Effects of Static and Dynamic Stretching on Sprint and Jump Performance in Boys

and Girls

Giorgos P. Paradisis, Panagiotis Pappas, Elias Zacharogiannis, Apostolοs Theodorou

and Athanasia Smirniotou

Athletics Sector, Department of Physical Education & Sport Science, National &

Kapodistrian University of Athens, Ethn. Antistasis 41, Dafni, Athens, 172 37, Greece

Date of submission:

Corresponding author: Giorgos P Paradisis, Athletics Sector, Department of Physical

Education & Sport Science, National & Kapodistrian University of Athens, Ethn.

Antistasis 41, Dafni, Athens, 172 37, Greece

Tel: + 30 210 727 6102, Fax: + 30 210 727 6141

E-mail: gparadi@phed.uoa.gr

Running title: effects of stretching on print and jump performance

No funding was received for this work from NIH, Wellcome Trust, Howard Hughes

Medical Institute, or any others. All authors report no conflict of interest.

*Title Page (Showing Author Information)

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ABSTRACT

The aims of this study were to compare the acute effects of static and dynamic stretching on

explosive power, flexibility and sprinting ability on adolescent boys and girls and to compare

any differences due to gender. Forty-eight active adolescent boys and girls were randomly

tested after static and dynamic stretching for 40 s on quadriceps, hamstrings, hip extensors

and plantar flexors; in the control condition they do not performed no stretching. Pre- and

post-treatment tests were performed to examine the effects of stretching on 20 m sprint run

(20SR), counter movement jump height (CMJ) and seat and reach flexibility test (SR). Static

stretching hindered 20SR and CMJ by 2.5% and 6.3% respectively, whereas improved SR by

12.1%.Dynamic stretching hindered 20SR and CMJ by 0.8% and 2.2% respectively, whereas

improved SR by 6.5%. Dynamic stretching produces less reduction in 20SR and CMJ than

static stretching; however the effect on SR was reverse. The acute effects of static stretching

on 20SR and SR were grater in girls than boys, whereas dynamic stretching produced greater

changes in SR for girls than boys. It can therefore be concluded that stretching produces

significant reduction on explosive power and sprinting performances in adolescent boys and

girls.

KEY WORDS: 20 m sprint run, counter movement jump, flexibility

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INTRODUCTION

Traditionally, it is believed that stretching in the warm-up routines has significant benefits,

including injury prevention and enhancement of athletic performance (14,31) by increasing

both the body’s core temperature and the speed of neuromuscular responses (1). Based on this

physiological response, athletes have employed extensive warm-up and stretch routines as

part of their preparation for training and competition. However, there is much experimental

evidence that does not support these beliefs, providing evidence that acute muscle stretching

might be detrimental to performances for which success is related to maximal force or torque

output (11,17,23,24,37). The reduction of performance has been linked to two main

mechanisms. Mechanically, static stretching causes a decrease in musculotendinous unit

(MTU) stiffness (36), leading to a lower rate of force production and a delay in muscle

activation (8,17,18). This should result in an increase in tendon slack, which would require

time to be taken in when the muscle attempts to contract (28), thereby leading to a less

effective transfer of force from muscle to lever (17,35). Neurologically, stretching involves

acute neural inhibition, resulting in an increase in autogenic inhibition, which decreases

neural drive to the muscle (7,15,18,28), leading to a decrease in muscle activation after a

muscle is stretched (12,34).

Even though the positive effects of stretching on flexibility are clear (2,3,26), there are some

uncertainties regarding the effects of stretching on jumping performance. Some studies

provide evidence of reduced performance (5,12,27,38) while others dispute this, showing no

effects (24,26,27).

Similarly, the relationship between pre-activity static stretching and sprint performance has

not been thoroughly investigated and contrary results have been reported. Nelson et al., (25)

found that static stretching negatively impacted 20SR performance by 1.3% on 16 collegiate

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track athletes, conjecturing that both the above mechanical and neurological mechanisms

contributed to the decrease in performance. Similar results (1.8% performance reduction)

were reported by Fletcher & Jones (10) in a study of 97 male rugby union players, which were

attributed to the above mechanical mechanism. Sayers et al., (30) also reported 2.0% increases

in 30 m time after static stretching of 20 elite female soccer players. Contrary to these results,

Vetter (33) found no effect of static and dynamic stretching on 30 m performance of 26

college students, whereas Little & Williams (19) reported that pre-activity static and dynamic

stretching improved 20SR by 1.7%.

Despite the controversies in the aforementioned studies, research to address the effect of

stretching on sprinting and jumping performance of adolescent boys and girls is limited. Thus,

in light of the reported uncertainties of sprinting and jumping performance following

stretching in adult subjects, the purpose of this study was to compare the effects of static and

dynamic stretching on explosive power, flexibility and 20SR time in adolescent boys and

girls. The secondary aim of the study was to examine the impact of one’s gender on the

response. It was hypothesized that static stretching would result in significant reduced

performance in 20SR and jumping, but would lead to significant improved flexibility. Given

the difference in the stimulus associated with dynamic stretching, it was hypothesized that the

specific effects of dynamic stretching might be different. Finally, it was hypothesized that

both stretching strategies would produce the same results for both boys and girls.

METHODS

Experimental Approach to the Problem

In order to test the aims of the study, the effects of three different warm-up protocols on

20SR, CMJ height and on seat and reach (SR) flexibility test, in both boys and girls were

investigated. The 3 protocols were (i) run without stretching (R); (ii) run plus dynamic stretch

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(RD); and run plus static stretch (RS). The 3 warm-up protocols were designed and chosen

based on previous research (15,23,33,37). Sprint times were measured using a TC-Timing

System by Brower (USA), CJ was measured using a switch mat by Bosco (Italy) and SR was

measured using a sit and reach box apparatus by Cranlea (UK). A 2 ×3 repeated measures

analysis of variance was used to measure differences in performance following the warm-up

protocols.

Subjects

Forty-eight active adolescent boys and girls participated in this study (age, 14.6 ± 1.7 years;

mass, 62.8 ± 12.4 kg; height, 1.68 ± 0.12 m).All participants were recreationally active in

sports, however, in order to participate in this study, they were asked to terminate other sport

activity.Written informed consent was obtained from each participant before data collection,

and the study received ethical approval from the appropriate Faculty Research Ethics

Committee of National & Kapodistrian University of Athens.

General Protocol Design

Participants attended three familiarization and six data collection sessions in an indoor

recreation gym. The gym was well lit and the ambient temperature was 25o C. During the

familiarization sessions participants were familiarized with the different stretching exercises

(static and dynamic), the sprint start position, the CJ and the SR test, while on the last day

age, height, mass and % of body fat were collected.

During the data collection sessions participants performed a 5 min run at a slow self-regulated

pace, immediately followed by the pre-tests. After that, participants performed one of the

three stretching protocols (static, dynamic and no stretching) in a random order, immediately

followed by the post-tests. During the pre and post-tests participants performed either the SR

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and the CMJ tests or the sprint testing in random order. All 6 sessions were completed during

the course of 21 days, so that approximately 48–72 hours separated each test day; this was to

minimize any performance changes that could occur over a longer time period. The SR and

CJ were performed on the same day, whereas the sprint tests were performed on different

days in order to minimize testing time and to avoid any interaction effects. Additionally, due

to the large number of participants, only ten participants were tested in each data collection

session.

Warm-up protocols

R: after the 5 min run and the pre-tests participants were seated for 6 min and did not perform

any stretching.

RS: after the 5 min run and the pre-tests participants performed the static stretching. Each

participant stretched the target muscle of the left leg slowly and carefully until reaching a

position that felt mild discomfort for 20 s. Immediately after, stretching was performed in the

same manner on the same target muscle of the right leg. This sequence was performed twice.

The next target muscle was stretched after a rest period of 15 s. The four muscle groups that

were stretched were the quadriceps, hamstrings, hip extensors and plantar flexors.

RD: after the 5 min run and the pre-tests participants performed the dynamic stretching. The

participants contracted the antagonist of the target muscle intentionally in standing upright

position and flexed or extended some joints once every 2 s, so that the target muscle was

stretched. This stretching was performed for 40 s. The procedure was performed on the left

leg at first and then on the right leg with a rest period of 15 s. The order of target muscles and

the rest periods were the same as those in the static stretching. Quadriceps: The participants

contracted their hamstrings intentionally and flexed knee joint so that heel touched their

buttock. Hamstrings: The participants contracted the hip flexors intentionally with knee

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extended and flexed their hip joint so that leg was swung up to the anterior aspect of the body.

Hip extensors: The participants contracted hip flexors intentionally with knee fixed and flexed

their hip joint so that thigh came up towards to chest. Plantar flexors: First, the participants

raised one foot from the floor and fully extended the knee. Then, they contracted their dorsi

flexors intentionally and dorsi flexed ankle joint so that toe was pointing upward.

Tests

The fastest sprint, the highest jump and the greater flexibility score of three trials were used

for statistical analysis. The take off position for the jump had to meet the following criteria:

maintain at least minimal heel contact to ground, have minimal hip flexion, and keep pre-

reach arms straight, as described below.

Sprint Run Test: The 20SR test started from an upright standing position (feet were

approximately 8 cm apart with toes on the 0-m start line, side by side in a parallel position

with toes pointed directly forward, weight was shifted forward on balls of the feet with a

slight heel disconnect from the ground), with hips and knees neither flexed nor rigid.

Participants were instructed to run as fast as possible for 20 m with a prior instruction not to

brake until after passing the 20-m mark, where rest between the three runs was 5 min.

Countermovement Jump Test: The ability of the participants to produce force vertically was

measured by testing the CMJ: starting from an erect standing position the downward counter-

movement was approximately to knee angle of 90o. In all the jumps the participants kept their

hands on their hips and performed three jumps. The height of rise of the centre of mass of the

body was calculated by using the formula d = vit + ½α t2 where vi is the initial velocity, t is

the flight time and α the gravitational acceleration. This method of calculation assumes that

the performer’s positions on the platform at take-off and landing are identical. The best of the

three trials (in terms of height) was selected for further analysis.

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Statistical Analyses

A two-way ANOVA with repeated measures (RANOVA) was used to establish if there were

any significant differences between the pre and post tests and the interventions (type of

stretching), and any interaction effects for each variable. For all the repeated-measures

ANOVAs, the assumption of sphericity was tested. Given that this assumption was not

violated, no adjustments were required. In the event of significant main effects, post-hoc tests

were used to identify the differences. To eliminate the possibility of type I errors in these post

hoc tests, a Bonferroni adjustment to reduce the alpha level was applied. A paired samples t-

test was performed to identify significant differences between pre and post values. To assess

the nature and strength of correlations between the analyzed variables, the Pearson’s product

moment correlation coefficient (r) was calculated. The significance level for the tests was set

at P ‹ 0.05.

RESULTS

A repeated-measures ANOVA showed a significant main effect for the pre- and post-tests for

20SR (F = 52.48; p< 0.05), CMJ (F =12,440; p < 0.05) and SR (F = 4.440; p < 0.05).

20 m sprint run: 20SR time increased significantly after the RS and RD protocols (Tukey, p <

0.05) by 2.5% and 0.8%, respectively, whereas it was not statistically significant after the R

protocol for all the participants (Table 1). After the RS warm-up protocol, 41 out of 47

participants increased the time in the 20SR (range = 0.02 – 1.05 s), whereas after the RD, 35

participants increased the time in the 20SR (range = 0.01 – 0.23 s). In terms of the effects on

male (N = 17) 20SR, there was a significant increase only after the RS protocol (Tukey, p

<0.05) by 1.4%, whereas it was not statistically significant after the R and RD protocols

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(Table 2). After the RS warm-up protocol, 13 out of 17 participants increased the time in the

20SR (range = 0.02 – 0.18 s). Similarly, in terms of the effects on female (N = 30) 20SR,

there was a significant increase only after the RS protocol (Tukey, p <0.05) by 3.2%, whereas

it was not statistically significant after the R and RD protocols (Table 3). After the RS warm-

up protocol, 28 out of 30 participants increased the time in the 20SR (range = 0.03 – 1.05 s).

Counter movement jump: CMJ decreased significantly after the RS, RD and R protocols

(Tukey, p < 0.05) by 6.3%, 2.2% and 2.6%, respectively for all the participants (Table 1).

After the RS warm-up protocol, 44 out of 47 participants decreased the CMJ (range = 0.1 –

7.4 cm), after the RD, 33 participants decreased the CMJ (range = 0.1 – 3.1 cm) and after the

R, 33 participants decreased the CMJ (range = 0.1 – 3.8 cm). In terms of the effects on males

(N = 17) CMJ decreased significantly after the RS protocol (Tukey, p <0.05) and RD (Tukey,

p <0.05) by 6.8% and 1.7% respectively, whereas it was not statistically significant after the

R (Table 2). After the RS warm-up protocol, all but one participant decreased the CMJ (range

= 0.1 – 7.4 cm). In terms of the effects on females (N = 30) CMJ decreased significantly after

the RS, RD and R protocols (Tukey, p <0.05) by 5.9%, 3.5% and 3.1% respectively (Table 3).

After the RS warm-up protocol, 28 out of 30 participants decreased the CMJ (range = 0.3 –

3.6 cm), after the RD, 22 out of 30 participants decreased the CMJ (range = 0.1 – 3.1 cm) and

after the R, 22 out of 30 participants decreased the CMJ (range = 0.1 – 2.8 cm).

Sit & reach: SR increased significantly after the RS, RD and R protocols (Tukey, p < 0.05) by

12.1%, 6.5% and 5.2%, respectively for all the participants (Table 1). After the RS warm-up

protocol, 37 out of 47 participants increased the SR (range = 1 – 10 cm), after the RD, 32

participants increased the SR (range = 1 – 6 cm) and after the R, 25 out of 47 participants

increased the SR (range = 1 – 9 cm). In terms of the effects on males (N = 17) SR increased

significantly after the RS protocol (Tukey, p <0.05) by 9.6%, whereas it was not statistically

significant after the RD and R (Table 2). After the RS warm-up protocol, 11 out of 17

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participants increased the SR (range = 1 – 6 cm). In terms of the effects on females (N = 30)

SR increased significantly after the RS, RD and R protocols (Tukey, p <0.05) by 13%, 7.3%

and 4.9% respectively (Table 3). After the RS warm-up protocol, 26 out of 30 participants

increased the SR (range = 1 – 10 cm), after the RD, 25 out of 30 participants increased the SR

(range = 1 – 6 cm) and after the R, 20 out of 30 participants increased the SR CMJ (range = 1

– 4 cm).

DISCUSSION

The main finding of this study was that stretching increased significantly 20SR time for both

RS and RD in adolescent boys and girls; however, the effect of RS (2.5%) was significantly

greater than that of RD (0.8%) (t = 2.57, p < 0.05). The analysis regarding gender revealed

statistical differences only after RS for both boys (1.4%) and girls (3.2%). Even though there

are no other studies with this age group, similar results were found by Sayers et al., (30) who

investigated the effects of 20 s static stretching on 3 muscles of each leg on 30 m sprint (2.0%

greater times for static stretching compared to no- stretching) on 12 female soccer players.

Fletcher & Jones (10) also found that 20 s stretching protocol on 7 muscles of each leg of 97

rugby players, produced 1.5% increases in 20SR time after static protocol, whereas dynamic

protocol decreased time by 1.9%. Nelson et al., (25) investigated the effects of a longer static

stretching protocol (4 × 30 s stretching protocol on 3 muscles of each leg) on 16 elite level

sprinters and reported that stretching increased 1.3% 20 m time by 1.3% compared to no-

stretching protocols. Finally, Fletcher & Anness (9) found that the combination of static and

dynamic stretching increased 50 m sprint time by 2.5% and 1.4% for male and female

respectively than dynamic only stretching protocol. On the other hand, Vetter (33) found no

changes in the 30 m sprint time after both static and dynamic stretching protocols (30 s

stretching on 3 muscles of each leg) on 26 college students, whereas Little & Williams

(19),using similar stretching protocols on 6 muscles on 18 male professional soccer players,

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reported that dynamic (2.37 ± 0.13 s) and static stretching (2.37 ± 0.12 s) protocols produced

significantly faster 20SR times than did the no stretching protocol (2.41 ± 0.13 s).

Jumps

CMJ decreased after R (2.6%), RS (6.3%) and RD (2.2%) in adolescent boys and girls;

however, the effect of RS was significantly greater than that of R and RD (f = 12.91, p <

0.05). The analysis regarding gender revealed statistical decreases after the RS and RD for

male, whereas in female CMJ decreased for all conditions (Table 2). McNeal and Sands (22)

is the only study that examined the effects of stretching on adolescent (13 girl gymnasts age

13.3 ± 2.6 yrs) and they reported a reduction in drop jump by 9.6%, following 3 assisted

stretching exercises of 30 s each. Cornwell et al., (5) researched the effects of a 30s hold per

each assisted stretching exercise protocol on static jump (SJ) and CMJ, and revealed

significant reductions (1.0 ± 0.3 cm and 1.2 ± 0.4 cm, respectively). However, the same

research group (6) reported 7.4% decrease in CMJ height but no change in SJ after stretching

for 180 s in each leg. Additionally, a significant decrease (1.24%) in muscle stiffness was

noted, but the magnitude of this change was probably not sufficient for it to have been a major

factor underlying the decline in CMJ performance. Paradoxically, after stretching, the SJ

exhibited a significant decrease in muscle electrical activity by 2.1%, but not the CMJ.

Finally, Cornwell et al., (6) concluded that an acute bout of stretching can impact negatively

upon the performance of a single joint CMJ, but it is unlikely that the mechanism responsible

is a depression of muscle activation or a change in musculotendinous stiffness. Young and

Behm (37) found that SJ was significantly reduced (7.8%) after static stretching involving 4

exercises each held for a total of 1 min compared to warm-up with no stretching. Similar

results have been reported by Behm et al., (4) and Hough et al., (13).

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However, Knudson et al., (15) used 3 static stretch exercises held for 3 × 15 s and found that

static stretching did not produce any changes into the kinematics of SJ, where similar results

have been reported by Koch et al., (16) who used 4 static stretch exercises performed with 10s

holds during an 8-minute period. Additionally, Power et al., (26) used 5 assisted and

unassisted static stretch exercises, each of which was held for 45 s and reported no changes on

jumping performance. Similar results have been reported by Samuel et al., (29) and Unick et

al., (32). Any discrepancy between the current findings and these previous studies might be

attributed to the fact that these protocols utilized longer stretch holds, more sets, or more

repetitions.

Flexibility

Sit-and-reach measurement indications were increased after R (5.2%), RS (12.1%) and RD

(6.5%) in adolescent boys and girls; however, the effect of RS was significant greater than

that of R and RD (f = 6.96, p < 0.05). The analysis regarding sex revealed statistical increases

after the RS for boys, whereas in girls SR increased after all conditions (Table 2). Similarly,

Bacurau et al., (2) reported 11.7% and 9.8% improvements in the SR after static and dynamic

stretching respectively, and Nelson and Kokkonen (24) found 9% improvements after passive

ballistic stretching, whereas Fowles et al. (11) reported 21% improvement in plantar flexion

ROM after static stretching. Additionally, Power et al., (26) used 5 assisted and unassisted

static stretch exercises, each of which was held for 45 s and reported 6% improvements on

SR. A possible explanation for the greater increase in flexibility after the static exercise may

be the viscoelastic stress relaxation that occurs when the muscle tissue is kept stretched in a

fixed position (20,21). The stress relaxation seems to be attributable to increased tendon

elasticity and a decreased muscle viscosity, which produces a decreased passive joint torque

(18).

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Mechanical (peripheral) and neurological (central) theories have been proposed as possible

mechanisms regarding the decrease in performance caused by stretching. Jumping

performance is an eccentric – concentric movement, whereas sprinting requires a continuous

cycle of rapid transition from eccentric to concentric muscle action. During the eccentric

phase, the series elastic component (SEC) lengthens, storing elastic energy to be reused in the

concentric phase of the stretch-shortening cycle, when the SEC springs back to its original

configuration (30). Mechanically, as Fletcher and Jones (10) suggested, after a bout of static

stretching, the SEC may already be lengthened, thereby impeding the preactivation of the

musculotendinous unit and decreasing its ability to store and reuse as much elastic energy

during the stretch-shortening cycle. Additionally, as the amount of elastic energy that can be

stored in the musculotendinous unit is a function of stiffness and static stretching reduces the

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

bout of static stretching (30). On the other hand, neurologically, it has been suggested that

stretching may cause neural inhibition (18,25,28), by inhibiting the myoelectric potentiation

initiated during the eccentric phase of the stretch-shortening cycle, which is responsible for

initiating muscle activation during the concentric phase. These mechanical and neurological

mechanisms might have contributed to the decrease in performance during the eccentric-

concentric phases of each stretch-shortening cycle, which affects the overall sprint

performance. The results of the present study support the hypothesis that these mechanisms

could be responsible for the decrease in 20SR performance.

Sayers et al., (30) reported that static stretching had a negative effect on the acceleration phase

of the sprint and the maximal-velocity phase of the sprint. Possible mechanisms responsible

for that could be neurological, (during both the acceleration and maximal velocity phases, the

myoelectric potentiation, may not be sufficient to produce a maximal response during the

concentric phase), mechanical (a muscle that has been statically stretched has more slack than

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an unstretched muscle) or both. Additionally, Nelson et al., (25) found that static stretching

resulted in decreased muscle strength endurance performance by placing some of the

available motor units in a fatigue-like state, therefore depleting the amount of motor units

available for recruitment during the performance activity. This led to the onset of fatigue

earlier in the activity and, therefore, to a decrease in performance. Given the repetitive use of

several muscles during sprinting, this concept could be applied to sprinting action (9);

however, whether a 20-m sprint is long enough for this particular mechanism to be considered

is unknown. Further research is needed to identify which of these mechanisms (central or

peripheral) is responsible for the deleterious effect of stretching and what extent each

mechanism has on performance.

PRACTICAL APPLICATIONS

Stretching in the warm-up routine produced significant acute decreases in performance in

adolescent boys & girls. The present study provides kinematical evidence, which describes

the nature of acute adaptations after stretching. Static stretching resulted in a 2.5% overall

acute decrease in 20SR time, a 6.3% decrease in CMJ, whereas SR was improved by 12.1%.

The hypothesis that static stretching would result in significant acute reduced performance in

20SR and jumping, but would lead to significant improved flexibility was supported.

Dynamic stretching produced a 0.8% overall acute decrease in 20SR time, a 2.23% decrease

in CMJ, whereas SR was improved by 6.5%. Dynamic stretching produces less reduction in

20SR and CMJ performances than static stretching, whereas the effects on flexibility were

reverse. The hypothesis that the specific effects of dynamic stretching might be different than

that of static stretching was supported. Finally, the hypothesis that both static and dynamic

stretching strategies would produce the same results in both boys and girls was not supported

as the acute effects of static stretching concerning 20 m sprint and flexibility were grater in

girls than boys, whereas dynamic stretching produced greater changes in flexibility for girls

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than boys. It can therefore be concluded that stretching produces significant reduction on

explosive power and sprinting performances in adolescent boys and girls. However, it has to

be remembered that athletes have accustomed themselves to include stretching in their warm

up routine. Thus, if someone acutely removes or reduces stretching from his/her usual warm-

up routine, this could lead to a reverse effect (18), as athletes might feel unable to perform

maximally without their “habitual routine”. Instead, an introductory strategy might be needed

in order athletes to understand the beneficial effects of the new adapted warm- up routine.

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Acknowledgments

This work has not been supported by any funding agency.

All authors report no conflict of interest.

Results of the present study do not constitute endorsement by the NSCA.

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Table 1. Mean s and % differences (post-pre tests) of 20 m, CMJ and SR of all participants (N = 47).

20 m (m) CMJ (cm) SR (cm)

R

Pre

Post

Δ%

3.65 ± 0.27

3.63 ± 0.31

-0.6

28.35 6.12

27.66 6.25*

-2.6

19.23 9.75

20.23 9.74*

5.2

RS

Pre

Post

Δ%

3.64 0.27

3.73 0.31*

2.5

28.78 5.99

26.96 5.88*

-6.3

19.17 9.27

21.49 9.26*

12.1

RD

Pre

Post

Δ%

3.63 0.28

3.66 0.29*

0.8

28.37 6.22

27.74 6.37*

-2.2

20.34 9.09

21.66 9.34*

6.5

* Significantly different from pre-training (P 0.05) as determined by repeated-measures analysis of variance and post-hoc Tukey tests.

Abbreviations: CMJ = counter movement jump, SR = seat and reach, R = warm-up without stretching, RS = warm-up with static stretching, RD =

warm-up with dynamic stretching, Δ % = percentage difference between pre and post test values.

Table

Table 2. Mean s and % differences of 20 m, CMJ and SR of male (N = 17) & female (N = 30).

20 m (m) CMJ(cm) SR (cm)

male female male female male female

R

Pre

Post

Δ%

3.56 ± 0.33

3.55 ± 0.32

-0.3

3.70 ± 0.22

3.67 ± 0.30

-0.8

32.11 7.44

31.64 7.36

-1.4

26.22 3.99

25.40 4.19*

-3.1

12.29 10.75

13.06 10.74

6.2

23.17 6.79

24.30 6.54*

4.9

RS

Pre

Post

Δ%

3.55 0.33

3.60 0.34*

1.4

3.69 0.22

3.81 0.26*

3.2

33.09 6.90

30.81 7.03*

-6.8

26.33 6.69

24.77 3.72*

-5.9

14.00 9.91

15.35 9.63*

9.6

22.10 7.59

24.97 7.09*

13.0

RD

Pre

Post

Δ%

3.53 0.35

3.56 0.33

0.9

3.69 0.21

3.72 0.22

0.8

32.07 7.69

31.52 7.88*

-1.7

26.26 4.02

25.60 4.12*

-2.5

14.18 10.19

14.77 10.23

4.2

23.83 6.24

25.57 6.07*

7.3

* Significantly different from pre-training (P 0.05) as determined by repeated-measures analysis of variance and post-hoc Tukey tests.

Abbreviations: CMJ = counter movement jump, SR = seat and reach, R = warm-up without stretching, RS = warm-up with static stretching, RD =

warm-up with dynamic stretching, Δ % = percentage difference between pre and post test values.