Soccer-Speed Agility Accel

8/2/2019 Soccer-Speed Agility Accel

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Three-Month Pre-Season Training Program to Improve Speed, Acceleration, Agility, andVertical Jump in Intercollegiate-Level Soccer Forwards

University of Texas at AustinConditioning for Competitive Athletes

7/10/01


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Soccer is a sport characterized by nearly constant movement for approximatelyninety minutes. The total distance covered is about 10 kilometers (Tumilty, 1993). Themovements involved in a soccer match include walking.jogging, striding, sprinting,moving laterally, backpedaling, jumping, and kicking. All field players (forwards,midfielders, and fullbacks) perform these actions. While the aerobic component ofsoccer (walking and jogging) comprises the majority of the total activity, the anaerobicactions (sprinting, moving laterally quickly, and jumping) are the activities that are mostvital to a good performance. Ithas been found that the differences between players fromhigh-level teams versus lower-level teams are greater for leg strength and powermeasures than for aerobic fitness measures (Wisloff; Helgerud, and Hoff, 1997, Davis,Brewer, and Atkin, 1992). This is especially true for the position of forward. It has beenfound that forwards tend to cover a greater percentage of their total game-distance whilesprinting (Tumilty, 1993, Bangsbo, Norregaard, and Thorso, 1991). A forward's primaryobjective is to score goals. In order to do this, a forward must be able to first get intoposition to score, and then be able to put the ball in the net. Speed, agility, and jumpingability all playa role in this. While skill in controlling the ball while trapping anddribbling are of extreme importance, explosiveness is what tends to separate greatforwards from good forwards. Possessing the ability to out-accelerate, out run, and out-jump a defender will allow a forward to maximize the number of opportunities he has toscore goals (Davis, Brewer, and Atkin, 1992). At many levels of soccer, from topEuropean professional1eagues to intercollegiate soccer in the United States, a great manygoals are scored when a winger crosses the ball to the center of the goal box from the


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flank (area near the sideline) and a forward heads the ball in. This is where the jumpingability plays a large role in a forward's success. Research has shown that forwards tendto have greater vertical jumping ability than midfielders (Reilly and Thomas, 1977, AI-Hazzaa, Almuzaini, AI-Refaee, Sulaiman, Dafterdar, Al-Ghamedi, and Al-Khuraiji,2001). Additionally, agility is important to allow a forward to get into position toreceive a ball, take a shot, or take a header. Forwards often make many quick cuts, withand without the ball for these very reasons. An agile forward is much more likely tocreate or move into an open (and thus advantageous) space than one who lacks suchagility. It is clear that speed and acceleration, agility, and jumping ability, are verybeneficial attributes for all soccer players, but especially forwards, to possess.

A major problem with soccer training programs is the partial negligence ofstrength and power development in the pre-season. This is due primarily to the focus onskill acquisition/practice and tactical practice (Tumilty, 1993). Often times the majorityof physical conditioning is of an aerobic nature, not an explosive one. Due to the criticalimportance of speed, agility, and vertical jumping ability to a forward's success, atraining program needs to be developed specifically to address these areas.

To design a program to improve some component of perfo nnance , one must firstunderstand the nature of that component and how it relates to the specific sport ofinterest. The components focused on here are running speed and acceleration, agility,and vertical jumping ability. While there is some definite crossover in the developmentof these attributes, they should each be addressed individually for maximal results.

Running speed in soccer is generally looked at over fairly short distances.Throughout the course of a soccer match, a forward will make many short sprints in an


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attempt to get into scoring position. These runs are usually in the range of 10-40 yards.Therefore it is important for a forward to be able to attain maximal velocity in a veryshort time. However, it is not necessary for such a player to maintain this maximal speedfor very long. There are times when a forward will make a sprint of 50-65 yards, but theyare rare. This type of sprint is still shorter than any track race, however. Thus, for thepurposes of this paper, speed will be defined as the running velocity over distances from15-40 yards.

Agility is defined as a person's ability to maintain proper body position andcontrol while quickly and smoothly changing direction of movement (Roozen, 1995).Forwards are constantly changing the direction of their movement, with and without theball. This type of movement utilizes an eccentric-concentric action of the musclesinvolved (Tumilty, 1993).

Vertical jumping ability is the same in soccer as in most sports. The nature ofvertical jumping in soccer is such that the forward generally has time to prepare for a

jump by performing a counter-movement. This is due to the time it takes for a crossed-ball to travel from the flank to the center of the field. Vertical jumping is probably themost overlooked aspect of soccer training. It has been noted that soccer players havelower vertical jumps than athletes from other sports (Gretchell, 1979). In light of this,special attention should be given to vertical jump development as it pertains to aforward's success.

Given the necessity of a soccer forward to possess speed, agility, andjumping ability, a pre-season workout must be designed to address those specific needs.A three-month pre-season training program would fit well into a college player's


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schedule. During the summer months leading up to the fall intercollegiate season, theplayer can work more on physical training of this nature than during the season due totime restraints imposed by skill practice, tactical practice, and games. These summermonths should also include aerobic and skill training to fully prepare the athlete for theupcoming season. The workout plan provided here will take into consideration that timewill be needed for these other aspects of performance as well, but it will not addressthem.

At the beginning of the training program, it is assumed that the participants havebeen exposed to fairly high levels of physical activity/stress via their previous collegiateseason, or their senior high school season. Additionally, some previous weight-trainingexperience is assumed. If this assumption were incorrect, then the athletes would have tostart out more slowly at lower weights/intensities to learn proper technique safely and tobuild up some initial strength. Ideally, this conditioning program should be preceded bysome general weight training (squats, dead-lifts, bench press, etc ... ) during the springsemester to prepare the athletes for the rigors of the upcoming training, particularly theplyometric training. Therefore this program has not been designed for an inexperiencedindividual. The progression included here would most likely be too much for someonewho is completely untrained.

All training sessions should be preceded and followed by a light jog of maybe 3-5minutes and 15-20 minutes of stretching the major muscle groups of the legs (hamstrings,quadriceps, hip adductors (groin), and calves). Additional stretching of the abdominalmuscles, shoulders, back and arms should be included as well. The conditioningexercises will be described below in detail and the specific scheduling of the workouts


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will be given in a table at the end of this paper. It should be noted that exercises aimed atimproving overall speed and exercises designed to improve acceleration are both listedunder "speed training exercises." Also, while not listed, a general upper body strengthprogram would be beneficial to the athletes' overall strength and performance. Thistraining program is designed to allow each day's activities to be completed in less than anhour and a half. This is to allow time for aerobic training, skill training, and to allow theprogram to be scheduled around jobs and other summertime activities in which theathletes might partake.

Speed Training ExercisesRun Form

In soccer, forwards generally only makes runs of 15-40 yards in length. Manyforwards are allowed to "get away with" poor running form over such short distances.However, they would be much more successful if they used better form all the time. Thebiggest problems that soccer players have are not using their arms properly and not takinglong enough strides (Alejo, 1996). The first drill to ensure proper running form involvesthe players running 4-6 60 yard jogs while focusing on striding out a little bit longer thanusual and swinging their arms properly. This is low intensity and will also serve as anadditional warm-up. This should be done following the prescribed warm-up at eachworkout session for the first two weeks.Knees and Butts

Another extended warm-up activity has the athletes do high-knees and butt-kickers, each one 25 yards down and 25 yards back. Not only will this help with the


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stretching out of the muscles to be used for sprinting, but also it will help to strengthenboth the hip flexors and extensors though a greater range of motion than they wouldexperience from normal running. This exercise can be performed after warm-ups beforeany workout during running or plyometric training for the entire duration of the program.Ladder

To improve the rate of leg turnover, the athletes will run though a "ladder" on theground. The ladder should be set-up using ropes such that the course is 10 yards longwith a "rung" or segment divider every two feel. The athlete must run though the"ladder" as quickly as possible while still stepping in each segment. Each athlete shouldcomplete 6-8 runs though the ladder (based on the week of training), with adequate timebetween runs to ensure that they are not fatigued. This will encourage "quick feet" to geta step down in each segment. The idea behind this exercise is to train the entireneuromuscular unit to contract and coordinate the muscles at very high speeds. This willnot only help improve a player's short-distance speed, it will help with game-actionrelated skills as well.Wind Sprints

To learn to run faster, the players have to do just that, run fast This exercise hasthe players sprint various distances at maximal effort. This distance should be variedbetween 30 and 75 yards from workout to workout. It is important that the playersmaintain proper form as it was practiced in the run form exercise. A workout sessionshould include 6-8 repetitions of this exercise. It is very important that the athletesreceive enough rest between sprints so that they are not completely fatigued during thesprints as this is a speed workout, not a lactate tolerance or aerobic workout (Alejo,


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1996). Further support for performing wind sprints can be found in the research ofDelecluse, Van Coppenolle, Willems, Van Leemputee, Diels, and Goris, (1995). Theyfound that following a nine-week treatment period, a group of participants that only didsprints once a week showed very similar increases in maximal sprinting speed as thegroups that did heavy resistance training and plyometric training in addition to sprintsonce a week. They attributed this similarity to the specificity of the velocity of trainingof the muscles used in sprinting.Accelerations

To perform this exercise a 100-yard long area must be marked and divided into25-yard segments by using highly visible cones. The athletes will jog the first segment,then run the second segment (about 75% maximal effort), stride the third segment, andthen all-out sprint the last segment. This will somewhat mimic the types of speedtransitions that the players will make in game situations and will give them someadditional speed training (Alejo, 1996). A session should include 4-8 of these runs.Chute Runs

Chute runs are maximal sprints done while harnessed to a fairly large running-parachute. This is a type of resisted running training. The larger-type resistance chutesare used to create a large amount of drag resistance, which will help to improveacceleration (Delecluse, 1997). As these runs are aimed at improving acceleration, theydo not need to be very long. A good distance for this type of training is 25-40 yards. Sixto eight of these chute runs should be completed during a workout. In addition toproviding excellent performance benefits, this type of training can add an element of funand variety to the training program.


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BoundingThis is the first type of plyometric workout incorporated into this training

program. It consists of the athletes leaping as far as possible, landing on the oppositefoot, and then leaping again without pausing. The athletes must be sure to leap as far aspossible each time. This exercise should be done over a distance of 40-60 yards per run,with 3-5 runs per workout. This is a type of eccentric-concentric contraction exerciseaimed at improving acceleration. The Delecluse, et al. (1995) study found that whilemaximum running speed was not improved via plyometric training, the initialacceleration phase of a sprint was improved. The sprint distance that was used in thisstudy was 100 meters. Most of the runs a forward will complete are less than half thatdistance. The distance of the soccer runs coincides with the acceleration phase of the1O~-meter sprint, which was improved by the plyometric training. Therefore it stands toreason that this type of training would greatly benefit a forward's acceleration and speedover 15-40 yard distances.

Agility Training ExercisesStep Hurdles

The set-up for this exercise includes placing small hurdles about 2 feet apart suchthat they create four segments between them. The athlete must start on the outside of oneof the end segments and move from one end of the hurdles to the other and then backagain (=one repetition). This must be done one leg at a time (not hopping) and as quicklyas possible. The athletes should complete three sets of five continuous repetitions of this


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exercise. This exercise helps to improve foot quickness laterally as well as overallagility.Hurdle Hops

The set-up for this exercise is the same as the step hurdles above. The onlydifference is that the athletes hop through the segments, with both legs together at alltimes and no pauses during a repetition. This is a more explosive action that has somecrossover benefit to vertical jumping development as well.Staggered Run

This exercise will help to improve the athletes' agility while running both forwardand backward. To set up this exercise a single cone must be place as the starting point.Then a second cone should be placed about 5 yards away at a 45-degree angle from thefirst cone (with respect to the "starting line"). The next cone should be placed 5 yardsaway from the second cone such that the three cones make a triangle. Add three morecones to the set-up such that a line from cone to cone would look like this (turn the pagecounterclockwise) W\. The athlete would move forward through this as fast as possibleby staying to the outside of each cone. After reaching the final cone, said athlete wouldretrace his steps while backpedaling. This constitutes one repetition. Each athlete shouldperform 4-7 repetitions. Two such grids could be set-up and this drill could be done in arelay-race format to encourage the players to move as quickly as possible and to havemore fun.

All of the above agility exercises serve to improve the neuromuscular system byforcing it to produce a large amount of force very quickly (i.e. high power).


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Additionally, these exercises help to make the athletes' ankles more flexible and strongerwhen faced with lateral stress.

Vertical Jump Training ExercisesCleans

This exercise incorporates weight training into the conditioning program. Thenumbers of sets and repetitions are listed in a table at the end of this paper. The ballisticmovements of this lift help to improve the power in the quadriceps and somewhat in thehamstrings, which can translate into improved vertical jump performance. This Olympic-style lift is very explosive in nature and is a movement similar to a vertical jump. It isimportant that the athletes take moderately long breaks of a minimum of two minutesbetween sets (Fleck and Kraemer, 1997).Box Jumps

This exercise involves the athletes jumping from a box that is two feet high andthen, upon landing, jumping up immediately as high as possible. This will help developthe athletes' coordination of the stretch-shorten cycle (Newton, Kraemer, and Hakkinen,1999). Research has both supported and rejected the use of box jumps to improvevertical jumping ability, thus is important to carefully track the athletes during the courseof this aspect of the training program (Young, Wilson, and Byrne, 1999).Jump Squats

These are ballistic squats that require special equipment to perform. They areperformed at a much higher velocity that regular squats. Research by Newton et al.(1999) found that an eight-week training program utilizing jump squats in addition to leg


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extension and flexion exercises produced much greater gains in vertical jumpperformance in strength-trained individuals than did training with slower-velocitystandard squats (with leg extension and flexion exercises as well). This applies to thisparticular training program, as the athletes should already have a solid base of strengthtraining. The amount of weight used for this exercise is given as a percentage of the pre-program 1RM for a traditional squat. The 1 RM for a traditional squat should be re-measured at the end of week 8 to ensure the athletes are lifting the correct weights.

Universal Leg Strength TrainingThis includes leg extension and leg flexion exercises (resistance exercises) aimed

at providing general leg strength and hypertrophy. These types oflifts have a very broadinfluence on all of the above parameters (speed, acceleration, agility and vertical jump).Also, this exercise will help to prevent injuries by maintaining overall leg strength.These exercises are to be done with both legs at the same time. The sets listed in theprogram should be completed for both lifts, leg extension and leg flexion (i.e. 8 total setsbetween the two ofthem).


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Exercises*before beginning program, see notes below

1 Day 1 Run form =4 runs Knees and Butts= 1each @ 50-yards eachleg extension and flexion 4 sets @ 10 RM Accelerations= 4 runs

Day 3 Run form= 4 runs Knees and Butts= 1 each @ SO-yards eachAccelerations= 4 runs leg extensions and flexion 4 sets @ 10 RM

DayS Run form= 4 runs Knees and Butts= 1each @ SO-yards eachStep Hurdles= 3 sets, 5 reps/set Wind Sprints= 5 @ 35 yards each

Day? Run form= 4 runs Ladder= six runsStep Hurdles= 3 sets 5 reps/set Leg extension and flexion 4 sets @ 8 RM

2 Day 2 Run form= 5 runs Hurdle Hops= 3 sets 3 reps/setBounding= 3 runs @40-yardseach leg extension and flexion 4 sets @ 8RM

Day 4 Run form= 5 runs ladder= six runsStaggered Run= 4 reps leg extension and flexion 4 sets @ 8RM

Day 6 Run form= 5 runs Bounding= 3 runs @ 40-yards eachChute Runs= 6 @ 30 yards each Wind Sprints= 5 @ 40 yards each

3 Day 1 Cleans= 4 sets 6 sets/rep @ 8 RM Accelerations= 5 runsLadder= 6 runs

Day 3 Jump Squats= 2 sets @ 60%, 1 @ 80% leg extension and flexion 4 sets @ 8 RMKnees and Butts= 1 each at 50 yards

DayS Cleans= 4 sets 6 reps/set @ 8 RM Box jumps= 2 sets 10 jumps/setDay? Jump Squats= 2 sets @ 60%, 2 @ 80% Hurdle Hops= 3 sets 4 reps/set

Knees and Butts= 1 each @ 50 yards each

4 Day2 Cleans= 3 sets 4 reps/set @ 5 RM leg extension and flexion 3 sets @ 6 RMKnees and Butts= 1 each @ 50-yards each ladder= 6 runs

Day4 Jump Squats= 2 sets @ 60%, 2 @ 80% Step Hurdles= 3 sets 5 reps/setHurdle Hops= 3 sets/ 4 reps a set

Day6 Cleans= 3 sets 4 reps/set @ 5 RM leg extension and flexion 3 sets @ 6 RM

5 Day 1 Jump Squats= 2 sets @ 60%, 2 @ 80% Cleans= 3 sets 4 reps/set @ 5 RMKnees and Butts= 1 each @ 50 yards each Accelerations= 6 runs

Day 3 Jump Squats= 2 sets @ 60%, 2 @ 80% Cleans= 3 sets 4 reps/set @ 5 RMKnees and Butts= 1 each @ 50 yards each

DayS Cleans= 3 sets 4 reps/set @ 5 RM Leg extension and flexion 3 sets @ 6 RMBox Jumps= 2 sets 12 jumps/set

Day? Jump Squats= 2 sets @ 60%, 2 @ 80% Knees and Butts= 1 each @ 50 yards each


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6 Day 2 Jump Squats= 2 sets @ 60%, 2 @ 80% Cleans= 3 sets 4 reps/set @ 5 RMLeg extension and flexion 3 sets @ 6 RM Hurdle Hops= 3 sets/5 reps a set

Day4 Bounding= 4 runs @ 40 yards each Chute Runs= 7 @ 30 yards eachWind Sprints= 7 @ 40 yards each

Day6 Knees and Butts= 1 each @ 50 yards each Ladder= 7 runsWind Sprints= 7 @ 40 yards each Bounding= 4 runs @40 yards each

7 Day 1 Jump Squats= 2 sets @60%, 2 @ 80% Cleans= 3 sets 4 reps/set @ 5 RMLeg extension and flexion 3 sets @ 6 RM Ladder= 7 runs

Day 3 Staggered Run= 5 reps Step Hurdles= 3 sets 6 reps/setHurdle Hops= 3 sets 6 reps/set

Day 5 Jump Squats= 2 sets @ 60%, 2 @ 80% Cleans= 3 sets 4 reps/set @ 5 RMLeg extension and flexion 3 sets@ 6 RM Box Jumps= 2 sets 12 jumps/set

Day 7 Knees and Butts= 1 each @ 50 yards each Ladder= 8 runsWind Sprints= 4 @ 50 yards each Wind Sprints= 4 @ 75 yards each

8 Day2 Jump Squats= 2 sets @ 60%, 2 @ 80% Cleans= 3 sets 4 reps/set @ 5 RMHurdle Hops= 4 sets 5 reps/set Step Hurdles= 4 sets 5 reps/set

Day 4 Knees and Butts= 1 each @ 50 yards each Bounding= 5 runs @ 50 yards eachWind Sprints= 8 @ 50 yards each

Day 6 Jump Squats= 2 sets @ 60%, 2 @ 80% Cleans= 3 sets 4 reps/set @ 5 RMLeg extension and flexion 3 sets @ 5 RM

9 Day 1 Jump Squats= 3 sets @ 60%, 2 @ 80%, 1 @ 90%' Cleans= 3 sets 4 reps/set @ 5 RMLeg extension and flexion 3 sets @ 5 RM Knees and Butts= 1 each @ 50 yards each

Day 3 Chute Runs= 8 @ 35 yards each Bounding= 5 runs @ 50 yards eachLadder= 9 runs Wind Sprints= 6 @ 40 yards each

DayS Jump Squats= 2 sets @ 60%, 2 @ 80%, 1 @ 90% Cleans= 3 sets 4 reps/set @ 5 RMLeg extension and flexion 3 sets @ 5 RM Box Jumps= 2 sets 12 jumps/set

Day7 Step Hurdles= 5 sets 5 reps/set Hurdle Hops= 4 sets S reps/setStaggered Run= 7 reps

10 Oay2 Knees and Butts= 1 each @ 50 yards each Ladder= 10 runsWind Sprints= 5 @ 50 yards each Wind Sprints=3 @ 75 yards

Day 4 Staggered Run= 8 reps Hurdle Hops= 4 sets 5 reps/setBox Jumps= 2 sets 14 jumps/set

Day 6 Jump Squats= 2 sets @ 60%, 2 @ 80%, 1 @ 90% Cleans= 3 sets 4 reps/set @ 5 RMLeg extension and flexion 3 sets @ 5 RM


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11 Day 1 Knees and Butts= 1 each @ 50 yards each Bounding= 5 runs @ 60 yards eachAccelerations= 8 runs

Day 3 Jump Squats= 2 sets @ 60%, 2 @ 80%, 1 @ 90% Cleans= 3 sets 4 reps/set @ 5 RMLeg extension and flexion 3 sets @ 5 RM

DayS Box Jumps= 2 sets 15 jumps/set Hurdle Hops= 4 sets 5 reps/setStaggered Run= 8 reps

Day 7 Jump Squats= 2 sets @60%, 2 @80%, 1@ 90% Cleans= 3 sets 4 reps/set @ 5 RMLeg extension and flexion 3 sets @ 4 RM

12 Day 2 Step Hurdles= 5 set 5 reps/set Hurdle Hops= 4 sets 5 reps/setStaggered Run= 8 reps

Day4 Jump Squats= 2 sets @ 60%, 2 @ 80%, 1@ 90% Cleans= 3 sets 4 reps/set @ 5 RMLeg extension and flexion 3 sets @ 4 RM

Day6 Knees and Butts= 1 each @ 50 yards each Accelerations= 8 runsWind Sprints= 8 @ 50 yards each

* note-all daily workouts should be completed in orderas listed from left to right and top to bottomnote- all leg extension and flexion sets include thesame number of reps as the RM while jump squatsets for weeks 3-7 include 6 reps, and the jumpsquat sets for weeks 8-12 include 5 reps


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References

Al-Hazzaa, H M., Almuzaini, K S., Al-Refaee, S.A, Sulaiman, M.A,Dafterdar, M. Y, Al-Ghamedi, A, &Al-Khuraiji, K N. (2001) Aerobic and anaerobicpower characteristics of Saudi elite soccer players. Journal of Sports Medicine andPhysical Fitness. 41. 54-61.

Alejo, B. Basic overview of speed training. In Coaching Soccer. 1996. MastersPress, Chicago, Illinois.

Bangsbo, J., Norregaard, 1.,& Thorso, F. (1991). Activity profile of competitionsoccer. Canadian Journal of Sports Sciences 16(2), 110116.

Chin, M. K, So, R C. H., Yuan, Y W. Y,u,R C. T., Wong, AS. K (1994).Cardiorespiratory fitness and isokinetic muscle strength of elite Asian junior soccerplayers. The Journal of Sports Medicine and Physical Fitness, 34, 250-257.

Davis, J. A, Brewer, J., & Atkin, D. (1992). Pre-season physiologicalcharacteristics of English first and second division soccer players. Journal of SportsSciences. 10,541-547.

Delecluse, C. (1997). Influence of strength training on sprint runningperformance. Sports Medicine, 24(3), 147-156.

Delecluse, D., Van Coppenolle, H, Willems, E., Van Leemputte, M., Diels, R, &Goris, M. (1995). Influence of high-resistance and high-velocity training on sprintperformance. Medicine and Science in Sports and Exercise, 27(8), 1203-1209.

Fleck, S. J. & Kraemer, W. J. Designing Resistance Training Programs. 1997.Human Kinetics, Champaign, Illinois.


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Gretchell, B., Physical Fitness: A Way of Life. 1979. John Wiley & Sons, NewYork, New York.

Newton, R. u., Kraemer, W. J,&Hakkinen, K (1999). Effects of ballistictraining on preseason preparation of elite volleyball players. Medicine and Science inSports and Exercise. 31(2), 323-330.

Reilly, T., &Thomas, V. (1977). Effects of a programme of pre-season trainingon the fitness of soccer players. Journal of Sports Medicine, 17,401-412.

Roozen, M. (1995) Setting up a month-long summer running, agility, and weightcamp. Strength and Conditioning Journal, 17(3),57-61.

Tumilty, D. (1993). Physiological characteristics of elite soccer players. SportsMedicine, 16(2), 80~96.

Wisloff, u., Helgerud, J., &Hoff, J. (1998). Strength and endurance of elitesoccer players. Medicine and Science in Sports and Exercise, 30(3), 462-467.

Worcik, M .. Power development through plyometric exercise. In CoachingSoccer. 1996. Masters Press. Chicago, Illinois.

Yap, C., Brown, L., &Woodman, G. (2000). Development of speed, agility, andquickness for the female soccer athlete. Strength and Conditioning Journal. 22(1), 9~12.

Young, W. B., Wilson, G. L, &Byrne, C. (1999). A comparison of drop jump.training methods: effects on leg extensor strength qualities and jumping performance.International Journal of Sports Medicine, 20, 295~303.

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Soccer-Speed Agility Accel