Biomechanics and Medicine in Swimming XI
Biomechanics and Medicine in Swimming XI
Biomechanics and Medicine in Swimming XI
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average age of 27.1 ± 5.9 years. When select<strong>in</strong>g subjects, the prerequisite<br />
was to have at least one year of tra<strong>in</strong><strong>in</strong>g <strong>and</strong> competitive experience <strong>in</strong><br />
triathlon, as well as be<strong>in</strong>g of satisfactory health.<br />
Table 1: Descriptive parameters<br />
AS±SD (m<strong>in</strong>-max)<br />
AGE (yrs) 27.1 ± 5.9 (18-39)<br />
body height (cm) 174.85 ± 7.28 (165.0-187.0)<br />
body mass (kg) 72.65 ± 11.18 (58.7-92.7)<br />
%BF (%) 13.4 ± 7.72 (4.0-26.2)<br />
AGE – years, body height (cm) , body mass (kg), %BF - Subcutaneous<br />
Body Fat<br />
Sample of Variables<br />
a) A set of variables for evaluat<strong>in</strong>g anthropometric characteristics<br />
Measurement of exam<strong>in</strong>ees’ morphological characteristics was carried<br />
out <strong>in</strong> accordance with the guidel<strong>in</strong>es of the International Biological<br />
Program (IBP, Mišigoj-Duraković 2008). Basic morphological variables<br />
were measured <strong>in</strong> order to determ<strong>in</strong>e the exam<strong>in</strong>ees’ morphological status.<br />
With the help of anthropometric <strong>in</strong>struments <strong>and</strong> a medical scale,<br />
the variables of body mass <strong>and</strong> body height were measured, while the<br />
subcutaneous body fat was established based on the method of biological<br />
impedance, us<strong>in</strong>g the Tanita BC-418 (TANITA, USA) scale. Eight<br />
electrodes (4 for the arms, 4 for the feet) are used to send a weak electric<br />
signal through the entire body. In those locations where the resistance,<br />
i.e. impedance is higher, the signal needs more time to travel, <strong>in</strong>dicat<strong>in</strong>g<br />
a higher content of subcutaneous body fat.<br />
b) Set of variables for evaluat<strong>in</strong>g functional abilities<br />
1)FS max (BPM ) - Maximum Heart Frequency, 2) V max (m/s) Maximum<br />
Speed, 3) LAC max (mmol/l) - Maximum Lactates, 4) FS anp-1 (BPM)<br />
- Anaerobic Threshold Heart Frequency („<strong>in</strong>tersection method“), 5)<br />
FS anp-2 (BPM) - Anaerobic Threshold Heart Frequency („4 mmol/l“),<br />
6) FS anp-3 (BPM) - Anaerobic Threshold Heart Frequency („D-max<br />
method“), 7) LAC anp-1 (mmol/l) - Anaerobic Threshold Lactates („<strong>in</strong>tersection<br />
method“), 8) LAC anp-2 (mmol/l) - Anaerobic Threshold<br />
Lactates („4 mmol/l“), 9) LAC anp-3 ( mmol/l) - Anaerobic Threshold<br />
Lactates („D-max method“).<br />
Specified parameters were measured dur<strong>in</strong>g one test protocol, while the<br />
variables were determ<strong>in</strong>ed based on three various methods.<br />
Prior to test<strong>in</strong>g, the exam<strong>in</strong>ees were acqua<strong>in</strong>ted with the test<strong>in</strong>g protocol<br />
which, with regard to the swimm<strong>in</strong>g test, consists of seven (7) 200<br />
meter sections with a 5 m<strong>in</strong>ute active rest regime <strong>in</strong> a small swimm<strong>in</strong>g<br />
pool. Each section is covered by apply<strong>in</strong>g a faster swimm<strong>in</strong>g pace, up<br />
to the maximum <strong>and</strong> at an even pace. How fast each exam<strong>in</strong>ee swam<br />
through a certa<strong>in</strong> section was determ<strong>in</strong>ed based on the best 200 meter<br />
result, the same be<strong>in</strong>g tested a few days prior to the swimm<strong>in</strong>g test. The<br />
obta<strong>in</strong>ed result was <strong>in</strong>creased by 5 seconds <strong>in</strong> order to get the fastest<br />
seventh section. Every previous section is also <strong>in</strong>creased by 5 seconds <strong>in</strong><br />
order to get the swimm<strong>in</strong>g pace for each set section which the swimmer<br />
must comply with. An example of calculat<strong>in</strong>g swimm<strong>in</strong>g speed for each<br />
of the set sections is shown <strong>in</strong> Table 6. Specified swimm<strong>in</strong>g pace was<br />
dictated by an assistant by the pool, us<strong>in</strong>g a whistle every 12.5 m, <strong>and</strong><br />
if the exam<strong>in</strong>ee was swimm<strong>in</strong>g at a set pace, then the assistant would<br />
whistle every 25 or 50 m. Dur<strong>in</strong>g test<strong>in</strong>g, the exam<strong>in</strong>ees wore a pulse<br />
meter (Polar RS 400, F<strong>in</strong>l<strong>and</strong>) the whole time, <strong>and</strong> at each section’s end,<br />
the concentration of lactates <strong>in</strong> the blood was measured with a Lactate<br />
Scout device (SensLab, Germany). Immediately prior to start<strong>in</strong>g a new<br />
section (about 15-30 seconds prior), the exam<strong>in</strong>ee would enter the pool<br />
<strong>and</strong> prepare for start. In order for the transmitter of the pulse meter to<br />
chaPter3.PhysioLogy<strong>and</strong>Bioenergetics<br />
be attached to the exam<strong>in</strong>ees’ chests, all the exam<strong>in</strong>ees wore swimsuits.<br />
Results obta<strong>in</strong>ed by measurement procedures were processed by a data<br />
analysis software system Statistic version 8.0. In order to determ<strong>in</strong>e statistically<br />
significant differences between various methods used to establish the<br />
anaerobic threshold of the subjects, the t-test was used for dependent samples.<br />
results<br />
Assessed means, st<strong>and</strong>ard deviation, m<strong>in</strong>imal <strong>and</strong> maximal results,<br />
skewness <strong>and</strong> kurtosis for certa<strong>in</strong> variables is presented <strong>in</strong> Table 2. Ttest<br />
for dependant variables showed that there is no statistical significant<br />
difference between FS anp-1 <strong>and</strong> FS anp-3 (Table 3).<br />
Table 2: Descriptive Values of Certa<strong>in</strong> Variables<br />
Valid N Mean M<strong>in</strong>imum Maximum Std.Dev. Skewness Kurtosis<br />
FSmax 13 180.15 170 192 7.50 0.065 -1.342<br />
LACmax 13 11.31 6.6 19.2 2.99 1.236 4.098<br />
Vmax 13 1.13 0.96 1.36 0.11 0.415 0.139<br />
LACanp-1 13 4.63 3.3 6 0.80 0.015 -0.705<br />
LACanp-2 13 4.00 4 4 0.00 -- --<br />
LACanp-3 13 4.98 3.3 7.3 1.15 0.521 0.006<br />
Table 3: T-test <strong>and</strong> Correlation Results<br />
FSanp-1<br />
FSanp-2<br />
FSanp-3<br />
P < .05000 FSanp-1 FSanp-2 FSanp-3<br />
R 1 0.88 0.91<br />
t (p) 3.87 (0.0022) -1.95 (0.07)<br />
R 0.88 1 0.74<br />
t (p) 3.87 (0.0022) -3.92 (0.0020)<br />
R 0.91 0.74 1<br />
t (p) -1.95 (0.07) -3.92 (0.0020)<br />
High correlation values (Table 3) are <strong>in</strong>dicative of a l<strong>in</strong>k between FS anp-1<br />
<strong>and</strong> FS anp-2 which shows that the purpose of measurement is the same<br />
<strong>and</strong> that predict<strong>in</strong>g results by us<strong>in</strong>g the D-max method based on the<br />
„<strong>in</strong>tersection” method is 82% successful, while predict<strong>in</strong>g results through<br />
the D-max method based on the 4 mmol/l method is much less successful,<br />
i.e. 54%.<br />
dIscussIon<br />
Large differences between maximum values of lactate <strong>in</strong> the blood suggest<br />
various degrees <strong>in</strong> which the body is able to react to acidosis. Naturally,<br />
those values are conditioned by tra<strong>in</strong><strong>in</strong>g as well, <strong>and</strong> if look<strong>in</strong>g at<br />
each exam<strong>in</strong>ee separately, it is noticeable that exam<strong>in</strong>ees that are more<br />
tra<strong>in</strong>ed are able to <strong>in</strong>crease speed one section after another, regardless<br />
of the rise of blood lactate <strong>and</strong> the decrease of pH value. Said values of<br />
maximum blood lactateise a generally accepted aerobic capacity parameter<br />
<strong>and</strong> the buffer<strong>in</strong>g ability of the muscles.<br />
Values of the maximum heart frequency <strong>in</strong> this test are the highest<br />
value achieved <strong>in</strong> a test, but the maximum. In order to achieve maximum<br />
heart frequency values, the test must be shorter, without <strong>in</strong>tervals <strong>and</strong><br />
more <strong>in</strong>tense.<br />
It would be logical that there are no statistically significant differences<br />
between all these measures because the object measured is the<br />
same. Table 3 shows a high correlation (r=0.91) between FSanp-1 („<strong>in</strong>tersection“<br />
method) <strong>and</strong> FSanp-3 (D-max method), while the t-test for<br />
dependant samples showed (Table 3) that no statistically significant differences<br />
exist, the same demonstrat<strong>in</strong>g that those two different measures<br />
for determ<strong>in</strong><strong>in</strong>g the anaerobic threshold are reliable <strong>in</strong> evaluat<strong>in</strong>g the<br />
anaerobic threshold <strong>in</strong> swimmers.<br />
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