Wetenschap en waterpolo


Echocardiographic data in hungarian top-level water polo players.
Med Sci Sports Exerc. 2005 Feb;37(2):323-8.
Pavlik G, Kemény D, Kneffel Z, Petrekanits M, Horváth P, Sidó Z.
Department of Health Sciences and Sports Medicine, Faculty of Physical Education and Sports Sciences, Semmelweis University, H-1123, Alkotás u. 44, H-1525, POB 69, Budapest, Hungary.

PURPOSE: Water polo is a sport involving extremely intense exercise training that might be expected to result in major cardiac adaptations. The purpose of our study was to evaluate cardiac size, determine VO(2max) of top-level water polo players, and compare the findings with those of other top-level athletes.
METHODS: Treadmill VO(2max) and 2D guided M-mode and Doppler echocardiographic data were obtained on players (N = 15) of the Olympic champion (Sydney 2000) Hungarian team and compared with data of Hungarian sedentary subjects (N = 19), and top-level endurance (N = 16) and power athletes (N = 15).
RESULTS: Aerobic power of the water polo players was significantly lower (57.8 +/- 12.3 mL.min(-1).kg(-1)) than that of endurance athletes (70.9 +/- 8.9), higher than sedentary controls (49.7 +/- 4.3), and not different from that of power athletes (50.5 +/- 6.0). Body size related mean left ventricular wall thickness (LVWT/BSA(0.5)) was the highest in the water polo players (16.8 +/- 1.5 vs 15.9 +/- 1.1 in endurance, 14.5 +/- 1.0 in the power athletes, and 12.8 +/- 0.6 mm.m in nonathletes). Left ventricular muscle mass (LVMM/BSA(1.5)) was higher in the water polo players (115 +/- 22 g.m) than in power athletes (86 +/- 12) or nonathletes (74 +/- 9) and similar to that of endurance athletes (112 +/- 15). Resting heart rate was lower in the water polo players (55.1 +/- 9.7 beats.m(-1)) and endurance athletes (59.3 +/- 10.6) than in power athletes (66.0 +/- 16.1) or in sedentary subjects (72.9 +/- 10.9).
CONCLUSIONS: Results indicate that high-level water polo results in marked cardiac hypertrophy that involves predominantly an increase of wall thickness, and in a VO(2max) lower than that of endurance athletes but similar to those of basketball and soccer players.

Blood pressure, heart rate and lipids in professional handball and water polo players
Med Pregl. 2005 Mar-Apr;58(3-4):168-74.
Jovanovic J, Jovanovic M.
Zavod za zdravstvenu zastitu radnika, Nis

INTRODUCTION: Blood pressure, heart rate and lipoprotein lipids are affected by family history, obesity, diet, smoking and physical activity habits. The aim of this paper was to estimate the values of blood pressure and heart rate in professional handball and water polo players before and after training and submaximal exercise test and to analyze the lipid state in these professional athletes in comparison with people who have never been in sports.
MATERIAL AND METHODS: The investigation included 30 professional handball players, 30 professional water polo players and 15 men who have never been in sports (control group). All groups were matched for age, smoking habits, family predisposition to arterial hypertension and dyslipidemia.
RESULTS: Between these groups there were statistically significant differences of blood pressure values and heart rate in the state of rest, after exercise test and after the training. There were also statistically significant differences of total cholesterol values, LDL cholesterol, triglycerides, HDL cholesterol, LDL cholesterol/HDL cholesterol ratio and total cholesterol/HDL ratio between these groups.
DISCUSSION: Differences between these groups can be explained by various values of body mass index, by activity of lipoprotein lipase in athletes, by body position during the sports activity, by thermoregulatory vasoconstriction in the water, and by effects of hydrostatic pressure and reflex mechanisms during swimming.
CONCLUSIONS: Cardiovascular reaction in professional athletes depends on the type of sports activity, body position and medium during training. Professional athletes have a lower atherogenic risk than non-sportsmen. Changes of blood pressure and heart rate after submaximal exercise test are not the same as changes after training.

On-water and dryland vertical jump in water polo players.
J Sports Med Phys Fitness. 2005 Mar;45(1):26-31.
2005 - Platanou T.
Laboratory of Aquatic Sports, Department of Physical Education and Sport Science, University of Athens, Athens, Greece.
AIM: The performance of the vertical jump constitutes a fundamental technical ability in many team sports, including water polo. The purpose of the present study was therefore twofold: firstly, to evaluate the ability of water polo players to move their bodies vertically off the water (on-water vertical jump), and secondly, to determine on the same players their lower bodies' explosive power ability, while performing a vertical jump on dry-land (dry-land vertical jump). We also investigated whether the performance of the on-water vertical jump depends on the position of the players in the game and on competition.
METHODS: Forty-three water polo players, were tested on-water and on dry-land. The on-water vertical jump was assessed using a board with a centimeter scale attached on it. A video camera that was placed facing the board was used to record the trials of the players.
RESULTS: The mean value of the on-water vertical jump was 68.3+/-4.6 cm, whereas the mean value of the dry-land vertical jump was 49.6+/-6.5 cm. The coefficient between the 2 jumps was very low (r=0.25). Significant differences between the 2 jumps according to the players' positions and to their level of competitiveness were found.
CONCLUSIONS: The performance of the on-water vertical jump correlates poorly with the explosive ability of the lower body as that which was assessed by the dry-land vertical jump. Furthermore, the ability to move the body vertically on-water differs significantly among players, depending on their position and on the level of competitiveness.

The anthropometrical and physiological characteristics of elite water polo players.
Eur J Appl Physiol. 2005 Sep;95(1):35-41.
Tsekouras YE, Kavouras SA, Campagna A, Kotsis YP, Syntosi SS, Papazoglou K, Sidossis LS.
Laboratory of Nutrition and Clinical Dietetics, Department of Nutrition and Dietetics, Harokopio University, 70 El Venizelou Av, Athens, 176-71, Greece.

In order to examine the physical and physiological demands of water polo, we assessed the profile of elite water polo players. Nineteen male professional water polo players (age: 25.5+/-5.0 years, height: 184.5+/-4.3 cm body mass: 90.7+/-6.4 kg) underwent body composition assessment by dual-energy X-ray absorptiometry. We also evaluated peak oxygen consumption VO2peak, lactate threshold (LT), energy cost of swimming (C s), anaerobic capacity and isokinetic shoulder strength. Body fat (%) was 16.8+/-4.4, lean mass (LM) 75.1+/-4.9 kg and bone mineral density (BMD) 1.37+/-0.07 g.cm(-2) . VO2peak was 57.9+/-7 ml.kg(-1). min(-1) . LT was identified at 3.9+/-0.7 mmol.l(-1) at a swimming velocity (v) of 1.33+/-0.05 m.s(-1) with a heart rate of 154+/-7 bpm, corresponding to an intensity of 83+/-9 of VO2peak. The average C s of swimming at the LT was 1.08+/-0.04 kJ.m(-1).C s at LT was correlated to body mass index (BMI) (r=0.22, P=0.04) and to swimming performance at 400 m (r=0.86, P=0.01) and 4 x 50 m (r=0.84, P<0.01). Internal rotator muscles were stronger compared to the external rotators by a 2:1 ratio. This study provides a quantitative representation of both physical and physiological demands of water polo and proposes a comprehensive battery of tests that can be used for assessing the status of a team.