Plyometrics is primarily used by coaches and sport scientists to improve explosive power among athletes who participate in dynamic, high intensity type of sports. One of the plyometric-related training methods that has received attention in recent years, is loaded or resistance (resistive) jump training. Limited research does, however, exist with regard to the benefits and use of this training method as well as in conjunction with other training methods, especially among team sport participants. It is against this background that the research objectives of this study were firstly, to examine the effects of a 4-week combined rugby-conditioning and resisted jump training program compared to a combined rugby-conditioning and normal jump training program, on selected physical, motor ability and anthropometric components of university-level rugby players. The second objective was to examine the acute effects of a resisted compared to a normal jump training session on selected physical and motor ability components of university-level rugby players. Thirty rugby players (age: 19.60 ± 0.79 years) from the first and second u/19 and u/21 rugby teams of a university in South Africa were randomly selected to participate in the first part of study. For the second part of the study thirty senior rugby players (1st and 2nd senior teams) (age: 21.78 ± 1.86 years) of the Rugby Institute at a university in South Africa were randomly selected to participate in the study. For both studies the thirty players were in turn randomly divided into two groups of fifteen players each. One group formed the experimental and the other group the control group. The first objective was tested by subjecting the players to a 4-week combined sport-specific and resisted plyometric training program (experimental group) or a combined sport-specific and normal plyometric training program to investigate the adaptations of body composition, lower body flexibility, explosive leg power, speed, agility and leg strength. After a 10-week period (“wash-out period”) during which subjects continued with their normal rugby-conditioning program, the same testing procedures as before, were executed by following a crossover design. In order to test the second objective of the study players’ body weight and height were firstly measured after which they were subjected to a thorough warm-up, followed by the execution of the flexibility;Vertical Jump Test (VJT); 5-, 10- and 20 m speed tests; the Illinois Agility Run Test (IART) and the 6RM (repetition maximum) Smith Machine Squat Test (6RM-SMST). The experimental group was subject to the resisted jump training session on the Vertimax whereas the control group executed the same exercises on the floor. Directly after the training session each of the players again completed the test battery. After the first week, a crossover design was implemented. Although the overall study (independent t-test and main effect ANOVA) results of the first study suggested that the experimental group experienced more positive changes, especially with regard to the body fat, skeletal mass and somatotype-related anthropometric and flexibility-related measurements, only relaxed upper-arm girth, ectomorphy, left Active-straight-leg-raise-test and the left Modified Thomas Quadriceps Test values showed significant differences (p < 0.05) when the two groups of players were compared. Although the experimental group demonstrated significantly better average scores in the majority of the last-mentioned components, this group experienced a significantly higher reduction in relaxed upper-arm girth due to the conditioning program than the control group. The main effect ANOVA results of the acute study showed that no significant differences were obtained for any of the measured components between an acute resisted and normal jump training session. To conclude, the study revealed that a 4-week combined rugby-conditioning and resisted jump training program (experimental group) did not benefit university-level rugby players significantly more with regard to selected physical, motor ability and anthropometric components than a combined rugby-conditioning and normal jump training program (control group). Furthermore, despite the fact that the acute resisted and normal jump training exercises met all the requirements to produce post-activation potentiation, the study results showed that these exercise sessions did not lead to any significant acute changes in the physical and motor ability components of university-level rugby players. / MA (Sport Science), North-West University, Potchefstroom Campus, 2014

Plyometrics is primarily used by coaches and sport scientists to improve explosive power among athletes who participate in dynamic, high intensity type of sports. One of the plyometric-related training methods that has received attention in recent years, is loaded or resistance (resistive) jump training. Limited research does, however, exist with regard to the benefits and use of this training method as well as in conjunction with other training methods, especially among team sport participants. It is against this background that the research objectives of this study were firstly, to examine the effects of a 4-week combined rugby-conditioning and resisted jump training program compared to a combined rugby-conditioning and normal jump training program, on selected physical, motor ability and anthropometric components of university-level rugby players. The second objective was to examine the acute effects of a resisted compared to a normal jump training session on selected physical and motor ability components of university-level rugby players. Thirty rugby players (age: 19.60 ± 0.79 years) from the first and second u/19 and u/21 rugby teams of a university in South Africa were randomly selected to participate in the first part of study. For the second part of the study thirty senior rugby players (1st and 2nd senior teams) (age: 21.78 ± 1.86 years) of the Rugby Institute at a university in South Africa were randomly selected to participate in the study. For both studies the thirty players were in turn randomly divided into two groups of fifteen players each. One group formed the experimental and the other group the control group. The first objective was tested by subjecting the players to a 4-week combined sport-specific and resisted plyometric training program (experimental group) or a combined sport-specific and normal plyometric training program to investigate the adaptations of body composition, lower body flexibility, explosive leg power, speed, agility and leg strength. After a 10-week period (“wash-out period”) during which subjects continued with their normal rugby-conditioning program, the same testing procedures as before, were executed by following a crossover design. In order to test the second objective of the study players’ body weight and height were firstly measured after which they were subjected to a thorough warm-up, followed by the execution of the flexibility;Vertical Jump Test (VJT); 5-, 10- and 20 m speed tests; the Illinois Agility Run Test (IART) and the 6RM (repetition maximum) Smith Machine Squat Test (6RM-SMST). The experimental group was subject to the resisted jump training session on the Vertimax whereas the control group executed the same exercises on the floor. Directly after the training session each of the players again completed the test battery. After the first week, a crossover design was implemented. Although the overall study (independent t-test and main effect ANOVA) results of the first study suggested that the experimental group experienced more positive changes, especially with regard to the body fat, skeletal mass and somatotype-related anthropometric and flexibility-related measurements, only relaxed upper-arm girth, ectomorphy, left Active-straight-leg-raise-test and the left Modified Thomas Quadriceps Test values showed significant differences (p < 0.05) when the two groups of players were compared. Although the experimental group demonstrated significantly better average scores in the majority of the last-mentioned components, this group experienced a significantly higher reduction in relaxed upper-arm girth due to the conditioning program than the control group. The main effect ANOVA results of the acute study showed that no significant differences were obtained for any of the measured components between an acute resisted and normal jump training session. To conclude, the study revealed that a 4-week combined rugby-conditioning and resisted jump training program (experimental group) did not benefit university-level rugby players significantly more with regard to selected physical, motor ability and anthropometric components than a combined rugby-conditioning and normal jump training program (control group). Furthermore, despite the fact that the acute resisted and normal jump training exercises met all the requirements to produce post-activation potentiation, the study results showed that these exercise sessions did not lead to any significant acute changes in the physical and motor ability components of university-level rugby players. / MA (Sport Science), North-West University, Potchefstroom Campus, 2014

This study aimed to investigate the response of trained intercollegiate and national level female athletes to twelve week depth-jump (DJ) training performed twice weekly with forty repetitions of DJs performed each training session. Results of statistical analysis revealed that only the .3 and .5 meter experimental group improved significantly on VJ ability. However, there was no significant increase in LS for either experimental group compared to the control group. It was concluded that DJ training from .3 and .5 meter heights is more optimal for increasing VJ ability of trained female athletes compared to the 0.75 and 1.1 meter heights as recommended by Verhoshanski for trained male athletes. It was also concluded that DJ training has the the ultimate purpose of developing explosive leg power not leg strength.

Title: Training jumps difficulty in sport aerobics. Objectives: Jumps difficulty in aerobic sports athletes seems to be most problematic part of the performance for large demands on the technical implementation. Aim of this study will therefore analyze the technical and didactic jumps difficulty developing a methodology and training. The work can use coaches and athletes, as a methodological material to correct the errors in the current design practice new jumps and difficulty. Methods: After studying literature, focusing on sports and gymnastic training, I used the specific chapters related to the technique performed jumps in sport aerobics. Video analysis, I analyzed the reports selected category of racing sports aerobics usually classified in terms of difficulty of the jumps. Results: Analysis of the technical difficulty of execution jumps according to the rules of sports aerobics, I proposed a number of methodological training jumps selected difficulty. Finally, I have said frequently occurring errors in the implementation of selected jumps. The work could help improve the technical aspects of performance sport aerobics athletes to achieve better performance. Keywords: Sport aerobic, fitness aerobic, aerobic team show, jumps, jump training, elements of difficulty, sports performance, sports...

The purpose of this study was to investigate two different plyometric training techniques for increasing vertical jumping ability. Twenty-four female high school volleyball players were matched for height and weight and distributed equally among three groups. Each subject performed a vertical jump test, Margaria power test, Wingate bicycle test, and an isokinetic leg strength test prior to and following six weeks of training. Plyometric training significantly (p<.05) improved vertical jumping ability and some indices of leg strength and power. Weighted plyometrics did not enhance performance more than plyometrics alone. These data support the view that plyometric training with or without added weights enhances vertical jumping and leg power.

Physical activity is critical to bone health. However, not all physical activity has optimum effect on bone health and metabolism. The purpose of this study was to determine the effects of a short term progressive jumping protocol on bone mineral density in college age Asian females. Sixteen participants aged18-28 years enrolled in the study. Participants were assigned to exercise (n=9) and control (n=8) groups. The exercise group completed a two-legged depth jump from an approximate 20cm stepbench followed immediately by a maximum vertical jump using arm swings for five days per week for two weeks. Each depth jump and vertical jump was performed ten times during each session. The exercise intervention progressed from one session per day to three sessions per day in ten days. The bone mineral density (BMD) by dualenergy x-ray absorptiometry (DXA), ground reaction force (GRF), bone specific physical activity questionnaire (BPAQ), and dietary log were administered to the participants pre- and post-intervention. The data were analysed using a dependent t-test and one-way repeated measures. There were no significant changes noted in BMD value in the study. The past BPAQ showed significant correlation to BMD change of left hip (p<0.01) in exercise group. The vertical GRF showed significant increase (p<0.05) in exercise group. It can be concluded from the study that intensity of the progressive jumping was intense enough to stimulate some changes in the bone metabolism.