Wetenschap en waterpolo


The relationship between blood lactate and heart rate responses to swim bench exercise and women's competitive water polo.
J Sports Sci. 1998 Apr;16(3):251-6. Konstantaki M, Trowbridge EA, Swaine IL.
Department of Medical Physics, University of Sheffield, UK.

The aim of this study was to explore the relationship between physiological responses to dry-land testing and to water polo playing. Eight female water polo players (mean+/-s: age 26.7+/-5.7 years, height 169+/-6 cm, body mass 65.3+/-7.0 kg) participated in two assessments. The first involved a discontinuous incremental arm test to exhaustion on an isokinetic swim bench. Blood lactate was determined from finger-prick blood samples and heart rate was recorded at increasing exercise intensities. The highest (peak) values for blood lactate (5.1+/-0.2 mmol l(-1)), exercise intensity (79+/-5.2 W) and heart rate (146+/-6 beats min(-1)) were recorded at exhaustion. Also, the exercise intensity and heart rate at a blood lactate concentration of 4 mmol l(-1) were established. The second assessment involved determination of blood lactate and heart rate immediately after each quarter of a different water polo game for each subject. The mean (+/-s(x)) blood lactate and heart rate for each quarter of the game were as follows: 3.5+/-0.4, 4.3+/-0.5, 4.3+/-0.7 and 4.6+/-0.5 mmol l(-1); 138+/-10, 149+/-12, 151+/-9 and 154+/-8 beats min(-1), respectively. None of the peak values on the swim bench correlated with blood lactate or heart rate responses to game-playing. However, the mean exercise intensity at 4 mmol l(-1) lactate (64+/-5 W) correlated with the fourth quarter values of both blood lactate concentration (r=-0.82, P=0.01) and heart rate (r=-0.93, P< 0.001). These results show that submaximal metabolic responses to exercise on a swim bench are closely correlated with metabolic responses to water polo game-playing.

Differences in several perceptual abilities between experts and novices in basketball, volleyball and water-polo.
Percept Mot Skills. 1998 Jun;86(3 Pt 1):899-912
Kioumourtzoglou E, Kourtessis T, Michalopoulou M, Derri V.
Democritus University of Thrace, Department of Physical Education and Sport Science, Komotini, Greece.

The aim of this study was to examine differences between experts and novices in a number of perceptual abilities. Three groups of elite athletes, 44 members of Greek national teams in basketball (n = 12), volleyball (n = 13), and water-polo (n = 19) were selected. Two groups of physical education students (ns = 18 and 21) were novices. The measured abilities were selected as the most important for an elite athlete by expert coaches in the three sports. The four most frequently selected abilities for each sport, according to the coaches' opinions, were finally assessed. Analysis showed that differences were fewer than expected. Basketball experts were better on prediction and selective attention. Volleyball experts performed better on perceptual speed, focused attention, prediction, and estimation of speed and direction of a moving object. Water-polo players had significantly better scores than the novices on decision-making, visual reaction time, and spatial orientation. It seems that the nature of each sport strongly influences the way perceptual abilities differentiate elite athletes from novices.

The use of a single case design to investigate the effect of a pre-performance routine on the water polo penalty shot.
J Sci Med Sport. 1998 Sep;1(3):143-55.
Marlow C, Bull SJ, Heath B, Shambrook CJ.
Chelsea School Research Centre, University of Brighton, UK.

The pre-performance routine (PPR) is proposed to assist the performance of closed skills by enhancing concentration (Crews and Boutcher, 1987) and the recall of optimal psychological and physiological states (Cohn, 1990). A multiple-baseline-across-individuals design was utilised to assess the effect of PPRs on water polo penalty shot performance. Three experienced male water polo players were assisted in designing a personalised multi-component PPR, which was rehearsed in accordance with a training program, and implemented prior to performing penalty shots in simulated trials. Mean performance scores increased for all players between pre and post intervention phases. A Split Middle analysis (White, 1974) further described performance trends and changes. Players 1 and 2 reversed negative baseline trends of -1.071 and -1.031 to positive post intervention trends of +1.011 and +1.011, producing respective positive changes in slope of +1.08 and +1.042. Player 3's baseline trend of +1.008 was reversed post intervention to -1.004, causing a negative change in slope of -1.012. Respective ratios of 1.38, 1.36 and 1.20, suggest a positive change in trend level immediately following PPR introduction. Binomial tests revealed improvements in all participant performances between stages (p<0.001). Results are reviewed in light of previous research and the utilisation of single-subject designs is discussed.

Applied physiology of water polo
Sports Med. 1998 Nov;26(5):317-34
Smith HK.
Department of Sport and Exercise Science, The University of Auckland, New Zealand.

Water polo has been played for over a century. While the rules of the game have evolved considerably over this time, the sport has consistently remained, physiologically, a highly demanding activity. Much attention has been paid to the technical and strategic elements of the game; however, despite the potential for improvements in athletic performance and the maintenance of athletes' health, there are few published studies (particularly in English) on the physical and physiological demands and adaptations to water polo training and competition. Game analyses have demonstrated that water polo is an 'intermittent' sport comprised of intense bursts of activity of <15 seconds duration with intervening, lower intensity intervals averaging <20 seconds duration. Physiological measurements obtained during game play indicate a cumulative effect of the repeated sequences of activities and suggest there is a high metabolic demand on the athletes. The multiple individual skills and movements required for playing water polo also place considerable demands on the neuromuscular system. Observations of the frequency and duration of the different activities, and of the physiological responses to participating in a water polo match, are initial sources of information for designing training programmes specific to the game and to the different playing positions. The physical and physiological attributes of elite water polo players offer some insight into the minimum requirements for participation and the adaptations that result from training and competition. Further systematic documentation and experimentation are required to facilitate the design and specification of individual training programmes and to better understand the long term effects of water polo on athletes' health.

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