Научная статья на тему '60 cm Drop Jump test assessment in 17 years old volleyball players in Albania under the influence of Plyometric Training'

60 cm Drop Jump test assessment in 17 years old volleyball players in Albania under the influence of Plyometric Training Текст научной статьи по специальности «Фундаментальная медицина»

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Ключевые слова
drop jump / volleyball / plyometric training

Аннотация научной статьи по фундаментальной медицине, автор научной работы — Lleshi Enkeleida

The assessment of vertical jump through 60cm Drop Jump Test under the influence of Plyometric Training (PT) is the main purpose of this study. PT has been conducted for 12 weeks with volleyball players in Albania. The data were taken prior to afterwards PT for 12 week. 20 volleyball players Experimental (EX) group 10 players with average Age 17±1, BH186.3±5.1, BW 74.3 ± 6.1, BMI 22.25% ± 3.4 and also Control group (CO) 10 players with average Age17±0.9, BH 185.9 ± 8.4, BW 70.2±8.6, BMI 20.37%±2.01 performed the test DJ60cm in the platform Leonardo® Ground Force Reaction Plate (GRFP) which express Force max (kN), Power max (w/kg), Time Contact (TCs), Air Time (TAs), TA/TCs. The 12 week programme was applied only by the EX group in 2 sessions in each week aiming plyometric exercises and 3 sessions with ball, while the CO group developed only 5 training session with ball. Both volleyball groups performed lower values at the beginning of the tests. The results obtained from PT in GRFP after 12 weeks showed an improvement in lower extremities Fmax and Pmax. EX group showed statistically proficiency improvement on 60cm DJ jump test from CO group. Plyometric exercises as part of a programme designed for volleyball players are necessary for improving vertical jump skills of the teams but also of the individual himself.

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Текст научной работы на тему «60 cm Drop Jump test assessment in 17 years old volleyball players in Albania under the influence of Plyometric Training»

60 cm Drop Jump test assessment in 17 years old volleyball players in Albania under the influence of Plyometric Training

References:

1. Bosco C., P. Komi, 1981. Prestretch potentiation of human skeletal muscle during ballistic movement. Acta Physiol. Scand. 111: 135-140 p.

2. Komi, P. V.,&C. Bosco.,1978.Utilization of stored elastic energy in leg extensor muscles by men and women. Med. Sci. Sports 10: 261-265 p.

3. Sheppard, M.&Chapman, D.&al.2009.U. Twelve-month training-induced changes in elite international volleyball players.Journal Strength Cond Res.volum 23, nr 7, 2096-2101 p.

4. Blattner, S. E., and L. Noble. (1979)Relative effects of isokinetic and plyometric training on vertical jumping performance. Res. Quar. 50: 583-588 p.

5. Clutch, D., M. Wilton, C. Mc Gown, and G. R. Bryce. (1983)The effect of depth jumps and weight training on leg strength and vertical jump. Res. Q. Exerc. Sport 54: 5-10 p.

6. Cometti, G., Cometti. D., 2009”LaPliometria (origini, teorie, allenamento)2a edizione italiana (Tivoli) Capitolo V; I TEST. Test di Bosco, 60-78 p.

7. Marell, M., Risalti, M.,2007. Il librodeiTest, Le prove di valutazionefisica per tuttigli sport; 80-85pp.

8. Carmelo Bosco Ph.D (2006).”Laforzamuscolare”Aspetti Fisiologici ed Applicazioni Pratiche” (Rome) Capitolo IV, La Forza Explosiva,103-110 p.

9. Daniel J. Gehri, Mark D. Ricard, Douglas M. Kleinerl, and Donald T. Kirkendall Journal of Strength and Conditioning Research, 1998, 12 (2), 85-89. National Strength & Conditioning Association A Comparison of Plyometric Training Techniques for Improving Vertical Jump Ability and Energy Production.

10. Adams, T. (1984). An investigation of selected plyometric training exercises on muscular leg strength and power. Track Field Qnar.Rear. 84 (1): 36-41p.

Lleshi Enkeleida, Sports University of Tirana PhD student at Sport Sciences Research Institute Sports University of Tirana Email: enlleshi@yahoo.com

60 cm Drop Jump test assessment in 17 years old volleyball players in Albania under the influence of Plyometric Training

Abstract: The assessment of vertical jump through 60cm Drop Jump Test under the influence of Plyometric Training (PT) is the main purpose of this study. PT has been conducted for 12 weeks with volleyball players in Albania. The data were taken prior to afterwards PT for 12 week. 20 volleyball players Experimental (EX) group 10 players with average Age 17±1, BH186.3±5.1, BW 74.3 ± 6.1, BMI 22.25% ± 3.4 and also Control group (CO) 10 players with average Age17±0.9, BH 185.9 ± 8.4, BW 70.2±8.6, BMI 20.37%±2.01 performed the test DJ60cm in the platform Leonardo® Ground Force Reaction Plate (GRFP) which express Force max (kN), Power max (w/kg), Time Contact (TCs), Air Time (TAs), TA/TCs. The 12 week programme was applied only by the EX group in 2 sessions in each week aiming plyometric exercises and 3 sessions with ball, while the CO group developed only 5 training session with ball. Both volleyball groups performed lower values at the beginning of the tests. The results obtained from PT in GRFP after 12 weeks showed an improvement in lower extremities Fmax and Pmax. EX group showed statistically proficiency improvement on 60cm DJ jump test from CO group. Plyometric exercises as part of a programme designed for volleyball players are necessary for improving vertical jump skills of the teams but also of the individual himself.

Keywords: drop jump, volleyball, plyometric training.

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Introduction

Volleyball is one of the most monitored sports in Albania. It is characterized by the activity of vertical jump performance in attack and block. Taking into consideration the importance of this activity for the performance result and the frequency in which they occur during a jump game Drop Jump (DJ) type is an important indicator in this sport. Several studies have shown a strong correlation between the performance in the vertical jump and the force or power. Vertical jump assessment is widely used as an alternative of the maximum assessment directly to the force and power of the lower extremities [5, 2503-2511]. The rate of force development is the development of maximum force in minimum time and is commonly used as an explosive force index [9, 318-329]. One of the training methods that coaches use during the athletes preparatory period are plyometric exercises. Plyometric exercises include rapid movement of continuous improvement in eccentric and concentric phases to increase the muscle strength in effect in order to perform a better efficient jump [7, 261-265]. Plyometric is a form of resistance exercise that refers to the stretch-shortening cycle (SSC) such as jumps or by doing vertical or horizontal jumps [2, 209-239]. Bosco in the 80’ proposed a simple way to assess the vertical jump. The tests he proposed may be accessed through a system with a force platform in contact capable to record during the vertical jump the time of flight and contact. This is one of the simplest ways for coaches to conduct the athletes training evaluation. By plyometric movement actions is achieved the performance of two conditions during vertical jump: the minimum contact time with the terrain and the maximum time of the later flight, these two conditions are associated with certain amount of falling that allows the development of maximum power that we realized through 60cm DJ test. Despite the large number of plyometric studies, few studies on the applied exercises did compare the effectiveness of plyo-metric exercises. Some researchers say that due to the nature of the plyometric exercises (muscle overload), the ability to control the intensity of exercise plays an important role in training [6, 763-767]. However, in order to control the training intensity it is necessary to know how it varies depending on the type of terrain, jump technique, type of jump (one or two feet,

vertical or horizontal, single or repeated) and the fall from height or from additional loads. For this reason they arrived at the conclusion that these plyometric jump techniques (e. g., amplitude of movement, time offlight, the contact with the ground) is an important factor to be taken into consideration for the preparation of a plyometric training. For the first time in our environments of the University of Sports in Tirana, Albania came a platform Leonardo® system Ground Reaction Force Plate (GRFP-NOVOTEC Medical, Pforzheim, Germany). And we developed a study with the juvenile volleyball National championship in Albania.

The experimental approach to the problem:

The data base were taken from volleyball players standard preparations of conditional for a 12 weeks period with 2 sessions in week, January and April. The objects of this study were the volleyball player who participate in volleyball National Championship in Albania trained 10 hours in week, the Experimental (EX) group has developed 3 hours in the gym the plyometric exercise development and 7 hours of general technical-tactical exercise Control (CO) group developed only 10 hours of general technical exercise in week.

Subject:

Volleyball player’s teams participated in the National Volleyball Championship in Albania. These teams were considered from the opinion of the volleyball community as teams composed by volleyball players with lots of perspective. The teams participating in this study are Tirana Volley which underwent our experimentation as the Experimental group and team Farka Volley was considered as the control group. All subjects received a clear explanation for participation in the 12 weeks study and they confirmed their participation.

Procedures and Methods:

24 hours before starting the test, the participants were not included in any activity that would result invalid for study. Volleyball players testing was done 24 hours after a day of absolute rest. We start with the assessments of anthropometric measurements and then to the tests in vertical jump performance of tests protocol [3, 60-78]. Drop Jump 60cm. all participants were informed about the tests on which was focused the research, it was also decided for a repetition ofmea-

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60 cm Drop Jump test assessment in 17 years old volleyball players in Albania under the influence of Plyometric Training

surements for specific testing. Then they performed in odd rule for all of these disciplines: DJ 60cm tests per-

maximum vertical jumps with hands in bowl with an formed in the platform (GRFP).

Table 1. - Average data volleyball players

Nr GROUPS Age Bady Hight (BH)cm BadyWeight (BW)kg BMI Kg/m%

10 EXS PERIMENT 17 186.3cm 74.3kg 22.25%

SD 1 5.1 6.1 3.4

10 CONTROLL 17 185.9cm 70.2kg 20.37%

SD 0.9 8.4 8.6 2.01

12 weeks of Plyometric Training

Tirana Volley team Experimental group developed during one week, on the scheduled days of Monday, Wednesday, 3 hours (2x90min) training with detailed training program for developing plyo-metric exercises in UST gym Fitness with time difference of 48 hours and 7 hours of general technical-tactical training with ball. Whereas men’s volleyball team Farka Volley considered as the Control Group developed only 10 hours of technical-tactical exercises with ball during the week (90min each day) under their coach’s training. For the PT developed with male volleyball player’s Experimental group

we used the plyometric exercises method by paying special attention to the training load or an exercise rating the program is clearly reflected in tab.2.3.

The program includes loads of intensive application such as horizontal jumps up to jumps over obstacles and jumps in depth. Intensity escalation is used not only within a training session but also from week to week. Another component that increases intensity training load is the use of heights of objects or used means which comes under the principle of progressiveness where initially were provided only the jumps with breakaway from the field and gradually the increase the height of the means [10, 222-225].

Table 2. - Plyometric training program used in weeks 1-6

Weeks 1 2 3 4 5 6

Vertical Jumps 3*10 3*10 3*10 3*10 4*10 4*10

Tuck Jumps 3*8 3*8 3*8 3*8 3*10 3*10

Multiple Jumps Footed over hurdles 3*8 3*8 3*8 3*8 3*10 3*10

Depth Jumps 4*8 4*8 4*8 4*8 4*10 4*10

Jump Down and Up off the box 3*8 3*8 3*8 3*8 4*8 4*8

Lateral bench Jumps 3*12 3*12 3*12 3*12 4*10 4*10

Table 3. - Plyometric training program used in weeks 7-12

Weeks 7 8 9 10 11 12

Vertical Jumps 4*10 4*10 4*10 4*10 5*8 5*8

Tuck Jumps 4*10 4*10 4*10 5*8 5*8 5*8

Multiple Jumps Footed over hurdles 3*8 3*8 3*8 4*8 4*8 4*8

Depth Jumps 4*8 4*8 4*8 5*8 5*8 5*8

Jump Down and Up off the box 3*8 3*8 4*8 5*8 5*8 5*8

Lateral bench Jumps 3*10 3*10 3*10 3*10 4*10 4*10

This program is detailed to improve vertical jump in juvenile volleyball players which involves the use of plyometric exercises to improve power and force and jumping. The establishment of a special volleyball program with plyometric exercises is created and based on the tests that we have developed as a specific to volleyball. This will help in identifying the individual needs of volleyball players in vertical jump performance. The PT is adapted in such a way to acquire the main movements performed during

the test thus improving technique exercises. The principles ofsportive training, such as progressiveness, compensation, the undulation of training loads were used for the establishment of the program. The plyometric as other forms of training is usually done only two or three times a week. Plyometric exercise program should start with low-intensity exercises, such as those described tables 2.3. Plyometric is thought to be one of the most important tools is boxes (cubes) for those who want to add another dimension

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of their training programs. developed specific tests in vertical jump GRFP

Result before and after 12 weeks of the 60cm DJ test. The

From what is shown above two volleyball teams obtained values are presented in Table 4.

Table 4. - All assessment variables by platforms Leonardo Machanographi (GRFP) show Pre and Post DJ60cm test results.

Nr EXPERIMENTAL PRE DJ 60 cm Fmax P max Time Contact Time Air TA/TC s

Pre kN Post Pre w/kg Post Pre Post Pre Post Pre Post

10 Average Team 3.39 3.62 35.42 31.20 0.348 0.356 0.552 0.514 1.66 1.88

Max. 4.16 4.87 42.68 42.3 0.489 0.515 0.608 0.608 2.21 2.21

Min. 2.39 2.39 27.04 19.86 0.236 0.249 0.504 0.444 1.1 0.86

SD ±0.6 ±0.8 ±6.3 ±6.3 ±0.07 ±0.08 ±0.03 ±0.05 ±0.3 ±0.3

Nr CONTROL POST DJ 60cm Fmax P max Time Contact Time Air TA/TC s

Pre kN Post Pre w/kg Post Pre Post Pre Post Pre Post

10 Average Team 3.16 3.21 35.03 35.93 0.348 0.322 0.552 0.609 1.68 1.82

Max. 3.76 4.89 39.83 46.35 0.489 0.439 0.608 0.655 2.21 2.87

Min. 2.86 2.28 28.73 30.25 0.236 0.214 0.504 0.535 1.1 1.38

SD ±0.2 ±0.7 ±3.8 ±5.4 ±0.07 ±0.06 ±0.03 ±0.03 ±0.3 ±0.4

Statistical Analyses

The Statistical analysis was performed using as a working environment IBM Statics 20. The used Statistical techniques include: a general descriptive analysis, the estimation of the data distribution (normality, variance homogeneity), hypotheses control research through techniques of difference between groups, ANOVA by repeated measurements with the time and/or group factors. Descriptive analysis was conducted by applying the

techniques of the difference between the groups, namely the analysis of variance with repeated measurements using as independent variables: the time (2 measurements Pre/Post model) and the group (Control/Experimental). Descriptive analysis results on variables of maximum Power and Maximum Force during pre and post measurements for the test “60cm Drop Jump “are gathered according to groups in Table 5.

Table 5. - Summary of Maximum Force and Maximum Power descriptive analysis and the time of measurement and groups

DESCRIPTIVE ANALYSIS

GRUPET FMax Pre FMax Post PMax Pre PMax Post

EXPERIMENTAL N 10 10 10 10

Median 3.2900 3.5250 36.9150 30.7850

Mean 3.3960 3.6260 35.4250 31.2070

Std. Deviation .62552 .85820 6.31201 6.38428

Kurtosis -1.266 -.975 -1.833 .130

Std. Error of Kurtosis 1.334 1.334 1.334 1.334

Skewness -.035 -.117 -.273 -.016

Std. Error of Skewness .687 .687 .687 .687

CONTROL N 10 10 10 10

Median 3.1200 3.1150 35.7300 34.4100

Mean 3.1630 3.2120 35.0370 35.9350

Std. Deviation .28375 .73298 3.86609 5.47068

Kurtosis .844 2.484 -1.100 -.428

Std. Error of Kurtosis 1.334 1.334 1.334 1.334

Skewness .911 1.307 -.328 .797

Std. Error of Skewness .687 .687 .687 .687

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60 cm Drop Jump test assessment in 17 years old volleyball players in Albania under the influence of Plyometric Training

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TOTAL N 20 20 20 20

Median 3.2050 3.3000 36.2900 32.3900

Mean 3.2795 3.4190 35.2310 33.5710

Std. Deviation .48761 .80528 5.09822 6.27424

Kurtosis -.266 -.643 -1.254 .246

Std. Error of Kurtosis .992 .992 .992 .992

Skewness .538 .480 -.221 .052

Std. Error of Skewness .512 .512 .512 .512

The results of descriptive analysis of the “Contact measurements and groups are presented below in

Time”, “Air time” “TA/TC” during Pre/Post Table 6.

Table 6. - Summary of descriptive analysis of the “Contact Time”, “Air Time” “TA/TC”

DESCRIPTIVE ANALYSIS

GRUPET KohKon-tak Pre KohaKon-tak Post KohaAjer Pre KohaAjer Post DJ 60cm TA/TC Pre DJ 60 cm TA/TCPost

EXPERIMENTAL N 10 10 10 10 10 10

Median .3395 .3310 .5560 .6485 1.6904 1.8643

Mean .3486 .3561 .5522 .6349 1.6603 1.8838

Std. Deviation .07670 .08856 .03322 .03815 .39540 .48418

Kurtosis -.216 -.656 -.831 .192 -1.455 -1.180

Std. Error of Kurtosis 1.334 1.334 1.334 1.334 1.334 1.334

Skewness .259 .693 .107 -1.152 .064 .300

Std. Error of Skewness .687 .687 .687 .687 .687 .687

CONTROL N 10 10 10 10 10 10

Median .3395 .3205 .5615 .5655 1.6904 1.7958

Mean .3486 .3221 .5622 .5694 1.6846 1.8225

Std. Deviation .07670 .06392 .04606 .05436 .38111 .34872

Kurtosis -.216 .194 .145 -1.419 -1.111 -.878

Std. Error of Kurtosis 1.334 1.334 1.334 1.334 1.334 1.334

Skewness .259 .169 .667 .273 -.091 .397

Std. Error of Skewness .687 .687 .687 .687 .687 .687

TOTAL N 20 20 20 20 20 20

Median .3395 .3245 .5590 .6115 1.6904 1.8001

Mean .3486 .3391 .5572 .6022 1.6724 1.8531

Std. Deviation .07466 .07716 .03942 .05673 .37817 .41187

Kurtosis -.498 .101 .207 -1.185 -1.299 -.870

Std. Error of Kurtosis .992 .992 .992 .992 .992 .992

Skewness .236 .701 .606 -.471 -.012 .385

Std. Error of Skewness .512 .512 .512 .512 .512 .512

According to a meta-analytic review [8, 349-355] plyometric training studies (PT) indicated that they provide accurate assesment on the size of the effects of exercise on different types of plyometric vertical jump. It is demonstrated that plyometric exercises statistically provide significant improvements and practically relevant in vertical jump height of the average effects ranging from 4.7% in Drop Jump (DJ). For this reason, studies have concluded that the jump

techniques or the amplitude ofmovement and the time of staying in the air (flight) and contact time is one of the most important factors to be taken into consideration for the implementation of a plyometric training program. [4, 1-15] has shown that vertical jump performance is determined by a complex interplay between several factors including maximum Force developed in muscles involved also the extent in which the force may be developed to achieve the vertical jump.

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Fmax_Pre Fmx_Post Pmax_Pre Pmax_Post ■ Experimental «Control

Graph 1. Maximum Force (Fmax) groups graphic presentation and Maximum Power (Pmax) groups graphic presentation

1,88

TA/TC_Pre TA/TC_Post

■ Experimental ■ Control

Graph 2. Time Air & Time Contact (TA/TC) graphic presentation

Moreover, the usage of the term power is a mechanical force built to show max jump performance in the quality of force development, impulse development and explosive power, by suggesting it as a necessary process in the performance of the players. [1, 590-593]. Developing maximum force in minimum time is usually used as an explosive force index [9, 318-329]. And the lack of significant correlation between the development of force and vertical jump is most likely caused by low power of statistical subjects’ number (n = 20). Regarding to DJ jupmp were reported that usually parameters are measured during the eccentric phase of their highest values rather than during the concetric phase.

In plyometric exercises which include mainly the lower extremities were performed in DJ jump as basic plyometric exercises that consist dropping (falling) from a cube (usually 0.3-0.6 m high),

and landing with two feet by absorbing the impact of eccentric phase, the followed by a powerful concentric movement. Like any power physical exercise the extremities force and power are determined by the volume of the jump or jump number developed in training or the intensity of work performed, which is usually defined by parameters such as ground reaction forces (GRFP) and the rate of force development.

Discussion:

The results descriptive statistical analysis on the dependent variable “TA/TC” presented in tab.6 showed the progress on increasing the performance in this exercise in both groups after attending the relevant training plan. In Post measurement training was noted an increase averaging 12:18 seconds where the average of the two groups was (1.85 ± 0:41) seconds in Post measurement compared to (1.67 ± 0:37)

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60 cm Drop Jump test assessment in 17 years old volleyball players in Albania under the influence of Plyometric Training

seconds in Post measurement. The control group in pre measurement did increase from (1.68 ± 12:38), to (1.82 ± 00:35) at the end of basic training plan. At the experimental group were seen changes from (1.66 ± 0.4) during Pre measurement and (1.88 ± 12:48) in Post measurement. From the analyses of distribution Normality Control with Kolmogorov-Smirnov test (sig. = 0.2) it resulted that the dependent variable “TA/TC” displays acceptable violations of the normal data distribution taking into consideration the small number of the selection (N = 20). Moreover, Leuven test results based on the average tried the variance homogeneity. From the analysis of Normality Control results that the two groups (control/experimental) have an acceptable (the acceptable limits of the Kolmogorov-Smirnov test) normal data distribution taking into consideration the small number of the selection. The results of variance Analysis (ANOVA) with 2 repeated measurements in freedom rates adjusted with Greenhouse-Geisser (F (1, 18) = 7.8, p = 0:12) evidenced a statistically significant difference between the two measurements, (sig. <0.5) leading us to the conclusion that the H1 hypothesis is accepted and the applied training plans were effective for increasing the performance of the volleyball players in 60cm jump Drop Test. Analysis of ANOVA 2 repeated measurements showed some statistically significant differences between the averages compared to TA/TC between Pre/Post measurements.

Conclusion

In the end of the study after we applied PT program to volleyball players in Albania for 12 weeks we came into the conclusion that the Plyometric training program found a statistically increased DJ60cm test implemented in the experimental group. Descriptive statistical analysis results for the dependent variable TA/TC indicated that the progress is evidenced in the increase in DJ 60cm test performance to the two groups after attending the training plan implemented in the experimental group. At the experimental group were seen changes Pre and Post measurements (1.66 ± 0.4) during Pre measurement and (1.88 ± 12:48) in Post measuring compared to the Control Group. From the Control of normality of distribution Analyses with Kolmogorov-Smirnov test (sig. = 0.2) resulted that the dependent variable “TA/TC” shows acceptable vulnerable of the normal distribution of data, taking into consideration the small number of the selection (N = 20). We think that 60cm DJ drop test from a height specified in this study is the key to defining a plyometric training base.This type of jump was developed during the plyometric training weeks and it shows the increase of jump’s flight time. There are several evidences that the regular participation in plyometric training program can improve the force and power measures of the athletes and as follows the increase of vertical jump. We assume that plyometric training was valuable for volleyball players in Albania.

References:

1. Cronin, J, Hing, R, and McNair, P. Reliability and validity of a linear position transducer for measuring jump performance. J Strength Cond Res 2004.18: 590-593 p.

2. Fleck, S. J., & Kraemer, W.J. (2004). Advanced training strategies. In S. J. Fleck &W. J. Kraemer (Eds.), Designing Resistance Training Programs (3rd ed. P. 209-239). Champaign, IL: Human Kinetics

3. Gilles Cometti, Dominique Cometti;”La Pliometria (origini, teorie, allenamento) 2a edizione italiana (Tivoli 2009)Capitolo V; I TEST. Test di Bosco 60-78 p.

4. HopkinsWG. Measures of reliability in sports medicine and science.Sports Med 30: 1-15, 2000.

5. Hara, M, Shibayama, A, Takeshita, D, and Fukashiro, S. 2006.The effect of arm swing on lower extremities in vertical jumping. J Biomech 39 (13): 2503-2511 p.

6. Jensen R.L., Ebben WP. (2005).Ground and knee joint reaction forces during variation of plyometric exercises.”In: Proceedings of the XXIII International Symposium of the Society of Biomechanics in Sports, (K. E. Gianikellis, ed.) Beijing, China: 222-225 p.

7. Komi, P. V.,&C. Bosco. (1978).Utilization of stored elastic energy in leg extensor muscles by men and women. Med. Sci. Sports 10: 261-265 p.

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8. Markovic, G. (2007). Does plyometric training improve vertical jump height? A metaanalytical review. British Journal of Sports Medicine, 41, 349-355 p.

9. Yu, B., Gabriel, D., Noble, L., and An, K. (1999). Estimate of the optimal cutoff frequency for the Butterworth low-pass digital filter. J Appl Biomech 15: 318-329 p.

10. Jensen R.L., Ebben WP. (2005). Ground and knee joint reaction forces during variation of plyometric exercises.”In: Proceedings of the XXIII International Symposium of the Society of Biomechanics in Sports, (K. E. Gianikellis, ed.) Beijing, China: 222-225 p.

Spahiu Elton, Erindi Altin, Sports University of Tirana PhD student at Sport Sciences E-mail: eltonsph@yahoo.it

Gender differences responses in isometric exercise

Abstract: Gender differences in cardiovascular responses to isometric exercise for sitting position and spine.The purpose of this study was to 1) determine whether cardiovascular responses to isometric exercise differ between genders, and 2) to determine if the behavior affects cardiovascular responses to isometric hand tightening (IHG) exercise.Sixteen women and sixteen men (age 22.6 ± 4.2 years) performed two tests (seated or spine) IHG maximum trials at 40% MVC a week away.Blood pressure (BP) and heart rate (HR) measurements were collected at rest (RT), the first minute of exercise (M1), before failure (PF), and 30 s of recovery after failure (RC).Mean arterial pressure (MAP), pulse pressure (PP), and the rate of pressure produces (RPP) were calculated from BP and HR data.Tests showed considerable time by gender interactions for diastolic blood pressure (DBP) and MAP. Males had DBP significantly higher than women in M1 (105.46 ± 14.97 vs. 92.59 ± 13:14 mmHg), PF (122.46 ± 11.23 vs 109.50 ± 13.72 mmHg) and RC (85, 83 ± 4.11 vs. 73.46 ± 8.35 mmHg) and higher MAP measurements that women in M1 (120.32 ± 13.76 vs 105.43 ± 13.76 mmHg), PF (136.44 ± 8.65 vs. 24.31 ± 13:34 mmHg), and RC (100.44 ± 8.21 vs. 87.67 ± 8.26 mmHg).DBP, MAP, and HR were significantly higher in the sitting position than in the spine position for both sexes.

Conclusions: 1) men significantly increase MAP and DBP after starting the exercise submaximal IHG through recovery regardless of position, 2) women have significantly lower measurement of blood pressure than men along the submaximal despite exercising attitude and 3) The attitude has important effects on the cardiovascular response during exercise submaximal IHG.4) The force exerted varies significantly in standing position compared to other positions.

Keywords: Cardiovascular responses, Isometric Handgrip, The force at different positions.

Introduction

Evaluation of isometric force in general average is about thirty percent greater in men than in women [1, 1-44]. With the initiation of isometric tension, increased heart rate, systolic blood pressure and diastolic blood pressure occurs [2,229-244] [3,120-135]. Then, Mitchell et al. [4, 45-54] suggested that cardiovascular responses to isometric exercise are greater when large muscle groups are in-

volved. So the gender differences in cardiovascular responses to static exercise is believed to be due to differences in the sympathetic-adrenal interactions pre sympathetic or cardiac level [7,245-251] [8,147-154]. While heart rate responses in stable submaximal static contractions tend to not be very different before, during or after exercise, blood pressure responses to exercise were significantly elevated before, during, and after exercise [6,863-868]. The

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