RESULTS AND DISCUSSIONS

74 CHAPTER IV RESULTS AND DISCUSSIONS 4.1 OVERVIEW This chapter deals with the analysis of data collected from the samples under study. The purpose of this study was to find out the effect of step aerobic exercises and plyometric exercises on selected physical fitness, physiological and skill performance variables among kendriya vidyalaya volleyball players. To achieve the purpose of the study thirty (30) male kendriya vidyalaya volleyball players were randomly selected as subjects and their age were 16-18 years. They were assigned into three groups, namely, step aerobics group (N=10), plyometric training group (N=10) and control group (N=10). I was experimented with step aerobic exercises, group II was experimented with plyometric exercises and the control group was not given any experiment. The variables selected for the study were physical fitness variables, muscular strength, explosive power and flexibility. The physiological variables selected for this study were vital capacity, and anaerobic power. The skill performance variables selected for this study was, service and attack in volleyball. The study was formulated as a true random group design consisting of a pre-test and post test. The groups were assigned as step aerobics training group, plyometric training group respectively. Pre tests were conducted for all the 30 subjects on selected physical fitness, physiological and skill performance variables. After the experimental period of twelve weeks post test were conducted for all the variables and the scores were recorded. The normality of the data were found through mean, standard deviation and F ratio and

75 the data collected were found to be normal. The differences between the initial and final scores in selected variables were subjected to statistical treatment using Analysis of Covariance (ANCOVA) to find out whether the mean differences were significant or not. 4.2 TEST OF SIGNIFICANCE This is the vital portion of the thesis achieving the conclusion by examining the hypotheses. The procedure of testing the hypotheses was either by accepting the hypotheses or rejecting the same in accordance with the results obtained in relation to the level of confidence. The test was usually called the test of significance since we test whether the differences between three groups or within many groups scores were significant or not. In this study, if the obtained F-value were greater than the table value, the hypotheses were accepted to the effect that there existed significant difference among the means of the groups compared, and if the obtained values were lesser than the required values, then the null hypotheses were accepted to the effect that there existed no significant differences among the means of the groups under study. 4.2.1 LEVEL OF SIGNIFICANCE The purpose of this study was to find out the effect of step aerobic exercises and plyometric exercises on selected physical fitness, physiological and skill performance variables among kendriya vidyalaya volleyball players. The data collected on selected criterion variables were subjected to statistical analysis using analysis of covariance (ANCOVA) to find out the significant difference if any, between the groups on selected criterion variables separately. In all the cases,.05 level of confidence was fixed to test the significance, which was considered as appropriate.

76 4.3 COMPUTATION OF ANALYSIS OF COVARIANCE AND POSTHOC TEST 4.3.1 RESULTS ON MUSCULAR STRENGTH. The fitness variable, muscular strength was measured through I RM test. The results on the effect of twelve weeks step aerobic exercises, plyometric exercises presented in Table IV. TABLE IV COMPUTATION OF ANALYSIS OF COVARIANCE ON MUSCULAR STRENGTH (Scores in Kg) Step Aerobics Plyometric Control sv ss df ms F ratio Pre Test 81.65 82.50 81.30 Between 7.167 2 3.81 Within 2507.125 27 92.86 0.04 Post Test 109.60 121.10 82.10 Between 8031.667 2 4015.83 Within 2242.200 27 83.04 48.36* Adjusted Post Test 109.60 121.10 82.1000 Between 7661.225 2 3830.61 Within 600.467 26 23.09 165.86* * Significant Table F-ratio at 0.05 level of confident for 2 and 27(df) =3.35 and 2 and 26 (df) = 3.37. Table IV shows that the pre test mean on muscular strength of step aerobics, plyometric and control group are 81.65, 82.50 and 81.30 respectively. The post test means showed differences due to twelve weeks of step aerobics, plyometric exercises on

77 muscular strength of the experimental and control group mean values recorded were 109.60, 121.10 and 82.10 kg respectively. The obtained F ratio value for pre test mean was 0.04 which was lesser than the required table value of 3.35 for significant at 0.05 level of confidence with the degrees of freedom 2 and 27.This proved that there was no significant difference between the groups at initial stage. The obtained F ratio value for post test mean was 48.36 which were greater than the table value of 3.35 for significant at 0.05 level of confidence with the degrees of freedom 2 and 27. This proved that the differences between the post test means of the subject were significant. The obtained F ratio value for adjusted test mean was 165.86 which were greater than the table value of 3.37 for significant at 0.05 level of confidence with the degrees of freedom 2 and 26. The result of the study shows that there was significant difference among the adjusted post test mean of three groups on muscular strength. Hence the adjusted post test mean f ratio value was found to be statistically significant and the result was subjected to Scheffe s post hoc test to find out the paired mean differences among the groups, and is presented in Table IV-A.

78 TABLE IV-A SCHEFFE S CONFIDENCE INTERVAL TEST SCORES ON MUSCULAR STRENGTH (Scores in Kg) s Step Aerobics Training Plyometric Training Control Difference Class Interval 109.60 121.10 11.50* 5.57 109.60 82.10 27.50* 5.57 121.10 82.10 39.00* 5.57 * Significant. The multiple mean comparisons shown in Table IV-A, proved that there existed significant differences between the adjusted means of plyometric group and control group, step aerobics and control group. There was significant difference between step aerobics and plyometric groups and plyometric group was found to be significantly better than step aerobics in increasing muscular strength of the subjects. The adjusted means on muscular strength were presented through bar diagram for better understanding of the result of the study in figure 1.

79 FIGURE 1 BAR DIAGRAM ON ORDERED ADJUSTED MEANS OF MUSCULAR STRENGTH (Scores in kg) 120 109.6 112.1 100 80 82.1 Kg 60 40 20 0 Step aerobic plyometric control s 4.3.2 DISCUSSIONS ON THE FINDINGS OF MUSCULAR STRENGTH The post hoc analysis through Scheffe s confidence test proved that due to twelve weeks treatment the step aerobics exercises group and plyometric exercises group improved muscular strength than control group and the differences were significant at 0.05 level. Results on muscular strength hint the advancement of the plyometric than the step aerobics and control group. The muscular strength can be tuned up with the help of the specific training modules which influences the muscular system on the basis of physiological changes such as reduce in mitochondrial density, marginally impacting capillary density, metabolic enzymes activities and intra muscular substance stores. These training modules induce the muscular system to adapt with and resulted in increases of muscular strength.

80 In accordance with the principle of training specificity the resistance training is the apt training method to excel the strength gain on the muscular system. Previous studies indicates that the neuromuscular adaptations such as increased inhibition of antagonist muscles as well as better activation and co-ordination of the synergistic muscles may account for the improvement in power out put (Komi, 1983; Lyttle, 1996) The findings of this study is in agreement with the findings of Arumugam. (2007) who analyzed the impact of plyometric training on the development of muscular strength and found significant development. The findings of the present study are also in agreement with the research findings of Toplica Stojanović1 (2004) who observed improvements in muscle strength, due to plyometric training. In this study, the volleyball players kendriya vidyayala would have significantly improved in muscular strength because of step aerobic exercises and plyometric training. 4.3.3 RESULTS ON EXPLOSIVE POWER The fitness variable, explosive power was measured through vertical jump test. The results on the effect of twelve weeks step aerobic exercises, plyometric exercises presented in Table V.

81 TABLE - V COMPUTATION OF ANALYSIS OF COVARIANCE ON EXPLOSIVE POWER (Scores in Centimeters) Pre Test Post Test Adjusted Post Test Step Aerobics Plyometric 34.20 34.10 34.20 42.00 48.50 34.60 42.0 48.50 34.60 Control sv ss df ms F ratio Between 0.07 2 0.03 Within 122.10 27 4.52 Between 967.40 2 483.70 Within 330.90 27 12.26 Between 971.52 2 485.76 Within 317.60 26 12.22 0.01 39.47* 39.77* * Significant. Table F-ratio at 0.05 level of confidence for 2 and 27(df) =3.35 and 2 and 26 (df) = 3.37. Table V shows that the pre test mean on explosive power of step aerobics, plyometric and control group are 34.20, 34.10 and 34.20 respectively. The post test means showed differences due to twelve weeks of step aerobics, plyometric exercises on explosive power of the experimental and control group mean values recorded were 42, 48.50 and 34.60 respectively. The obtained F ratio value for pre test mean was 0.01 which was lesser than the required table value of 3.35 for significant at 0.05 level of confidence with the degrees of freedom 2 and 27.This proved that there was no significant difference between the groups at initial stage.

82 The obtained F ratio value for post test mean was 39.47 which were greater than the table value of 3.35 for significant at 0.05 level of confidence with the degrees of freedom 2 and 27. This proved that the differences between the post test means of the subject were significant. The obtained F ratio value for adjusted test mean was 39.77 which were greater than the table value of 3.37 for significant at 0.05 level of confidence with the degrees of freedom 2 and 26. The result of the study shows that there was significant difference among the adjusted post test mean of three groups on explosive power. Hence the adjusted post test mean F ratio value was found to be significant and the result was subjected to Scheffe s post hoc test to find out the paired mean differences and is presented in table V-A. TABLE VI-A SCHEFFE S CONFIDENCE INTERVAL TEST SCORES ON EXPLOSIVE POWER (Scores in Centimeters) s Step Aerobics Training Plyometric Training Control Difference Class Interval 42.00 48.50 6.50* 4.06 42.00 34.60 7.4* 4.06 48.50 34.60 13.9* 4.06 *significant

83 Table VI-A shows that the adjusted the post test mean difference on explosive power between step aerobics and plyometric, step aerobics and control and plyometric and control group respectively. It was proved that there existed significant differences between the adjusted means of step aerobics and control group, plyometric group and control group. There was significant difference between plyometric group and step aerobic group and plyometric group was found to be better than step aerobics in improving explosive power of the subjects. The adjusted means on explosive power were presented through bar diagram for better understanding of the result of the study in figure 2. FIGURE 2 BAR DIAGRAM ON ORDERED ADJUSTED MEANS OF EXPLOSIVE POWER (Scores in Centimeters) Centimeters 50 45 40 35 30 25 20 15 10 5 0 48.5 42 34.6 Step aerobic plyometric control s

84 4.3.4 DISCUSSIONS ON THE FINDINGS OF EXPLOSIVE POWER Based on the results obtained, it was found that the development of explosive power due to plyometric training. In reviewing such effect of plyometric training on explosive power improved better than the other two groups. The muscle elasticity feature and the miotatic reflex (the stretch reflex) play an important role in the plyometric method. The reflex to stretch muscles includes the SSC (the stretch shortening cycle). A better adaptation of the CNS and a greater growth increase in strength and vertical jumping during explosive type strength training has been proven by the research findings of many authors (Wilson, Newton, Murphy, & Humphreys, 1993; Harris, Stone, O'Bryan, Proulx, & Johnson, 1999). Considering the fact that the height of volleyball players can not be changed during the course of training, the height within reach during a spike or block (the vertical jump) can be increased by sport training. One of the fundamental goals of volleyball training is to "build" explosive type strength "into" not only the biochemical structure, but also many other structures of volleyball techniques (Kostić, 1995, 54).This explosive type strength is defined as the individual ability of the neuromuscular system to show signs of strain in the shortest time possible (Verhošanski, 1979, 65). The spike and block actions are dominated by the corresponding explosive type strength which is referred to as the player's vertical jump, which is usually the key to winning points (Toplica Stojanović1 2004) In this study, the volleyball players Kendriya Vidyayala would have significantly improved in explosive power because of step aerobic exercises and plyometric training. 4.3.5 RESULTS ON FLEXIBILTY The fitness variable, flexibility was measured through sit and reach test. The result on the effect of twelve weeks step aerobic exercises and plyometric exercises is presented in Table VI.

85 TABLE VI COMPUTATION OF ANALYSIS OF COVARIANCE ON FLEXIBILITY (Scores in Centimeters) Step Aerobics Plyometric Control sv ss df ms F ratio Pre Test 23.20 23.50 23.20 Between.600 2.300 Within 129.70 27 4.80 0.06 Post Test 27.90 28.50 23.40 Between 155.40 2 77.70 Within 137.80 27 5.10 15.24* Adjusted Post Test 27.97 28.35 23.47 Between 147.41 2 73.70 Within 72.68 26 2.79 26.36* Required table value of for significant at 0.05 level of confidence for degrees of freedom 2 and 27(df) =3.35 and 2 and 26 (df) = 3.37. * Significant. Table VI shows that the pre test mean on flexibility of step aerobics, plyometric and control group are 23.20, 23.50 and 23.20 centimeters respectively. The post test means showed differences due to twelve weeks of step aerobics, plyometric exercises on flexibility of the experimental and control group mean values recorded were 27.90, 28.50 and 23.40 centimeters respectively. The obtained f ratio value for pre test mean was 0.06 which were lesser than the required table value of 3.37 for significant at 0.05 level of confidence with the degrees of freedom 2 and 27. This proved that there was no significant difference between the groups at initial stage.

86 The obtained f ratio value for post test mean was 15.24 which were greater than the table value of 3.37 for significant at 0.05 level of confidence with the degrees of freedom 2 and 27. This proved that the differences between the post test means of the subject were significant. The obtained f ratio value for adjusted test mean was 26.39 which were greater than the table value of 3.37 for significant at 0.05 level of confidence with the degrees of freedom 2 and 26. The result of the study shows that there was significant difference among the adjusted post test mean of three groups on flexibility. Hence the adjusted post test mean f ratio value was found to be significant and the result was subjected to Scheffe s post hoc test to find out which of the paired means had a significant difference, and is presented in table IX. TABLE VI-A SCHEFFE S CONFIDENCE INTERVAL TEST SCORES ON FLEXIBLITY (Scores in Centimeters) s Step Aerobics Training Plyometric Training Control Difference Class Interval 27.97 28.35 0.38 1.90 27.97 23.47 4.5* 1.90 28.35 23.47 4.88* 1.90 *Significant

87 The multiple mean comparisons shown in Table VI-A, proved that there existed significant differences between the adjusted means of plyometric group and control group, step aerobics and control group. There was no significant difference between step aerobics and plyometric groups and step aerobics group. The adjusted means on flexibility were presented through bar diagram for better understanding of the result of the study in figure 3. FIGURE 3 BAR DIAGRAM ON ORDERED ADJUSTED MEANS OF FLEXIBILITY (Scores in Centimeters) 30 27.97 28.35 25 23.47 Centimeters 20 15 10 5 0 Step aerobic plyometric control s 4.3.6 DISCUSSIONS ON THE FINDINGS OF FLEXIBILITY The results presented in Table IX showed that obtained adjusted means on flexibility among step aerobics was 27.60 followed by plyometric group with mean value of 26.60 and control group mean values of 24.70. The differences among pretest scores, post test scores and adjusted mean scores of the subjects were statistically treated using ANCOVA and F values obtained were 6.94, 12.25 and 9.69 respectively. It was found

88 that obtained F value on pre test scores was significant and the obtained F values on post test significant and adjusted means was significant at 0.05 level of confidence as this was greater than the required table F value of 3.37.The post hoc analysis through Scheffe s Confidence test proved that due to twelve weeks treatment the step aerobics exercises group improved flexibility than control group and the differences were significant at 0.05 level. The post hoc analysis between the experimental groups, namely step aerobics group and plyometric group proved that there was significant difference. The findings of this study is in agreement with the findings of Viskić,et.al. (2007) who analyzed the impact of special programmed physical education including dance, aerobics and rhythmic gymnastics on the development of motor and functional abilities and found significant development of coordination/agility and specific rhythm coordination, functional aerobic ability, repetitive and explosive strength and flexibility, along with significant reduction of overweight and adipose tissue. In this study, the obese engineering college students weight and adipose tissue would have significantly reduced and strength and flexibility improved because of floor aerobic exercises which enabled the subjects to perform significantly better in sit and reach test. In this study, the volleyball players kendriya vidyayala would have significantly improved in flexibility because of step aerobic exercises and plyometric training. 4.3.7 RESULTS ON ANAEROBIC POWER The results of analysis of covariance on data collected prior to and after the experimental period on variables among the step aerobics, plyometric training and Control group were presented in tables.

89 TABLE VII COMPUTATION OF ANALYSIS OF COVARIANCE ON ANAEROBIC POWER (Scores in Seconds) Step Aerobics Plyometric Control sv ss df ms F ratio Pre Test 6.74 6.74 6.75 Between 0.00 2 6.33 Within 0.28 27 0.1 0.01 Post Test 6.24 6.16 6.59 Between 1.03 2 0.51 Within 0.75 27 0.03 18.51* Adjusted Post Test 6.24 6.16 6.59 Between 1.01 2 0.51 Within 0.63 26 0.02 20.97* Required table value of for significant at 0.05 level of confident for degrees of freedom 2 and 27(df) =3.35 and 2 and 26 (df) = 3.37. * Significant. Table VII shows that the pre test mean on anaerobic power of step aerobics, plyometric and control group are 6.74, 6.74 and 6.75 respectively. The post test means showed differences due to 12 weeks of step aerobics, plyometric exercises on anaerobic power of the experimental and control group mean values recorded were 6.24, 6.16 and 6.59 seconds respectively. The obtained f ratio value for pre test mean was 0.01 which was lesser than the required table value of 3.35 for significant at 0.05 level of confidence with the degrees of freedom 2 and 27. This proved that there was no significant difference between the groups at initial stage.

90 The obtained f ratio value for post test mean was 18.51which was greater than the table value of 3.35 for significant at 0.05 level of confidence with the degrees of freedom 2 and 27. This proved that the difference between the post test means of the subject was significant. The obtained f ratio value for adjusted test mean was 20.97 which were greater than the table value of 3.37 for significant at 0.05 level of confidence with the degrees of freedom 2 and 26. The result of the study shows that there was significant difference among the adjusted post test mean of three groups on anaerobic power. Hence the adjusted post test mean f ratio value was found to be significant and the result was subjected to Scheffe s post hoc test to find out the paired mean differences among the groups, and was presented in table VII-A. TABLE VII-A SCHEFFE S CONFIDENCE INTERVAL TEST SCORES ON ANAEROBIC POWER (Scores in Seconds) s Step Aerobics Training Plyometric Training Control Difference Class Interval 6.24 6.16 0.08 0.16 6.24 6.59 0.39* 0.16 6.16 6.59 0.43* 0.16 *Significant

91 The multiple mean comparisons shown in Table VII-A, proved that there existed significant differences between the adjusted means of plyometric group and control group, step aerobics and control group. There was no significant difference between step aerobics and plyometric group. The adjusted means on flexibility were presented through bar diagram for better understanding of the result of the study in figure 4. FIGURE 4 BAR DIAGRAM ON ORDERED ADJUSTED MEANS OF ANAEROBIC POWER (Scores in Seconds) 6.6 6.59 6.5 6.4 Seconds 6.3 6.2 6.24 6.16 6.1 6 5.9 Step aerobic plyometric control s 4.3.8 DISCUSSIONS ON THE FINDINGS OF ANAEROBIC POWER Basically anaerobic power is the product of strength and power. Generally the anaerobic capacity is the non- oxygen fueled mechanism, and it underlies the training

92 modalities that induce the muscular system to adapt with the specific type of training the subjects were treated with the power related training of plyometric training with the purpose of developing the base of strength and power. As for as plyometric training is concerned, it evokes anaerobic power because of its nature since it uses adenosine triphosphate and creatine phosphate (ATP/CP) for its energy source which is non-oxygen fueled mechanism. It has been accorded with the study of Rahman Rahimi ( 2005). In his study he stated that plyometric training is capable of improving the vertical jump ability, muscular strength, and anaerobic power. In other words, the role of plyometrics is to facilitate the neuromuscular system into making a more rapid transition from eccentric to concentric contractions, whereby maximal ballistic force is generated (Adams,K., et al. 1992). This lends support to the theories of Gambetta (1986); O Shea (1985); Yessis and Hatfield (1982), who believe that plyometric training is the link between speed and strength. In this study, the volleyball players of Kendriya Vidyalaya significantly improved anaerobic power because of step and plyometric training which enabled the subjects to perform significantly better in 50 yard test. 4.3.9 RESULTS ON VITAL CAPACITY The physiological variable, vital capacity was measured through Spirometer. The results on the effect of twelve weeks varied aerobic exercises is presented in Table XII

93 TABLE VIII COMPUTATION OF ANALYSIS OF COVARIANCE ON VITAL CAPACITY (Scores in Milliliters) Step Aerobics Plyo metric Control sv ss df ms F ratio Pre Test 32600 32400 32460 Between 2106.667 2 1053.33 Within 19700440.00 27 72979.26.014 Post Test 40500 40000 33330 Between 3204926.667 2 1602463.333 Within 3097010.00 27 114704.07 13.97* Adjusted Post Test 40500 40000 33330 Between 3176586.538 2 1588293.269 Within 2349525.426 26 90366.36 17.58* Required table value of for significant at 0.05 level of confident for degrees of freedom 2 and 27(df) =3.35 and 2 and 26 (df) = 3.37. * Significant. Table VIII shows that the pre test mean on vital capacity of step aerobics, plyometric and control group are 32600, 32400 and 32460 respectively. The post test means showed differences due to twelve weeks of step aerobics, plyometric exercises on anaerobic power of the experimental and control group mean values recorded were 40500, 40000 and 33330 milliliters respectively. The obtained f ratio value for pre test mean was 0.01 which was lesser than the required table value 3.35 for significant at 0.05 level of confidence with the degrees of freedom 2 and 27. This proved that there was no significant difference between the groups at initial stage.

94 The obtained f ratio value for post test mean was 13.97 which was greater than the table value of 3.35 for significant at 0.05 level of confidence with the degrees of freedom 2 and 27. This proved that the difference between the post test means of the subject was significant. The obtained f ratio value for adjusted test mean was 17.58 which was greater than the table value of 3.37 for significant at 0.05 level of confidence with the degrees of freedom 2 and 26. The results of this study indicate that there was statistically significant difference among the adjusted post-test means of step aerobics group, plyometric training group, and control group on vital capacity. Therefore, it was concluded that there is significant difference among the adjusted post-test means of step aerobics group, plyometric training group, and control on vital capacity. To determine which of the paired means had a significant difference, the Scheffe s test was used as post-hoc test and the results are presented in the table VIII-A. TABLE VIII-A SCHEFFE S CONFIDENCE INTERVAL TEST SCORES ON VITAL CAPACITY Step Aerobics Training s Plyometric Training (Scores in Milliliters) Control Difference Class Interval 40500 40000 500* 349.02 40500 33330 717* 349.02 *significant 40000 33330 667* 349.02

95 Table VIII-A, shows that the adjusted the post test mean difference on vital capacity between step aerobics and plyometric, step aerobics and control and plyometric and control group respectively. It was proved that there existed significant differences between the adjusted means of step aerobics and control group, plyometric group and control group. There was significant difference between plyometric group and step aerobics group and step aerobics group was found to be significantly better than plyometric group in improving vital capacity of the subjects. The adjusted means on vital capacity were presented through bar diagram for better understanding of the result of the study in figure- 5 FIGURE 5 BAR DIAGRAM ON ORDERED ADJUSTED MEANS OF VITAL CAPACITY (Scores in Milliliters) Milliliters 45000 40000 35000 30000 25000 20000 15000 10000 5000 0 40500 40000 33330 STEP AEROBICS PLYOMETRIC CONTROL s 4.3.10 DISCUSSIONS ON THE FINDINGS OF VITAL CAPACITY The results presented in Table XII showed that obtained adjusted means on vital capacity among step aerobics was 40000 followed by plyometric trainings group with mean value of 405003 and control group mean values of 33330. The differences among

96 pretest scores, post test scores and adjusted mean scores of the subjects were statistically treated using ANCOVA and F values obtained were 0.014, 13.97 and 17.58 mm respectively. It was found that obtained F value on pre test scores was not significant and the obtained F values on post test and adjusted means were significant at 0.05 level of confidence as these were greater than the required table F value of 3.37. The post hoc analysis through Scheffe s Confidence test proved that due to twelve weeks treatment the step aerobics and plyometric exercises group improved vital capacity than control group and the differences were significant at 0.05 level. The post hoc analysis between the experimental groups, namely step aerobics group and plyometric exercise group proved that there was significant difference between the means and plyometric exercises were proved to be significantly better than step aerobic exercises in improving the vital capacity. The findings of this study were in agreement with the findings of Selvalakshmi (2007) conducted a study on effect of varied aerobic training program on obese women and found vital capacity showed significant improvement due to varied aerobic exercises. Torre et.al. (2005) found aerobic step dance using an overload strategy significantly increased HR max and VO2 max. In this study, the kenderiya vidyalay students heart rate and VO2 max would have increased, which resulted in improved vital capacity of the subjects. Hence, vital capacity of the step aerobics and plyometric groups were significantly better than control group. Among the treatment groups plyometric group was significantly better than step aerobic exercises in improving vital capacity. 4.3.11 RESULTS ON SERVICE follows. The results on skill performance variables such as jump service are discussed as

97 TABLE IX COMPUTATION OF ANALYSIS OF COVARIANCE ON SERVICE (Scores in Points) Step Aerobics Plyometric Control sv ss df ms F ratio Pre Test 5.46 5.64 4.96 Between 2.46 2 1.23 Within 26.66 27 0.99 1.25 Post Test 6.35 7.09 5.12 Between 19.74 2 9.87 Within 16.79 27 0.62 15.87* Adjusted Post Test 6.35 7.09 5.12 Between 10.61 2 5.30 Within 4.77 26 0.18 28.92* *significant Required table value of for significant at 0.05 level of confident for degrees of freedom 2 and 27(df) =3.35 and 2 and 26 (df) = 3.37. * Significant. Table IX shows that the pre test mean on service of step aerobics, plyometric and control group are 5.46, 5.64 and 4.96, respectively. The post test means showed differences due to twelve weeks of step aerobics, plyometric exercises on service of the experimental and control group mean values recorded were 6.35, 7.09 and 5.12 in points respectively. The obtained f ratio value for pre test mean was 1.25 which was lesser than the required table value of 3.35 for significant at 0.05 level of confidence with the degrees of freedom 2 and 27.

98 This proved that there was no significant difference between the groups at initial stage. The obtained f ratio value for post test mean was 15.87 which was greater than the table value of 3.35 for significant at 0.05 level of confidents with the degrees of freedom 2 and 27. This proved that the difference between the post test means of the subject was significant. The obtained f ratio value for adjusted test mean was 28.92 which was greater than the table value of 3.37 for significant at 0.05 level of confidents with the degrees of freedom 2 and 26. The result of the study shows that there was significant difference among the adjusted post test mean of three groups on service. Hence the adjusted post test mean of ratio value was found to be significant and the result was subjected to Scheffe s post hoc test to find out the paired mean differences and is presented in table IX-A. TABLE IX-A SCHEFFE S CONFIDENCE INTERVAL TEST SCORES ON SERVICE (Scores in Points) Step Aerobics Training s Plyometric Training Control Difference Class Interval 6.35 7.09 0.74* 0.49 6.35 5.12 1.23* 0.49 *significant 7.09 5.12 1.97* 0.49

99 Table IX-A shows that the adjusted the post test mean difference on service ability between step aerobics and plyometric, step aerobics and control and plyometric and control group respectively. It was proved that there existed significant differences between the adjusted means of step aerobics and control group, plyometric group and control group. There was significant difference between plyometric group and step aerobics group and plyometric group was found to be significantly better than step aerobics in improving service ability of the Volleyball players. The adjusted means on service were presented through bar diagram for better understanding of the result of the study in figure- 6 FIGURE 6 BAR DIAGRAM ON ORDERED ADJUSTED MEANS OF SERVICE (Scores in Points) Points 8 7 6 5 4 3 2 1 0 7.09 6.35 5.12 Step aerobics plyometirc control s 4.3.12 DISCUSSIONS ON THE FINDINGS OF SERVICE The results on skill performance variables such as service are discussed as follows. Generally the skills of the game are developed on the basis of physical components of the skills; service is one of the important skills which are the means to start the game. The action and execution of service is depends upon the neuromuscular co-ordination for

100 the approach to the ball and transfer of force from the body to the hitting hand. As far as the skills are concerned the neuromuscular co-ordination plays a predominant role in the successful execution with the help of the required fitness components. According to Adams (et al. 1992) the powerful muscular stimulus from the muscular system contributes the explosive actions and the neuromuscular efficiency by the plyometric training. The finding of this study were in agreement with the findings of Arumugam (2007) conducted a study of the effect of resistance plyometric and complex training on volleyball players and found that the serving ability showed significant improvement due to these trainings. In this study, the volleyball players of Kendriya Vidyalaya significantly improved serving ability power because of step and plyometric training which enabled the subjects to perform significantly better in service test in volleyball. 4.3.13 RESULTS ON ATTACK The results on skill performance variables such as attack-hit are discussed as follows. Pre Test Post Test Adjusted Post Test *significant TABLE X COMPUTATION OF ANALYSIS OF COVARIANCE ON ATTACK Step Aerobics Plyometric 4.44 4.42 4.45 5.37 5.93 4.90 5.37 5.93 4.90 (Scores in points) Control sv ss df ms F ratio Between 0.01 2 0.00 Within 14.02 27 0.52 Between 5.37 2 2.69 Within 6.92 27 0.26 Between 5.57 2 2.79 Within 2.36 26 0.09 0.01 10.48* 30.67*

101 Required table value of for significant at 0.05 level of confident for degrees of freedom 2 and 27(df) =3.35 and 2 and 26 (df) = 3.37. *Significant. Table X shows that the pre test mean on attack of step aerobics, plyometric and control group are 4.44, 4.42 and 4.45 respectively. The post test means showed differences due to twelve weeks of step aerobics, plyometric exercises on attack of the experimental and control group mean values recorded were 5.37, 5.93 and 4.90 in points respectively. The obtained f ratio value for pre test mean was 0.01 which was lesser than the required table value of 3.35 for significant at 0.05 level of confidence with the degrees of freedom 2 and 27. This proved that there was no significant difference between the groups at initial stage. The obtained f ratio value for post test mean was 10.48 which was greater than the table value of 3.35 for significant at 0.05 level of confidents with the degrees of freedom 2 and 27. This proved that the difference between the post test means of the subject was significant. The obtained f ratio value for adjusted test mean was 30.67 which were greater than the table value of 3.37 for significant at 0.05 level of confidence with the degrees of freedom 2 and 26. The result of the study shows that there was significant difference among the adjusted post test mean of three groups on attack. The results of this study indicate that there was statistically significant difference among the adjusted post-test means of step aerobics group, plyometric training group, and control group on attack in volleyball. Therefore, it was concluded that there is significant

102 difference among the adjusted post-test means of step aerobics group, plyometric training group, and control on attack in volleyball. To determine which of the paired means had a significant difference, the Scheffe s test was used as post-hoc test and the results are presented in the table X-A. TABLE X-A SCHEFFE S CONFIDENCE INTERVAL TEST SCORES ON ATTACK (Scores in Points) s Step Aerobics Training Plyometric Training Control Difference Class Interval 5.37 5.93 0.56* 0.35 5.37 4.90 0.47* 0.35 5.93 4.90 1.03* 0.35 Table X-A shows that the adjusted the post test mean difference on attack between step aerobics and plyometric, step aerobics and control and plyometric and control group respectively. The multiple mean comparisons shown in the table XVII proved that there existed significant differences between the adjusted means of step aerobics and control group, plyometric group and control group. There was significant difference between plyometric group and step aerobic group and plyometric group was found to be significantly better than step aerobics in improving attack hit of the subjects. The adjusted means on attack hit were presented through bar diagram for better understanding of the result of the study in figure- 7

103 FIGURE 7 BAR DIAGRAM ON ORDERED ADJUSTED MEANS OF ATTACK (Scores in Points) 6 5 5.37 5.93 4.9 4 Points 3 2 1 0 Step aerobics plyometric control s 4.3.14 DISCUSSIONS ON THE FINDINGS OF ATTACK as follows. The results on skill performance variables such as attack in volleyball are discussed The exciting skill in the game volleyball is attack. Each and every player is interested and attracted to the action of attack-hit. The basic physical component required for this thrilling action are, a good vertical jump, co-ordinate approach, time and place of contact the ball in the air. Discussing the results on attack, the most effective training was the plyometric training. As per this study the plyometric exercise group dominating in the development of attacking skill in volleyball.

104 This study is in accordance with Bénédicte Forthomme et.al. (2005) who suggested in his study that some specific strength and physical characteristics correlated significantly with spike performance in high-level volleyball practice. Strength and conditioning programmes, that facilitate the capacity for football players to develop forceful and rapid concentric action, through plantar flexion of the ankle, as well as extension of the knee and hip, may be highly profitable for skill development. Hakkinen (1993) stated in his study that significant increases took place in the maximal vertical jumping heights in the squat and in the counter movement jump as well as in the spike and block jumps during competitive season. Tsunawake et al (2003) in his study stated that the female volleyball players and basketball players evaluated, had the physical abilities needed to win the championship in the Japan Inter-high School meets. In this study the plyometric training had a significant improvement. The finding of this study were in agreement with the findings of Arumugam (2007) conducted a study of the effect of resistance plyometric and complex training on volleyball players and found that the attack hit in volleyball showed significant improvement due to these trainings. In this study, the volleyball players of Kendriya Vidyalaya significantly improved attack skill because of step and plyometric training which enabled the subjects to perform significantly better in attack test in volleyball. 4.4 DISCUSSION ON HYPOTHESES The formulated hypotheses of this study were, The hypothesis number one, It was hypothesized that the plyometric training may significantly improve the selected physical fitness variables such as muscular strength, and explosive power among volleyball players than the step aerobics training group and control group.

105 Based on the results of this study, the formulated above hypotheses no 1 is accepted at 0.05 level of confidence for the selected variables of plyometric training group. Hypothesis number two, It was hypothesized that the step aerobics group may significantly improve inflexibility, among volleyball players than the plyometric training group and control group. Based on the obtained results of this study, the formulated above hypotheses no 2 is accepted at 0.05 level of confidence for the selected variables of step aerobics training group. Hypothesis number three, It was hypothesized that the step aerobics group may significantly improve in physiological variables such as anaerobic power and vital capacity, among volleyball players than the plyometric training group and control group. The results obtained from this study, the formulated above hypotheses no 3 is partially rejected in the case of anaerobic power and partially accepted in the case of vital capacity, at 0.05 level of confidence for the selected variables of step aerobics group. Hypothesis number four, It was hypothesized that there may be a significant improvement in skill performance variable such as service and attack due to plyometric training group than the step aerobics group and control group. Based on the results of this study, the formulated above hypotheses no 4 is accepted at 0.05 level of confidence for the selected variables of plyometric training group. Hypothesis number five

106 It was hypothesized that the control group may not have statistically significant improvement in all the selected variables, when compare to plyometric group and step aerobics group. The result of this study reveals that, the formulated above hypotheses no 5 is accepted at 0.05 level of confidence for the selected variables of control group.