The Effect of Static Stretching on Phases Of

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THE EFFECT OF STATIC STRETCHING ON PHASES OFSPRINT PERFORMANCE IN ELITE SOCCER PLAYERS

ADAM L. SAYERS, RICHARD S. FARLEY, DANA K. FULLER, COLBY B. JUBENVILLE,AND JENNIFER L. CAPUTO

Middle Tennessee State University, Murfreesboro, Tennessee

ABSTRACT

Sayers, AL, Farley, RS, Fuller, DK, Jubenville, CB, and Caputo, JL.

The effect of static stretching on phases of sprint performance in

elite soccer players. J Strength Cond Res 22(5): 14161421,

2008The purpose of this study was to determine which phase of

a 30-m sprint (acceleration and/or maximal velocity) was affected

by preperformance static stretching. Data were collected from

20 elite female soccer players. On two nonconsecutive days,

participants were randomly assigned to either the stretch or no-

stretch condition. On the first day, the athletes in the no-stretch

condition completed a standard warm-up protocol and then

performed three 30-m sprints, with a 2-minute rest between each

sprint. The athletes in the stretch condition performed the stan-

dard warm-up protocol, completed a stretching routine of the

hamstrings, quadriceps, and calf muscles, and then immediately

performed three 30-m sprints, also with a 2-minute rest between

each sprint. On the second day, the groups were reversed, and

identical procedures were followed. One-way repeated-measures

analyses of variance revealed a statistically significant difference

in acceleration (p , 0.0167), maximal-velocity sprint time (p ,

0.0167), and overall sprint time (p, 0.0167) between the stretch

and no-stretch conditions. Static stretching before sprinting

resulted in slower times in all three performance variables. These

findings provide evidence that static stretching exerts a negative

effect on sprint performance and should not be included as part

of the preparation routine for physical activity that requires sprinting.

KEY WORDS static stretching, sprint performance, acceleration,

maximal velocity

INTRODUCTION

Static stretching is alleged to have several benefitsincluding injury prevention and enhancement of

athletic performance (10,20). However, severalrecent studies have questioned these widely held

beliefs, producing results that not only contradict the

perceived advantages of static stretching but also indicate

that stretching can have a detrimental effect on athletic or

muscle performance.The effect of static stretching on various aspects of

performance, such as maximal strength and explosive force

production, has been investigated (2,3,5,6,8,9,2226). How-

ever, the relationship between preactivity static stretchingand sprint performance has been sparsely explored. Static

stretching has been found to negatively impact 20-m sprint

performance in collegiate track athletes (15). Sprint perfor-

mance was inhibited after static stretching, and stretching the

muscles in one leg had the same negative effect as stretching

the muscles in both legs, suggesting a central nervous system

(CNS) mechanism. The investigators also conjectured that

reduced stiffness of the musculotendinous unit contributed

to the decrease in performance (15). A similar relationship

between static stretching and sprint performance has been

observed in male rugby union players (7). While also pos-

tulating that the detriment in performance could be attrib-

uted to reduced stiffness of the musculotendinous unit, theinvestigators noted that static stretching changes tendon

structure, increasing the compliance of the tendon and,

therefore, reducing force production and delaying muscle

activation.The effect of static stretching on high-speed motor

capacities (including acceleration and maximal velocity) in

professional soccer players has also been investigated (14).

Contrary to previous findings, static stretching was found to

have no effect on sprint performance. However, in this study,

acceleration and maximal velocity were measured not in one

continuous sprint but as two separate components.

Although the aforementioned studies address the effect of

static stretching on overall sprint performance, there is noexisting research on the effect of static stretching on the

different phases of a continuous sprint. The acceleration

phase of a sprint can be measured for a distance of 10 m from

a stationary start, and maximum velocity can be recorded for

a distance of 20 m from a flying start (13). Therefore, a 30-m

sprint can be divided into two phases: the acceleration phase

(010 m) and the maximal-velocity phase (1030 m).The potential impact of static stretching on sprinting is

important to soccer players because sprint running comprises

Address correspondence to Adam L. Sayers, [email protected].

22(5)/14161421

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a relatively large portion of a players activity pattern duringa game. In the game of soccer, sprint bouts occur approxi-

mately every 90 seconds, with sprinting constituting up to11% of total distance covered (20). Additionally, 96% ofsprints during a soccer game are for distances of 30 m or less.

No previous studies have been performed on the effects of

static stretching for a 30-m distance. Given the paucity ofdata on stretching and athletic performance in soccer players,and the importance of sprinting to the game of soccer,

research on this topic is warranted.Therefore, the purpose of the study was to determine

which phase of a 30-m sprint is impacted by preperformance

static stretching in elite female soccer players. It washypothesized that static stretching before a 30-m sprint

would result in an increase in overall sprint time comparedwith the no-stretch condition. Additionally, it was hypoth-esized that static stretching before a 30-m sprint would result

in an increase in the time spent in the acceleration phase andthe maximal-velocity phase of the sprint compared with the

no-stretch condition.

METHODS

Approach to the Problem

Twenty subjects were randomly assigned to either a stretchor no-stretch condition. For the no-stretch condition, eachparticipant completed a standard warm-up protocol and then

performed three 30-m sprints. The first sprint time was notrecorded, and the best time of the next two sprints was usedfor analysis. When in the stretch condition, each participant

completed the standard warm-up protocol before undertak-

ing the stretching intervention and then performing three30-m sprints. The 30-m sprint was analyzed in two phases.Acceleration was measured for the first 10 m, and maximal

velocity was measured for the final 20 m.

Subjects

Participants included elite female soccer players (N = 20)from a professional female team that participates in theWomens Professional Soccer League, ranging in age from18 to 29 years. The subjects were asked to complete

a questionnaire detailing playing history and experience.Participation was voluntary. Players with any form ofphysical injury at the time of data collection were excluded

from the study. Injuries were identified through a self-reportingprocess. Approval was granted from the university institutional

review board, and the staff of the soccer team also approvedplayer participation in this study. Testing occurred during thethird week of a 12-week season. During the season, the

subjects practiced three times per week and played one game,with no additional weight training being undertaken. Each day

of testing occurred after a rest day. The subjects were asked torefrain from caffeine intake on each testing day and to avoid

food consumption in the 2 hours before testing.

Stretching Protocol

A common limitation among studies investigating the effects

of static stretching on various dependent performancevariables is the lack of quantification of the stretchingintervention. The vast majority of previous work describes

the participant stretching or being stretched to the onset of

discomfort or pain. In the present study, an attempt toquantify this intervention was incorporated by finding each

participants maximum stretch capacity of two out of thethree muscles being stretched. Each participant then per-

formed the stretches in the protocol to 85% of her individualmaximum capacity.

Maximal hamstring flexibility was measured using the

backsaver sit-and-reachassessment with an Acuflex 1 modifiedflexibility sit-and-reach test box. One leg was measured at

a time. Participants sat with shoes removed and one legextended, with the foot against the box. The leg not being

measured was bent at the knee, with the sole of the foot flat onthe ground. Participants then reached along the measuring line

as far as possible with the hands on top of each other, palmsdown, and extended leg held flat. The farthest point of threeattempts represented maximal hamstring stretch. The pro-cedure was then repeated with the other leg.

Calf flexibility was measured using an adjustable tilt board.Participants were asked to stand with their back against

a wall, remove their shoes, and place one foot on the tiltboard, with the heel still touching the ground. The otherleg was bent at the knee, with the sole of the foot flat on the

wall. The angle of the tilt board was increased until the heelleft the ground. At this point, the angle of the tilt board was

measured with a protractor. The specific angle representedmaximal calf flexibility. The procedure was then repeated

with the other leg.The third and final stretch involved the quadriceps and hip

flexors and was adapted from Alters no. 92 stretch (1). Theparticipants began in a supine position. They flexed the kneeof one leg and brought the heel back toward the buttocks.

They then grasped the ankle with the hand and pulled the heeltoward the buttocks. The stretch was increased throughoutthe range of motion until the participant acknowledged the

onset of discomfort.

Sprint Measurement

Each participant was required to complete three 30-m sprintsfrom a standing start. Sprints were timed using a Speedtrap

2 automated timing device (Brower Timing Systems, Utah),using a pressure pad and two electronic timing gates. The

pressure pad was placed at the start line, with the participantplacing the lead foot on the pad. When the participant beganthe sprint, the foot released the pressure on the pad and the

timer started. The electronic timing gates were set at 2 m highand 1 m apart and were placed at 10 and 30 m from the start

line. The timing gate at 10 m recorded the time for theacceleration phase of the sprint (010 m). The timing gate at

30 m stopped the timer and recorded the total time taken to

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sprint 30 m. Time spent in the maximal-velocity phase wascalculated by subtracting the acceleration time from theoverall time.

Procedures

Data collection was completed on three nonconsecutive days.

On the first day, the participants completed the informedconsent form in addition to the playing-history questionnaire.Baseline data were collected on this day, along with maximal

stretch capacity of the hamstrings and calf muscles. On thesecond day,the participants wererandomly assigned to one of

the two conditions: stretch or no-stretch. All testing tookplace on an indoor, artificial playing surface, with theparticipants wearing their preferred indoor soccer shoes,

because this type of shoe is similar to soccer cleats worn onnatural playing surfaces. The participants performed thefollowing light mobility exercises before stretching or

sprinting as used by Nelson et al. (15): jog 800 m, forwardskips 4 3 30 m, side shuffles 4 3 30 m, and backward skips

43

30 m. The no-stretch condition group then performedthree 30-m sprints. The first sprint was not timed, becausethis was used as a familiarization exercise. The next two

sprints were timed, with a rest period of 2 minutes betweeneach sprint, as used by Fletcher and Jones (7). The best

overall time of the two sprints was used for analysis. Figure 1depicts the timeline for the procedures followed by the no-

stretch condition group.After completing the warm-up protocol, the stretch

condition group performed the stretching intervention under

the supervision of qualified strength and conditioning coaches.The stretching intervention consisted of statically stretch-

ing the hamstrings, calf muscles, and quadriceps. With regard

to the hamstring and calf stretches, the participants stretchedto 85% of their maximal capacity for each leg and held the

position for 30 seconds. The quadriceps stretch was increasedthroughout the range of motion until the participantacknowledged the onset of discomfort similar to that felt

during normal stretching activities. The stretch was held for30 seconds, at which point the participant stretched the other

leg. The stretches were completed in a randomized order,with a 10- to 20-second rest between each stretch. Each

stretch was completed once, constituting one completestretch cycle. The cycle of stretches was completed three

times. Participants in this group then performed a trial run,followed by two timed sprints, with rest periods consistent

with the no-stretch condition group. Figure 2 depicts thetimeline for the procedures followed by the stretch conditiongroup. The final day of testing consisted of an identical pro-cedure, with participants performing the opposite condition to

eliminate any order-of-testing effect.

Statistical Analyses

Acceleration was measured for a distance of 10 m, with the

players beginning in a stationary position. Maximal velocitywasrecorded forthe last 20 m of the30-msprint.Reliabilityof

the overall sprint, acceleration, and maximal-velocity

measures was assessed using an interclass correlation co-efficient on the second and third sprint times recorded byeach participant when in the no-stretch condition. Means and

standard deviations of study variables were calculated. One-way repeated-measures analyses of variance were used to

compare acceleration times between the stretch and no-stretch conditions, maximal-velocity times between the

stretch and no-stretch conditions, and overall times betweenthe stretch and no-stretch conditions. An alpha level of p,0.0167 (i.e., 0.05/3) was used to maintain the total at 0.05 for

the three tests. See Howell (10) for a description of the

Bonferroni procedure.

RESULTS

Description of Participants

Descriptive statistics for the sample are presented in Table 1,along with means and standard deviations from each variable

in both conditions. The average length of playing experienceat the elite level was 3 years. Three participants were

excluded from the study because of injury. The interclass

Figure 1. Timeline for no-stretch condition.


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correlation coefficients for 30-m sprint time, acceleration, andmaximal velocity were 0.999, 0.993, and 0.991, respectively.

One-way repeated-measures analyses of variance were

used to analyze the difference in sprint performance betweenthe stretch and no-stretch conditions. The result of the Ftestfor the overall 30-m sprint time, using Wilks lambda, was

F(1,19) = 22.18, p, 0.0167. Statistical power for this analysiswas 0.99, and partial eta squared was 0.54. Static stretching

before the 30-m sprint resulted in an increase in overall sprinttime when compared with the no-stretch condition.

Static stretching before the 30-m sprint resulted in anincrease in the time spent in the acceleration phase of the

sprint compared with the no-stretch condition (F(1, 19) =6.65, p, 0.0167). Statistical power for this analysis was 0.69,and partial eta squared was 0.26. Likewise, static stretching

before the 30-m sprint resulted in an increase in the timespent in the maximal-velocity phase of the sprint compared

with the no-stretch condition (F(1, 19) = 16.42, p, 0.0167).Statistical power for this analysis was 0.97, and partial eta

squared was 0.46.

DISCUSSION

Static stretching before sprinting negatively affected perfor-mance. A bout of static stretching before performing a 30-msprint resulted in a significant increase in time to complete the

sprint among elite female soccer players, when comparedwith the time to sprint this distance without stretching. Thisfinding supports the work of Fletcher and Jones (7) and

Nelson et al. (15), who documented a similar detriment fora distance of 20 m in rugby players and track athletes,

respectively. A significant difference was found in theacceleration phase of the sprint between the stretch and

no-stretch condition. Static stretching had a negative affecton acceleration. Additionally, a significant difference wasfound in the maximal-velocity phase of the sprint, providing

Figure 2. Timeline for stretch condition.

TABLE 1. Descriptive statistics of study variables(N = 20).

Characteristic Mean SD

Age (y) 19.35 0.99Height (in) 64.43 2.82Weight (lb) 132.86 8.67Overall sprint time (s)

Stretch 4.91* 0.27No stretch 4.81 0.28

Acceleration (s)Stretch 1.93* 0.14No stretch 1.88 0.14

Maximal velocity (s)Stretch 2.99* 0.15No stretch 2.92 0.17

*p , 0.0167.



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evidence that static stretching before performance diminishesthe maximum speed of an elite female soccer player.

Mechanical (peripheral) and neurological (central) theories

have been postulated as potential mechanisms behind thedecrease in performance caused by static stretching. Fletcherand Jones (7) compared the detriment in running perfor-

mance after a bout of stretching with the performancedecreases in drop jump height found by Young and Elliott

(25). Sprinting requires a rapid transition from eccentric toconcentric muscle action, as does performing a drop jump,

albeit with the latter using a single stretch-shortening cycle,and the former using several in continuous fashion. Fletcher

and Jones (7) suggest that static stretching primarily affectsthe eccentric phase of the stretch-shortening cycle. Duringthis phase, the series elastic component (SEC) lengthens,

storing elastic energy to be reused in the concentric phase ofthe stretch-shortening cycle, when the SEC springs back to

its original configuration (17). However, after a bout of staticstretching, the SEC may already be lengthened, thereby

impeding the preactivation of the musculotendinous unit anddecreasing its ability to store and reuse as much elastic energyduring the stretch-shortening cycle.

Additionally, Shorten (19) reports that the amount of

elastic energy that can be stored in the musculotendinousunit is a function of stiffness. Therefore, because static

stretching reduces the stiffness of the musculotendinous unit,less elastic energy can be retained and used after a bout of

static stretching. This peripheral mechanism may havecontributed to the decrease in overall sprint performanceexperienced by participants in this study.

Neurologically, it has been suggested that stretching maycause a decrease in neural transmission from the CNS to the

muscle, a phenomenon known as neural inhibition (12,15,18).Specifically, stretching inhibits the myoelectric potentiationinitiated during the eccentric phase of the stretch-shortening

cycle, which is responsible for initiating muscle activationduring the concentric phase. Hence, a decrease in perfor-mance during the concentric phase of each stretch-shortening

cycle of the sprint would result. The results of the presentstudy support the notion that a mechanical mechanism,

a neurological mechanism, or a combination of both could beresponsible for the decrease in 30-m sprint performance.

Given the repetitive use of several muscles during sprinting,the potential effect of stretching on muscle strength endur-

ance cannot be ignored. Nelson et al. (16) found that static

stretching resulted in decreased muscle strength enduranceperformance. They postulate that the observed performance

decrement was a result of static stretching placing some ofthe available motor units in a fatigue-like state, therefore

depleting the amount of motor units available for recruitmentduring the performance activity. This led to the onset offatigue earlier in the activity and, therefore, to a decrease in

performance. This concept can be applied to sprinting, in thatoverall sprint time could be negatively affected by a stretch-ing-induced decrease in the number of motor units available

for recruitment, thereby hastening fatigue and reducingsprint performance. However, whether a 30-m sprint is longenough for this particular mechanism to be considered is

unknown.Static stretching had a negative effect on the acceleration

phase of the sprint and the maximal-velocity phase of the

sprint. There are mechanical differences between these sprintphases. During acceleration, maximum stride length has not

yet been reached. As such, in this phase of the sprint,the stretch-shortening cycle time is of shorter duration.

Maximum stride length only occurs when the runner hasreached peak speedthat is, during the maximal-velocity

phase. Additionally, ground-contact time is longer during theacceleration phase.

From a neurological standpoint, a decrease in neural drive

from the CNS to the muscle would occur throughout thecourse of the sprint, regardless of the speed at which the

sprinter is traveling. Theoretically, during the accelerationphase, the myoelectric potentiation, a stretch reflex that

increases muscle activation during the concentric phase,initiated during the eccentric phase of the stretch-shorteningcycle, may not be sufficient to produce a maximal responseduring the concentric phase. Similarly, during the maximal-

velocity phase, when both stride length and the stretch-shortening cycle duration are at their respective greatest, the

stretch-induced inhibition of neural transmission may alsoresult in an insufficient stretch reflex during the concentric

phase, therefore causing a decrease in performance.Mechanically, a muscle that has been statically stretched

has more slack than an unstretched muscle (4). During the

acceleration phase of a sprint, muscle contractions occur ata slower rate than during the maximal-velocity phase. There-

fore, there is more time for the force generated in the muscleto be transferred to the bone to cause joint movement.

However, even given the slower contraction rate, the forcegenerated by a stretched muscle still does not match that ofan unstretched muscle because of the excess slack. Becausemuscle contraction speed is at its greatest during the

maximal-velocity phase, the detriment in performancecaused by the excess slack in the muscle may hamper the

maximum contraction rate to a greater extent, resulting inslower maximum muscle contraction after an acute bout of

static stretching. In addition, the stretch-induced slack in themuscle may prevent maximal storage and reuse of elastic

energy during the stretch-shortening cycle in both phases of

the sprint. Research to identify which of these mechanisms(central or peripheral) is responsible for the deleterious effect

of stretching would offer further insight into this topic. It ispossible that a combination of both mechanisms could exist;

further research might be needed to identify the extent towhich each mechanism has an influence on performance.

PRACTICAL APPLICATIONS

Static stretching can reduce maximal running speed during

a 30-m sprint. It is important that coaches, athletes, physical


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educators, and other persons involved in either undertakingor administeringactivitiesduring which success can be depen-dent on maximal performance are aware of the potential

negative affects of static stretching before performance orcompetition. The largest difference in overall sprint perfor-mance between the stretch and no-stretch condition was 0.39

seconds, and the mean difference was 0.1 seconds. In a sprintthat takes 45 seconds to complete, this difference can be

critical. The stretching-induced detriment exhibited herecould mean beating an opponent to the ball to create a goal-

scoring opportunity, or recovering defensively to prevent anopportunity for the opposing team. In elite soccer, the ability

of each player to perform to his or her maximal potential isespecially important, because even the smallest detail canmean the difference between winning and losing. Given this,

gaining every possible advantage over ones opponent is vital.Additionally, at the elite level, accelerating and sprinting at

ones maximal velocity are considered to be two differentaspects of speed and, as such, are trained separately. It can

now be said that static stretching before training either ofthese aspects of speed negatively affects performance.

The results of this study, coupled with supporting researchin this area, suggest that static stretching should not be

included in a warm-up routine before participating in anyactivity that requires maximal sprinting. Previous investiga-

tors have suggested that a warm-up including dynamicexercises that replicate movements to be performed during

the activity are beneficial to performance, although furtherinvestigation is needed in this area (7).

REFERENCES

1. Alter, MJ. Science of Stretching. Champaign: Human Kinetics, 1988.2. Behm, DG, Button, DC, and Butt, JC. Factors affecting force

loss with prolonged stretching. Can J Appl Physiol 26: 261272,2001.

3. Bradley, PS, Olsen, PD, and Portas, MD. The effect of static, ballistic,and proprioceptive neuromuscular facilitation stretching on vertical

jump performance. J Strength Cond Res 21: 223226, 2007.

4. Cornwell, A, Nelson, AG, Heise, GD, and Sidaway, B. Acute effectsof passive muscle stretching on vertical jump performance. J Hum

Mov Stud 40: 307324, 2001.

5. Cramer, JT, Housh, TJ, Johnson, GO, Miller, JM, Coburn, JW, andBeck, TW. Acute effects of static stretching on peak torque inwomen. J Strength Cond Res 18: 236241, 2004.

6. Cramer, JT, Housh, TJ, Weir, JP, Johnson, GO, Coburn, JW, andBeck, TW. The acute effects of static stretching on peak torque,mean power output, electromyography, and mechanomyography.Euro J Appl Physiol93: 530539, 2005.

7. Fletcher, IM and Jones, B. The effect of different warm-up stretchprotocols on 20-meter sprint performance in trained rugby unionplayers. J Strength Cond Res 18: 885888, 2004.

8. Fowles, JR, Sale, D G, and MacDougall, JD. Reduced strength afterpassive stretch of the human plantarflexors. J Appl Physiol89:11791188, 2000.

9. Herbert, RD and Gabriel, M. Effects of stretching before and afterexercising on muscle soreness and risk of injury: systematic review.

BMJ 325: 468470, 2002.

10. Howell, D. Fundamental Statistics for the Behavioral SciencesBelmont,

CA: Brooks/ColeThompson Learning, 2004.11. Kokkenen, J, Nelson, AG, and Cornwell, A. Acute muscle stretching

inhibits maximal strength performance. Res Q Exerc Sports69:411415, 1998.

12. Kubo, K, Kanehisa, H, Kawakami, Y, and Fukunaga, T. Influenceof static stretching on viscoelastic properties of human tendonstructures in vivo. J Appl Physiol90: 520527, 2001.

13. Little, T and Williams, AG. Specificity of acceleration, maximumspeed, and agility in professional soccer players. J Strength Cond Res19: 7678, 2005.

14. Little, T and Williams, AG. Effects of differential stretchingprotocols during warm-ups on high-speed motor capacities inprofessional soccer players. J Strength Cond Res 20: 203207, 2006.

15. Nelson, AG, Driscoll, NM, Landin, DK, Young, MA, andSchexnayder, IC. Acute effects of passive muscle stretching on sprint

performance. J Sports Sci23: 449454, 2005.16. Nelson, AG, Kokkenen, J, and Arnall, DA. Acute muscle stretching

inhibits muscle strength endurance performance. J Strength Cond Res19: 338343, 2005.

17. Potach, DH and Chu, DA. Plyometric training. In: Essentials ofStrength Training and Conditioning Baechle, TR and Earle, RW. eds.Champaign: Human Kinetics, 2000. pp. 427470.

18. Rosenbaum, D and Hennig, E. The influence of stretching andwarm-up exercises on Achilles tendon reflex activity. J Sports Sci13:481490, 1995.

19. Shorten, MR. Muscle elasticity and human performance. Med SciSports Exerc25: 118, 1987.

20. Stolen, T, Chamari, K, Castagna, C, and Wisloff, U. Physiology ofsoccer: an update. Sports Med35: 501536, 2005.

21. Thacker, SB, Gilchrist, J, Stroup, DF, and Kimsey, CD, Jr. The impact

of stretching on sports injury risk: a systematic review of theliterature. Med Sci Sports Exerc36: 371378, 2004.

22. Unick, J, Kieffer, S, Cheesman, W, and Feeney, A. The acute effectsof static and ballistic stretching on vertical jump performance intrained women. J Strength Cond Res 19: 206212, 2005.

23. Wallmann, HW, Mercer, JA, and McWhorter, JW. Surfaceelectromyographic assessment of the effect of static stretching of thegastrocnemius on vertical jump performance. J Strength Cond Res19:684688, 2005.

24. Yamaguchi, T, Ishii, K, Yamanaka, M, and Yasuda, K. Acute effectof static stretching on power output during concentric dynamicconstant external resistance leg extension. J Strength Cond Res 20:804810, 2006.

25. Young, W and Elliott, S. Acute effects of static stretching,proprioceptive neuromuscular facilitation stretching, and maximumvoluntary contractions on explosive force production and jumpingperformance. Res Q Exerc Sports 72: 273277, 2001.

26. Young, WB and Behm, DG. Effects of running, static stretchingand practice jumps on explosive force production and jumpingperformance. J Sports Med Phys Fitness43: 2127, 2003.



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The Effect of Static Stretching on Phases Of