Effects of whole body vibration on strength and jumping performance in volleyball and beach volleyball players

The primary aim of this study was to examine the effects of 6-week strength training with whole body vibration (WBV) on leg strength and jumping performance in volleyball and beach volleyball players. Twenty-three sub-elite male volleyball (VB; n=12) and beach volleyball players (BVB; n=11) aged 21.2±3.0 years were divided into two groups and subjected to 6 weeks of strength training (three one-hour sessions per week): (I) 12 players (6 VB and 6 BVB players) underwent training with WBV (30-40 Hz, 1.7-2.5 mm, 3.0-5.7 g), and (II) 11 players (6 VB and 5 BVB players) underwent traditional strength training. Squat jump (SJ) and countermovement squat jump (CMJ) measurements by the Ergo Tester contact platform and maximum leg press test (1RM) were conducted. Three-factor (2 time x 2 WBV use x 2 discipline) analysis of variance for SJ, CMJ and 1RM revealed a significant time main effect (p<0.001), a WBV use effect (p<0.001) and a discipline effect (p<0.001). Significantly greater improvements in the SJ (p<0.001) and CMJ (p<0.001) and in 1RM (p<0.001) were found in the WBV training groups than in traditional training groups. Significant 3-way interaction effects (training, WBV use, discipline kind) were also found for SJ, CMJ and 1RM (p=0.001, p<0.001, p=0.001, respectively). It can be concluded that implementation of 6-week WBV training in routine practice in volleyball and beach volleyball players increases leg strength more and leads to greater improvement in jump performance than traditional strength training, but greater improvements can be expected in beach volleyball players than in volleyball players.

Newt Loken jumping near Crisler Arena sign

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An account of the jumping mouse of Canada, Dipus canadensis.

Mode of access: Internet.

Interindividual Differences in Leg Muscle Mass and Pyruvate Kinase Activity Correlate with Interindividual Differences in Jumping Performance of Hyla multilineata

Frog jumping is an excellent model system for examining the structural basis of interindividual variation in burst locomotor performance. Some possible factors that affect jump performance, such as total body size, hindlimb length, muscle mass, and muscle mechanical and biochemical properties, were analysed at the interindividual (intraspecies) level in the tree frog Hyla multilineata. The aim of this study was to determine which of these physiological and anatomical variables both vary between individuals and are correlated with interindividual variation in jump performance. The model produced via stepwise linear regression analysis of absolute data suggested that 62% of the interindividual variation in maximum jump distance could be explained by a combination of interindividual variation in absolute plantaris muscle mass, total hindlimb muscle mass ( excluding plantaris muscle), and pyruvate kinase activity. When body length effects were removed, multiple regression indicated that the same independent variables explained 43% of the residual interindividual variation in jump distance. This suggests that individuals with relatively large jumping muscles and high pyruvate kinase activity for their body size achieved comparatively large maximal jump distances for their body size.

Government relations, government regulations: jumping through the hoops

Over the last decade, telehealth in Australia has been primarily facilitated and driven by government funding. The government now has a major policy initiative in online health. However, in pursuing the broad initiative there is a danger that some of the smaller components can get lost, and this is probably what has happened to telehealth. There appear to be a number of steps required if telehealth in Australia is to keep up the pace of development that occurred in the 1990s, as we move into what is now being called the era of e-health, involving broadband Internet health service delivery. This area is changing extremely rapidly and is increasingly migrating away from the public sector in Australia, where most of the developmental work has occurred, and into the private sector. Many of the issues that require consideration within the domain of e-health in Australia are also relevant to other countries. E-health will significantly change the way that health-care is practised in future, and it is clear that it is the human factors that are more difficult to overcome, rather than the technological ones.

Government relations, government regulations: Jumping through the hoops

Over the last decade, telehealth in Australia has been primarily facilitated and driven by government funding. The government now has a major policy initiative in online health. However, in pursuing the broad initiative there is a danger that some of the smaller components can get lost, and this is probably what has happened to telehealth. There appear to be a number of steps required if telehealth in Australia is to keep up the pace of development that occurred in the 1990s, as we move into what is now being called the era of e-health, involving broadband Internet health service delivery. This area is changing extremely rapidly and is increasingly migrating away from the public sector in Australia, where most of the developmental work has occurred, and into the private sector. Many of the issues that require consideration within the domain of e-health in Australia are also relevant to other countries. E-health will significantly change the way that health-care is practised in future, and it is clear that it is the human factors that are more difficult to overcome, rather than the technological ones.

Dropout dynamics in pulsed quantum dot lasers due to mode jumping

We examine the response of a pulse pumped quantum dot laser both experimentally and numerically. As the maximum of the pump pulse comes closer to the excited-state threshold, the output pulse shape becomes unstable and leads to dropouts. We conjecture that these instabilities result from an increase of the linewidth enhancement factor α as the pump parameter comes close to the excitated state threshold. In order to analyze the dynamical mechanism of the dropout, we consider two cases for which the laser exhibits either a jump to a different single mode or a jump to fast intensity oscillations. The origin of these two instabilities is clarified by a combined analytical and numerical bifurcation diagram of the steady state intensity modes.

Nonlinear periodic problems with a jumping reaction

We consider a periodic problem driven by the scalar $p-$Laplacian and with a jumping (asymmetric) reaction. We prove two multiplicity theorems. The first concerns the nonlinear problem ($1

Vertical jumping tests versus wingate anaerobic test in female volleyball players: The role of age

Single and continuous vertical jumping tests, as well as the Wingate anaerobic test (WAnT), are commonly used to assess the short-term muscle power of female volleyball players; however, the relationship among these tests has not been studied adequately. Thus, the aim of the present study was to examine the relationship of single and continuous vertical jumps with the WAnT in female volleyball players. Seventy adolescent (age 16.0 ˘ 1.0 years, body mass 62.5 ˘ 7.1 kg, height 170.4 ˘ 6.1 cm, body fat 24.2% ˘ 4.3%) and 108 adult female volleyball players (age 24.8 ˘ 5.2 years, body mass 66.5 ˘ 8.7 kg, height 173.2 ˘ 7.4 cm, body fat 22.0% ˘ 5.1%) performed the squat jump (SJ), countermovement jump (CMJ), Abalakov jump (AJ), 30 s Bosco test and WAnT (peak power, Ppeak; mean power, Pmean). Mean power in the Bosco test was correlated (low to large magnitude) with Pmean of the WAnT (r = 0.27, p = 0.030 in adolescents versus r = 0.56, p < 0.001 in adults). SJ, CMJ and AJ also correlated with Ppeak (0.28 ď r ď 0.46 in adolescents versus 0.58 ď r ď 0.61 in adults) and with Pmean (0.43 ď r ď 0.51 versus 0.67 ď r ď 0.71, respectively) of the WAnT (p < 0.05). In summary, the impact of the Bosco test and WAnT on muscle power varied, especially in the younger age group. Single jumping tests had larger correlations with WAnT in adults than in adolescent volleyball players. These findings should be taken into account by volleyball coaches and fitness trainers during the assessment of short-term muscle power of their athletes.

Extreme sports as a facilitator of ecocentricity and positive life changes

Extreme sports and extreme sports participants have been most commonly explored from a negative perspective, for example the 'need to take unnecessary risks'. This study reports on findings that indicate a more positive experience. A phenomenological method was used via unstructured interviews with 15 extreme sports participants and other first hand accounts. The extreme sports included B.A.S.E. jumping, big wave surfing, extreme skiing, waterfall kayaking, extreme mountaineering and solo rope-free climbing. Results indicate that participating in activities that involve a real chance of death, fear and the realisation that nature in its extreme is far greater and more powerful than humanity triggers positive life changes, and an eco-centric standpoint.