Wetenschap en waterpolo


Ocular injury rates in college sports.
Med Sci Sports Exerc. 2008 Mar;40(3):428-32
Youn J, Sallis RE, Smith G, Jones K.
Department of Sports Medicine, Kaiser Permanente Southern California, Fontana, CA, USA.

PURPOSE: To determine the rate of eye injury sustained in 12 college sports in order to assess whether there is a high risk of ocular eye injury in some sports.
METHODS: From the fall of 1990 through the spring of 2006 at an NCAA Division III college, all ocular injuries that occurred while participating in a varsity sport and reported to the training room were retrospectively analyzed to obtain an ocular injury rate per sport.
RESULTS: This study included 5921 participants during a 16-yr period. During this time, 10 ocular injuries were sustained in five different sports. Five (50%) occurred while playing men's basketball, one (10%) in women's basketball, two (20%) in men's water polo, one (10%) in baseball, and one (10%) while playing women's soccer.
CONCLUSION: The rate of ocular injury as a result of participation in baseball, basketball, cross-country, football, golf, soccer, swimming and diving, track and field, water polo, softball, or volleyball is very low. Hence, any discussion with athletes regarding the utility of eye protection while participating in any of these sports should focus on the athlete's past ocular history instead of the sport to be played.

Heart rhythm abnormalities in middle-aged veteran elite athletes
Georgian Med News. 2008 Jun;(159):31-4
Sharashdze NS, Pagava ZT, Saatashvili GA, Agladze RA.

Disrrhythmia is frequent finding in high competitive athletes. Majority of heart rhythm abnormalities in athletes, suggested being benign, however, prognostic value of it is not yet well established. Purpose of the present study was to investigate heart rhythm and relationship of heart rhythm abnormalities with LV mass in veteran elite athletes. 30 veteran elite athletes (16 soccer players and 14 water-polo players) aged 30-50 were studied. They formed main group. Inclusion criteria: >10 years of active sports activity and >5 years after competitive sports cessation. All athletes were symptom free. Control group consists of 30 age - matched sedentary healthy individuals. In all study subjects ambulatory 24 hour ECG was recorded and, LV mass, dimensions and function by ultrasound-Doppler technique was evaluated. LV mass by Devereux formula was calculated and indexed to body surface area. Student's t-test for continuous variables, Descriptive statistics and Fisher's exact test for categorical variables were used. A P-value of <0.05 was considered to be statistically significant. Mean heart rate in former athletes group was 62+/-6 ,and 69+/-9, in control group. Night HR in athletes group was 48+/-8 and 55+/-5 in control group. Differences between groups were statistically significant (p<0,01). Complex arrhythmias were found in 4 athletes and none in control group First degree AV block presented in 6 athletes and in 2 controls. Second degree AV block (Mobitz II) was found in 4 athletes and none in controls. LV mass index was higher in ex-athletes (91,42 g/m, than in controls (84,02 g/m ) .differences between groups was statistically significant - p<0,05. Profound Bradycardia and heart conductivity abnormalities as well as complex arrhythmias were more frequent findings in athletes as compared with healthy sedentary subjects. Heart Rhythm abnormalities were associated with enhanced LV mass in Veteran athletes. Hence, veteran elite athletes may be at increased risk of life threatening arrhythmias. However, prognostic value of heart rhythm disturbances in veteran athletes has to be studied.

Morphological and functional characteristics of the left ventricle in athletes of various ages, and performing at various levels
Orv Hetil. 2008 Jun 8;149(23):1085-94.
Kneffel Z.
Semmelweis Egyetem, Testnevelési és Sporttudományi Kar Nevelés- és Sporttudományi Doktori Iskola Budapest Alkotás u. 44. 1123.

One of the most important effects of regular physical training is the adaptation of the cardiovascular system. The basic importance of an "athlete's heart" is manifested in two fields, one is public health, the other competitive sport. AIM: 1. Can the higher E/A quotient of physically active persons be explained by the training bradycardia, or can it be supposed as an independent effect of regular physical exercise? 2. Which training-induced heart characteristics seem to be different in players of various ball-games? 3. How are cardiac data related to the relative aerobic power as most indicative index of endurance performance? METHODS: Two-dimensionally guided M-mode and Doppler echocardiographic data of different athletic and non-athletic subjects were compared with each other, differences between data of different athletic groups were also analysed. RESULTS: 1. E/A quotient characterises left ventricular (LV) diastolic function, but it highly depends on the heart rate. The higher E/A found in young athletes does not seem to be an independent effect of the regular physical training. 2. Investigating the data of different ball-game-players, characteristic differences were seen. In the myocardial hypertrophy and in the resting heart rate water polo players were the best, volleyball players the worst, but the values of the latter were also better than those of non-athletes. 3. In the pooled group of non-athletes and of competitors of several kinds of sports (endurance athletes, ball-game-players, power-and-sprint-events athletes) all measured parameters correlated significantly with the relative maximal oxygen consumption. CONCLUSIONS: 1. The higher E/A in elderly subjects suggests that regular physical training can diminish the age-associated impairment of diastolic function. 2. For the high intensity training and for the long competition period a special endurance training program would be useful for volleyball players. 3. The higher was the proportion of endurance activity in the training and competitive program, the stronger were the correlations with the relative aerobic capacity.

A time-motion analysis of international women's water polo match play.

Int J Sports Physiol Perform. 2008 Sep;3(3):305-19.

D'Auria S, Gabbett T.

Athlete and Coach Support Services, Queensland Academy of Sport, Queensland, Australia.

PURPOSE: The purpose of this study was to investigate the physiological demands of field players in international women's water polo match play.
METHODS: Video footage was collected at the 13th FINA Women's Water Polo World Cup in Perth in 2002. Video recordings were analyzed using a simple hand-based notation system to record predefined activity durations, frequencies, and corresponding subjective intensities.
RESULTS: Average exercise bout duration was 7.4 +/- 2.5 s and exercise to rest ratio within play 1:1.6 +/- 0.6. The average pattern of exercise was represented by 64.0 +/- 15.3% swimming, 13.1 +/- 9.2% contested swimming, 14.0 +/- 11.6% wrestling, and 8.9 +/- 7.1% holding position. Significant differences existed between outside and center players for percentage time swimming (67.5 +/- 14.0% vs 60.2 +/- 13.3%, P = .002) and wrestling (9.9 +/- 9.3% vs 18.4 +/- 11.1%, P = .000). A significant difference was found in the number (P = .017) and duration (P = .010) of high-intensity activity (HIA) bouts performed each quarter for outside (1.8 +/- 2.2 bouts, 7.0 +/- 3.4 s) and center players (1.2 +/- 1.5 bouts, 5.2 +/- 3.4 s). Positional differences in HIA were the result of a significant difference (P = .000) in the number of maximal/near maximal swims (outside 1.2 +/- 1.5 and center 0.5 +/- 0.9 per quarter).
CONCLUSIONS: This study characterizes international women's water polo match play as a highly intermittent activity. Swimming, particularly high intensity, has greater significance to outside players, whereas wrestling has greater significance to center players.

Effects of combination oral contraceptives on strength development in women athletes.

J Strength Cond Res. 2008 Sep;22(5):1625-32
Nichols AW, Hetzler RK, Villanueva RJ, Stickley CD, Kimura IF.
Division of Sports Medicine, Department of Family Medicine and Community Health, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, USA.

This study was designed to investigate the effects of combination oral contraceptive agents (OCAs) on strength and torque production in collegiate women softball and water polo athletes who participated in a 12-week strength development program. A double-blind research design was used to mask subjects to the main outcome of interest. Thirty-one women collegiate softball and water polo players were divided into experimental (OCA users, n = 13), and control (non-OCA users, n = 18) groups. All subjects participated in the same supervised 12-week preseason strength development program. One-repetition maximum bench press (1RMBP), 10-repetition maximum leg extension (10RMLE), isokinetic peak torque bench press (IKBP), and isokinetic peak torque leg extension (IKLE) data were collected at weeks 0 (pre-test), 4, 8, and 12 (post-test). Significant increases in strength and torque production over time were identified regardless of group for 1RMBP, 10RMLE, and IKLE. No significant differences in IKBP torque production occurred during the 12-week strength training program. No significant differences in 1RMBP, 10RMLE, IKBP, or IKLE occurred between the OCA users and the non-OCA users groups. It was concluded that, within the limitations of the study, the use of combination OCAs did not provide sufficient androgenic effect to increase strength gains beyond the stimulus of the training protocol.

Experts opinion about system of the performance evaluation criteria weighted per positons in the water polo game.
Coll Antropol. 2008 Sep;32(3):851-61.
Hraste M, Dizdar D, Trninic V.
Faculty of Natural Sciences, Mathematics and Kinesiology, University of Split, Split, Croatia.

The goal of the research was to define experts opinion about adequate criteria for water polo players' actual quality evaluation and to determine experts opinion about weight coefficients (ponders) of the here defined criteria across the playing positions in the game of water polo. Based upon the expertise performed by ten water polo professionals, the relative importance coefficients with regard to playing positions in the game were determined for twenty seven performance evaluation criteria. High degree of interobserves' agreement was obtained regarding all positions (from 0.93 to 0.96). In concordance with the obtained results the particular playing positions were explicitly described, as well as the similarities and the differences between them were determined from the aspect of the single criteria importance. The research results could be usefully applied by the water polo practitioners for the selection and follow-up of players during training programme implementation, and for programming, control and evaluation of transformational effects.

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