EISSN
ISSN 1519-9088
1676-5133
Analysis
of the frequency and backstroke
length in
50, 100
and
200m
tests in
swimming
Victor José Polli1 [email protected]
Gabriel Fernandes Jacomel1 [email protected]
Thiago Gonsaga de Souza2 [email protected]
Caroline Ruschel3 [email protected]
Gustavo Ricardo Schütz2 [email protected]
Luciana Gassenferth Araújo2 [email protected]
Helio Roesler2 [email protected]
doi:10.3900/fpj.8.6.417.e
Polli VJ, Jacomel GF, Souza TG, Ruschel C, Schütz GR, Araújo LG, Roesler H. Analysis of the frequency and backstroke length in 50, 100 and
200m tests in swimming. Fit Perf J. 2009 Nov-Dec;8(6):417-21.
ABSTRACT
Introduction: This study aimed to analyze and compare the stroke efficiency indicators: average velocity (Av),
stroke rate (SR) and stroke length (SL) on 50m, 100m and 200m backstroke events. Materials and Methods:
Fourteen swimmers (seven men and seven women) were intentionally selected, mean age 20±4 years old among
the 16 finalists of the 50m, 100m and 200m backstroke in XXXVI Brazilian Absolute Swimming Championship José Finkel Trophy 2007, held in the Greater Florianópolis, SC, Brazil. The variables were described by average,
standard deviation and coefficient of variation, as all different distances were compared trough ANOVA oneway (Tukey Post-Hoc) and correlated through Pearson correlation test (p<0.05). Results: The results are in
accordance to the literature: the smaller distances have a higher SR and a lesser SL with a higher Av. The values
are reversed for larger distances, where it has a lesser SR and a higher SL, but Av decreases. Discussion: For
coaches and swimmers, it is suggested to develop the technical aspects for a better combination of SR and SL,
aiming at an ideal balance to maintain higher speed independently on the distance.
KEYWORDS
Swimming; Athletic Performance; Biomechanics.
Bolsista de Iniciação Científica PROBIC/UDESC – Universidade do Estado de Santa Catarina – UDESC – Florianópolis/SC – Brazil
Universidade do Estado de Santa Catarina – UDESC – Florianópolis/SC – Brazil
3
Bolsista FINEP – Universidade do Estado de Santa Catarina – UDESC – Florianópolis/SC – Brazil
1
2
Copyright© 2009 by Colégio Brasileiro de Atividade Física, Saúde e Esporte
Fit Perf J | Rio de Janeiro | 8 | 6 | 417-421 | Nov/Dec 2009
Fit Perf J. 2009 Nov-Dec;8(6):417-21.
417
P olli , J acomel , S ouza , R uschel , S chütz , A raújo , R oesler
Análise
da frequência e do comprimento de braçada em provas de
50, 100
e
200m
costas na natação
RESUMO
Introdução: Este estudo objetivou analisar e comparar os indicadores de eficiência de nado: velocidade média (Vm), frequência de braçada (FB)
e o comprimento de braçada (CB) nas provas de 50, 100 e 200m nado costas. Materiais e Métodos: Foram selecionados intencionalmente
14 nadadores (sete homens e sete mulheres), com média de idade de 20±4 anos dentre os 16 finalistas das provas no XXXVI Campeonato
Brasileiro Absoluto de Natação (Troféu José Finkel). Para determinação das variáveis, as provas foram filmadas (30Hz) e as imagens, posteriormente
analisadas. Descreveram-se as variáveis por média, desvio padrão e coeficiente de variação, comparadas nas diferentes distâncias por ANOVA
one-way (pós-teste de Tukey) e correlacionadas através do teste de correlação de Pearson, adotando-se um nível de significância de 5% (p<0,05).
Resultados: Os resultados obtidos vão ao encontro dos achados na literatura: menores distâncias apresentam maior FB e menor CB, com uma
maior Vm. O comportamento se inverte em maiores distâncias de prova, com menor FB, maior CB e menor Vm. Discussão: Para treinadores e
nadadores, sugere-se que sejam desenvolvidos os aspectos técnicos para uma melhor combinação entre a FB e o CB, objetivando um equilíbrio
ideal, a fim de manter maior velocidade independentemente da distância.
PALAVRAS-CHAVE
Natação; Desempenho Atlético; Biomecânica.
Análisis
de la frecuencia y largura del brazada en las pruebas de
50, 100
y
200m
espalda en la natación
RESUMEN
Introducción: Este estudio tuvo como objetivo analizar y comparar los indicadores de eficiencia de la natación: la velocidad media (Vm),
frecuencia (FB) y largura del brazada (CB) en las pruebas de 50, 100 y 200m espalda. Materiales y Métodos: Fueron escogidos, de forma
intencionada, 14 nadadores (siete hombres y siete mujeres), con una media de edad de 20±4 años entre los 16 finalistas de las pruebas en el
XXXVI Campeonato Brasileño Absoluto de Natación (Trofeo José Finkel 2007). Para determinar las variables, las pruebas fueron filmadas (30Hz) y,
posteriormente, las imágenes fueron analizadas. Las variables fueran descriptas por la media, desvío estándar, coeficiente de variación, comparadas
en las diferentes distancias por ANOVA one-way (pos-test de Tukey) y correlacionadas a través de los testes de correlación de Pearson, en los
cuales el nivel de significancia fijado fue de 5% (p<0,05). Resultados: Los resultados obtenidos en este estudio son iguales a los hallados en
la literatura: en las menores distancias nadadas, hay una mayor FB y un CB menor, así como una Vm mayor. Los valores se van invirtiendo para
distancias mayores con una FB menor y mayor CB, pero la Vm disminuye. Discusión: Para los entrenadores y nadadores, se sugiere que desarrollen
los aspectos técnicos para mejor combinación entre la frecuencia y largura de brazada, con el objetivo de un equilibrio óptimo, a fin de que se
mantenga la mayor velocidad independiente de la distancia nadada.
PALABRAS CLAVE
Natación; Rendimiento Atlético; Biomecánica.
INTRODUCTION
Technique is understood as the set of procedures and
knowledge capable of propitiating the execution of a specific activity, of variable complexity, with the least wastage
and the maximum success; and technique preparation as
the set of activities and teaching that the athlete absorbs,
aiming at the execution of a sportive movement with the
maximum of efficacy and the least effort1.
In swimming, the aim of a swimmer is to go through
the complete distance of a test (according to its regulation) in the smallest possible time2. Aiming at the
best performance, several studies about swimmer’s
techniques components have been carried out3,4,5,6,7.
Some of the technique elements verified and studied
418
by trainers and researchers are the efficacy indicators
of swimming, described by Hay2 as the backstroke frequency (BF, defined by the number of backstroke per
minute) and the backstroke length (BL, defined by the
distance traversed by the swimmer in a backstroke
cycle). These indicators have been studied since the
1970’s8,9,10,11,12,13,14,15. In the swimmer’s preparation,
according to Maglischo16, it is important to determine
the BF and BL and an ideal combination of these elements, letting the tests rhythmical and efficient, by
means of the control and maintenance learning of this
combination during all test’s distance. Depending on
how are the coordinates, Alberty et al.6 presume that
the BF and BL interfere in the swimming velocity (mean
Fit Perf J. 2009 Nov-Dec;8(6):417-21.
T ests
velocity, mV), creating propulsive and resistible impulses in backstrokes.
In order to find the perfect combination between BF
and BL, analyses are done through swimming competitions shooting, like the Olympic Games and the Worldwide Championship, providing details about the performance17,18. Despite the great number of studies that
consider these indicators, most of them are focused on
analyses of the crawl style11,13,14,19, but few were carried
out concerning the other styles18,20,21,22, an area that is
still needs further studies for affirmations and comparisons.
In this context, this study aimed at analyzing and
comparing BF, BL and the mV of swimmers in 50, 100
and 200m backstroke tests.
MATERIALS AND METHODS
This study was approved by the Ethics and Research
Committee with Human Beings of Universidade do Estado de Santa Catarina (Udesc), protocol n. 48/2008.
All subjects agreed to take part in the research by means
of assigning the Informed Consent Form, as established
by Resolution 96/96 from the National Health Counsel
(NHS), which treats of the ethical requests for the realization of human beings researches.
Fourteen swimmers participated (seven men and
seven women) from this descriptive and correlation
study, with a mean age of 20±4 years old, intentionally selected among the finalists of 50,100 and 200m
tests from backstroke style of the XXXVI Campeonato
Brasileiro Absoluto de Natação (Troféu José Finkel
2007), carried out in the Great Florianópolis, state of
Santa Catarina.
As inclusion criteria, the following were adopted:
male and female swimmers who participated in the 50,
100 and 200m tests of backstroke style and that were
classified for the final “A” (8 greatest times) or “B” (9th to
16th better times) of all the three tests of this style. The
swimmers that could not be classified for the final “A” or
“B” for all the mentioned tests were excluded.
The following variables were defined and verified:
a) mean Velocity of swimming (mV), expressed in meters
per second (m.s-1): obtained by dividing the distance
by the obtained time in seconds by the charts counting, since the swimmer’s head passed through the
initial 15m up to the instant that the swimmer’s head
surpassed the final 15m demarcation, totalizing 20m
swimming;
b) BF, in backstroke cycles per minute (cycles.min-1):
each cycle represented by two complete backstrokes
was obtained considering the interval since the first
complete backstroke accomplished after the initial
Fit Perf J. 2009 Nov-Dec;8(6):417-21.
of
50, 100
and
200 m
backstroke in swimming
15m demarcation, up to the last complete backstroke
before the final 15m demarcation;
c) BL, expressed in meters per cycle (m.cycle-1): distance
ran during one backstroke cycle, obtained by dividing
mV by BF23.
The variables were verified from acquired video images; a video camera, MiniDV type, with a 30Hz acquisition frequency, positioned 25m from the departure edge
(middle of the pool), in a 15m-height and perpendicular to the event, was used 24. The images of the A and
B finals from the 50, 100 and 200m male and female
backstroke were recorded, completing 12 tests. Each test
was filed separately and the images, analyzed using the
images edition software Intervideo WinProducer 3.0.
The backstrokes counting was carried out by the researchers, one athlete each 50m, resulting in a partial in
the 50m test, two partials in the 100m tests and four partials for the 200m and, then, the mean for each test distance was determined. The measuration in the central 20m
of the pool happens in order to avoid events related to the
departure of the turns, since in these moments the athletes
can remain during most of time totally submergence.
For organization and data analysis, the descriptive
statistics, with mean, standard deviation and variation
coefficient, was used. It was opted to present data divided by genre, due to considerable differences presented
between men and women21. After being verified the normality of data by the Shapiro-Wilk’s test (p=0.128 for
mV; p=0.859 for BL; and p=0.291 for BF), two forms
of analysis were opted: a) comparison between the variables mV, BL and BF, in the different distances, by the
ANOVA one-way test and complemented by the Tukey’s
post-test; b) correlation between BF, BL and mV in the different distances, carried out through the Person’s correlation test. A 5% significance level was adopted (p<0.05).
RESULTS
In Table 1, the results concerning BF, BL and mV in
50,100 and 200m tests, from male and female were
presented.
According to Pestana and Gageiro25, the results from
this study have a low variation coefficient (lower than
15%), which allows a comparison between the means
found.
In Table 2, the results concerning the correlation
value between BF, BL and mV in the 50,100 and 200m
backstroke distances, for the male, female and general
groups, are presented.
The correlations between BL and the BF for the 50,
100 and 200m distances were inversely proportionally
and presented significant values for all the classes.
419
P olli , J acomel , S ouza , R uschel , S chütz , A raújo , R oesler
Table 1 - Results from BF, BL and mV in 50, 100 and 200m backstroke tests
50m
BFa
[cycle.min-1]
BLb
[m.ciclo-1]
mVc
[m.s-1]
Male
52.1±2.7
-0.052*
2.04±0.10
-4.90%*
1.77±0.03
-1.80%*
100m
Female
51.6±2.3
-0.077*
1.79±0.14
-8.20%*
1.53±0.02
-1.90%*
Male
45.0±1.9
-0.042*
2.22±0.10
-4.50%*
1.66±0.03
-1.80%*
200m
Femake
44.0±2.4
-0.055*
1.95±0.11
-5.90%*
1.43±0.02
-1.60%*
Male
37.8±3.2
-0.084*
2.41±0.15
-6.20%*
1.51±0.04
-2.90%*
Female
38.3±1.1
-0.029*
2.06±0.06
-2.90%*
1.31±0.02
-1.60%*
Mean±standard deviation (*variation coefficient).
a
p=0.00, ANOVA one-way, between: 50x100m p=0.00; 50x200m p=0.00; 100x200m p=0.00 (Tukey’s post-test); bp=0.00, ANOVA oneway, between: 50x100m p=0.07; 50x200m p=0.00; 100x200m p=0.11 (Tukey’s post-test); cp=0.00, ANOVA one-way, between: 50x100m
p=0.07; 50x200m p=0.00; 100x200m p=0.01 (Tukey’s post-test).
Table 2 - Correlation between the variables in different
distances test
50m
Female
Male
100m Female
Male
200m Female
Male
BLxBF
-0.96*
-0.93*
-0.97*
-0.9*
-0.85**
-0.96*
BLxmV
0.28
-0.04
-0.37
0.4
0.22
-0.69
BFxmV
-0.03
0.39
0.53
0.02
0.28
0.85**
*Significant correlation to 0.01 value; **significant correlation to
0.05 value.
For the mV and BL, no significant correlations were
obtained in all the distances. A significant correlation between the BF and the mV was also found between men
in 200m distance.
DISCUSSION
The values found in this study for BF and BL are similar to the findings of Arrelano et al.18, who analyzed the
backstroke’s characteristics in the 100m back test during
a juniors competition. Authors observed the mean values
of BF of 46.0 cycles.min-1 in male and 44.9 cycles.min-1
in female; and for BL, 2.10m for men and 1.91m for
women.
It can be seen that BF was lower in the largest distances, for both sexes, agreeing with the reports from
Pai, Hay and Wilson22, who analyzed 15 athletes from
both sexes in 100 and 200m tests freestyle, backstroke,
breaststroke and butterfly stroke. These results were also
found for Craig and Pendergast21 for the 100 and 200m
backstroke tests, as well as in different studies of distances in crawl swimming11.
As for BL, the highest values were observed for the
longest tests both for men, and women. Pai, Hay and
Wilson22 when analyzing backstroke swimming tests
found similar results for women, but not in the same
tendency for men. Different results were found in Craig
and Pendergast21 study, when analyzing 100 and 200m
420
backstroke tests, observing a higher value of BL for both
sexes in bigger swam distances.
In another point of view, Camargo14, who compared
the mean BF of the free 50m test with mean BF of the free
10m test first partial from 1996 Atlanta Olympic Games
finalists, observed a mean decrease of 6.7 cycles.min-1
for the free 100m partial related to the free 50m test.
In this study, when carrying out this analysis option, a
mean decrease of 6.2 cycles.min-1 was observed, when
compared to the backstroke 50m test with the first partial
backstroke 100m. It is a similar result to the one found
for the backstroke 100m test and the first 100m partial
of test of 200m backstroke, with a mean decrease of 6.0
cycles.min-1.
By observing the mV, it was verified that, for all the
tests, higher mV values corresponded to higher BF values
and lower BL values. These results encounter the findings
of Craig and Pendergast21, who analyzed the four types
in small meters and described that the increase of swim
speed resulted in the combination of BF increase and
BL decrease. Gatti et al.13 obtained similar results when
analyzing BF and BL for the 200m freestyle distance in
different swimming intensities, in which the BF had an
increase of 52.63% and BL, a decrease of 19.48% between the intensities of 80 and 100% with a mV increase.
Maglischo16 incites the use of BF as an easier learning instrument of test rhythm implementation searching
an ideal BL, in order to maintain a higher mV during the
swam distance.
For the female group, the correlations between BF
and BL are close to the values found by Perez24 (-0.85)
for the 100 and 200m backstroke distances, differently
from the male group (-0.45) for the same distances.
Caputo et al.11, when correlating BF and mV between
16 male subjects for the free 50, 100 and 200m distances, found r-values: -0.05; -0.01; 0.28, respectively.
Different results found in this study were found: r=0.39;
0.024; 0.85 for the male group in the 50, 100 and
200m backstroke distances, respectively.
Fit Perf J. 2009 Nov-Dec;8(6):417-21.
T ests
The results discovered in this study encounter with
the literature findings: in the lower swimming distances,
we have a higher frequency and a lower BL, as well as
a higher mean speed of swim. Values invert for higher distances, in which the BF decreases and the BL increases, however the swim speed decreases. For athletes
and trainers, it is suggested to develop technical aspects
combining increase frequency to a great BL, in order to
maintain swim speed independently from swam distance.
REFERENCES
1.
Dantas EHM. A prática da preparação física. 4ª ed. Rio de Janeiro:
Shape; 2003.
2.
Hay JG. The Biomechanics of sports techniques. New Jersey: PraticeHall; 1985.
3.
Marinho D, Fernandes R [Internet]. A posição corporal nas técnicas
alternadas em natação pura desportiva. Efdeportes.com. 2003;9(63)
[citado em: 2009 set 3]. Disponível em: http://www.efdeportes.com/
efd63/natacao.htm.
4.
Castro F, Minghelli F, Floss F, Guimarães A. Body roll angles in front
crawl swimming at different velocities. In: Chatard JC, editor. [Presented
at 9o Biomechanics and Medicine in Swimming. St. Etienne, France:
University of St. Etienne]. 2003;111-4.
of
50, 100
and
200 m
backstroke in swimming
[Apresentado no X Congresso Brasileiro de Biomecânica; 2003 Jun.
3-6; Ouro Preto, Minas Gerais, Universidade Federal de Minas Gerais].
2003. p.132-5.
13.
Gatti RGO, Erichsen AO, Melo SIL. Respostas fisiológicas e
biomecânicas de nadadores em diferentes intensidades de nado. Rev
Bras Cineantropom Desempenho Hum. 2004;6(1):26-35. 14.
Camargo CER. Variação da freqüência de braçada de um nadador
entre a prova de 50 metros livre e sua parcial desta distância na prova
de 100 livre. [dissertação]. Florianópolis: Universidade do Estado de
Santa Catarina. Mestrado em Ciências do Movimento Humano; 2005. 15.
Deminice R, Papotti M, Zagatto AM, Prado Júnior MV. Validade do
teste de 30 minutos (T-30), na determinação da capacidade aeróbia,
parâmetros de braçada e performance aeróbia de nadadores treinados.
Rev Bras Med Esporte. 2007;13(3):195-99. 16.
Maglischo EW. Swimming even faster. Mountain View: Mayfield
Publishing Company; 1993. 17.
Haljand R [Internet]. Technical preparation of swimming starts turns
and strokes. Estonia: Tallinn University of Education Sciences; 1998
[atualizada em 2009 Jul. 12; acesso em 2009 Set. 3]. Disponível em:
http://www.swim.ee/models/methods.html. 18.
Arrelano R, Sanchez-Molina J, Navarro F, Aymerich JD. Analysis of 100
m Backstroke, Breastroke, Butterfly and Freestyle Swimmers at the 2001
European Youth Olympic Days. In: Chatard JC, editor. Biomechanics
and Medicine in Swimming IX. Saint Etienne (France): University of Saint
Etienne; 2003. p. 255-60. 19.
Santos S, Silva CR, Dominicano LP. Determinação do comportamento da
freqüência e do comprimento de braçadas em diferentes velocidades
de nado. [Apresentado no X Congresso Brasileiro de Biomecânica;
2003 Jun 3-6; Ouro Preto, Minas Gerais. Ouro Preto: Universidade
Federal de Minas Gerais] 2003. p. 136-9. 20.
Chatard JC, Girold S, Caudal N, Cossor J, Mason B. Analysis of the
200m Events in the Sydney Olympic Games. In: Chatard JC, editor.
Biomechanics and Medicine in Swimming IX. Saint Etienne (France):
University of Saint Etienne; 2003. p. 261-4.
5.
Pereira S, Araujo L, Freitas E, Gatti R, Silveira G, Roesler H. et al.
Biomechanical analysis of turn in front crawl swimming. Rev Port Cienc
Desporto. 2006;6:77-9.
6.
Alberty M, Sidney M, Pelayo P, Toussaint H M. Stroking Characteristics
during Time to Exhaustion Tests. Med Sci Sports Exerc. 2009;41(3):637-44.
7.
Soriano PP, Bellock S, Costa GB, Martinez AE. Effects of three Feedback
Conditions on Aerobic Swim Speeds. J Sport Sci Med. 2009;8(1):30-6.
21.
8.
East DE. Swimming: an analysis of stroke frequency, stroke lenght and
performance. New Zealand Journal of Health, Physical Education and
Recreation. 1970;3:16-27. Craig AB, Pendergast DR. Relationships of Stroke Rate, distance
per stroke, and velocity in competitive swimming. Med Sci Sports.
1979;11(3):278-83. 22.
9.
Ungerechts, B. Uber den Wert der Zugzahl. Ermittlung im Schwimmsport.
Leistungssport. 1979;5:353-6. Pai Y, Hay JG, Wilson BD. Stroking techniques of elite swimmers. J Sports
Sci. 1984;2(3):225-39. 23.
10.
Hay JG. The status of research on the Biomechanics of swimming.
In: Ungerechts BE, Wilke K, Reischle K, editors. Swimming Science V.
Illinois: Human Kinetics Publishers; 1988. p. 3-14. Hay JG. Biomecânica das técnicas desportivas. 2ª ed. Rio de Janeiro:
Interamericana; 1981. 24.
11.
Caputo F, Lucas RD, Greco CC, Denadai BS. Características da
braçada em diferentes distâncias no nado crawl e correlações com a
performance. Rev Bras Ciênc Mov. 2000;8(3):7-13. Perez AJ. Correlação de freqüência de braçada e distâncias médias de
braçadas com tempo atingido em provas competitivas por nadadores
brasileiros. Rev Bras Biomecânica. 2001;2(3):15-21. 25.
Pestana MH, Gageiro JN. Análise de dados para ciências sociais: a
complementaridade do SPSS. 2ª ed. Lisboa: Silabo; 2003.
12.
Santos S, Silva CR, Dominicano LP. A relação entre o comprimento e
a freqüência de braçadas na estratégia de provas curtas de natação.
Fit Perf J. 2009 Nov-Dec;8(6):417-21.
Received on: 07/24/09 – Accepted on: 10/11/09.
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