. However, the experiment showed an inability of the subjects to apply the repetitive preload exposure to their training programs.
From these experiments, it is apparently clear that plyometrics is crucial in the muscle functioning of athletes and should be adopted in their routines to enhance their performance. Taking an instance of volleyball players, they need to jump all the time in successions, an activity that needs an intensive plyometrics program that will ensure that their strength and conditioning level is high in order to compete favorably. Nevertheless, research has shown that plyometrics can help reduce risks of injury for athletes hence the establishment plyometric training programs will lead to the immense success of our athletes. Moreover, the plyometrics training exercise not only strengthens the body muscles but they also improve their stretching and contraction abilities making them less prone to injuries that athletes are prone to (Lloyd et al., 2012).
Overall, in all these experiments geared towards determining the effects of Horizontal and vertical plyometric exercises had on athletes, qualitative research method was greatly used integrated with random sampling techniques for data collection. However, these techniques had several setbacks. The sample chosen was just a very small subset of the population thereby making it challenging to derive conclusions regarding the entire population set. Nevertheless, the qualitative methodology was very involving and required the immense involvement of the participants and the researcher for the entire research duration spanning between six to ten weeks. The sampling was also biased since almost all the participants in the experiments were all male.
In addition to the setbacks of the research methodologies, several ethical issues arose in the study that needed to be addressed before the study could move on, some of these included the need for collaborative work between the participants and the accountability of the researchers to the participants. The two were addressed by signing a mutual agreement before the practice that rendered the researcher accountable to their subjects and both parties agreeing to work collaboratively in realizing the goals of the research. Professional boundaries also needed to be maintained by the researchers to limit the flow of unnecessary information between the researchers and the participants that would impact negatively on the final results.
Tables and Diagrams
Table 1

The diagram above is an extract from a study conducted at the University of Texas to determine the effect of six weeks of plyometrics training on an athlete and if the six weeks were capable of improving an athlete’s agility and therefore, the overall performance. Agility is the ability of the body to control its position while rapidly changing speed and direction while agility training on the hand involves training programs that are aimed at improving an athlete’s neural and muscular functions to ensure that the body response to speed does not lead to loss of control of positions and that an athlete is able to maintain control of their body regardless of swift twists and turns. To this end, the research sought to determine the extent of agility improvement after a six-week plyometrics training program. The participants were randomly separated into two groups, the control group, and the training group. The control group was not subjected to any form of plyometrics training while the training group was subjected to various plyometrics drills as can be identified from the table 1 above.
The test was done on a six-week period of training since from a physiological point of view, six weeks are sufficient to stress the body’s central nervous system without excessively straining it or causing unnecessary fatigue that may interfere with results. The training group was subjected to intense scrutiny twice a week with sufficient instructions on how to perform the drills. Before any training session, tests were carried out to determine the variations in a sum of attributes of the participant in order to help the researchers draw conclusions on the extent of the impacts of the training exercises on athletes. The tests were the Illinois agility testing, the T-test, and force plate test. The T-test was to estimate the participants’ velocity with changes in direction while the Illinois agility test measured the participant’s acceleration capabilities, ability to decelerate, and ability to make sharp turns and twists and to course at a varied angles. The third test, the Force Plate Test was a measure of the ground contact time in order to determine the quickness of the athlete and the power.
The three tests done prior to the experiment were used to determine the base times which were later compared with the times recorded after the six weeks period. The empirical results showed that the T-test score improved by 4.86%, the Illinois test score improved by 2.93% while the force plate test score improved by 10%. The conclusions were that plyometric training is beneficial to athletes and that it helps improve their agility. The research also came to a conclusion that there was the possibility of improving an athlete’s agility over a six week period that the program could be effectively implemented by athletes in improving their overall performance in athletics. In addition, the researchers also established that the outcomes were immensely positive and they were indicators of the immense benefits that plyometric both vertical and horizontal plyometric exercises could have on athletes strength, agility and overall performance whether the person taking the exercise is a professional in athletics or not
Diagram 1

Source: http://www.ideafit.com/fitness-library/explosive-power
The diagram above shows a basic jump session that shows an individual performing a plyometric jump, the picture is an ideal representation of the plyometrics exercise since the initial squat position enables an individual to stretch the leg muscles before the sudden contraction that catapults the individual upwards. Ideally, the time between the squat and the actual jump should be as short as possible (Toumi et al, 2004). A shorter duration between the stretching of the muscles is referred to as an eccentric action, and the contraction of the muscle during the actual jump is referred to as a concentric action, also known as plyometrics. Even though there may be variation in the exercise or use of different tools to help in the exercise such as bench, the basic idea behind the exercise remains the same. The intensity of the exercise also depends on an individual’s strength and the reason for the exercise. The level of fitness of an individual also determines the intensity of the work-out that an individual can perform safely.
Diagram 2

Source: https://en.wikipedia.org/wiki/PlyometricsThe diagram above is another actual representation of a group of individuals doing plyometrics exercises and as can be clearly seen from the diagram, the level of plyometrics needed for this exercise is higher and may require people with a higher fitness level.
Table2

The diagram above is a table showing a training regime that can be used for a squat-plyometric program. The program, ideally, uses a six-week period for optimal results. In the squat program, the number represents the number of sets of squats that an individual can follow and the number of repetitions in each set. In the plyometrics program, there are a number of exercises and activities for individuals to follow. These include depth jumping, double leg hopping, split squatting, walking, as well as standing. For such a program, it is important for an individual to ensure that that they follow the program religiously for optimal results.
The effect of Plyometrics on the Vertical jump
There is a current raging debate between the effect of slow stretching and fast stretching of the muscles during plyometrics and the effect they could have on an individual’s performance, most of the discussions addressing the subject have never been able to draw meaningful a conclusion. While the Eastern European nations and other proponents of the shock method of plyometrics argue that the ‘true plyometrics’ is the most effective method of achieving optimal performance, others seek to differ and argue that even slower methods produce the same results. For instance, in the United States and other western countries, they prefer using the slower method. Their athletes are doing well and this has helped fuel if it is really necessary to undergo the intense plyometric exercises that traditional proponents of the exercise support. Various studies to determine the effects of slow and the fast methods have been done with varying results, but none has had the ability to settle the issue once and for all. A more recent study was carried out by Toumi in collaboration with a group of other researchers to identify the effect of plyometric exercise that was either conducted using the shock technique or the gradual technique on jump exercises. In this study, thirty males were used as subjects for the experiment. The ages of these males ranged from 19 to 22 years of age. The subjects were subsequently split into three random groups, the control group, and two other training groups.
Both groups were subjected to varied exercise procedures conducted over a period of eight weeks in which they were exposed to training four times every week and the concentration of the exercises incremented after a span of every two weeks. The first group would flex their muscles to form a 90-degree angle with a velocity of 0.4m/s and the other group a 0.2m/s velocity level. Each exercise conducted consisted of six sets of repetitions with 10 repetitions in each set. Maximal isometric force, counter-movement jumps, maximal concentric force, and squat jump exercises were performed prior to the exercise and immediately after the eight-week period. The subjects were filmed throughout the exercise and the periods were split and classified into the eccentric phase, the concentric phase, and the transition phase. In both the training groups, the results showed that there was an increase in leg extension force after the eight-week period. From an empirical analysis, the categories that showed improvement included the short jump and the counter-movement jumps. However, the first training group with shorter duration times showed significant changes in the force measurements compared to the second group that did slower methods. The conclusion of the research was that the group with shorter durations between the jumps, or that used the shock method, showed better performance results. Perhaps, the research would help settle the debate as to which method among the two is more effective. Nevertheless, settling this debate is a matter that is not about to settled soon with so many factors and circumstances determining the performance of an athlete such as nutrition, age, and duration of exercise. While both arguments may make sense to different sets of conditions, one thing that transcends both schools of thought is that the plyometric training method is beneficial to athletes (Adams et al., 1992). The level of performance may differ depending on the method preferred but both methods will register improved performance after a period of time.
Plyometric vs Isometric training
Plyometric training exercises involve the stretching of muscles followed by the contraction of the same muscle. These two phases are commonly referred to as eccentric and concentric phases of the muscles when performed in quick succession form, what is popularly known as plyometrics. Essentially, the plyometric training involves the changing of an angle of the muscles and the angle joints. The most common plyometric exercise involves jumping up and down where the joint angle makes a 90-degree angle before rapidly contracting to results into a jump. On the other hand, Isometric training is an exercise that does not involve any movement of the joints or of the muscles. However, both the practices are used to add more strength to the muscles of the athlete or the people undertaking the exercise. Nonetheless, while there is no visible change in the angle of the joint, or movement of the joints, there is an internal movement of the muscles and stretching that occurs when conducting isomeric training routines.
Both of these techniques are strengthening techniques and help an individual in increasing muscle power. The isometric training routines exercise the strength of the muscles as it stretches to respond to the force applied to the muscles, almost similar to plyometric exercise. However, the Plyometric training has an advantage over isometric training in that it also helps in improving the agility of the individual and provides a combination of both speed and power while the isometric training techniques focus on muscle strength. The plyometric training exercises also help prevent injuries to athletes, the agility movements of the training program enable an individual to make sudden sharp twists and turns without causing injuries to the muscles within. On the contrary, isometric training exercises only focus on adding strength to the muscle, as a result, the muscles become stiff and reduce their flexibility and are prone to injuries when subjected to a situation involving sudden sharp twins and turns.
While each of the two techniques shows individual advantages over the other and different adaptation to different needs, one may want to do both which is not advisable. The option should be dependent on the sports one is involved in, plyometric training is suitable for sports often requiring sharp twists and turns such as lawn tennis. Lots of twists and turns are also involved in football thereby necessitating the need to settle on plyometrics over the isometric form of training. However, for other sports such as weight lifting requiring massive strength without the need to twist and turn, then isometric exercises may be the best option in that case. Whatever the option chosen, exercises should follow a given routine and it is advisable that the advice of a gym instructor should be sought before embarking on some exercises for proper and optimal results. Nutritional requirements also come in handy in complementing the exercise and in helping in the fast repair of the tissues during intensive workouts. In this regard, a nutritionist advice should go hand in hand with the gym instructions to ensure that there are optimal results from the various exercises.
Conclusion
In a nutshell, it is apparent that the plyometric exercise is poised to play a big role in the careers of athletes in determining their levels of performances as illustrated from in the various studies conducted by various the different researchers mentioned above. The plyometric training procedures help vary the increase in the horizontal as well as the vertical movements of joints. The training procedures focus on the strength of the muscles as well as the speed element (Vossen, 2000), these two elements are crucial in sports performance and thus, help support the ideas behind the plyometric training procedures. Moreover, the plyometric training procedures are critical in helping reduce the injury risks as suggested in the studies above. Some of the benefits of the plyometric training have been identified throughout the paper and various studies done on the subject have been discussed. Additionally, it is worth noting that the use of either horizontal or vertical plyometric training may not be sufficient, a combination of the two methods is certainly effective. With athletes as the main focus of this forms of exercises, it is crucial that plyometric training programs be adopted to enhance their performance even as other athletic teams across the globe try to find ways of maximizing the potential of their teams to enhance their performance improving their performances.
Nevertheless, owing to its massive potential to improve the vertical and horizontal movements, coaches, strength and conditioning trainers need to include the plyometric exercises in training their clients and players to optimize their potential and enhance their performance. Various researches and studies conducted in the past have also shown that plyometrics helps improve the agility of an individual, in addition, improving the power element (Herrero &Izquierdo, 2006). This also stands out clearly in the succeeding studies conducted by Dalwinder Singh and Sukhwinder Singh discussed in earlier sections of this paper. Besides, the plyometric exercises go a long way in improving force development and speed endurance that are of immense benefits in other sports like netball, volleyball, basketball, high jump and many other sports where great force and speed endurance is greatly required. Thus, the adoption of plyometric exercises in the training of sportsmen in these fields will see an improvement in the performance of the entire sports sector.
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. The Journal of Strength & Conditioning Research, 6(1), 36-41.
Burgess, K. E., Connick, M. J., Graham-Smith, P., & Pearson, S. J. (2007). Plyometric vs. isometric training influences on tendon properties and muscle output. The Journal of Strength & Conditioning Research, 21(3), 986-989.
Cadore, E. L., Pinheiro, E., Izquierdo, M., Correa, C. S., Radaelli, R., Martins, J. B., …& Pinto, R. S. (2013). Neuromuscular, hormonal, and metabolic responses to different plyometric training volumes in rugby players. The Journal of Strength & Conditioning Research, 27(11), 3001-3010.
Carter, A. B., Kaminski, T. W., Douex Jr, A. T., Knight, C. A., & Richards, J. G. (2007). Effects of high volume upper extremity plyometric training on throwing velocity and functional strength ratios of the shoulder rotators in collegiate baseball players. The Journal of Strength & Conditioning Research,21(1), 208-215.
Carter, J., & Greenwood, M. (2014). Complex training reexamined: Review and recommendations to improve strength and power. Strength & Conditioning Journal, 36(2), 11-19.
Chelly, M. S., Hermassi, S., &Shephard, R. J. (2015). Effects of in-season short-term plyometric training program on sprint and jump.
de Villarreal, E. S. S., González-Badillo, J. J., &Izquierdo, M. (2008). Low and moderate plyometric training frequency produces greater jumping and sprinting gains compared with high frequency. The Journal of Strength & Conditioning Research, 22(3), 715-725.
Herrero, J. A., &Izquierdo, M. (2006). Electromyostimulation and plyometric training effects on jumping and sprint time. studies, 18, 29.
Hewett, T. E., Stroupe, A. L., Nance, T. A., & Noyes, F. R. (1996). Plyometric training in female athletes decreased impact forces and increased hamstring torques. The American Journal of Sports Medicine, 24(6), 765-773.
Houghton, L. A., Dawson, B. T., &Rubenson, J. (2013). Effects of plyometric training on achilles tendon properties and shuttle running during a simulated cricket batting innings. The Journal of Strength & Conditioning Research, 27(4), 1036-1046.
Kijowksi, K. N., Capps, C. R., Goodman, C. L., Erickson, T. M., Knorr, D. P., Triplett, N. T., … & McBride, J. M. (2015). SHORT-TERM RESISTANCE AND PLYOMETRIC TRAINING IMPROVES ECCENTRIC PHASE KINETICS IN JUMPING. The Journal of Strength & Conditioning Research.
Kotzamanidis, C. (2006). Effect of plyometric training on running performance and vertical jumping in prepubertal boys. The Journal of Strength & Conditioning Research, 20(2), 441-445.
Lloyd, R. S., Oliver, J. L., Hughes, M. G., & Williams, C. A. (2012). The effects of 4-weeks of plyometric training on reactive strength index and leg stiffness in male youths. The Journal of Strength & Conditioning Research, 26(10), 2812-2819.
Luebbers, P. E., Potteiger, J. A., Hulver, M. W., Thyfault, J. P., Carper, M. J., & Lockwood, R. H. (2003). Effects of plyometric training and recovery on vertical jump performance and anaerobic power. The Journal of Strength & Conditioning Research, 17(4), 704-709.
Markovic, G., Jukic, I., Milanovic, D., &Metikos, D. (2007). Effects of sprint and plyometric training on muscle function and athletic performance. The Journal of Strength & Conditioning Research, 21(2), 543-549.
Meylan, C., &Malatesta, D. (2009). Effects of in-season plyometric training within soccer practice on explosive actions of young players. The Journal of Strength & Conditioning Research, 23(9), 2605-2613.
Miller, M. G., Herniman, J. J., Ricard, M. D., Cheatham, C. C., & Michael, T. J. (2006). The effects of a 6-week plyometric training program on agility. Journal of sports science & medicine, 5(3), 459.
Saunders, P. U., Telford, R. D., Pyne, D. B., Peltola, E. M., Cunningham, R. B., Gore, C. J., & Hawley, J. A. (2006). Short-term plyometric training improves running economy in highly trained middle and long distance runners. The Journal of Strength & Conditioning Research, 20(4), 947-954.
Scott, S. L., & Docherty, D. (2004). Acute effects of heavy preloading on vertical and horizontal jump performance. The Journal of Strength & Conditioning Research, 18(2), 201-205.
Ramírez-Campillo, R., Meylan, C., Álvarez, C., Henríquez-Olguín, C., Martínez, C., Cañas-Jamett, R., …&Izquierdo, M. (2014). Effects of in-season low-volume high-intensity plyometric training on explosive actions and endurance of young soccer players. The Journal of Strength & Conditioning Research, 28(5), 1335-1342.
Ronnestad, B. R., Kvamme, N. H., Sunde, A., &Raastad, T. (2008). Short-term effects of strength and plyometric training on sprint and jump performance in professional soccer players. The Journal of Strength & Conditioning Research, 22(3), 773-780.
Turner, A. P., Bellhouse, S., Kilduff, L. P., & Russell, M. (2015). Postactivation potentiation of sprint acceleration performance using plyometric exercise. The Journal of Strength & Conditioning Research, 29(2), 343-350.
Toumi, H., Best, T. M., Martin, A., F’guyer, S., &Poumarat, G. (2004). Effects of eccentric phase velocity of plyometric training on the vertical jump.International journal of sports medicine, 25(5), 391-398.
Váczi, M., Tollár, J., Meszler, B., Juhász, I., &Karsai, I. (2013). Short-term high-intensity plyometric training program improves strength, power, and agility in male soccer players. Journal of human kinetics, 36(1), 17-26.
Vossen, J. F., Kramer, J. E., Burke, D. G., &Vossen, D. P. (2000). Comparison of Dynamic Push-Up Training and Plyometric Push-Up Training on Upper-Body Power and Strength. The Journal of Strength & Conditioning Research, 14(3), 248-253.