Biomechanics and Medicine in Swimming XI

BiomechanicsandmedicineinswimmingXi
abilities in a swimming flume. 3) Special strength training parameters.
The biological age of the swimmers (BA) was defined by the authors’
own methods (Timakova 1985, 2006) Depending on a difference between
chronologic age (CA) and BA, all swimmers were distributed into
5 groups: R 1 - 1-2 years of retardation on rates of maturation; R 2 – more
than 2 years retardation; N - age norm; А 1 - 1-2 years acceleration on
rates of maturation; А 2 - acceleration of more than 2 years. Investigation
results were processed using standard statistical methods and correlation
analysis. Methods of factor-typological description of objects were
also used.
results
The materials in table 1 belong to the contingent of swimmers which
displayed the peak of sport achievement in the middle of the 1990s. As
we can see, the majority of tested swimmers belong to the 13-14 year
age group. With advancing age the number of surveyed girls decreased,
whereas the boys did not decrease to the same extent. The most essential
differences in this age contingent of girls and boys are shown in the
character of biological development.
The norm age development of swimmers across all age groups
dominates. However, in the girls’ aged 13-14 we mark the general shift
towards delays in puberty. In male groups the trend of shift, on the contrary,
is clearly visible as age acceleration. It is characteristic that in cases
of acceleration of development this is not found in the senior girls’ age
groups at all. Among the high level swimmers of senior age groups the
shift in selection related to the tendency of puberty delay is recognized.
Table 1. Swimmer age distribution in relation to personal rates of biological
development in %
Age
girls
n R2 R1 N A1 A2 tot.
12 4 - - 3.6 1.2 - 4.8
13 19 3.6 4.8 9.6 4.8 - 22.9
14 37 6.0 16.3 1928 3.0 - 44.6
15 10 3.6 6.0 2.4 - - 12.1
16 8 1.2 3.6 4.8 - - 9.6
17 5 - 2.4 3.6 - - 6.0
total
boys
83 14.5 33.1 43.4 9.1 - 100
13 21 - 2.7 4.4 5.3 6.2 18.6
14 35 - 3.5 8.0 8.9 10.6 31.0
15 17 - 0.9 9.7 3.5 0.9 15.0
16 15 - - 10.6 1.8 0.9 13.3
17 13 0.9 1.8 6.2 2.7 - 11.5
18 12 1.7 0.9 3.6 4.4 - 10.6
total 113 2.6 9.7 42.5 26.4 18.6 100
Tables 2 and 3 give the percentage distribution of swimmers in age
groups among their top ranked representatives. Data in these tables emphasises
essentially different trends of a natural selection of girls and
boys. Among the strongest representatives of the age groups, female
types with normal and slowed rate of development dominate. On the
contrary, for the best representatives of the male groups a more complicated
picture of distribution of the rate of biological development
was shown, though the above mentioned tendencies of natural selection
prevailed.
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Table 2. Distribution of biological development types among top ranked
girl swimmers (1990s Generation, n = 109), %
Age,
Years
n %
Biological Development Type
R2 R1 N A1
12 9 8.26 11.11 33.33 22.22 33.33
13 24 22.02 8.33 41.67 50.0 ¾
14 49 44.95 12.24 40.82 46.94 ¾
15 24 22.02 4.17 45.83 50.0 ¾
16 3 2.75 66.67 33.33 ¾ ¾
Table 3. Distribution of biological development types among top ranked
boy swimmers
(1990s Generation, n = 63), %
Age,
Years
n %
Biological Development Type
R2 R1 N A1 A2
13 11 17.47 9.09 9.09 ¾ 45.46 36.36
14 28 44.44 7.14 35.71 14.29 35.72 7.14
15 14 22.22 ¾ 7.14 50.0 42.86 ¾
16 10 15.87 ¾ ¾ 60.0 30.0 10.0
Table 4. Distribution of 2000s swimmers Generation on biological development
type, %
Age, Girls (n=25) Boys (n=35)
Years R2 R1 N R2 R1 N A1 13 33.3 33.3 33.3 – – – –
14 12.5 25.0 62.5 – – – –
15 18.2 18.2 63.6 – – – 100.0
16 66.7 – 33.3 – 17.1 60.7 22.2
17 – – – 21.4 35.7 28.6 14.3
18-19 – – – 33.33* 33.3 33.3 ¾
* At the age of 18 years and older in groups with R2 development there
are cases with delay rates of puberty of more than 2 and 3 years.
In table 4, data of swimmers with achievement peaks in the first decade of
the 2000s are presented. Some of these swimmers competed as members
of the national team at the Beijing Olympic Games. The characteristic
feature of this generation is a representation shift to the senior age groups.
Only at the age of 13 years in girls are all three types of biological development
equally represented. At the age of 14 and 15 years, the majority of
girls correspond to their age norm in terms of development. However, at
the age of 16 years the number of girls with a delay of processes of puberty
is increased. In the young men, with the increase of years the variety of
types of development grows; moreover the shift towards a delay in tempo
of puberty strengthens. With the aim to reveal the reasons of such different
dynamics of sport achievement growth in swimmers after 14 years
of age, we have carried out an auto-classification of all tested parameters.
In table 5 the average values of parameters of the largest numerical
classes of swimmers are given. The featured particularity of girls in
comparison with boys is a higher parameter of sport achievement level.
At the same time they do not differ on age, parameters of biological
maturity and swimming career duration. As well, girls come short on
morpho-functional parameters and especially on integrated characteristics
of capacity and efficiency of the aerobic mechanism of power supply,
compared with boys. However the ECG analysis of girls before the test
was identical to the boys, but girls had higher parameters of cardiovascular
system adaptation after testing to the point of exhaustion (in a
flume). We want to emphasize that at a later stage, none of the female
swimmers from this class reached the level of elite competition.