Biomechanics and Medicine in Swimming XI

General Indexes of Crawl Swimming Velocity of
Junior Water Polo Players in a Match
Bratusa, F.Z. 1 , Perisic, s.M. 2 , dopsaj, J.M. 1
1Faculty of Sport and Physical Education, University of Belgrade, Belgrade,
Serbia
2UFK Sports Recreational Center Tasmajdan, Belgrade, Serbia
The aim of this research is to define crawl swimming velocity realized
by junior water polo players during a match. Over a four year period,
35 water polo players have been observed at the age of 16 years. It was
established that there is no statistically significant difference of crawl
technique swimming velocity between the quarters of a match (F=1.903,
p =0.127). It was also determined that there are no differences of swimming
velocity distribution with regard to quarters (F=5.269, p = 0.153).
The given fact can be a consequence of adaptation to the applied training
load of dominantly aerobic type, but also to the tactical choices during
play. The obtained results should not be generalized and it does not
mean that the same results would be obtained if this category were to be
observed on the international level.
Key words: water polo, crawl technique, swimming velocity
IntroductIon
Water polo is among those sports with predominantly non stereotypical
movements and situations, with a constant change of dynamic and
motor behaviour. Water polo has swimming efforts that are predominant
in the course of a match (swimming volume, intensity, combination
of different swimming techniques and different swimming distances),
conditions that require elite water polo players to have developed well
all three energy systems, aerobic, alactate and lactate (Pinnington et al.,
1988; Dopsaj and Matković, 1994; Smith, H. 1999).
A water polo game is not represented only by basic movements
(swimming) but also by a great number of specific movements in the
water performed in a horizontal and a vertical position. In these positions,
a great number of elements of technique with the ball are performed
(passing, receiving, shooting on goal), without the ball (pass over, jumps
out, blocks), contacts with the opponent player (duels), without contact
with opponent player (basic position), (Bratusa at al 2003). All of this indicates
the complexity of water polo as well as of the training process itself,
regarding better technical and tactical preparation of water polo players.
In the course of a match a water polo player spends around 37% of
overall playing time in the horizontal position, and for around 90% of
the swims the crawl technique is used (Dopsaj and Matković, 1994).
This indicates that the horizontal position is a less represented activity
during a match compared to others. The horizontal position, i.e. movement
parallel with the water surface, includes swimming by using crawl,
backstroke and breaststroke and combinations of these techniques.
The aim of this study is to define the swimming velocity of players in a
horizontal position, i.e. crawl technique swimming velocity, realized by
junior water polo players during a match, as it is the most represented
technique.
Method
The motor activity of each selected player was monitored at matches
played in the state championship or cup. Only one player was monitored
during each match.
By video analysis, all swimming movement phases were registered
during a water polo match. By chronometry, the duration of each swim
per effort was recorded. The length of the covered distances were determined
by the analysis of video recordings and use of markers placed
along the outline of the playing area at 2 nd , 4 th , 7 th , 10 th , 15 th , 20 th , 23 rd
and 28 th meter.
chaPter4.trainingandPerformance
The sample consisted of 35 junior water polo players. The players
were monitored at the final competitions of championship and cup
of Serbia and Montenegro from March 2004 to April 2008. The test
encompassed four generations of the junior category (the age of 16).
The players were members of the following clubs: Water polo clubs: VK
“Partizan”: N=9, VK “Crvena Zvezda”: N=6, VK “Beograd”: N=7, VK
“Primorac”: N=3, VK “Vojvodina”: N=3, VK “Zemun”: N=2, VK “Nis”:
N=2, VK “Becej”: N=1, VK “Jadran”: N=1. and VK “Student” N=1. The
criteria for selection were that they were regularly players of the first
formation of their teams, playmakers, successful water polo players,
and played the most minutes per match. The majority of the players
monitored are now members of youth national teams. The variables in
this research covered the structure of the crawl technique. The following
variables were observed: 1) Average swimming velocity during the
match (V M-crawl – average crawl technique swimming velocity realized
by a player during the match expressed in m·s -1 ) . 2) Average swimming
velocity per quarter (V Q-crawl) - average crawl technique swimming
velocity realized by a player during the each quarter expressed in m·s -1 ).
3) Distribution of swimming velocity during the match (DV M-crawl ) –
the swims realized by a player at low, moderate, medium, near maximal
or maximal velocity during the match, expressed in percentages. 4)
Distribution of swims per quarter according to the swimming velocity
(DV Q-crawl ) – covered sections realized by a player at low, moderate, medium,
near maximal or maximal velocity during the each quarter, expressed
in percentages.
The results were elaborated by descriptive statistical analysis and
ANOVA in order to establish differences of the observed variables between
the quarters (Hair et al. 1995).
Table 1. Descriptive statistics
N Mean SD cV
Quarters m·s- 1 m·s- 1 (%)
95% Confidence
Interval for Mean
Lower
Bound
Upper
Bound
Min Max
m·s- 1 m·s- 1
1.00 500 1.385 .358 25.86 1.354 1.416 .667 3.226
2.00 398 1.343 .363 27.00 1.307 1.379 .605 3.008
3.00 425 1.353 .357 26.42 1.319 1.387 .595 2.979
4.00 359 1.331 .328 24.67 1.297 1.365 .660 2.727
Total 1682 1.356 .353 26.06 1.339 1.372 .595 3.226
results
Table 1 displays the values of basic descriptive statistics of average
swimming velocity during the match and per quarter. The average
swimming velocity realized by the observed water polo players during
the match was 1.356±0.353 m·s -1 , and per quarter – in the first quarter
1.385±0.350 m·s -1 , in the second quarter 1.343±0.362 m·s -1 ; in the third
quarter 1.353±0.357 m·s -1 and in the fourth quarter 1.331±0.328 m·s -1
(Figure 1)
Figure 1 .Average swimming velocities per quarter by intensity category
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